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Wu J, Quraishi IH, Zhang Y, Bromwich M, Kaczmarek LK. Disease-causing Slack potassium channel mutations produce opposite effects on excitability of excitatory and inhibitory neurons. Cell Rep 2024; 43:113904. [PMID: 38457342 PMCID: PMC11013952 DOI: 10.1016/j.celrep.2024.113904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 12/18/2023] [Accepted: 02/16/2024] [Indexed: 03/10/2024] Open
Abstract
The KCNT1 gene encodes the sodium-activated potassium channel Slack (KCNT1, KNa1.1), a regulator of neuronal excitability. Gain-of-function mutations in humans cause cortical network hyperexcitability, seizures, and severe intellectual disability. Using a mouse model expressing the Slack-R455H mutation, we find that Na+-dependent K+ (KNa) and voltage-dependent sodium (NaV) currents are increased in both excitatory and inhibitory cortical neurons. These increased currents, however, enhance the firing of excitability neurons but suppress that of inhibitory neurons. We further show that the expression of NaV channel subunits, particularly that of NaV1.6, is upregulated and that the length of the axon initial segment and of axonal NaV immunostaining is increased in both neuron types. Our study on the coordinate regulation of KNa currents and the expression of NaV channels may provide an avenue for understanding and treating epilepsies and other neurological disorders.
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Affiliation(s)
- Jing Wu
- Department of Pharmacology, Yale School of Medicine, New Haven, CT 06520, USA
| | - Imran H Quraishi
- Department of Neurology, Yale Comprehensive Epilepsy Center, Yale School of Medicine, New Haven, CT 06520, USA
| | - Yalan Zhang
- Department of Pharmacology, Yale School of Medicine, New Haven, CT 06520, USA
| | - Mark Bromwich
- Department of Pharmacology, Yale School of Medicine, New Haven, CT 06520, USA
| | - Leonard K Kaczmarek
- Department of Pharmacology, Yale School of Medicine, New Haven, CT 06520, USA; Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, CT 06520, USA.
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2
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El-Sayed A, Refaai M, Ateya A. Doppler ultrasonographic scan, gene expression and serum profile of immune, APPs and antioxidant markers in Egyptian buffalo-cows with clinical endometritis. Sci Rep 2024; 14:5698. [PMID: 38459095 PMCID: PMC10923904 DOI: 10.1038/s41598-024-56258-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 03/04/2024] [Indexed: 03/10/2024] Open
Abstract
The objective of this study was to elaborate Doppler ultrasonographic scan, genetic resistance and serum profile of markers associated with endometritis susceptibility in Egyptian buffalo-cows. The enrolled animals were designed as; twenty five apparently healthy buffalo-cows considered as a control group and twenty five infected buffalo with endometritis. There were significant (p < 0.05) increased of cervical diameter, endometrium thickness, uterine horn diameter, TAMEAN, TAMAX and blood flow through middle uterine artery with significant decrease of PI and RI values in endometritis buffalo-cows. Gene expression levels were considerably higher in endometritis-affected buffaloes than in resistant ones for the genes A2M, ADAMTS20, KCNT2, MAP3K4, MAPK14, FKBP5, FCAMR, TLR2, IRAK3, CCl2, EPHA4, and iNOS. The RXFP1, NDUFS5, TGF-β, SOD3, CAT, and GPX genes were expressed at substantially lower levels in endometritis-affected buffaloes. The PCR-DNA sequence verdicts of healthy and affected buffaloes revealed differences in the SNPs in the amplified DNA bases related to endometritis for the investigated genes. However, MAP3K4 elicited a monomorphic pattern. There was a significant decrease of red blood cells (RBCs) count, Hb and packed cell volume (PCV) with neutrophilia, lymphocytosis and monocytosis in endometritis group compared with healthy ones. The serum levels of Hp, SAA, Cp, IL-6, IL-10, TNF-α, NO and MDA were significantly (P˂0.05) increased, along with reduction of CAT, GPx, SOD and TAC in buffalo-cows with endometritis compared to healthy ones. The variability of Doppler ultrasonographic scan and studied genes alongside alterations in the serum profile of investigated markers could be a reference guide for limiting buffalo endometritis through selective breeding of natural resistant animals.
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Affiliation(s)
- Ahmed El-Sayed
- Department of Animal Health and Poultry, Animal and Poultry Production Division, Desert Research Center (DRC), Cairo, Egypt
| | - Mohamed Refaai
- Diagnostic Imaging and Endoscopy Unit, Agriculture Research Centre, Animal Reproduction Research Institute, Giza, Egypt
| | - Ahmed Ateya
- Department of Development of Animal Wealth, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt.
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3
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Zhang J, Liu S, Fan J, Yan R, Huang B, Zhou F, Yuan T, Gong J, Huang Z, Jiang D. Structural basis of human Slo2.2 channel gating and modulation. Cell Rep 2023; 42:112858. [PMID: 37494189 DOI: 10.1016/j.celrep.2023.112858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 06/16/2023] [Accepted: 07/07/2023] [Indexed: 07/28/2023] Open
Abstract
The sodium-activated Slo2.2 channel is abundantly expressed in the brain, playing a critical role in regulating neuronal excitability. The Na+-binding site and the underlying mechanisms of Na+-dependent activation remain unclear. Here, we present cryoelectron microscopy (cryo-EM) structures of human Slo2.2 in closed, open, and inhibitor-bound form at resolutions of 2.6-3.2 Å, revealing gating mechanisms of Slo2.2 regulation by cations and a potent inhibitor. The cytoplasmic gating ring domain of the closed Slo2.2 harbors multiple K+ and Zn2+ sites, which stabilize the channel in the closed conformation. The open Slo2.2 structure reveals at least two Na+-sensitive sites where Na+ binding induces expansion and rotation of the gating ring that opens the inner gate. Furthermore, a potent inhibitor wedges into a pocket formed by pore helix and S6 helix and blocks the pore. Together, our results provide a comprehensive structural framework for the investigation of Slo2.2 channel gating, Na+ sensation, and inhibition.
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Affiliation(s)
- Jiangtao Zhang
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; College of Life Science and Technology, Key Laboratory of Molecular Biophysics of MOE, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Shiqi Liu
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing 100191, China; IDG/McGovern Institute for Brain Research, Peking University, Beijing 100871, China
| | - Junping Fan
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Department of Chemical Biology, College of Chemistry and Molecular Engineering, Synthetic and Functional Biomolecules Center, and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Rui Yan
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Bo Huang
- Beijing StoneWise Technology Co Ltd., Haidian District, Beijing, China
| | - Feng Zhou
- Beijing StoneWise Technology Co Ltd., Haidian District, Beijing, China
| | - Tian Yuan
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing 100191, China; IDG/McGovern Institute for Brain Research, Peking University, Beijing 100871, China
| | - Jianke Gong
- College of Life Science and Technology, Key Laboratory of Molecular Biophysics of MOE, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Zhuo Huang
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing 100191, China; IDG/McGovern Institute for Brain Research, Peking University, Beijing 100871, China.
| | - Daohua Jiang
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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4
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Donnan AM, Schneider AL, Russ-Hall S, Churilov L, Scheffer IE. Rates of Status Epilepticus and Sudden Unexplained Death in Epilepsy in People With Genetic Developmental and Epileptic Encephalopathies. Neurology 2023; 100:e1712-e1722. [PMID: 36750385 PMCID: PMC10115508 DOI: 10.1212/wnl.0000000000207080] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Accepted: 01/05/2023] [Indexed: 02/09/2023] Open
Abstract
BACKGROUND AND OBJECTIVES The genetic developmental and epileptic encephalopathies (DEEs) comprise a large group of severe epilepsy syndromes, with a wide phenotypic spectrum. Currently, the rates of convulsive status epilepticus (CSE), nonconvulsive status epilepticus (NCSE), and sudden unexplained death in epilepsy (SUDEP) in these diseases are not well understood. We aimed to describe the proportions of patients with frequently observed genetic DEEs who developed CSE, NCSE, mortality, and SUDEP. Understanding the risks of these serious presentations in each genetic DEE will enable earlier diagnosis and appropriate management. METHODS In this retrospective analysis of patients with a genetic DEE, we estimated the proportions with CSE, NCSE, and SUDEP and the overall and SUDEP-specific mortality rates for each genetic diagnosis. We included patients with a pathogenic variant in the genes SCN1A, SCN2A, SCN8A, SYNGAP1, NEXMIF, CHD2, PCDH19, STXBP1, GRIN2A, KCNT1, and KCNQ2 and with Angelman syndrome (AS). RESULTS The cohort comprised 510 individuals with a genetic DEE, in whom we observed CSE in 47% and NCSE in 19%. The highest proportion of CSE occurred in patients with SCN1A-associated DEEs, including 181/203 (89%; 95% CI 84-93) patients with Dravet syndrome and 8/15 (53%; 95% CI 27-79) non-Dravet SCN1A-DEEs. CSE was also notable in patients with pathogenic variants in KCNT1 (6/10; 60%; 95% CI 26-88) and SCN2A (8/15; 53%; 95% CI 27-79). NCSE was common in patients with non-Dravet SCN1A-DEEs (8/15; 53%; 95% CI 27-79) and was notable in patients with CHD2-DEEs (6/14; 43%; 95% CI 18-71) and AS (6/19; 32%; 95% CI 13-57). There were 42/510 (8%) deaths among the cohort, producing a mortality rate of 6.1 per 1,000 person-years (95% CI 4.4-8.3). Cases of SUDEP accounted for 19/42 (48%) deaths. Four genes were associated with SUDEP: SCN1A, SCN2A, SCN8A, and STXBP1. The estimated SUDEP rate was 2.8 per 1,000 person-years (95% CI 1.6-4.3). DISCUSSION We showed that proportions of patients with CSE, NCSE, and SUDEP differ for commonly encountered genetic DEEs. The estimates for each genetic DEE studied will inform early diagnosis and management of status epilepticus and SUDEP and inform disease-specific counseling for patients and families in this high-risk group of conditions.
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Affiliation(s)
- Alice M Donnan
- From the Epilepsy Research Centre (A.M.D., A.L.S., S.R.-H., I.E.S.), Department of Medicine, The University of Melbourne, Austin Health; Melbourne Medical School (L.C.), Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville; The Florey Institute of Neurosciences and Mental Health (L.C., I.E.S.), Melbourne; and Department of Paediatrics (I.E.S.), The University of Melbourne, Royal Children's Hospital, and Murdoch Children's Research Institute, Victoria, Australia
| | - Amy L Schneider
- From the Epilepsy Research Centre (A.M.D., A.L.S., S.R.-H., I.E.S.), Department of Medicine, The University of Melbourne, Austin Health; Melbourne Medical School (L.C.), Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville; The Florey Institute of Neurosciences and Mental Health (L.C., I.E.S.), Melbourne; and Department of Paediatrics (I.E.S.), The University of Melbourne, Royal Children's Hospital, and Murdoch Children's Research Institute, Victoria, Australia
| | - Sophie Russ-Hall
- From the Epilepsy Research Centre (A.M.D., A.L.S., S.R.-H., I.E.S.), Department of Medicine, The University of Melbourne, Austin Health; Melbourne Medical School (L.C.), Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville; The Florey Institute of Neurosciences and Mental Health (L.C., I.E.S.), Melbourne; and Department of Paediatrics (I.E.S.), The University of Melbourne, Royal Children's Hospital, and Murdoch Children's Research Institute, Victoria, Australia
| | - Leonid Churilov
- From the Epilepsy Research Centre (A.M.D., A.L.S., S.R.-H., I.E.S.), Department of Medicine, The University of Melbourne, Austin Health; Melbourne Medical School (L.C.), Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville; The Florey Institute of Neurosciences and Mental Health (L.C., I.E.S.), Melbourne; and Department of Paediatrics (I.E.S.), The University of Melbourne, Royal Children's Hospital, and Murdoch Children's Research Institute, Victoria, Australia
| | - Ingrid E Scheffer
- From the Epilepsy Research Centre (A.M.D., A.L.S., S.R.-H., I.E.S.), Department of Medicine, The University of Melbourne, Austin Health; Melbourne Medical School (L.C.), Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville; The Florey Institute of Neurosciences and Mental Health (L.C., I.E.S.), Melbourne; and Department of Paediatrics (I.E.S.), The University of Melbourne, Royal Children's Hospital, and Murdoch Children's Research Institute, Victoria, Australia.
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5
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Odgis JA, Gallagher KM, Rehman AU, Marathe P, Bonini KE, Sebastin M, Di Biase M, Brown K, Kelly NR, Ramos MA, Thomas-Wilson A, Guha S, Okur V, Ganapathi M, Elkhoury L, Edelmann L, Zinberg RE, Abul-Husn NS, Diaz GA, Greally JM, Suckiel SA, Jobanputra V, Horowitz CR, Kenny EE, Wasserstein MP, Gelb BD. Detection of mosaic variants using genome sequencing in a large pediatric cohort. Am J Med Genet A 2023; 191:699-710. [PMID: 36563179 PMCID: PMC10266700 DOI: 10.1002/ajmg.a.63062] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 11/07/2022] [Accepted: 11/18/2022] [Indexed: 12/24/2022]
Abstract
The increased use of next-generation sequencing has expanded our understanding of the involvement and prevalence of mosaicism in genetic disorders. We describe a total of eleven cases: nine in which mosaic variants detected by genome sequencing (GS) and/or targeted gene panels (TGPs) were considered to be causative for the proband's phenotype, and two of apparent parental mosaicism. Variants were identified in the following genes: PHACTR1, SCN8A, KCNT1, CDKL5, NEXMIF, CUX1, TSC2, GABRB2, and SMARCB1. In addition, we identified one large duplication including three genes, UBE3A, GABRB3, and MAGEL2, and one large deletion including deletion of ARFGAP1, EEF1A2, CHRNA4, and KCNQ2. All patients were enrolled in the NYCKidSeq study, a research program studying the communication of genomic information in clinical care, as well as the clinical utility and diagnostic yield of GS for children with suspected genetic disorders in diverse populations in New York City. We observed variability in the correlation between reported variant allele fraction and the severity of the patient's phenotype, although we were not able to determine the mosaicism percentage in clinically relevant tissue(s). Although our study was not sufficiently powered to assess differences in mosaicism detection between the two testing modalities, we saw a trend toward better detection by GS as compared with TGP testing. This case series supports the importance of mosaicism in childhood-onset genetic conditions and informs guidelines for laboratory and clinical interpretation of mosaic variants detected by GS.
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Affiliation(s)
- Jacqueline A. Odgis
- The Institute for Genomic Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Katie M. Gallagher
- Department of Pediatrics, Division of Pediatric Genetic Medicine, Children’s Hospital at Montefiore/Montefiore Medical Center/Albert Einstein College of Medicine, Bronx, NY, USA
| | - Atteeq U. Rehman
- Molecular Diagnostics, New York Genome Center, New York, NY, USA
| | - Priya Marathe
- The Institute for Genomic Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Katherine E. Bonini
- The Institute for Genomic Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Monisha Sebastin
- Department of Pediatrics, Division of Pediatric Genetic Medicine, Children’s Hospital at Montefiore/Montefiore Medical Center/Albert Einstein College of Medicine, Bronx, NY, USA
| | - Miranda Di Biase
- Department of Pediatrics, Division of Pediatric Genetic Medicine, Children’s Hospital at Montefiore/Montefiore Medical Center/Albert Einstein College of Medicine, Bronx, NY, USA
| | - Kaitlyn Brown
- Department of Pediatrics, Division of Pediatric Genetic Medicine, Children’s Hospital at Montefiore/Montefiore Medical Center/Albert Einstein College of Medicine, Bronx, NY, USA
| | - Nicole R. Kelly
- Department of Pediatrics, Division of Pediatric Genetic Medicine, Children’s Hospital at Montefiore/Montefiore Medical Center/Albert Einstein College of Medicine, Bronx, NY, USA
| | - Michelle A. Ramos
- Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Institute for Health Equity Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | | | - Saurav Guha
- Molecular Diagnostics, New York Genome Center, New York, NY, USA
| | - Volkan Okur
- Molecular Diagnostics, New York Genome Center, New York, NY, USA
| | | | | | | | - Randi E. Zinberg
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Obstetrics, Gynecology and Reproductive Science, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Noura S. Abul-Husn
- The Institute for Genomic Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - George A. Diaz
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - John M. Greally
- Department of Pediatrics, Division of Pediatric Genetic Medicine, Children’s Hospital at Montefiore/Montefiore Medical Center/Albert Einstein College of Medicine, Bronx, NY, USA
| | - Sabrina A. Suckiel
- The Institute for Genomic Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Vaidehi Jobanputra
- Molecular Diagnostics, New York Genome Center, New York, NY, USA
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY, USA
| | - Carol R. Horowitz
- Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Institute for Health Equity Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Eimear E. Kenny
- The Institute for Genomic Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Melissa P. Wasserstein
- Department of Pediatrics, Division of Pediatric Genetic Medicine, Children’s Hospital at Montefiore/Montefiore Medical Center/Albert Einstein College of Medicine, Bronx, NY, USA
| | - Bruce D. Gelb
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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6
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Ye Z, Bennett MF, Neal A, Laing JA, Hunn MK, Wittayacharoenpong T, Todaro M, Patel SK, Bahlo M, Kwan P, O'Brien TJ, Scheffer IE, Berkovic SF, Perucca P, Hildebrand MS. Somatic Mosaic Pathogenic Variant Gradient Detected in Trace Brain Tissue From Stereo-EEG Depth Electrodes. Neurology 2022; 99:1036-1041. [PMID: 36192176 DOI: 10.1212/wnl.0000000000201469] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 09/09/2022] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND AND OBJECTIVES Mosaic pathogenic variants restricted to the brain are increasingly recognized as a cause of focal epilepsies. We aimed to identify a mosaic pathogenic variant and its anatomical gradient in brain DNA derived from trace tissue on explanted stereoelectroencephalography (SEEG) electrodes. METHODS We studied a patient with nonlesional multifocal epilepsy undergoing presurgical evaluation with SEEG. After explantation, the electrodes were divided into 3 pools based on their brain location (right posterior quadrant, left posterior quadrant, hippocampus/temporal neocortex). Tissue from each pool was processed for trace DNA that was whole genome amplified prior to high-depth exome sequencing. Droplet digital PCR was performed to quantify mosaicism. A brain-specific glial fibrillary acidic protein (GFAP) assay enabled cell-of-origin analysis. RESULTS We demonstrated a mosaic gradient for a novel pathogenic KCNT1 loss-of-function variant (c.530G>A, p.W177X) predicted to lead to nonsense-mediated decay. Strikingly, the mosaic gradient correlated strongly with the SEEG findings because the highest variant allele frequency was in the right posterior quadrant, reflecting the most epileptogenic region on EEG studies. An elevated GFAP level indicated enrichment of brain-derived cells in SEEG cell suspension. DISCUSSION This study demonstrates a proof of concept that mosaic gradients of pathogenic variants can be established using trace tissue from explanted SEEG electrodes.
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Affiliation(s)
- Zimeng Ye
- From the Department of Medicine (Austin Health) (Z.Y., M.F.B., S.K.P., I.E.S., S.F.B., P.P., M.S.H.), University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research, Parkville; Department of Medical Biology (M.F.B., M.B.), The University of Melbourne, Parkville; Department of Neurology (A.N., P.K., T.J.O.B., P.P.), Royal Melbourne Hospital, Parkville; Department of Neurology (A.N., J.A.L., T.W., M.T., P.K., T.J.O.B., P.P.), Alfred Hospital, Melbourne; Department of Medicine (A.N., P.K., T.J.O.B.), Royal Melbourne Hospital, University of Melbourne, Parkville; Department of Neurosciences (A.N., J.A.L., T.W., M.T., P.K., T.J.O.B., P.P.), The Central Clinical School, Monash University, Melbourne; Department of Neurology (A.N.), St Vincent's Hospital, Fitzroy; Department of Neurosurgery (M.K.H.), The Alfred Hospital, Melbourne; Florey Institute of Neuroscience and Mental Health (S.K.P., I.E.S.), Heidelberg; Murdoch Children's Research Institute (I.E.S., M.S.H.), Parkville; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Parkville; and Bladin-Berkovic Comprehensive Epilepsy Program (S.F.B., P.P.), Department of Neurology, Austin Health, Heidelberg, Australia
| | - Mark F Bennett
- From the Department of Medicine (Austin Health) (Z.Y., M.F.B., S.K.P., I.E.S., S.F.B., P.P., M.S.H.), University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research, Parkville; Department of Medical Biology (M.F.B., M.B.), The University of Melbourne, Parkville; Department of Neurology (A.N., P.K., T.J.O.B., P.P.), Royal Melbourne Hospital, Parkville; Department of Neurology (A.N., J.A.L., T.W., M.T., P.K., T.J.O.B., P.P.), Alfred Hospital, Melbourne; Department of Medicine (A.N., P.K., T.J.O.B.), Royal Melbourne Hospital, University of Melbourne, Parkville; Department of Neurosciences (A.N., J.A.L., T.W., M.T., P.K., T.J.O.B., P.P.), The Central Clinical School, Monash University, Melbourne; Department of Neurology (A.N.), St Vincent's Hospital, Fitzroy; Department of Neurosurgery (M.K.H.), The Alfred Hospital, Melbourne; Florey Institute of Neuroscience and Mental Health (S.K.P., I.E.S.), Heidelberg; Murdoch Children's Research Institute (I.E.S., M.S.H.), Parkville; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Parkville; and Bladin-Berkovic Comprehensive Epilepsy Program (S.F.B., P.P.), Department of Neurology, Austin Health, Heidelberg, Australia
| | - Andrew Neal
- From the Department of Medicine (Austin Health) (Z.Y., M.F.B., S.K.P., I.E.S., S.F.B., P.P., M.S.H.), University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research, Parkville; Department of Medical Biology (M.F.B., M.B.), The University of Melbourne, Parkville; Department of Neurology (A.N., P.K., T.J.O.B., P.P.), Royal Melbourne Hospital, Parkville; Department of Neurology (A.N., J.A.L., T.W., M.T., P.K., T.J.O.B., P.P.), Alfred Hospital, Melbourne; Department of Medicine (A.N., P.K., T.J.O.B.), Royal Melbourne Hospital, University of Melbourne, Parkville; Department of Neurosciences (A.N., J.A.L., T.W., M.T., P.K., T.J.O.B., P.P.), The Central Clinical School, Monash University, Melbourne; Department of Neurology (A.N.), St Vincent's Hospital, Fitzroy; Department of Neurosurgery (M.K.H.), The Alfred Hospital, Melbourne; Florey Institute of Neuroscience and Mental Health (S.K.P., I.E.S.), Heidelberg; Murdoch Children's Research Institute (I.E.S., M.S.H.), Parkville; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Parkville; and Bladin-Berkovic Comprehensive Epilepsy Program (S.F.B., P.P.), Department of Neurology, Austin Health, Heidelberg, Australia
| | - Joshua A Laing
- From the Department of Medicine (Austin Health) (Z.Y., M.F.B., S.K.P., I.E.S., S.F.B., P.P., M.S.H.), University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research, Parkville; Department of Medical Biology (M.F.B., M.B.), The University of Melbourne, Parkville; Department of Neurology (A.N., P.K., T.J.O.B., P.P.), Royal Melbourne Hospital, Parkville; Department of Neurology (A.N., J.A.L., T.W., M.T., P.K., T.J.O.B., P.P.), Alfred Hospital, Melbourne; Department of Medicine (A.N., P.K., T.J.O.B.), Royal Melbourne Hospital, University of Melbourne, Parkville; Department of Neurosciences (A.N., J.A.L., T.W., M.T., P.K., T.J.O.B., P.P.), The Central Clinical School, Monash University, Melbourne; Department of Neurology (A.N.), St Vincent's Hospital, Fitzroy; Department of Neurosurgery (M.K.H.), The Alfred Hospital, Melbourne; Florey Institute of Neuroscience and Mental Health (S.K.P., I.E.S.), Heidelberg; Murdoch Children's Research Institute (I.E.S., M.S.H.), Parkville; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Parkville; and Bladin-Berkovic Comprehensive Epilepsy Program (S.F.B., P.P.), Department of Neurology, Austin Health, Heidelberg, Australia
| | - Martin K Hunn
- From the Department of Medicine (Austin Health) (Z.Y., M.F.B., S.K.P., I.E.S., S.F.B., P.P., M.S.H.), University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research, Parkville; Department of Medical Biology (M.F.B., M.B.), The University of Melbourne, Parkville; Department of Neurology (A.N., P.K., T.J.O.B., P.P.), Royal Melbourne Hospital, Parkville; Department of Neurology (A.N., J.A.L., T.W., M.T., P.K., T.J.O.B., P.P.), Alfred Hospital, Melbourne; Department of Medicine (A.N., P.K., T.J.O.B.), Royal Melbourne Hospital, University of Melbourne, Parkville; Department of Neurosciences (A.N., J.A.L., T.W., M.T., P.K., T.J.O.B., P.P.), The Central Clinical School, Monash University, Melbourne; Department of Neurology (A.N.), St Vincent's Hospital, Fitzroy; Department of Neurosurgery (M.K.H.), The Alfred Hospital, Melbourne; Florey Institute of Neuroscience and Mental Health (S.K.P., I.E.S.), Heidelberg; Murdoch Children's Research Institute (I.E.S., M.S.H.), Parkville; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Parkville; and Bladin-Berkovic Comprehensive Epilepsy Program (S.F.B., P.P.), Department of Neurology, Austin Health, Heidelberg, Australia
| | - Thanomporn Wittayacharoenpong
- From the Department of Medicine (Austin Health) (Z.Y., M.F.B., S.K.P., I.E.S., S.F.B., P.P., M.S.H.), University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research, Parkville; Department of Medical Biology (M.F.B., M.B.), The University of Melbourne, Parkville; Department of Neurology (A.N., P.K., T.J.O.B., P.P.), Royal Melbourne Hospital, Parkville; Department of Neurology (A.N., J.A.L., T.W., M.T., P.K., T.J.O.B., P.P.), Alfred Hospital, Melbourne; Department of Medicine (A.N., P.K., T.J.O.B.), Royal Melbourne Hospital, University of Melbourne, Parkville; Department of Neurosciences (A.N., J.A.L., T.W., M.T., P.K., T.J.O.B., P.P.), The Central Clinical School, Monash University, Melbourne; Department of Neurology (A.N.), St Vincent's Hospital, Fitzroy; Department of Neurosurgery (M.K.H.), The Alfred Hospital, Melbourne; Florey Institute of Neuroscience and Mental Health (S.K.P., I.E.S.), Heidelberg; Murdoch Children's Research Institute (I.E.S., M.S.H.), Parkville; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Parkville; and Bladin-Berkovic Comprehensive Epilepsy Program (S.F.B., P.P.), Department of Neurology, Austin Health, Heidelberg, Australia
| | - Marian Todaro
- From the Department of Medicine (Austin Health) (Z.Y., M.F.B., S.K.P., I.E.S., S.F.B., P.P., M.S.H.), University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research, Parkville; Department of Medical Biology (M.F.B., M.B.), The University of Melbourne, Parkville; Department of Neurology (A.N., P.K., T.J.O.B., P.P.), Royal Melbourne Hospital, Parkville; Department of Neurology (A.N., J.A.L., T.W., M.T., P.K., T.J.O.B., P.P.), Alfred Hospital, Melbourne; Department of Medicine (A.N., P.K., T.J.O.B.), Royal Melbourne Hospital, University of Melbourne, Parkville; Department of Neurosciences (A.N., J.A.L., T.W., M.T., P.K., T.J.O.B., P.P.), The Central Clinical School, Monash University, Melbourne; Department of Neurology (A.N.), St Vincent's Hospital, Fitzroy; Department of Neurosurgery (M.K.H.), The Alfred Hospital, Melbourne; Florey Institute of Neuroscience and Mental Health (S.K.P., I.E.S.), Heidelberg; Murdoch Children's Research Institute (I.E.S., M.S.H.), Parkville; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Parkville; and Bladin-Berkovic Comprehensive Epilepsy Program (S.F.B., P.P.), Department of Neurology, Austin Health, Heidelberg, Australia
| | - Sheila K Patel
- From the Department of Medicine (Austin Health) (Z.Y., M.F.B., S.K.P., I.E.S., S.F.B., P.P., M.S.H.), University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research, Parkville; Department of Medical Biology (M.F.B., M.B.), The University of Melbourne, Parkville; Department of Neurology (A.N., P.K., T.J.O.B., P.P.), Royal Melbourne Hospital, Parkville; Department of Neurology (A.N., J.A.L., T.W., M.T., P.K., T.J.O.B., P.P.), Alfred Hospital, Melbourne; Department of Medicine (A.N., P.K., T.J.O.B.), Royal Melbourne Hospital, University of Melbourne, Parkville; Department of Neurosciences (A.N., J.A.L., T.W., M.T., P.K., T.J.O.B., P.P.), The Central Clinical School, Monash University, Melbourne; Department of Neurology (A.N.), St Vincent's Hospital, Fitzroy; Department of Neurosurgery (M.K.H.), The Alfred Hospital, Melbourne; Florey Institute of Neuroscience and Mental Health (S.K.P., I.E.S.), Heidelberg; Murdoch Children's Research Institute (I.E.S., M.S.H.), Parkville; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Parkville; and Bladin-Berkovic Comprehensive Epilepsy Program (S.F.B., P.P.), Department of Neurology, Austin Health, Heidelberg, Australia
| | - Melanie Bahlo
- From the Department of Medicine (Austin Health) (Z.Y., M.F.B., S.K.P., I.E.S., S.F.B., P.P., M.S.H.), University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research, Parkville; Department of Medical Biology (M.F.B., M.B.), The University of Melbourne, Parkville; Department of Neurology (A.N., P.K., T.J.O.B., P.P.), Royal Melbourne Hospital, Parkville; Department of Neurology (A.N., J.A.L., T.W., M.T., P.K., T.J.O.B., P.P.), Alfred Hospital, Melbourne; Department of Medicine (A.N., P.K., T.J.O.B.), Royal Melbourne Hospital, University of Melbourne, Parkville; Department of Neurosciences (A.N., J.A.L., T.W., M.T., P.K., T.J.O.B., P.P.), The Central Clinical School, Monash University, Melbourne; Department of Neurology (A.N.), St Vincent's Hospital, Fitzroy; Department of Neurosurgery (M.K.H.), The Alfred Hospital, Melbourne; Florey Institute of Neuroscience and Mental Health (S.K.P., I.E.S.), Heidelberg; Murdoch Children's Research Institute (I.E.S., M.S.H.), Parkville; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Parkville; and Bladin-Berkovic Comprehensive Epilepsy Program (S.F.B., P.P.), Department of Neurology, Austin Health, Heidelberg, Australia
| | - Patrick Kwan
- From the Department of Medicine (Austin Health) (Z.Y., M.F.B., S.K.P., I.E.S., S.F.B., P.P., M.S.H.), University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research, Parkville; Department of Medical Biology (M.F.B., M.B.), The University of Melbourne, Parkville; Department of Neurology (A.N., P.K., T.J.O.B., P.P.), Royal Melbourne Hospital, Parkville; Department of Neurology (A.N., J.A.L., T.W., M.T., P.K., T.J.O.B., P.P.), Alfred Hospital, Melbourne; Department of Medicine (A.N., P.K., T.J.O.B.), Royal Melbourne Hospital, University of Melbourne, Parkville; Department of Neurosciences (A.N., J.A.L., T.W., M.T., P.K., T.J.O.B., P.P.), The Central Clinical School, Monash University, Melbourne; Department of Neurology (A.N.), St Vincent's Hospital, Fitzroy; Department of Neurosurgery (M.K.H.), The Alfred Hospital, Melbourne; Florey Institute of Neuroscience and Mental Health (S.K.P., I.E.S.), Heidelberg; Murdoch Children's Research Institute (I.E.S., M.S.H.), Parkville; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Parkville; and Bladin-Berkovic Comprehensive Epilepsy Program (S.F.B., P.P.), Department of Neurology, Austin Health, Heidelberg, Australia
| | - Terence J O'Brien
- From the Department of Medicine (Austin Health) (Z.Y., M.F.B., S.K.P., I.E.S., S.F.B., P.P., M.S.H.), University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research, Parkville; Department of Medical Biology (M.F.B., M.B.), The University of Melbourne, Parkville; Department of Neurology (A.N., P.K., T.J.O.B., P.P.), Royal Melbourne Hospital, Parkville; Department of Neurology (A.N., J.A.L., T.W., M.T., P.K., T.J.O.B., P.P.), Alfred Hospital, Melbourne; Department of Medicine (A.N., P.K., T.J.O.B.), Royal Melbourne Hospital, University of Melbourne, Parkville; Department of Neurosciences (A.N., J.A.L., T.W., M.T., P.K., T.J.O.B., P.P.), The Central Clinical School, Monash University, Melbourne; Department of Neurology (A.N.), St Vincent's Hospital, Fitzroy; Department of Neurosurgery (M.K.H.), The Alfred Hospital, Melbourne; Florey Institute of Neuroscience and Mental Health (S.K.P., I.E.S.), Heidelberg; Murdoch Children's Research Institute (I.E.S., M.S.H.), Parkville; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Parkville; and Bladin-Berkovic Comprehensive Epilepsy Program (S.F.B., P.P.), Department of Neurology, Austin Health, Heidelberg, Australia
| | - Ingrid E Scheffer
- From the Department of Medicine (Austin Health) (Z.Y., M.F.B., S.K.P., I.E.S., S.F.B., P.P., M.S.H.), University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research, Parkville; Department of Medical Biology (M.F.B., M.B.), The University of Melbourne, Parkville; Department of Neurology (A.N., P.K., T.J.O.B., P.P.), Royal Melbourne Hospital, Parkville; Department of Neurology (A.N., J.A.L., T.W., M.T., P.K., T.J.O.B., P.P.), Alfred Hospital, Melbourne; Department of Medicine (A.N., P.K., T.J.O.B.), Royal Melbourne Hospital, University of Melbourne, Parkville; Department of Neurosciences (A.N., J.A.L., T.W., M.T., P.K., T.J.O.B., P.P.), The Central Clinical School, Monash University, Melbourne; Department of Neurology (A.N.), St Vincent's Hospital, Fitzroy; Department of Neurosurgery (M.K.H.), The Alfred Hospital, Melbourne; Florey Institute of Neuroscience and Mental Health (S.K.P., I.E.S.), Heidelberg; Murdoch Children's Research Institute (I.E.S., M.S.H.), Parkville; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Parkville; and Bladin-Berkovic Comprehensive Epilepsy Program (S.F.B., P.P.), Department of Neurology, Austin Health, Heidelberg, Australia
| | - Samuel F Berkovic
- From the Department of Medicine (Austin Health) (Z.Y., M.F.B., S.K.P., I.E.S., S.F.B., P.P., M.S.H.), University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research, Parkville; Department of Medical Biology (M.F.B., M.B.), The University of Melbourne, Parkville; Department of Neurology (A.N., P.K., T.J.O.B., P.P.), Royal Melbourne Hospital, Parkville; Department of Neurology (A.N., J.A.L., T.W., M.T., P.K., T.J.O.B., P.P.), Alfred Hospital, Melbourne; Department of Medicine (A.N., P.K., T.J.O.B.), Royal Melbourne Hospital, University of Melbourne, Parkville; Department of Neurosciences (A.N., J.A.L., T.W., M.T., P.K., T.J.O.B., P.P.), The Central Clinical School, Monash University, Melbourne; Department of Neurology (A.N.), St Vincent's Hospital, Fitzroy; Department of Neurosurgery (M.K.H.), The Alfred Hospital, Melbourne; Florey Institute of Neuroscience and Mental Health (S.K.P., I.E.S.), Heidelberg; Murdoch Children's Research Institute (I.E.S., M.S.H.), Parkville; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Parkville; and Bladin-Berkovic Comprehensive Epilepsy Program (S.F.B., P.P.), Department of Neurology, Austin Health, Heidelberg, Australia
| | - Piero Perucca
- From the Department of Medicine (Austin Health) (Z.Y., M.F.B., S.K.P., I.E.S., S.F.B., P.P., M.S.H.), University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research, Parkville; Department of Medical Biology (M.F.B., M.B.), The University of Melbourne, Parkville; Department of Neurology (A.N., P.K., T.J.O.B., P.P.), Royal Melbourne Hospital, Parkville; Department of Neurology (A.N., J.A.L., T.W., M.T., P.K., T.J.O.B., P.P.), Alfred Hospital, Melbourne; Department of Medicine (A.N., P.K., T.J.O.B.), Royal Melbourne Hospital, University of Melbourne, Parkville; Department of Neurosciences (A.N., J.A.L., T.W., M.T., P.K., T.J.O.B., P.P.), The Central Clinical School, Monash University, Melbourne; Department of Neurology (A.N.), St Vincent's Hospital, Fitzroy; Department of Neurosurgery (M.K.H.), The Alfred Hospital, Melbourne; Florey Institute of Neuroscience and Mental Health (S.K.P., I.E.S.), Heidelberg; Murdoch Children's Research Institute (I.E.S., M.S.H.), Parkville; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Parkville; and Bladin-Berkovic Comprehensive Epilepsy Program (S.F.B., P.P.), Department of Neurology, Austin Health, Heidelberg, Australia
| | - Michael S Hildebrand
- From the Department of Medicine (Austin Health) (Z.Y., M.F.B., S.K.P., I.E.S., S.F.B., P.P., M.S.H.), University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research, Parkville; Department of Medical Biology (M.F.B., M.B.), The University of Melbourne, Parkville; Department of Neurology (A.N., P.K., T.J.O.B., P.P.), Royal Melbourne Hospital, Parkville; Department of Neurology (A.N., J.A.L., T.W., M.T., P.K., T.J.O.B., P.P.), Alfred Hospital, Melbourne; Department of Medicine (A.N., P.K., T.J.O.B.), Royal Melbourne Hospital, University of Melbourne, Parkville; Department of Neurosciences (A.N., J.A.L., T.W., M.T., P.K., T.J.O.B., P.P.), The Central Clinical School, Monash University, Melbourne; Department of Neurology (A.N.), St Vincent's Hospital, Fitzroy; Department of Neurosurgery (M.K.H.), The Alfred Hospital, Melbourne; Florey Institute of Neuroscience and Mental Health (S.K.P., I.E.S.), Heidelberg; Murdoch Children's Research Institute (I.E.S., M.S.H.), Parkville; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Parkville; and Bladin-Berkovic Comprehensive Epilepsy Program (S.F.B., P.P.), Department of Neurology, Austin Health, Heidelberg, Australia.
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7
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Qunies AM, Mishra NM, Spitznagel BD, Du Y, Acuña VS, David Weaver C, Emmitte KA. Structure-activity relationship studies in a new series of 2-amino-N-phenylacetamide inhibitors of Slack potassium channels. Bioorg Med Chem Lett 2022; 76:129013. [PMID: 36184030 PMCID: PMC10230575 DOI: 10.1016/j.bmcl.2022.129013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 09/20/2022] [Accepted: 09/26/2022] [Indexed: 11/02/2022]
Abstract
In this Letter we describe structure-activity relationship (SAR) studies conducted in five distinct regions of a new 2-amino-N-phenylacetamides series of Slack potassium channel inhibitors exemplified by recently disclosed high-throughput screening (HTS) hit VU0606170 (4). New analogs were screened in a thallium (Tl+) flux assay in HEK-293 cells stably expressing wild-type human (WT) Slack. Selected analogs were screened in Tl+ flux versus A934T Slack and other Slo family members Slick and Maxi-K and evaluated in whole-cell electrophysiology (EP) assays using an automated patch clamp system. Results revealed the series to have flat SAR with significant structural modifications resulting in a loss of Slack activity. More minor changes led to compounds with Slack activity and Slo family selectivity similar to the HTS hit.
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Affiliation(s)
- Alshaima'a M Qunies
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA; Graduate School of Biomedical Sciences, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Nigam M Mishra
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | | | - Yu Du
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA; Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Valerie S Acuña
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - C David Weaver
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA; Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Kyle A Emmitte
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA.
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8
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Khan MM, Wu S, Chen CH, Regehr WG. Unusually Slow Spike Frequency Adaptation in Deep Cerebellar Nuclei Neurons Preserves Linear Transformations on the Subsecond Timescale. J Neurosci 2022; 42:7581-7593. [PMID: 35995561 PMCID: PMC9546444 DOI: 10.1523/jneurosci.1869-21.2022] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 06/30/2022] [Accepted: 08/12/2022] [Indexed: 02/02/2023] Open
Abstract
Purkinje cells (PCs) are spontaneously active neurons of the cerebellar cortex that inhibit glutamatergic projection neurons within the deep cerebellar nuclei (DCN) that provide the primary cerebellar output. Brief reductions of PC firing rapidly increase DCN neuron firing. However, prolonged reductions of PC inhibition, as seen in some disease states, certain types of transgenic mice, during optogenetic suppression of PC firing, and in acute slices of the cerebellum, do not lead to large, sustained increases in DCN firing. Here we test whether DCN neurons undergo spike frequency adaptation that could account for these properties. We perform current-clamp recordings at near physiological temperature in acute brain slices from mice of both sexes to examine how DCN neurons respond to prolonged depolarizations. DCN neuron adaptation is exceptionally slow and bidirectional. A depolarizing current step evokes large initial increases in firing that decay to ∼20% of the initial increase within ∼10 s. We find that spike frequency adaptation in DCN neurons is mediated by a novel mechanism that is independent of the most promising candidates, including calcium entry and Na+-activated potassium channels mediated by Slo2.1 and Slo2.2 Slow adaptation allows DCN neurons to gradually and bidirectionally adapt to prolonged currents but to respond linearly to current injection on rapid timescales. This suggests that an important consequence of slow adaptation is that DCN neurons respond linearly to the rate of PC firing on rapid timescales but adapt to slow firing rate changes of PCs on long timescales.SIGNIFICANCE STATEMENT Excitatory neurons in the cerebellar nuclei provide the primary output from the cerebellum. This study finds that these neurons exhibit very slow bidirectional spike frequency adaptation that has important implications for cerebellar function. This mechanism allows neurons in the cerebellar nuclei to adapt to long-lasting changes in synaptic drive while also remaining responsive to short-term changes in excitatory or inhibitory drive.
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Affiliation(s)
- Mehak M Khan
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115
| | - Shuting Wu
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115
| | - Christopher H Chen
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115
| | - Wade G Regehr
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115
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9
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Zhou F, Metzner K, Engel P, Balzulat A, Sisignano M, Ruth P, Lukowski R, Schmidtko A, Lu R. Slack Potassium Channels Modulate TRPA1-Mediated Nociception in Sensory Neurons. Cells 2022; 11:cells11101693. [PMID: 35626730 PMCID: PMC9140117 DOI: 10.3390/cells11101693] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 05/15/2022] [Accepted: 05/17/2022] [Indexed: 12/13/2022] Open
Abstract
The transient receptor potential (TRP) ankyrin type 1 (TRPA1) channel is highly expressed in a subset of sensory neurons where it acts as an essential detector of painful stimuli. However, the mechanisms that control the activity of sensory neurons upon TRPA1 activation remain poorly understood. Here, using in situ hybridization and immunostaining, we found TRPA1 to be extensively co-localized with the potassium channel Slack (KNa1.1, Slo2.2, or Kcnt1) in sensory neurons. Mice lacking Slack globally (Slack−/−) or conditionally in sensory neurons (SNS-Slack−/−) demonstrated increased pain behavior after intraplantar injection of the TRPA1 activator allyl isothiocyanate. By contrast, pain behavior induced by the TRP vanilloid 1 (TRPV1) activator capsaicin was normal in Slack-deficient mice. Patch-clamp recordings in sensory neurons and in a HEK cell line transfected with TRPA1 and Slack revealed that Slack-dependent potassium currents (IKS) are modulated in a TRPA1-dependent manner. Taken together, our findings highlight Slack as a modulator of TRPA1-mediated, but not TRPV1-mediated, activation of sensory neurons.
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Affiliation(s)
- Fangyuan Zhou
- Institute of Pharmacology and Clinical Pharmacy, Goethe University, 60438 Frankfurt am Main, Germany; (F.Z.); (K.M.); (P.E.); (A.B.); (A.S.)
| | - Katharina Metzner
- Institute of Pharmacology and Clinical Pharmacy, Goethe University, 60438 Frankfurt am Main, Germany; (F.Z.); (K.M.); (P.E.); (A.B.); (A.S.)
| | - Patrick Engel
- Institute of Pharmacology and Clinical Pharmacy, Goethe University, 60438 Frankfurt am Main, Germany; (F.Z.); (K.M.); (P.E.); (A.B.); (A.S.)
| | - Annika Balzulat
- Institute of Pharmacology and Clinical Pharmacy, Goethe University, 60438 Frankfurt am Main, Germany; (F.Z.); (K.M.); (P.E.); (A.B.); (A.S.)
| | - Marco Sisignano
- Institute of Clinical Pharmacology, Pharmazentrum Frankfurt/ZAFES, Goethe University, 60590 Frankfurt am Main, Germany;
| | - Peter Ruth
- Department of Pharmacology, Toxicology and Clinical Pharmacy, University of Tübingen, 72076 Tübingen, Germany; (P.R.); (R.L.)
| | - Robert Lukowski
- Department of Pharmacology, Toxicology and Clinical Pharmacy, University of Tübingen, 72076 Tübingen, Germany; (P.R.); (R.L.)
| | - Achim Schmidtko
- Institute of Pharmacology and Clinical Pharmacy, Goethe University, 60438 Frankfurt am Main, Germany; (F.Z.); (K.M.); (P.E.); (A.B.); (A.S.)
| | - Ruirui Lu
- Institute of Pharmacology and Clinical Pharmacy, Goethe University, 60438 Frankfurt am Main, Germany; (F.Z.); (K.M.); (P.E.); (A.B.); (A.S.)
- Correspondence: ; Tel.: +49-69-798-29377
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10
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Younis NS, Mohamed ME, Alolayan AA, Alhussain GY, Al-Mousa HA, Alshamrani JA, AlMutayib MM, AlQahtani MM, Alhaddad ZA, Alfarhan ZS, AlOmran ZA, Almostafa MM. Identification of epilepsy concomitant candidate genes recognized in Saudi epileptic patients. Eur Rev Med Pharmacol Sci 2022; 26:2143-2157. [PMID: 35363364 DOI: 10.26355/eurrev_202203_28362] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Saudi Genome program is a revolutionary nationwide transformation initiative of Saudi Vision 2030. The program goals are to recognize and reduce the incidence of genetic diseases in the Kingdom of Saudi Arabia (KSA). Accordingly, the program will establish the foundation for personalized and genomic medicine in the KSA. Epilepsy has a high prevalence in KSA reaching around 6.54 of 1000 individuals with a subsequent massive financial burden. One of the main risk factors for this high prevalence and associated with increased risk of epilepsy development is consanguinity marriage, which is traditional in KSA. In this review, we executed a comprehensive state-of-art literature review regarding epilepsy genetics to offer a perception into the genes associated with epilepsy recognized in Saudi epileptic patients. Several genes' mutations were incorporated in this review including AFG3L2, ASPM, ATN1, ATP1A2, BMP5, CCDC88A, C12orf57, DNAJA1, EML1, ERLIN2, FRRS1L, GABRG3, NRXN3, MDH1, KCNJ10, KCNMA1, KCNT1, KIAA0226, OPHN1, PCCA, PCCB, PEX, PGAP2, PI4K2A, PODXL, PRICKLE1, PNKP, RELN, SCN2A, SCN1B, SLC2A1, SLC19A3, SLC25, SIAH1, SYNJ1, SZT2, TBCK, TMX2, TSC1, TSC2, TSEN, WDR45B, WWOX, UBR, UGDH, and YIF1B. For each of these genes, we tried to explain a little about the gene associated proteins and their roles in epilepsy development.
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Affiliation(s)
- N S Younis
- Department of Pharmaceutical Sciences, College of Clinical Pharmacy, King Faisal University, Al-Ahsa, Saudi Arabia.
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Zhang Q, Liu Y, Xu J, Teng Y, Zhang Z. The Functional Properties, Physiological Roles, Channelopathy and Pharmacological Characteristics of the Slack (KCNT1) Channel. Adv Exp Med Biol 2022; 1349:387-400. [PMID: 35138624 DOI: 10.1007/978-981-16-4254-8_18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The KCNT1 gene encodes the sodium-activated potassium channel that is abundantly expressed in the central nervous system of mammalians and plays an important role in reducing neuronal excitability. Structurally, the KCNT1 channel is absent of voltage sensor but possesses a long C-terminus including RCK1 and RCK2domain, to which the intracellular sodium and chloride bind to activate the channel. Recent publications using electron cryo-microscopy (cryo-EM) revealed the open and closed structural characteristics of the KCNT1 channel and co-assembly of functional domains. The activation of the KCNT1 channel regulates various physiological processes including nociceptive behavior, itch, spatial learning. Meanwhile, malfunction of this channel causes important pathophysiological consequences, including Fragile X syndrome and a wide spectrum of seizure disorders. This review comprehensively describes the structure, expression patterns, physiological functions of the KCNT1 channel and emphasizes the channelopathy of gain-of-function KCNT1 mutations in epilepsy.
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Affiliation(s)
- Qi Zhang
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu Province, China
- Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, Jiangsu Province, China
| | - Ye Liu
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu Province, China
- Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, Jiangsu Province, China
| | - Jie Xu
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu Province, China
- Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, Jiangsu Province, China
| | - Yue Teng
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu Province, China
- Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, Jiangsu Province, China
| | - Zhe Zhang
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu Province, China.
- Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, Jiangsu Province, China.
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Gururaj S, Palmer EE, Sheehan GD, Kandula T, Macintosh R, Ying K, Morris P, Tao J, Dias KR, Zhu Y, Dinger ME, Cowley MJ, Kirk EP, Roscioli T, Sachdev R, Duffey ME, Bye A, Bhattacharjee A. A De Novo Mutation in the Sodium-Activated Potassium Channel KCNT2 Alters Ion Selectivity and Causes Epileptic Encephalopathy. Cell Rep 2018; 21:926-933. [PMID: 29069600 DOI: 10.1016/j.celrep.2017.09.088] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 06/12/2017] [Accepted: 09/26/2017] [Indexed: 12/31/2022] Open
Abstract
Early infantile epileptic encephalopathies (EOEE) are a debilitating spectrum of disorders associated with cognitive impairments. We present a clinical report of a KCNT2 mutation in an EOEE patient. The de novo heterozygous variant Phe240Leu SLICK was identified by exome sequencing and confirmed by Sanger sequencing. Phe240Leu rSlick and hSLICK channels were electrophysiologically, heterologously characterized to reveal three significant alterations to channel function. First, [Cl-]i sensitivity was reversed in Phe240Leu channels. Second, predominantly K+-selective WT channels were made to favor Na+ over K+ by Phe240Leu. Third, and consequent to altered ion selectivity, Phe240Leu channels had larger inward conductance. Further, rSlick channels induced membrane hyperexcitability when expressed in primary neurons, resembling the cellular seizure phenotype. Taken together, our results confirm that Phe240Leu is a "change-of-function" KCNT2 mutation, demonstrating unusual altered selectivity in KNa channels. These findings establish pathogenicity of the Phe240Leu KCNT2 mutation in the reported EOEE patient.
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Affiliation(s)
- Sushmitha Gururaj
- Pharmacology and Toxicology, University at Buffalo - The State University of New York, Buffalo, NY 14214, USA
| | - Elizabeth Emma Palmer
- Sydney Children's Hospital, Randwick, NSW 2031, Australia; University of New South Wales, Sydney, NSW 2031, Australia; Genetics of Learning Disability Service, Waratah, NSW 2298, Australia
| | - Garrett D Sheehan
- Pharmacology and Toxicology, University at Buffalo - The State University of New York, Buffalo, NY 14214, USA
| | - Tejaswi Kandula
- Sydney Children's Hospital, Randwick, NSW 2031, Australia; University of New South Wales, Sydney, NSW 2031, Australia
| | | | - Kevin Ying
- Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Sydney, NSW 2298, Australia
| | - Paula Morris
- Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Sydney, NSW 2298, Australia
| | - Jiang Tao
- Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Sydney, NSW 2298, Australia
| | - Kerith-Rae Dias
- Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Sydney, NSW 2298, Australia
| | - Ying Zhu
- Genetics of Learning Disability Service, Waratah, NSW 2298, Australia; SEALS Pathology, Randwick, NSW 2031, Australia
| | - Marcel E Dinger
- University of New South Wales, Sydney, NSW 2031, Australia; Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Sydney, NSW 2298, Australia
| | - Mark J Cowley
- University of New South Wales, Sydney, NSW 2031, Australia; Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Sydney, NSW 2298, Australia
| | - Edwin P Kirk
- Sydney Children's Hospital, Randwick, NSW 2031, Australia; University of New South Wales, Sydney, NSW 2031, Australia; SEALS Pathology, Randwick, NSW 2031, Australia
| | - Tony Roscioli
- Sydney Children's Hospital, Randwick, NSW 2031, Australia; University of New South Wales, Sydney, NSW 2031, Australia; SEALS Pathology, Randwick, NSW 2031, Australia
| | - Rani Sachdev
- Sydney Children's Hospital, Randwick, NSW 2031, Australia; University of New South Wales, Sydney, NSW 2031, Australia
| | - Michael E Duffey
- Physiology and Biophysics, University at Buffalo - The State University of New York, Buffalo, NY 14214, USA
| | - Ann Bye
- Sydney Children's Hospital, Randwick, NSW 2031, Australia; University of New South Wales, Sydney, NSW 2031, Australia
| | - Arin Bhattacharjee
- Pharmacology and Toxicology, University at Buffalo - The State University of New York, Buffalo, NY 14214, USA; Program for Neuroscience, University at Buffalo - The State University of New York, Buffalo, NY 14214, USA.
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13
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McTague A, Nair U, Malhotra S, Meyer E, Trump N, Gazina EV, Papandreou A, Ngoh A, Ackermann S, Ambegaonkar G, Appleton R, Desurkar A, Eltze C, Kneen R, Kumar AV, Lascelles K, Montgomery T, Ramesh V, Samanta R, Scott RH, Tan J, Whitehouse W, Poduri A, Scheffer IE, Chong WKK, Cross JH, Topf M, Petrou S, Kurian MA. Clinical and molecular characterization of KCNT1-related severe early-onset epilepsy. Neurology 2018; 90:e55-e66. [PMID: 29196579 PMCID: PMC5754647 DOI: 10.1212/wnl.0000000000004762] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 09/26/2017] [Indexed: 11/20/2022] Open
Abstract
OBJECTIVE To characterize the phenotypic spectrum, molecular genetic findings, and functional consequences of pathogenic variants in early-onset KCNT1 epilepsy. METHODS We identified a cohort of 31 patients with epilepsy of infancy with migrating focal seizures (EIMFS) and screened for variants in KCNT1 using direct Sanger sequencing, a multiple-gene next-generation sequencing panel, and whole-exome sequencing. Additional patients with non-EIMFS early-onset epilepsy in whom we identified KCNT1 variants on local diagnostic multiple gene panel testing were also included. When possible, we performed homology modeling to predict the putative effects of variants on protein structure and function. We undertook electrophysiologic assessment of mutant KCNT1 channels in a xenopus oocyte model system. RESULTS We identified pathogenic variants in KCNT1 in 12 patients, 4 of which are novel. Most variants occurred de novo. Ten patients had a clinical diagnosis of EIMFS, and the other 2 presented with early-onset severe nocturnal frontal lobe seizures. Three patients had a trial of quinidine with good clinical response in 1 patient. Computational modeling analysis implicates abnormal pore function (F346L) and impaired tetramer formation (F502V) as putative disease mechanisms. All evaluated KCNT1 variants resulted in marked gain of function with significantly increased channel amplitude and variable blockade by quinidine. CONCLUSIONS Gain-of-function KCNT1 pathogenic variants cause a spectrum of severe focal epilepsies with onset in early infancy. Currently, genotype-phenotype correlations are unclear, although clinical outcome is poor for the majority of cases. Further elucidation of disease mechanisms may facilitate the development of targeted treatments, much needed for this pharmacoresistant genetic epilepsy.
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Affiliation(s)
- Amy McTague
- From Molecular Neurosciences (A.M., E.M., A., A.N., M.A.K.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health; Department of Neurology (A.M., A., A.N., C.E., J.H.C., M.A.K.) and Neuroradiology (W.K.C.), Great Ormond Street Hospital for Children, London, UK; Florey Institute of Neuroscience and Mental Health (U.N., E.V.G., I.E.S., S.P.), Melbourne, Australia; Department of Biological Sciences (S.M., M.T.), Institute of Structural and Molecular Biology, Birkbeck College, University of London; Regional Molecular Genetics Laboratory (N.T., R.H.S.), North East Thames Regional Genetics Service, and Department of Clinical Genetics (A.V.K., R.H.S.), Great Ormond Street Hospital, London, UK; Department of Paediatric Neurology (S.A.), Red Cross War Memorial Children's Hospital, Cape Town, South Africa; Department of Paediatric Neurology (G.A.), Addenbrooke's Hospital, Cambridge; Roald Dahl EEG Unit (R.A.), Department of Neurology, and Department of Neurology (R.K.), Alder Hey Children's Hospital, Liverpool; Department of Paediatric Neurology (A.D.), Sheffield Children's Hospital; Clinical Neurosciences (C.E., J.H.C.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London; Institute of Infection and Global Health (R.K.), University of Liverpool; Department of Paediatric Neurology (K.L.), Evelina Children's Hospital, Guys and St. Thomas' NHS Foundation Trust, London; Department of Clinical Genetics (T.M.), Northern Genetics Service; Department of Pediatric Neurology (V.R.), Great North Children's Hospital, Newcastle Upon Tyne; Department of Paediatric Neurology (R.S.), University Hospital Leicester Children's Hospital; Department of Paediatric Neurology (J.T.), Royal Manchester Children's Hospital; Department of Paediatric Neurology (W.W.), Nottingham University Hospitals NHS Trust, UK; Epilepsy Genetics Program (A. Poduri), Department of Neurology, Boston Children's Hospital; Department of Neurology (A. Poduri), Harvard Medical School, Boston, MA; University of Melbourne (I.E.S.), Austin Health and Royal Children's Hospital, Australia; and Department of Medicine (S.P.), Royal Melbourne Hospital, University of Melbourne, Australia. Dr. Malhotra is currently at the Department of Biochemistry, University of Cambridge, UK.
| | - Umesh Nair
- From Molecular Neurosciences (A.M., E.M., A., A.N., M.A.K.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health; Department of Neurology (A.M., A., A.N., C.E., J.H.C., M.A.K.) and Neuroradiology (W.K.C.), Great Ormond Street Hospital for Children, London, UK; Florey Institute of Neuroscience and Mental Health (U.N., E.V.G., I.E.S., S.P.), Melbourne, Australia; Department of Biological Sciences (S.M., M.T.), Institute of Structural and Molecular Biology, Birkbeck College, University of London; Regional Molecular Genetics Laboratory (N.T., R.H.S.), North East Thames Regional Genetics Service, and Department of Clinical Genetics (A.V.K., R.H.S.), Great Ormond Street Hospital, London, UK; Department of Paediatric Neurology (S.A.), Red Cross War Memorial Children's Hospital, Cape Town, South Africa; Department of Paediatric Neurology (G.A.), Addenbrooke's Hospital, Cambridge; Roald Dahl EEG Unit (R.A.), Department of Neurology, and Department of Neurology (R.K.), Alder Hey Children's Hospital, Liverpool; Department of Paediatric Neurology (A.D.), Sheffield Children's Hospital; Clinical Neurosciences (C.E., J.H.C.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London; Institute of Infection and Global Health (R.K.), University of Liverpool; Department of Paediatric Neurology (K.L.), Evelina Children's Hospital, Guys and St. Thomas' NHS Foundation Trust, London; Department of Clinical Genetics (T.M.), Northern Genetics Service; Department of Pediatric Neurology (V.R.), Great North Children's Hospital, Newcastle Upon Tyne; Department of Paediatric Neurology (R.S.), University Hospital Leicester Children's Hospital; Department of Paediatric Neurology (J.T.), Royal Manchester Children's Hospital; Department of Paediatric Neurology (W.W.), Nottingham University Hospitals NHS Trust, UK; Epilepsy Genetics Program (A. Poduri), Department of Neurology, Boston Children's Hospital; Department of Neurology (A. Poduri), Harvard Medical School, Boston, MA; University of Melbourne (I.E.S.), Austin Health and Royal Children's Hospital, Australia; and Department of Medicine (S.P.), Royal Melbourne Hospital, University of Melbourne, Australia. Dr. Malhotra is currently at the Department of Biochemistry, University of Cambridge, UK
| | - Sony Malhotra
- From Molecular Neurosciences (A.M., E.M., A., A.N., M.A.K.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health; Department of Neurology (A.M., A., A.N., C.E., J.H.C., M.A.K.) and Neuroradiology (W.K.C.), Great Ormond Street Hospital for Children, London, UK; Florey Institute of Neuroscience and Mental Health (U.N., E.V.G., I.E.S., S.P.), Melbourne, Australia; Department of Biological Sciences (S.M., M.T.), Institute of Structural and Molecular Biology, Birkbeck College, University of London; Regional Molecular Genetics Laboratory (N.T., R.H.S.), North East Thames Regional Genetics Service, and Department of Clinical Genetics (A.V.K., R.H.S.), Great Ormond Street Hospital, London, UK; Department of Paediatric Neurology (S.A.), Red Cross War Memorial Children's Hospital, Cape Town, South Africa; Department of Paediatric Neurology (G.A.), Addenbrooke's Hospital, Cambridge; Roald Dahl EEG Unit (R.A.), Department of Neurology, and Department of Neurology (R.K.), Alder Hey Children's Hospital, Liverpool; Department of Paediatric Neurology (A.D.), Sheffield Children's Hospital; Clinical Neurosciences (C.E., J.H.C.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London; Institute of Infection and Global Health (R.K.), University of Liverpool; Department of Paediatric Neurology (K.L.), Evelina Children's Hospital, Guys and St. Thomas' NHS Foundation Trust, London; Department of Clinical Genetics (T.M.), Northern Genetics Service; Department of Pediatric Neurology (V.R.), Great North Children's Hospital, Newcastle Upon Tyne; Department of Paediatric Neurology (R.S.), University Hospital Leicester Children's Hospital; Department of Paediatric Neurology (J.T.), Royal Manchester Children's Hospital; Department of Paediatric Neurology (W.W.), Nottingham University Hospitals NHS Trust, UK; Epilepsy Genetics Program (A. Poduri), Department of Neurology, Boston Children's Hospital; Department of Neurology (A. Poduri), Harvard Medical School, Boston, MA; University of Melbourne (I.E.S.), Austin Health and Royal Children's Hospital, Australia; and Department of Medicine (S.P.), Royal Melbourne Hospital, University of Melbourne, Australia. Dr. Malhotra is currently at the Department of Biochemistry, University of Cambridge, UK
| | - Esther Meyer
- From Molecular Neurosciences (A.M., E.M., A., A.N., M.A.K.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health; Department of Neurology (A.M., A., A.N., C.E., J.H.C., M.A.K.) and Neuroradiology (W.K.C.), Great Ormond Street Hospital for Children, London, UK; Florey Institute of Neuroscience and Mental Health (U.N., E.V.G., I.E.S., S.P.), Melbourne, Australia; Department of Biological Sciences (S.M., M.T.), Institute of Structural and Molecular Biology, Birkbeck College, University of London; Regional Molecular Genetics Laboratory (N.T., R.H.S.), North East Thames Regional Genetics Service, and Department of Clinical Genetics (A.V.K., R.H.S.), Great Ormond Street Hospital, London, UK; Department of Paediatric Neurology (S.A.), Red Cross War Memorial Children's Hospital, Cape Town, South Africa; Department of Paediatric Neurology (G.A.), Addenbrooke's Hospital, Cambridge; Roald Dahl EEG Unit (R.A.), Department of Neurology, and Department of Neurology (R.K.), Alder Hey Children's Hospital, Liverpool; Department of Paediatric Neurology (A.D.), Sheffield Children's Hospital; Clinical Neurosciences (C.E., J.H.C.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London; Institute of Infection and Global Health (R.K.), University of Liverpool; Department of Paediatric Neurology (K.L.), Evelina Children's Hospital, Guys and St. Thomas' NHS Foundation Trust, London; Department of Clinical Genetics (T.M.), Northern Genetics Service; Department of Pediatric Neurology (V.R.), Great North Children's Hospital, Newcastle Upon Tyne; Department of Paediatric Neurology (R.S.), University Hospital Leicester Children's Hospital; Department of Paediatric Neurology (J.T.), Royal Manchester Children's Hospital; Department of Paediatric Neurology (W.W.), Nottingham University Hospitals NHS Trust, UK; Epilepsy Genetics Program (A. Poduri), Department of Neurology, Boston Children's Hospital; Department of Neurology (A. Poduri), Harvard Medical School, Boston, MA; University of Melbourne (I.E.S.), Austin Health and Royal Children's Hospital, Australia; and Department of Medicine (S.P.), Royal Melbourne Hospital, University of Melbourne, Australia. Dr. Malhotra is currently at the Department of Biochemistry, University of Cambridge, UK
| | - Natalie Trump
- From Molecular Neurosciences (A.M., E.M., A., A.N., M.A.K.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health; Department of Neurology (A.M., A., A.N., C.E., J.H.C., M.A.K.) and Neuroradiology (W.K.C.), Great Ormond Street Hospital for Children, London, UK; Florey Institute of Neuroscience and Mental Health (U.N., E.V.G., I.E.S., S.P.), Melbourne, Australia; Department of Biological Sciences (S.M., M.T.), Institute of Structural and Molecular Biology, Birkbeck College, University of London; Regional Molecular Genetics Laboratory (N.T., R.H.S.), North East Thames Regional Genetics Service, and Department of Clinical Genetics (A.V.K., R.H.S.), Great Ormond Street Hospital, London, UK; Department of Paediatric Neurology (S.A.), Red Cross War Memorial Children's Hospital, Cape Town, South Africa; Department of Paediatric Neurology (G.A.), Addenbrooke's Hospital, Cambridge; Roald Dahl EEG Unit (R.A.), Department of Neurology, and Department of Neurology (R.K.), Alder Hey Children's Hospital, Liverpool; Department of Paediatric Neurology (A.D.), Sheffield Children's Hospital; Clinical Neurosciences (C.E., J.H.C.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London; Institute of Infection and Global Health (R.K.), University of Liverpool; Department of Paediatric Neurology (K.L.), Evelina Children's Hospital, Guys and St. Thomas' NHS Foundation Trust, London; Department of Clinical Genetics (T.M.), Northern Genetics Service; Department of Pediatric Neurology (V.R.), Great North Children's Hospital, Newcastle Upon Tyne; Department of Paediatric Neurology (R.S.), University Hospital Leicester Children's Hospital; Department of Paediatric Neurology (J.T.), Royal Manchester Children's Hospital; Department of Paediatric Neurology (W.W.), Nottingham University Hospitals NHS Trust, UK; Epilepsy Genetics Program (A. Poduri), Department of Neurology, Boston Children's Hospital; Department of Neurology (A. Poduri), Harvard Medical School, Boston, MA; University of Melbourne (I.E.S.), Austin Health and Royal Children's Hospital, Australia; and Department of Medicine (S.P.), Royal Melbourne Hospital, University of Melbourne, Australia. Dr. Malhotra is currently at the Department of Biochemistry, University of Cambridge, UK
| | - Elena V Gazina
- From Molecular Neurosciences (A.M., E.M., A., A.N., M.A.K.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health; Department of Neurology (A.M., A., A.N., C.E., J.H.C., M.A.K.) and Neuroradiology (W.K.C.), Great Ormond Street Hospital for Children, London, UK; Florey Institute of Neuroscience and Mental Health (U.N., E.V.G., I.E.S., S.P.), Melbourne, Australia; Department of Biological Sciences (S.M., M.T.), Institute of Structural and Molecular Biology, Birkbeck College, University of London; Regional Molecular Genetics Laboratory (N.T., R.H.S.), North East Thames Regional Genetics Service, and Department of Clinical Genetics (A.V.K., R.H.S.), Great Ormond Street Hospital, London, UK; Department of Paediatric Neurology (S.A.), Red Cross War Memorial Children's Hospital, Cape Town, South Africa; Department of Paediatric Neurology (G.A.), Addenbrooke's Hospital, Cambridge; Roald Dahl EEG Unit (R.A.), Department of Neurology, and Department of Neurology (R.K.), Alder Hey Children's Hospital, Liverpool; Department of Paediatric Neurology (A.D.), Sheffield Children's Hospital; Clinical Neurosciences (C.E., J.H.C.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London; Institute of Infection and Global Health (R.K.), University of Liverpool; Department of Paediatric Neurology (K.L.), Evelina Children's Hospital, Guys and St. Thomas' NHS Foundation Trust, London; Department of Clinical Genetics (T.M.), Northern Genetics Service; Department of Pediatric Neurology (V.R.), Great North Children's Hospital, Newcastle Upon Tyne; Department of Paediatric Neurology (R.S.), University Hospital Leicester Children's Hospital; Department of Paediatric Neurology (J.T.), Royal Manchester Children's Hospital; Department of Paediatric Neurology (W.W.), Nottingham University Hospitals NHS Trust, UK; Epilepsy Genetics Program (A. Poduri), Department of Neurology, Boston Children's Hospital; Department of Neurology (A. Poduri), Harvard Medical School, Boston, MA; University of Melbourne (I.E.S.), Austin Health and Royal Children's Hospital, Australia; and Department of Medicine (S.P.), Royal Melbourne Hospital, University of Melbourne, Australia. Dr. Malhotra is currently at the Department of Biochemistry, University of Cambridge, UK
| | - Apostolos Papandreou
- From Molecular Neurosciences (A.M., E.M., A., A.N., M.A.K.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health; Department of Neurology (A.M., A., A.N., C.E., J.H.C., M.A.K.) and Neuroradiology (W.K.C.), Great Ormond Street Hospital for Children, London, UK; Florey Institute of Neuroscience and Mental Health (U.N., E.V.G., I.E.S., S.P.), Melbourne, Australia; Department of Biological Sciences (S.M., M.T.), Institute of Structural and Molecular Biology, Birkbeck College, University of London; Regional Molecular Genetics Laboratory (N.T., R.H.S.), North East Thames Regional Genetics Service, and Department of Clinical Genetics (A.V.K., R.H.S.), Great Ormond Street Hospital, London, UK; Department of Paediatric Neurology (S.A.), Red Cross War Memorial Children's Hospital, Cape Town, South Africa; Department of Paediatric Neurology (G.A.), Addenbrooke's Hospital, Cambridge; Roald Dahl EEG Unit (R.A.), Department of Neurology, and Department of Neurology (R.K.), Alder Hey Children's Hospital, Liverpool; Department of Paediatric Neurology (A.D.), Sheffield Children's Hospital; Clinical Neurosciences (C.E., J.H.C.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London; Institute of Infection and Global Health (R.K.), University of Liverpool; Department of Paediatric Neurology (K.L.), Evelina Children's Hospital, Guys and St. Thomas' NHS Foundation Trust, London; Department of Clinical Genetics (T.M.), Northern Genetics Service; Department of Pediatric Neurology (V.R.), Great North Children's Hospital, Newcastle Upon Tyne; Department of Paediatric Neurology (R.S.), University Hospital Leicester Children's Hospital; Department of Paediatric Neurology (J.T.), Royal Manchester Children's Hospital; Department of Paediatric Neurology (W.W.), Nottingham University Hospitals NHS Trust, UK; Epilepsy Genetics Program (A. Poduri), Department of Neurology, Boston Children's Hospital; Department of Neurology (A. Poduri), Harvard Medical School, Boston, MA; University of Melbourne (I.E.S.), Austin Health and Royal Children's Hospital, Australia; and Department of Medicine (S.P.), Royal Melbourne Hospital, University of Melbourne, Australia. Dr. Malhotra is currently at the Department of Biochemistry, University of Cambridge, UK
| | - Adeline Ngoh
- From Molecular Neurosciences (A.M., E.M., A., A.N., M.A.K.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health; Department of Neurology (A.M., A., A.N., C.E., J.H.C., M.A.K.) and Neuroradiology (W.K.C.), Great Ormond Street Hospital for Children, London, UK; Florey Institute of Neuroscience and Mental Health (U.N., E.V.G., I.E.S., S.P.), Melbourne, Australia; Department of Biological Sciences (S.M., M.T.), Institute of Structural and Molecular Biology, Birkbeck College, University of London; Regional Molecular Genetics Laboratory (N.T., R.H.S.), North East Thames Regional Genetics Service, and Department of Clinical Genetics (A.V.K., R.H.S.), Great Ormond Street Hospital, London, UK; Department of Paediatric Neurology (S.A.), Red Cross War Memorial Children's Hospital, Cape Town, South Africa; Department of Paediatric Neurology (G.A.), Addenbrooke's Hospital, Cambridge; Roald Dahl EEG Unit (R.A.), Department of Neurology, and Department of Neurology (R.K.), Alder Hey Children's Hospital, Liverpool; Department of Paediatric Neurology (A.D.), Sheffield Children's Hospital; Clinical Neurosciences (C.E., J.H.C.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London; Institute of Infection and Global Health (R.K.), University of Liverpool; Department of Paediatric Neurology (K.L.), Evelina Children's Hospital, Guys and St. Thomas' NHS Foundation Trust, London; Department of Clinical Genetics (T.M.), Northern Genetics Service; Department of Pediatric Neurology (V.R.), Great North Children's Hospital, Newcastle Upon Tyne; Department of Paediatric Neurology (R.S.), University Hospital Leicester Children's Hospital; Department of Paediatric Neurology (J.T.), Royal Manchester Children's Hospital; Department of Paediatric Neurology (W.W.), Nottingham University Hospitals NHS Trust, UK; Epilepsy Genetics Program (A. Poduri), Department of Neurology, Boston Children's Hospital; Department of Neurology (A. Poduri), Harvard Medical School, Boston, MA; University of Melbourne (I.E.S.), Austin Health and Royal Children's Hospital, Australia; and Department of Medicine (S.P.), Royal Melbourne Hospital, University of Melbourne, Australia. Dr. Malhotra is currently at the Department of Biochemistry, University of Cambridge, UK
| | - Sally Ackermann
- From Molecular Neurosciences (A.M., E.M., A., A.N., M.A.K.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health; Department of Neurology (A.M., A., A.N., C.E., J.H.C., M.A.K.) and Neuroradiology (W.K.C.), Great Ormond Street Hospital for Children, London, UK; Florey Institute of Neuroscience and Mental Health (U.N., E.V.G., I.E.S., S.P.), Melbourne, Australia; Department of Biological Sciences (S.M., M.T.), Institute of Structural and Molecular Biology, Birkbeck College, University of London; Regional Molecular Genetics Laboratory (N.T., R.H.S.), North East Thames Regional Genetics Service, and Department of Clinical Genetics (A.V.K., R.H.S.), Great Ormond Street Hospital, London, UK; Department of Paediatric Neurology (S.A.), Red Cross War Memorial Children's Hospital, Cape Town, South Africa; Department of Paediatric Neurology (G.A.), Addenbrooke's Hospital, Cambridge; Roald Dahl EEG Unit (R.A.), Department of Neurology, and Department of Neurology (R.K.), Alder Hey Children's Hospital, Liverpool; Department of Paediatric Neurology (A.D.), Sheffield Children's Hospital; Clinical Neurosciences (C.E., J.H.C.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London; Institute of Infection and Global Health (R.K.), University of Liverpool; Department of Paediatric Neurology (K.L.), Evelina Children's Hospital, Guys and St. Thomas' NHS Foundation Trust, London; Department of Clinical Genetics (T.M.), Northern Genetics Service; Department of Pediatric Neurology (V.R.), Great North Children's Hospital, Newcastle Upon Tyne; Department of Paediatric Neurology (R.S.), University Hospital Leicester Children's Hospital; Department of Paediatric Neurology (J.T.), Royal Manchester Children's Hospital; Department of Paediatric Neurology (W.W.), Nottingham University Hospitals NHS Trust, UK; Epilepsy Genetics Program (A. Poduri), Department of Neurology, Boston Children's Hospital; Department of Neurology (A. Poduri), Harvard Medical School, Boston, MA; University of Melbourne (I.E.S.), Austin Health and Royal Children's Hospital, Australia; and Department of Medicine (S.P.), Royal Melbourne Hospital, University of Melbourne, Australia. Dr. Malhotra is currently at the Department of Biochemistry, University of Cambridge, UK
| | - Gautam Ambegaonkar
- From Molecular Neurosciences (A.M., E.M., A., A.N., M.A.K.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health; Department of Neurology (A.M., A., A.N., C.E., J.H.C., M.A.K.) and Neuroradiology (W.K.C.), Great Ormond Street Hospital for Children, London, UK; Florey Institute of Neuroscience and Mental Health (U.N., E.V.G., I.E.S., S.P.), Melbourne, Australia; Department of Biological Sciences (S.M., M.T.), Institute of Structural and Molecular Biology, Birkbeck College, University of London; Regional Molecular Genetics Laboratory (N.T., R.H.S.), North East Thames Regional Genetics Service, and Department of Clinical Genetics (A.V.K., R.H.S.), Great Ormond Street Hospital, London, UK; Department of Paediatric Neurology (S.A.), Red Cross War Memorial Children's Hospital, Cape Town, South Africa; Department of Paediatric Neurology (G.A.), Addenbrooke's Hospital, Cambridge; Roald Dahl EEG Unit (R.A.), Department of Neurology, and Department of Neurology (R.K.), Alder Hey Children's Hospital, Liverpool; Department of Paediatric Neurology (A.D.), Sheffield Children's Hospital; Clinical Neurosciences (C.E., J.H.C.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London; Institute of Infection and Global Health (R.K.), University of Liverpool; Department of Paediatric Neurology (K.L.), Evelina Children's Hospital, Guys and St. Thomas' NHS Foundation Trust, London; Department of Clinical Genetics (T.M.), Northern Genetics Service; Department of Pediatric Neurology (V.R.), Great North Children's Hospital, Newcastle Upon Tyne; Department of Paediatric Neurology (R.S.), University Hospital Leicester Children's Hospital; Department of Paediatric Neurology (J.T.), Royal Manchester Children's Hospital; Department of Paediatric Neurology (W.W.), Nottingham University Hospitals NHS Trust, UK; Epilepsy Genetics Program (A. Poduri), Department of Neurology, Boston Children's Hospital; Department of Neurology (A. Poduri), Harvard Medical School, Boston, MA; University of Melbourne (I.E.S.), Austin Health and Royal Children's Hospital, Australia; and Department of Medicine (S.P.), Royal Melbourne Hospital, University of Melbourne, Australia. Dr. Malhotra is currently at the Department of Biochemistry, University of Cambridge, UK
| | - Richard Appleton
- From Molecular Neurosciences (A.M., E.M., A., A.N., M.A.K.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health; Department of Neurology (A.M., A., A.N., C.E., J.H.C., M.A.K.) and Neuroradiology (W.K.C.), Great Ormond Street Hospital for Children, London, UK; Florey Institute of Neuroscience and Mental Health (U.N., E.V.G., I.E.S., S.P.), Melbourne, Australia; Department of Biological Sciences (S.M., M.T.), Institute of Structural and Molecular Biology, Birkbeck College, University of London; Regional Molecular Genetics Laboratory (N.T., R.H.S.), North East Thames Regional Genetics Service, and Department of Clinical Genetics (A.V.K., R.H.S.), Great Ormond Street Hospital, London, UK; Department of Paediatric Neurology (S.A.), Red Cross War Memorial Children's Hospital, Cape Town, South Africa; Department of Paediatric Neurology (G.A.), Addenbrooke's Hospital, Cambridge; Roald Dahl EEG Unit (R.A.), Department of Neurology, and Department of Neurology (R.K.), Alder Hey Children's Hospital, Liverpool; Department of Paediatric Neurology (A.D.), Sheffield Children's Hospital; Clinical Neurosciences (C.E., J.H.C.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London; Institute of Infection and Global Health (R.K.), University of Liverpool; Department of Paediatric Neurology (K.L.), Evelina Children's Hospital, Guys and St. Thomas' NHS Foundation Trust, London; Department of Clinical Genetics (T.M.), Northern Genetics Service; Department of Pediatric Neurology (V.R.), Great North Children's Hospital, Newcastle Upon Tyne; Department of Paediatric Neurology (R.S.), University Hospital Leicester Children's Hospital; Department of Paediatric Neurology (J.T.), Royal Manchester Children's Hospital; Department of Paediatric Neurology (W.W.), Nottingham University Hospitals NHS Trust, UK; Epilepsy Genetics Program (A. Poduri), Department of Neurology, Boston Children's Hospital; Department of Neurology (A. Poduri), Harvard Medical School, Boston, MA; University of Melbourne (I.E.S.), Austin Health and Royal Children's Hospital, Australia; and Department of Medicine (S.P.), Royal Melbourne Hospital, University of Melbourne, Australia. Dr. Malhotra is currently at the Department of Biochemistry, University of Cambridge, UK
| | - Archana Desurkar
- From Molecular Neurosciences (A.M., E.M., A., A.N., M.A.K.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health; Department of Neurology (A.M., A., A.N., C.E., J.H.C., M.A.K.) and Neuroradiology (W.K.C.), Great Ormond Street Hospital for Children, London, UK; Florey Institute of Neuroscience and Mental Health (U.N., E.V.G., I.E.S., S.P.), Melbourne, Australia; Department of Biological Sciences (S.M., M.T.), Institute of Structural and Molecular Biology, Birkbeck College, University of London; Regional Molecular Genetics Laboratory (N.T., R.H.S.), North East Thames Regional Genetics Service, and Department of Clinical Genetics (A.V.K., R.H.S.), Great Ormond Street Hospital, London, UK; Department of Paediatric Neurology (S.A.), Red Cross War Memorial Children's Hospital, Cape Town, South Africa; Department of Paediatric Neurology (G.A.), Addenbrooke's Hospital, Cambridge; Roald Dahl EEG Unit (R.A.), Department of Neurology, and Department of Neurology (R.K.), Alder Hey Children's Hospital, Liverpool; Department of Paediatric Neurology (A.D.), Sheffield Children's Hospital; Clinical Neurosciences (C.E., J.H.C.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London; Institute of Infection and Global Health (R.K.), University of Liverpool; Department of Paediatric Neurology (K.L.), Evelina Children's Hospital, Guys and St. Thomas' NHS Foundation Trust, London; Department of Clinical Genetics (T.M.), Northern Genetics Service; Department of Pediatric Neurology (V.R.), Great North Children's Hospital, Newcastle Upon Tyne; Department of Paediatric Neurology (R.S.), University Hospital Leicester Children's Hospital; Department of Paediatric Neurology (J.T.), Royal Manchester Children's Hospital; Department of Paediatric Neurology (W.W.), Nottingham University Hospitals NHS Trust, UK; Epilepsy Genetics Program (A. Poduri), Department of Neurology, Boston Children's Hospital; Department of Neurology (A. Poduri), Harvard Medical School, Boston, MA; University of Melbourne (I.E.S.), Austin Health and Royal Children's Hospital, Australia; and Department of Medicine (S.P.), Royal Melbourne Hospital, University of Melbourne, Australia. Dr. Malhotra is currently at the Department of Biochemistry, University of Cambridge, UK
| | - Christin Eltze
- From Molecular Neurosciences (A.M., E.M., A., A.N., M.A.K.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health; Department of Neurology (A.M., A., A.N., C.E., J.H.C., M.A.K.) and Neuroradiology (W.K.C.), Great Ormond Street Hospital for Children, London, UK; Florey Institute of Neuroscience and Mental Health (U.N., E.V.G., I.E.S., S.P.), Melbourne, Australia; Department of Biological Sciences (S.M., M.T.), Institute of Structural and Molecular Biology, Birkbeck College, University of London; Regional Molecular Genetics Laboratory (N.T., R.H.S.), North East Thames Regional Genetics Service, and Department of Clinical Genetics (A.V.K., R.H.S.), Great Ormond Street Hospital, London, UK; Department of Paediatric Neurology (S.A.), Red Cross War Memorial Children's Hospital, Cape Town, South Africa; Department of Paediatric Neurology (G.A.), Addenbrooke's Hospital, Cambridge; Roald Dahl EEG Unit (R.A.), Department of Neurology, and Department of Neurology (R.K.), Alder Hey Children's Hospital, Liverpool; Department of Paediatric Neurology (A.D.), Sheffield Children's Hospital; Clinical Neurosciences (C.E., J.H.C.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London; Institute of Infection and Global Health (R.K.), University of Liverpool; Department of Paediatric Neurology (K.L.), Evelina Children's Hospital, Guys and St. Thomas' NHS Foundation Trust, London; Department of Clinical Genetics (T.M.), Northern Genetics Service; Department of Pediatric Neurology (V.R.), Great North Children's Hospital, Newcastle Upon Tyne; Department of Paediatric Neurology (R.S.), University Hospital Leicester Children's Hospital; Department of Paediatric Neurology (J.T.), Royal Manchester Children's Hospital; Department of Paediatric Neurology (W.W.), Nottingham University Hospitals NHS Trust, UK; Epilepsy Genetics Program (A. Poduri), Department of Neurology, Boston Children's Hospital; Department of Neurology (A. Poduri), Harvard Medical School, Boston, MA; University of Melbourne (I.E.S.), Austin Health and Royal Children's Hospital, Australia; and Department of Medicine (S.P.), Royal Melbourne Hospital, University of Melbourne, Australia. Dr. Malhotra is currently at the Department of Biochemistry, University of Cambridge, UK
| | - Rachel Kneen
- From Molecular Neurosciences (A.M., E.M., A., A.N., M.A.K.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health; Department of Neurology (A.M., A., A.N., C.E., J.H.C., M.A.K.) and Neuroradiology (W.K.C.), Great Ormond Street Hospital for Children, London, UK; Florey Institute of Neuroscience and Mental Health (U.N., E.V.G., I.E.S., S.P.), Melbourne, Australia; Department of Biological Sciences (S.M., M.T.), Institute of Structural and Molecular Biology, Birkbeck College, University of London; Regional Molecular Genetics Laboratory (N.T., R.H.S.), North East Thames Regional Genetics Service, and Department of Clinical Genetics (A.V.K., R.H.S.), Great Ormond Street Hospital, London, UK; Department of Paediatric Neurology (S.A.), Red Cross War Memorial Children's Hospital, Cape Town, South Africa; Department of Paediatric Neurology (G.A.), Addenbrooke's Hospital, Cambridge; Roald Dahl EEG Unit (R.A.), Department of Neurology, and Department of Neurology (R.K.), Alder Hey Children's Hospital, Liverpool; Department of Paediatric Neurology (A.D.), Sheffield Children's Hospital; Clinical Neurosciences (C.E., J.H.C.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London; Institute of Infection and Global Health (R.K.), University of Liverpool; Department of Paediatric Neurology (K.L.), Evelina Children's Hospital, Guys and St. Thomas' NHS Foundation Trust, London; Department of Clinical Genetics (T.M.), Northern Genetics Service; Department of Pediatric Neurology (V.R.), Great North Children's Hospital, Newcastle Upon Tyne; Department of Paediatric Neurology (R.S.), University Hospital Leicester Children's Hospital; Department of Paediatric Neurology (J.T.), Royal Manchester Children's Hospital; Department of Paediatric Neurology (W.W.), Nottingham University Hospitals NHS Trust, UK; Epilepsy Genetics Program (A. Poduri), Department of Neurology, Boston Children's Hospital; Department of Neurology (A. Poduri), Harvard Medical School, Boston, MA; University of Melbourne (I.E.S.), Austin Health and Royal Children's Hospital, Australia; and Department of Medicine (S.P.), Royal Melbourne Hospital, University of Melbourne, Australia. Dr. Malhotra is currently at the Department of Biochemistry, University of Cambridge, UK
| | - Ajith V Kumar
- From Molecular Neurosciences (A.M., E.M., A., A.N., M.A.K.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health; Department of Neurology (A.M., A., A.N., C.E., J.H.C., M.A.K.) and Neuroradiology (W.K.C.), Great Ormond Street Hospital for Children, London, UK; Florey Institute of Neuroscience and Mental Health (U.N., E.V.G., I.E.S., S.P.), Melbourne, Australia; Department of Biological Sciences (S.M., M.T.), Institute of Structural and Molecular Biology, Birkbeck College, University of London; Regional Molecular Genetics Laboratory (N.T., R.H.S.), North East Thames Regional Genetics Service, and Department of Clinical Genetics (A.V.K., R.H.S.), Great Ormond Street Hospital, London, UK; Department of Paediatric Neurology (S.A.), Red Cross War Memorial Children's Hospital, Cape Town, South Africa; Department of Paediatric Neurology (G.A.), Addenbrooke's Hospital, Cambridge; Roald Dahl EEG Unit (R.A.), Department of Neurology, and Department of Neurology (R.K.), Alder Hey Children's Hospital, Liverpool; Department of Paediatric Neurology (A.D.), Sheffield Children's Hospital; Clinical Neurosciences (C.E., J.H.C.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London; Institute of Infection and Global Health (R.K.), University of Liverpool; Department of Paediatric Neurology (K.L.), Evelina Children's Hospital, Guys and St. Thomas' NHS Foundation Trust, London; Department of Clinical Genetics (T.M.), Northern Genetics Service; Department of Pediatric Neurology (V.R.), Great North Children's Hospital, Newcastle Upon Tyne; Department of Paediatric Neurology (R.S.), University Hospital Leicester Children's Hospital; Department of Paediatric Neurology (J.T.), Royal Manchester Children's Hospital; Department of Paediatric Neurology (W.W.), Nottingham University Hospitals NHS Trust, UK; Epilepsy Genetics Program (A. Poduri), Department of Neurology, Boston Children's Hospital; Department of Neurology (A. Poduri), Harvard Medical School, Boston, MA; University of Melbourne (I.E.S.), Austin Health and Royal Children's Hospital, Australia; and Department of Medicine (S.P.), Royal Melbourne Hospital, University of Melbourne, Australia. Dr. Malhotra is currently at the Department of Biochemistry, University of Cambridge, UK
| | - Karine Lascelles
- From Molecular Neurosciences (A.M., E.M., A., A.N., M.A.K.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health; Department of Neurology (A.M., A., A.N., C.E., J.H.C., M.A.K.) and Neuroradiology (W.K.C.), Great Ormond Street Hospital for Children, London, UK; Florey Institute of Neuroscience and Mental Health (U.N., E.V.G., I.E.S., S.P.), Melbourne, Australia; Department of Biological Sciences (S.M., M.T.), Institute of Structural and Molecular Biology, Birkbeck College, University of London; Regional Molecular Genetics Laboratory (N.T., R.H.S.), North East Thames Regional Genetics Service, and Department of Clinical Genetics (A.V.K., R.H.S.), Great Ormond Street Hospital, London, UK; Department of Paediatric Neurology (S.A.), Red Cross War Memorial Children's Hospital, Cape Town, South Africa; Department of Paediatric Neurology (G.A.), Addenbrooke's Hospital, Cambridge; Roald Dahl EEG Unit (R.A.), Department of Neurology, and Department of Neurology (R.K.), Alder Hey Children's Hospital, Liverpool; Department of Paediatric Neurology (A.D.), Sheffield Children's Hospital; Clinical Neurosciences (C.E., J.H.C.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London; Institute of Infection and Global Health (R.K.), University of Liverpool; Department of Paediatric Neurology (K.L.), Evelina Children's Hospital, Guys and St. Thomas' NHS Foundation Trust, London; Department of Clinical Genetics (T.M.), Northern Genetics Service; Department of Pediatric Neurology (V.R.), Great North Children's Hospital, Newcastle Upon Tyne; Department of Paediatric Neurology (R.S.), University Hospital Leicester Children's Hospital; Department of Paediatric Neurology (J.T.), Royal Manchester Children's Hospital; Department of Paediatric Neurology (W.W.), Nottingham University Hospitals NHS Trust, UK; Epilepsy Genetics Program (A. Poduri), Department of Neurology, Boston Children's Hospital; Department of Neurology (A. Poduri), Harvard Medical School, Boston, MA; University of Melbourne (I.E.S.), Austin Health and Royal Children's Hospital, Australia; and Department of Medicine (S.P.), Royal Melbourne Hospital, University of Melbourne, Australia. Dr. Malhotra is currently at the Department of Biochemistry, University of Cambridge, UK
| | - Tara Montgomery
- From Molecular Neurosciences (A.M., E.M., A., A.N., M.A.K.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health; Department of Neurology (A.M., A., A.N., C.E., J.H.C., M.A.K.) and Neuroradiology (W.K.C.), Great Ormond Street Hospital for Children, London, UK; Florey Institute of Neuroscience and Mental Health (U.N., E.V.G., I.E.S., S.P.), Melbourne, Australia; Department of Biological Sciences (S.M., M.T.), Institute of Structural and Molecular Biology, Birkbeck College, University of London; Regional Molecular Genetics Laboratory (N.T., R.H.S.), North East Thames Regional Genetics Service, and Department of Clinical Genetics (A.V.K., R.H.S.), Great Ormond Street Hospital, London, UK; Department of Paediatric Neurology (S.A.), Red Cross War Memorial Children's Hospital, Cape Town, South Africa; Department of Paediatric Neurology (G.A.), Addenbrooke's Hospital, Cambridge; Roald Dahl EEG Unit (R.A.), Department of Neurology, and Department of Neurology (R.K.), Alder Hey Children's Hospital, Liverpool; Department of Paediatric Neurology (A.D.), Sheffield Children's Hospital; Clinical Neurosciences (C.E., J.H.C.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London; Institute of Infection and Global Health (R.K.), University of Liverpool; Department of Paediatric Neurology (K.L.), Evelina Children's Hospital, Guys and St. Thomas' NHS Foundation Trust, London; Department of Clinical Genetics (T.M.), Northern Genetics Service; Department of Pediatric Neurology (V.R.), Great North Children's Hospital, Newcastle Upon Tyne; Department of Paediatric Neurology (R.S.), University Hospital Leicester Children's Hospital; Department of Paediatric Neurology (J.T.), Royal Manchester Children's Hospital; Department of Paediatric Neurology (W.W.), Nottingham University Hospitals NHS Trust, UK; Epilepsy Genetics Program (A. Poduri), Department of Neurology, Boston Children's Hospital; Department of Neurology (A. Poduri), Harvard Medical School, Boston, MA; University of Melbourne (I.E.S.), Austin Health and Royal Children's Hospital, Australia; and Department of Medicine (S.P.), Royal Melbourne Hospital, University of Melbourne, Australia. Dr. Malhotra is currently at the Department of Biochemistry, University of Cambridge, UK
| | - Venkateswaran Ramesh
- From Molecular Neurosciences (A.M., E.M., A., A.N., M.A.K.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health; Department of Neurology (A.M., A., A.N., C.E., J.H.C., M.A.K.) and Neuroradiology (W.K.C.), Great Ormond Street Hospital for Children, London, UK; Florey Institute of Neuroscience and Mental Health (U.N., E.V.G., I.E.S., S.P.), Melbourne, Australia; Department of Biological Sciences (S.M., M.T.), Institute of Structural and Molecular Biology, Birkbeck College, University of London; Regional Molecular Genetics Laboratory (N.T., R.H.S.), North East Thames Regional Genetics Service, and Department of Clinical Genetics (A.V.K., R.H.S.), Great Ormond Street Hospital, London, UK; Department of Paediatric Neurology (S.A.), Red Cross War Memorial Children's Hospital, Cape Town, South Africa; Department of Paediatric Neurology (G.A.), Addenbrooke's Hospital, Cambridge; Roald Dahl EEG Unit (R.A.), Department of Neurology, and Department of Neurology (R.K.), Alder Hey Children's Hospital, Liverpool; Department of Paediatric Neurology (A.D.), Sheffield Children's Hospital; Clinical Neurosciences (C.E., J.H.C.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London; Institute of Infection and Global Health (R.K.), University of Liverpool; Department of Paediatric Neurology (K.L.), Evelina Children's Hospital, Guys and St. Thomas' NHS Foundation Trust, London; Department of Clinical Genetics (T.M.), Northern Genetics Service; Department of Pediatric Neurology (V.R.), Great North Children's Hospital, Newcastle Upon Tyne; Department of Paediatric Neurology (R.S.), University Hospital Leicester Children's Hospital; Department of Paediatric Neurology (J.T.), Royal Manchester Children's Hospital; Department of Paediatric Neurology (W.W.), Nottingham University Hospitals NHS Trust, UK; Epilepsy Genetics Program (A. Poduri), Department of Neurology, Boston Children's Hospital; Department of Neurology (A. Poduri), Harvard Medical School, Boston, MA; University of Melbourne (I.E.S.), Austin Health and Royal Children's Hospital, Australia; and Department of Medicine (S.P.), Royal Melbourne Hospital, University of Melbourne, Australia. Dr. Malhotra is currently at the Department of Biochemistry, University of Cambridge, UK
| | - Rajib Samanta
- From Molecular Neurosciences (A.M., E.M., A., A.N., M.A.K.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health; Department of Neurology (A.M., A., A.N., C.E., J.H.C., M.A.K.) and Neuroradiology (W.K.C.), Great Ormond Street Hospital for Children, London, UK; Florey Institute of Neuroscience and Mental Health (U.N., E.V.G., I.E.S., S.P.), Melbourne, Australia; Department of Biological Sciences (S.M., M.T.), Institute of Structural and Molecular Biology, Birkbeck College, University of London; Regional Molecular Genetics Laboratory (N.T., R.H.S.), North East Thames Regional Genetics Service, and Department of Clinical Genetics (A.V.K., R.H.S.), Great Ormond Street Hospital, London, UK; Department of Paediatric Neurology (S.A.), Red Cross War Memorial Children's Hospital, Cape Town, South Africa; Department of Paediatric Neurology (G.A.), Addenbrooke's Hospital, Cambridge; Roald Dahl EEG Unit (R.A.), Department of Neurology, and Department of Neurology (R.K.), Alder Hey Children's Hospital, Liverpool; Department of Paediatric Neurology (A.D.), Sheffield Children's Hospital; Clinical Neurosciences (C.E., J.H.C.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London; Institute of Infection and Global Health (R.K.), University of Liverpool; Department of Paediatric Neurology (K.L.), Evelina Children's Hospital, Guys and St. Thomas' NHS Foundation Trust, London; Department of Clinical Genetics (T.M.), Northern Genetics Service; Department of Pediatric Neurology (V.R.), Great North Children's Hospital, Newcastle Upon Tyne; Department of Paediatric Neurology (R.S.), University Hospital Leicester Children's Hospital; Department of Paediatric Neurology (J.T.), Royal Manchester Children's Hospital; Department of Paediatric Neurology (W.W.), Nottingham University Hospitals NHS Trust, UK; Epilepsy Genetics Program (A. Poduri), Department of Neurology, Boston Children's Hospital; Department of Neurology (A. Poduri), Harvard Medical School, Boston, MA; University of Melbourne (I.E.S.), Austin Health and Royal Children's Hospital, Australia; and Department of Medicine (S.P.), Royal Melbourne Hospital, University of Melbourne, Australia. Dr. Malhotra is currently at the Department of Biochemistry, University of Cambridge, UK
| | - Richard H Scott
- From Molecular Neurosciences (A.M., E.M., A., A.N., M.A.K.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health; Department of Neurology (A.M., A., A.N., C.E., J.H.C., M.A.K.) and Neuroradiology (W.K.C.), Great Ormond Street Hospital for Children, London, UK; Florey Institute of Neuroscience and Mental Health (U.N., E.V.G., I.E.S., S.P.), Melbourne, Australia; Department of Biological Sciences (S.M., M.T.), Institute of Structural and Molecular Biology, Birkbeck College, University of London; Regional Molecular Genetics Laboratory (N.T., R.H.S.), North East Thames Regional Genetics Service, and Department of Clinical Genetics (A.V.K., R.H.S.), Great Ormond Street Hospital, London, UK; Department of Paediatric Neurology (S.A.), Red Cross War Memorial Children's Hospital, Cape Town, South Africa; Department of Paediatric Neurology (G.A.), Addenbrooke's Hospital, Cambridge; Roald Dahl EEG Unit (R.A.), Department of Neurology, and Department of Neurology (R.K.), Alder Hey Children's Hospital, Liverpool; Department of Paediatric Neurology (A.D.), Sheffield Children's Hospital; Clinical Neurosciences (C.E., J.H.C.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London; Institute of Infection and Global Health (R.K.), University of Liverpool; Department of Paediatric Neurology (K.L.), Evelina Children's Hospital, Guys and St. Thomas' NHS Foundation Trust, London; Department of Clinical Genetics (T.M.), Northern Genetics Service; Department of Pediatric Neurology (V.R.), Great North Children's Hospital, Newcastle Upon Tyne; Department of Paediatric Neurology (R.S.), University Hospital Leicester Children's Hospital; Department of Paediatric Neurology (J.T.), Royal Manchester Children's Hospital; Department of Paediatric Neurology (W.W.), Nottingham University Hospitals NHS Trust, UK; Epilepsy Genetics Program (A. Poduri), Department of Neurology, Boston Children's Hospital; Department of Neurology (A. Poduri), Harvard Medical School, Boston, MA; University of Melbourne (I.E.S.), Austin Health and Royal Children's Hospital, Australia; and Department of Medicine (S.P.), Royal Melbourne Hospital, University of Melbourne, Australia. Dr. Malhotra is currently at the Department of Biochemistry, University of Cambridge, UK
| | - Jeen Tan
- From Molecular Neurosciences (A.M., E.M., A., A.N., M.A.K.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health; Department of Neurology (A.M., A., A.N., C.E., J.H.C., M.A.K.) and Neuroradiology (W.K.C.), Great Ormond Street Hospital for Children, London, UK; Florey Institute of Neuroscience and Mental Health (U.N., E.V.G., I.E.S., S.P.), Melbourne, Australia; Department of Biological Sciences (S.M., M.T.), Institute of Structural and Molecular Biology, Birkbeck College, University of London; Regional Molecular Genetics Laboratory (N.T., R.H.S.), North East Thames Regional Genetics Service, and Department of Clinical Genetics (A.V.K., R.H.S.), Great Ormond Street Hospital, London, UK; Department of Paediatric Neurology (S.A.), Red Cross War Memorial Children's Hospital, Cape Town, South Africa; Department of Paediatric Neurology (G.A.), Addenbrooke's Hospital, Cambridge; Roald Dahl EEG Unit (R.A.), Department of Neurology, and Department of Neurology (R.K.), Alder Hey Children's Hospital, Liverpool; Department of Paediatric Neurology (A.D.), Sheffield Children's Hospital; Clinical Neurosciences (C.E., J.H.C.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London; Institute of Infection and Global Health (R.K.), University of Liverpool; Department of Paediatric Neurology (K.L.), Evelina Children's Hospital, Guys and St. Thomas' NHS Foundation Trust, London; Department of Clinical Genetics (T.M.), Northern Genetics Service; Department of Pediatric Neurology (V.R.), Great North Children's Hospital, Newcastle Upon Tyne; Department of Paediatric Neurology (R.S.), University Hospital Leicester Children's Hospital; Department of Paediatric Neurology (J.T.), Royal Manchester Children's Hospital; Department of Paediatric Neurology (W.W.), Nottingham University Hospitals NHS Trust, UK; Epilepsy Genetics Program (A. Poduri), Department of Neurology, Boston Children's Hospital; Department of Neurology (A. Poduri), Harvard Medical School, Boston, MA; University of Melbourne (I.E.S.), Austin Health and Royal Children's Hospital, Australia; and Department of Medicine (S.P.), Royal Melbourne Hospital, University of Melbourne, Australia. Dr. Malhotra is currently at the Department of Biochemistry, University of Cambridge, UK
| | - William Whitehouse
- From Molecular Neurosciences (A.M., E.M., A., A.N., M.A.K.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health; Department of Neurology (A.M., A., A.N., C.E., J.H.C., M.A.K.) and Neuroradiology (W.K.C.), Great Ormond Street Hospital for Children, London, UK; Florey Institute of Neuroscience and Mental Health (U.N., E.V.G., I.E.S., S.P.), Melbourne, Australia; Department of Biological Sciences (S.M., M.T.), Institute of Structural and Molecular Biology, Birkbeck College, University of London; Regional Molecular Genetics Laboratory (N.T., R.H.S.), North East Thames Regional Genetics Service, and Department of Clinical Genetics (A.V.K., R.H.S.), Great Ormond Street Hospital, London, UK; Department of Paediatric Neurology (S.A.), Red Cross War Memorial Children's Hospital, Cape Town, South Africa; Department of Paediatric Neurology (G.A.), Addenbrooke's Hospital, Cambridge; Roald Dahl EEG Unit (R.A.), Department of Neurology, and Department of Neurology (R.K.), Alder Hey Children's Hospital, Liverpool; Department of Paediatric Neurology (A.D.), Sheffield Children's Hospital; Clinical Neurosciences (C.E., J.H.C.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London; Institute of Infection and Global Health (R.K.), University of Liverpool; Department of Paediatric Neurology (K.L.), Evelina Children's Hospital, Guys and St. Thomas' NHS Foundation Trust, London; Department of Clinical Genetics (T.M.), Northern Genetics Service; Department of Pediatric Neurology (V.R.), Great North Children's Hospital, Newcastle Upon Tyne; Department of Paediatric Neurology (R.S.), University Hospital Leicester Children's Hospital; Department of Paediatric Neurology (J.T.), Royal Manchester Children's Hospital; Department of Paediatric Neurology (W.W.), Nottingham University Hospitals NHS Trust, UK; Epilepsy Genetics Program (A. Poduri), Department of Neurology, Boston Children's Hospital; Department of Neurology (A. Poduri), Harvard Medical School, Boston, MA; University of Melbourne (I.E.S.), Austin Health and Royal Children's Hospital, Australia; and Department of Medicine (S.P.), Royal Melbourne Hospital, University of Melbourne, Australia. Dr. Malhotra is currently at the Department of Biochemistry, University of Cambridge, UK
| | - Annapurna Poduri
- From Molecular Neurosciences (A.M., E.M., A., A.N., M.A.K.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health; Department of Neurology (A.M., A., A.N., C.E., J.H.C., M.A.K.) and Neuroradiology (W.K.C.), Great Ormond Street Hospital for Children, London, UK; Florey Institute of Neuroscience and Mental Health (U.N., E.V.G., I.E.S., S.P.), Melbourne, Australia; Department of Biological Sciences (S.M., M.T.), Institute of Structural and Molecular Biology, Birkbeck College, University of London; Regional Molecular Genetics Laboratory (N.T., R.H.S.), North East Thames Regional Genetics Service, and Department of Clinical Genetics (A.V.K., R.H.S.), Great Ormond Street Hospital, London, UK; Department of Paediatric Neurology (S.A.), Red Cross War Memorial Children's Hospital, Cape Town, South Africa; Department of Paediatric Neurology (G.A.), Addenbrooke's Hospital, Cambridge; Roald Dahl EEG Unit (R.A.), Department of Neurology, and Department of Neurology (R.K.), Alder Hey Children's Hospital, Liverpool; Department of Paediatric Neurology (A.D.), Sheffield Children's Hospital; Clinical Neurosciences (C.E., J.H.C.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London; Institute of Infection and Global Health (R.K.), University of Liverpool; Department of Paediatric Neurology (K.L.), Evelina Children's Hospital, Guys and St. Thomas' NHS Foundation Trust, London; Department of Clinical Genetics (T.M.), Northern Genetics Service; Department of Pediatric Neurology (V.R.), Great North Children's Hospital, Newcastle Upon Tyne; Department of Paediatric Neurology (R.S.), University Hospital Leicester Children's Hospital; Department of Paediatric Neurology (J.T.), Royal Manchester Children's Hospital; Department of Paediatric Neurology (W.W.), Nottingham University Hospitals NHS Trust, UK; Epilepsy Genetics Program (A. Poduri), Department of Neurology, Boston Children's Hospital; Department of Neurology (A. Poduri), Harvard Medical School, Boston, MA; University of Melbourne (I.E.S.), Austin Health and Royal Children's Hospital, Australia; and Department of Medicine (S.P.), Royal Melbourne Hospital, University of Melbourne, Australia. Dr. Malhotra is currently at the Department of Biochemistry, University of Cambridge, UK
| | - Ingrid E Scheffer
- From Molecular Neurosciences (A.M., E.M., A., A.N., M.A.K.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health; Department of Neurology (A.M., A., A.N., C.E., J.H.C., M.A.K.) and Neuroradiology (W.K.C.), Great Ormond Street Hospital for Children, London, UK; Florey Institute of Neuroscience and Mental Health (U.N., E.V.G., I.E.S., S.P.), Melbourne, Australia; Department of Biological Sciences (S.M., M.T.), Institute of Structural and Molecular Biology, Birkbeck College, University of London; Regional Molecular Genetics Laboratory (N.T., R.H.S.), North East Thames Regional Genetics Service, and Department of Clinical Genetics (A.V.K., R.H.S.), Great Ormond Street Hospital, London, UK; Department of Paediatric Neurology (S.A.), Red Cross War Memorial Children's Hospital, Cape Town, South Africa; Department of Paediatric Neurology (G.A.), Addenbrooke's Hospital, Cambridge; Roald Dahl EEG Unit (R.A.), Department of Neurology, and Department of Neurology (R.K.), Alder Hey Children's Hospital, Liverpool; Department of Paediatric Neurology (A.D.), Sheffield Children's Hospital; Clinical Neurosciences (C.E., J.H.C.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London; Institute of Infection and Global Health (R.K.), University of Liverpool; Department of Paediatric Neurology (K.L.), Evelina Children's Hospital, Guys and St. Thomas' NHS Foundation Trust, London; Department of Clinical Genetics (T.M.), Northern Genetics Service; Department of Pediatric Neurology (V.R.), Great North Children's Hospital, Newcastle Upon Tyne; Department of Paediatric Neurology (R.S.), University Hospital Leicester Children's Hospital; Department of Paediatric Neurology (J.T.), Royal Manchester Children's Hospital; Department of Paediatric Neurology (W.W.), Nottingham University Hospitals NHS Trust, UK; Epilepsy Genetics Program (A. Poduri), Department of Neurology, Boston Children's Hospital; Department of Neurology (A. Poduri), Harvard Medical School, Boston, MA; University of Melbourne (I.E.S.), Austin Health and Royal Children's Hospital, Australia; and Department of Medicine (S.P.), Royal Melbourne Hospital, University of Melbourne, Australia. Dr. Malhotra is currently at the Department of Biochemistry, University of Cambridge, UK
| | - W K Kling Chong
- From Molecular Neurosciences (A.M., E.M., A., A.N., M.A.K.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health; Department of Neurology (A.M., A., A.N., C.E., J.H.C., M.A.K.) and Neuroradiology (W.K.C.), Great Ormond Street Hospital for Children, London, UK; Florey Institute of Neuroscience and Mental Health (U.N., E.V.G., I.E.S., S.P.), Melbourne, Australia; Department of Biological Sciences (S.M., M.T.), Institute of Structural and Molecular Biology, Birkbeck College, University of London; Regional Molecular Genetics Laboratory (N.T., R.H.S.), North East Thames Regional Genetics Service, and Department of Clinical Genetics (A.V.K., R.H.S.), Great Ormond Street Hospital, London, UK; Department of Paediatric Neurology (S.A.), Red Cross War Memorial Children's Hospital, Cape Town, South Africa; Department of Paediatric Neurology (G.A.), Addenbrooke's Hospital, Cambridge; Roald Dahl EEG Unit (R.A.), Department of Neurology, and Department of Neurology (R.K.), Alder Hey Children's Hospital, Liverpool; Department of Paediatric Neurology (A.D.), Sheffield Children's Hospital; Clinical Neurosciences (C.E., J.H.C.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London; Institute of Infection and Global Health (R.K.), University of Liverpool; Department of Paediatric Neurology (K.L.), Evelina Children's Hospital, Guys and St. Thomas' NHS Foundation Trust, London; Department of Clinical Genetics (T.M.), Northern Genetics Service; Department of Pediatric Neurology (V.R.), Great North Children's Hospital, Newcastle Upon Tyne; Department of Paediatric Neurology (R.S.), University Hospital Leicester Children's Hospital; Department of Paediatric Neurology (J.T.), Royal Manchester Children's Hospital; Department of Paediatric Neurology (W.W.), Nottingham University Hospitals NHS Trust, UK; Epilepsy Genetics Program (A. Poduri), Department of Neurology, Boston Children's Hospital; Department of Neurology (A. Poduri), Harvard Medical School, Boston, MA; University of Melbourne (I.E.S.), Austin Health and Royal Children's Hospital, Australia; and Department of Medicine (S.P.), Royal Melbourne Hospital, University of Melbourne, Australia. Dr. Malhotra is currently at the Department of Biochemistry, University of Cambridge, UK
| | - J Helen Cross
- From Molecular Neurosciences (A.M., E.M., A., A.N., M.A.K.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health; Department of Neurology (A.M., A., A.N., C.E., J.H.C., M.A.K.) and Neuroradiology (W.K.C.), Great Ormond Street Hospital for Children, London, UK; Florey Institute of Neuroscience and Mental Health (U.N., E.V.G., I.E.S., S.P.), Melbourne, Australia; Department of Biological Sciences (S.M., M.T.), Institute of Structural and Molecular Biology, Birkbeck College, University of London; Regional Molecular Genetics Laboratory (N.T., R.H.S.), North East Thames Regional Genetics Service, and Department of Clinical Genetics (A.V.K., R.H.S.), Great Ormond Street Hospital, London, UK; Department of Paediatric Neurology (S.A.), Red Cross War Memorial Children's Hospital, Cape Town, South Africa; Department of Paediatric Neurology (G.A.), Addenbrooke's Hospital, Cambridge; Roald Dahl EEG Unit (R.A.), Department of Neurology, and Department of Neurology (R.K.), Alder Hey Children's Hospital, Liverpool; Department of Paediatric Neurology (A.D.), Sheffield Children's Hospital; Clinical Neurosciences (C.E., J.H.C.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London; Institute of Infection and Global Health (R.K.), University of Liverpool; Department of Paediatric Neurology (K.L.), Evelina Children's Hospital, Guys and St. Thomas' NHS Foundation Trust, London; Department of Clinical Genetics (T.M.), Northern Genetics Service; Department of Pediatric Neurology (V.R.), Great North Children's Hospital, Newcastle Upon Tyne; Department of Paediatric Neurology (R.S.), University Hospital Leicester Children's Hospital; Department of Paediatric Neurology (J.T.), Royal Manchester Children's Hospital; Department of Paediatric Neurology (W.W.), Nottingham University Hospitals NHS Trust, UK; Epilepsy Genetics Program (A. Poduri), Department of Neurology, Boston Children's Hospital; Department of Neurology (A. Poduri), Harvard Medical School, Boston, MA; University of Melbourne (I.E.S.), Austin Health and Royal Children's Hospital, Australia; and Department of Medicine (S.P.), Royal Melbourne Hospital, University of Melbourne, Australia. Dr. Malhotra is currently at the Department of Biochemistry, University of Cambridge, UK
| | - Maya Topf
- From Molecular Neurosciences (A.M., E.M., A., A.N., M.A.K.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health; Department of Neurology (A.M., A., A.N., C.E., J.H.C., M.A.K.) and Neuroradiology (W.K.C.), Great Ormond Street Hospital for Children, London, UK; Florey Institute of Neuroscience and Mental Health (U.N., E.V.G., I.E.S., S.P.), Melbourne, Australia; Department of Biological Sciences (S.M., M.T.), Institute of Structural and Molecular Biology, Birkbeck College, University of London; Regional Molecular Genetics Laboratory (N.T., R.H.S.), North East Thames Regional Genetics Service, and Department of Clinical Genetics (A.V.K., R.H.S.), Great Ormond Street Hospital, London, UK; Department of Paediatric Neurology (S.A.), Red Cross War Memorial Children's Hospital, Cape Town, South Africa; Department of Paediatric Neurology (G.A.), Addenbrooke's Hospital, Cambridge; Roald Dahl EEG Unit (R.A.), Department of Neurology, and Department of Neurology (R.K.), Alder Hey Children's Hospital, Liverpool; Department of Paediatric Neurology (A.D.), Sheffield Children's Hospital; Clinical Neurosciences (C.E., J.H.C.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London; Institute of Infection and Global Health (R.K.), University of Liverpool; Department of Paediatric Neurology (K.L.), Evelina Children's Hospital, Guys and St. Thomas' NHS Foundation Trust, London; Department of Clinical Genetics (T.M.), Northern Genetics Service; Department of Pediatric Neurology (V.R.), Great North Children's Hospital, Newcastle Upon Tyne; Department of Paediatric Neurology (R.S.), University Hospital Leicester Children's Hospital; Department of Paediatric Neurology (J.T.), Royal Manchester Children's Hospital; Department of Paediatric Neurology (W.W.), Nottingham University Hospitals NHS Trust, UK; Epilepsy Genetics Program (A. Poduri), Department of Neurology, Boston Children's Hospital; Department of Neurology (A. Poduri), Harvard Medical School, Boston, MA; University of Melbourne (I.E.S.), Austin Health and Royal Children's Hospital, Australia; and Department of Medicine (S.P.), Royal Melbourne Hospital, University of Melbourne, Australia. Dr. Malhotra is currently at the Department of Biochemistry, University of Cambridge, UK
| | - Steven Petrou
- From Molecular Neurosciences (A.M., E.M., A., A.N., M.A.K.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health; Department of Neurology (A.M., A., A.N., C.E., J.H.C., M.A.K.) and Neuroradiology (W.K.C.), Great Ormond Street Hospital for Children, London, UK; Florey Institute of Neuroscience and Mental Health (U.N., E.V.G., I.E.S., S.P.), Melbourne, Australia; Department of Biological Sciences (S.M., M.T.), Institute of Structural and Molecular Biology, Birkbeck College, University of London; Regional Molecular Genetics Laboratory (N.T., R.H.S.), North East Thames Regional Genetics Service, and Department of Clinical Genetics (A.V.K., R.H.S.), Great Ormond Street Hospital, London, UK; Department of Paediatric Neurology (S.A.), Red Cross War Memorial Children's Hospital, Cape Town, South Africa; Department of Paediatric Neurology (G.A.), Addenbrooke's Hospital, Cambridge; Roald Dahl EEG Unit (R.A.), Department of Neurology, and Department of Neurology (R.K.), Alder Hey Children's Hospital, Liverpool; Department of Paediatric Neurology (A.D.), Sheffield Children's Hospital; Clinical Neurosciences (C.E., J.H.C.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London; Institute of Infection and Global Health (R.K.), University of Liverpool; Department of Paediatric Neurology (K.L.), Evelina Children's Hospital, Guys and St. Thomas' NHS Foundation Trust, London; Department of Clinical Genetics (T.M.), Northern Genetics Service; Department of Pediatric Neurology (V.R.), Great North Children's Hospital, Newcastle Upon Tyne; Department of Paediatric Neurology (R.S.), University Hospital Leicester Children's Hospital; Department of Paediatric Neurology (J.T.), Royal Manchester Children's Hospital; Department of Paediatric Neurology (W.W.), Nottingham University Hospitals NHS Trust, UK; Epilepsy Genetics Program (A. Poduri), Department of Neurology, Boston Children's Hospital; Department of Neurology (A. Poduri), Harvard Medical School, Boston, MA; University of Melbourne (I.E.S.), Austin Health and Royal Children's Hospital, Australia; and Department of Medicine (S.P.), Royal Melbourne Hospital, University of Melbourne, Australia. Dr. Malhotra is currently at the Department of Biochemistry, University of Cambridge, UK
| | - Manju A Kurian
- From Molecular Neurosciences (A.M., E.M., A., A.N., M.A.K.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health; Department of Neurology (A.M., A., A.N., C.E., J.H.C., M.A.K.) and Neuroradiology (W.K.C.), Great Ormond Street Hospital for Children, London, UK; Florey Institute of Neuroscience and Mental Health (U.N., E.V.G., I.E.S., S.P.), Melbourne, Australia; Department of Biological Sciences (S.M., M.T.), Institute of Structural and Molecular Biology, Birkbeck College, University of London; Regional Molecular Genetics Laboratory (N.T., R.H.S.), North East Thames Regional Genetics Service, and Department of Clinical Genetics (A.V.K., R.H.S.), Great Ormond Street Hospital, London, UK; Department of Paediatric Neurology (S.A.), Red Cross War Memorial Children's Hospital, Cape Town, South Africa; Department of Paediatric Neurology (G.A.), Addenbrooke's Hospital, Cambridge; Roald Dahl EEG Unit (R.A.), Department of Neurology, and Department of Neurology (R.K.), Alder Hey Children's Hospital, Liverpool; Department of Paediatric Neurology (A.D.), Sheffield Children's Hospital; Clinical Neurosciences (C.E., J.H.C.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London; Institute of Infection and Global Health (R.K.), University of Liverpool; Department of Paediatric Neurology (K.L.), Evelina Children's Hospital, Guys and St. Thomas' NHS Foundation Trust, London; Department of Clinical Genetics (T.M.), Northern Genetics Service; Department of Pediatric Neurology (V.R.), Great North Children's Hospital, Newcastle Upon Tyne; Department of Paediatric Neurology (R.S.), University Hospital Leicester Children's Hospital; Department of Paediatric Neurology (J.T.), Royal Manchester Children's Hospital; Department of Paediatric Neurology (W.W.), Nottingham University Hospitals NHS Trust, UK; Epilepsy Genetics Program (A. Poduri), Department of Neurology, Boston Children's Hospital; Department of Neurology (A. Poduri), Harvard Medical School, Boston, MA; University of Melbourne (I.E.S.), Austin Health and Royal Children's Hospital, Australia; and Department of Medicine (S.P.), Royal Melbourne Hospital, University of Melbourne, Australia. Dr. Malhotra is currently at the Department of Biochemistry, University of Cambridge, UK.
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14
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Zhu X, Padmanabhan R, Copeland B, Bridgers J, Ren Z, Kamalakaran S, O'Driscoll-Collins A, Berkovic SF, Scheffer IE, Poduri A, Mei D, Guerrini R, Lowenstein DH, Allen AS, Heinzen EL, Goldstein DB. A case-control collapsing analysis identifies epilepsy genes implicated in trio sequencing studies focused on de novo mutations. PLoS Genet 2017; 13:e1007104. [PMID: 29186148 PMCID: PMC5724893 DOI: 10.1371/journal.pgen.1007104] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 12/11/2017] [Accepted: 11/07/2017] [Indexed: 12/22/2022] Open
Abstract
Trio exome sequencing has been successful in identifying genes with de novo mutations (DNMs) causing epileptic encephalopathy (EE) and other neurodevelopmental disorders. Here, we evaluate how well a case-control collapsing analysis recovers genes causing dominant forms of EE originally implicated by DNM analysis. We performed a genome-wide search for an enrichment of "qualifying variants" in protein-coding genes in 488 unrelated cases compared to 12,151 unrelated controls. These "qualifying variants" were selected to be extremely rare variants predicted to functionally impact the protein to enrich for likely pathogenic variants. Despite modest sample size, three known EE genes (KCNT1, SCN2A, and STXBP1) achieved genome-wide significance (p<2.68×10−6). In addition, six of the 10 most significantly associated genes are known EE genes, and the majority of the known EE genes (17 out of 25) originally implicated in trio sequencing are nominally significant (p<0.05), a proportion significantly higher than the expected (Fisher’s exact p = 2.33×10−17). Our results indicate that a case-control collapsing analysis can identify several of the EE genes originally implicated in trio sequencing studies, and clearly show that additional genes would be implicated with larger sample sizes. The case-control analysis not only makes discovery easier and more economical in early onset disorders, particularly when large cohorts are available, but also supports the use of this approach to identify genes in diseases that present later in life when parents are not readily available. Trio exome sequencing and de novo mutation (DNM) analysis has been the main approach to discovering genes responsible for severe sporadic disorders, including a range of neurodevelopmental disorders. This approach requires sequencing parents, identifying DNMs from trio sequence data, and comparing the observed rate of DNMs to the expected. In this study, we adopted a case-control design, performed a gene-based collapsing analysis, and rediscovered several of the epileptic encephalopathy (EE) genes originally implicated by DNM analysis of EE trios. Our collapsing analysis focused on ultra-rare, highly impactful variants (“qualifying variants”) by filtering against large-scale population datasets, and this approach revealed that most of the standing variation can be filtered out and DNMs are enriched in “qualifying variants”. Our study suggests that a case-control analysis approach can be used to identify disease genes with causal mutations that are predominantly de novo in place of trio-based analysis methods. This offers an efficient and cost effective alternative approach when large-scale trio sequencing is not possible.
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Affiliation(s)
- Xiaolin Zhu
- Institute for Genomic Medicine, Columbia University Medical Center, New York, NY, United States of America
| | - Raghavendra Padmanabhan
- Institute for Genomic Medicine, Columbia University Medical Center, New York, NY, United States of America
| | - Brett Copeland
- Institute for Genomic Medicine, Columbia University Medical Center, New York, NY, United States of America
| | - Joshua Bridgers
- Institute for Genomic Medicine, Columbia University Medical Center, New York, NY, United States of America
| | - Zhong Ren
- Institute for Genomic Medicine, Columbia University Medical Center, New York, NY, United States of America
| | - Sitharthan Kamalakaran
- Institute for Genomic Medicine, Columbia University Medical Center, New York, NY, United States of America
| | | | - Samuel F. Berkovic
- Epilepsy Research Centre, Department of Medicine, University of Melbourne at Austin Health, Heidelberg, Australia
| | - Ingrid E. Scheffer
- Epilepsy Research Centre, Department of Medicine, University of Melbourne at Austin Health, Heidelberg, Australia
- Florey Institute for Neuroscience and Mental Health, University of Melbourne, Heidelberg, Australia
- Departments of Paediatrics and Neurology, Royal Children's Hospital, University of Melbourne, Melbourne, Australia
| | - Annapurna Poduri
- Epilepsy Genetics Program and Department of Neurology, Harvard Medical School, Boston, MA, United States of America
| | - Davide Mei
- Pediatric Neurology Unit and Laboratories, Meyer Children’s Hospital, University of Florence, Florence, Italy
| | - Renzo Guerrini
- Pediatric Neurology Unit and Laboratories, Meyer Children’s Hospital, University of Florence, Florence, Italy
- IRCCS Stella Maris Foundation, Pisa, Italy
| | - Daniel H. Lowenstein
- Department of Neurology, University of California, San Francisco, San Francisco, California, United States of America
| | - Andrew S. Allen
- Department of Biostatistics and Bioinformatics, Duke University, Durham, North Carolina, United States of America
| | - Erin L. Heinzen
- Institute for Genomic Medicine, Columbia University Medical Center, New York, NY, United States of America
| | - David B. Goldstein
- Institute for Genomic Medicine, Columbia University Medical Center, New York, NY, United States of America
- Department of Medicine, Royal College of Surgeons in Ireland, St Stephen's Green, Dublin, Ireland
- * E-mail:
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15
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Tejada MA, Hashem N, Calloe K, Klaerke DA. Heteromeric Slick/Slack K+ channels show graded sensitivity to cell volume changes. PLoS One 2017; 12:e0169914. [PMID: 28222129 PMCID: PMC5319697 DOI: 10.1371/journal.pone.0169914] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 12/22/2016] [Indexed: 12/16/2022] Open
Abstract
Slick and Slack high-conductance K+ channels are found in the CNS, kidneys, pancreas, among other organs, where they play an important role in cell excitability as well as in ion transport processes. They are both activated by Na+ and Cl- but show a differential regulation by cell volume changes. Slick has been shown to be regulated by cell volume changes, whereas Slack is insensitive. α-subunits of these channels form homomeric as well as heteromeric channels. It is the aim of this work to explore whether the subunit composition of the Slick/Slack heteromeric channel affects the response to osmotic challenges. In order to provide with the adequate water permeability to the cell membrane of Xenopus laevis oocytes, mRNA of aquaporin 1 was co-expressed with homomeric or heteromeric Slick and Slack α-subunits. Oocytes were superfused with hypotonic or hypertonic buffers and changes in currents were measured by two-electrode voltage clamp. This work presents the first heteromeric K+ channel with a characteristic graded sensitivity to small and fast changes in cell volume. Our results show that the cell volume sensitivity of Slick/Slack heteromeric channels is dependent on the number of volume sensitive Slick α-subunits in the tetrameric channels, giving rise to graded cell volume sensitivity. Regulation of the subunit composition of a channel may constitute a novel mechanism to determine volume sensitivity of cells.
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Affiliation(s)
- Maria A. Tejada
- Department of Physiology, IKVH, Faculty of Health and Medical Sciences, University of Copenhagen, Dyrlaegevej, Frederiksberg C, Denmark
| | - Nadia Hashem
- Department of Physiology, IKVH, Faculty of Health and Medical Sciences, University of Copenhagen, Dyrlaegevej, Frederiksberg C, Denmark
| | - Kirstine Calloe
- Department of Physiology, IKVH, Faculty of Health and Medical Sciences, University of Copenhagen, Dyrlaegevej, Frederiksberg C, Denmark
| | - Dan A. Klaerke
- Department of Physiology, IKVH, Faculty of Health and Medical Sciences, University of Copenhagen, Dyrlaegevej, Frederiksberg C, Denmark
- * E-mail:
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16
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Abstract
The magnocellular neurosecretory cells (MNCs) of the hypothalamus secrete the neurohormones vasopressin and oxytocin. The systemic release of these hormones depends on the rate and pattern of MNC firing and it is therefore important to identify the ion channels that contribute to the electrical behaviour of MNCs. In the present study, we report evidence for the presence of Na(+) -activated K(+) (KN a ) channels in rat MNCs. KN a channels mediate outwardly rectifying K(+) currents activated by the increases in intracellular Na(+) that occur during electrical activity. Although the molecular identity of native KN a channels is unclear, their biophysical properties are consistent with those of expressed Slick (slo 2.1) and Slack (slo 2.2) proteins. Using immunocytochemistry and Western blot experiments, we found that both Slick and Slack proteins are expressed in rat MNCs. Using whole cell voltage clamp techniques on acutely isolated rat MNCs, we found that inhibiting Na(+) influx by the addition of the Na(+) channel blocker tetrodotoxin or the replacement of Na(+) in the external solution with Li(+) caused a significant decrease in sustained outward currents. Furthermore, the evoked outward current density was significantly higher in rat MNCs using patch pipettes containing 60 mm Na(+) than it was when patch pipettes containing 0 mm Na(+) were used. Our data show that functional KN a channels are expressed in rat MNCs. These channels could contribute to the activity-dependent afterhyperpolarisations that have been identified in the MNCs and thereby play a role in the regulation of their electrical behaviour.
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Affiliation(s)
- V Bansal
- Department of Physiology, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - T E Fisher
- Department of Physiology, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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Stringer S, Minică CC, Verweij KJH, Mbarek H, Bernard M, Derringer J, van Eijk KR, Isen JD, Loukola A, Maciejewski DF, Mihailov E, van der Most PJ, Sánchez-Mora C, Roos L, Sherva R, Walters R, Ware JJ, Abdellaoui A, Bigdeli TB, Branje SJT, Brown SA, Bruinenberg M, Casas M, Esko T, Garcia-Martinez I, Gordon SD, Harris JM, Hartman CA, Henders AK, Heath AC, Hickie IB, Hickman M, Hopfer CJ, Hottenga JJ, Huizink AC, Irons DE, Kahn RS, Korhonen T, Kranzler HR, Krauter K, van Lier PAC, Lubke GH, Madden PAF, Mägi R, McGue MK, Medland SE, Meeus WHJ, Miller MB, Montgomery GW, Nivard MG, Nolte IM, Oldehinkel AJ, Pausova Z, Qaiser B, Quaye L, Ramos-Quiroga JA, Richarte V, Rose RJ, Shin J, Stallings MC, Stiby AI, Wall TL, Wright MJ, Koot HM, Paus T, Hewitt JK, Ribasés M, Kaprio J, Boks MP, Snieder H, Spector T, Munafò MR, Metspalu A, Gelernter J, Boomsma DI, Iacono WG, Martin NG, Gillespie NA, Derks EM, Vink JM. Genome-wide association study of lifetime cannabis use based on a large meta-analytic sample of 32 330 subjects from the International Cannabis Consortium. Transl Psychiatry 2016; 6:e769. [PMID: 27023175 PMCID: PMC4872459 DOI: 10.1038/tp.2016.36] [Citation(s) in RCA: 110] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 12/21/2015] [Indexed: 01/15/2023] Open
Abstract
Cannabis is the most widely produced and consumed illicit psychoactive substance worldwide. Occasional cannabis use can progress to frequent use, abuse and dependence with all known adverse physical, psychological and social consequences. Individual differences in cannabis initiation are heritable (40-48%). The International Cannabis Consortium was established with the aim to identify genetic risk variants of cannabis use. We conducted a meta-analysis of genome-wide association data of 13 cohorts (N=32 330) and four replication samples (N=5627). In addition, we performed a gene-based test of association, estimated single-nucleotide polymorphism (SNP)-based heritability and explored the genetic correlation between lifetime cannabis use and cigarette use using LD score regression. No individual SNPs reached genome-wide significance. Nonetheless, gene-based tests identified four genes significantly associated with lifetime cannabis use: NCAM1, CADM2, SCOC and KCNT2. Previous studies reported associations of NCAM1 with cigarette smoking and other substance use, and those of CADM2 with body mass index, processing speed and autism disorders, which are phenotypes previously reported to be associated with cannabis use. Furthermore, we showed that, combined across the genome, all common SNPs explained 13-20% (P<0.001) of the liability of lifetime cannabis use. Finally, there was a strong genetic correlation (rg=0.83; P=1.85 × 10(-8)) between lifetime cannabis use and lifetime cigarette smoking implying that the SNP effect sizes of the two traits are highly correlated. This is the largest meta-analysis of cannabis GWA studies to date, revealing important new insights into the genetic pathways of lifetime cannabis use. Future functional studies should explore the impact of the identified genes on the biological mechanisms of cannabis use.
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Affiliation(s)
- S Stringer
- Department of Complex Trait Genetics, VU Amsterdam, Center for Neurogenomics and Cognitive Research, Amsterdam, The Netherlands
- Department of Psychiatry, Academic Medical Centre, Amsterdam, The Netherlands
| | - C C Minică
- Department of Biological Psychology/Netherlands Twin Register, VU University, Amsterdam, The Netherlands
| | - K J H Verweij
- Department of Biological Psychology/Netherlands Twin Register, VU University, Amsterdam, The Netherlands
- Neuroscience Campus Amsterdam, Amsterdam, The Netherlands
- Department of Developmental Psychology and EMGO Institute for Health and Care Research, VU University, Amsterdam, The Netherlands
| | - H Mbarek
- Department of Biological Psychology/Netherlands Twin Register, VU University, Amsterdam, The Netherlands
| | - M Bernard
- The Hospital for Sick Children Research Institute, Toronto, Canada
| | - J Derringer
- Department of Psychology, University of Illinois Urbana-Champaign, Champaign, IL, USA
| | - K R van Eijk
- Department of Human Neurogenetics, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
| | - J D Isen
- Department of Psychology, University of Minnesota, Minneapolis, MN, USA
| | - A Loukola
- Department of Public Health, Hjelt Institute, University of Helsinki, Helsinki, Finland
| | - D F Maciejewski
- Department of Developmental Psychology and EMGO Institute for Health and Care Research, VU University, Amsterdam, The Netherlands
| | - E Mihailov
- Estonian Genome Center, University of Tartu, Tartu, Estonia
| | - P J van der Most
- Department of Epidemiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - C Sánchez-Mora
- Psychiatric Genetics Unit, Vall d'Hebron Research Institute (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
- Department of Psychiatry, Hospital Universitari Vall d'Hebron, Barcelona, Spain
- Biomedical Network Research Centre on Mental Health (CIBERSAM), Barcelona, Spain
| | - L Roos
- Twin Research and Genetic Epidemiology, King's College London, London, UK
| | - R Sherva
- Biomedical Genetics Department, Boston University School of Medicine, Boston, MA, USA
| | - R Walters
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - J J Ware
- School of Social and Community Medicine, University of Bristol, Bristol, UK
- MRC Integrative Epidemiology Unit (IEU), University of Bristol, Bristol, UK
| | - A Abdellaoui
- Department of Biological Psychology/Netherlands Twin Register, VU University, Amsterdam, The Netherlands
| | - T B Bigdeli
- Department of Psychiatry, Virginia Institute for Psychiatric and Behavior Genetics, Virginia Commonwealth University, Richmond, VA, USA
| | - S J T Branje
- Research Centre Adolescent Development, Utrecht University, Utrecht, The Netherlands
| | - S A Brown
- Department of Psychology and Psychiatry, University of California San Diego, La Jolla, CA, USA
| | - M Bruinenberg
- The LifeLines Cohort Study, University of Groningen, Groningen, The Netherlands
| | - M Casas
- Department of Psychiatry, Hospital Universitari Vall d'Hebron, Barcelona, Spain
- Biomedical Network Research Centre on Mental Health (CIBERSAM), Barcelona, Spain
- Department of Psychiatry and Legal Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - T Esko
- Estonian Genome Center, University of Tartu, Tartu, Estonia
| | - I Garcia-Martinez
- Psychiatric Genetics Unit, Vall d'Hebron Research Institute (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
- Department of Psychiatry, Hospital Universitari Vall d'Hebron, Barcelona, Spain
| | - S D Gordon
- Genetic Epidemiology, Molecular Epidemiology and Neurogenetics Laboratories, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - J M Harris
- Twin Research and Genetic Epidemiology, King's College London, London, UK
| | - C A Hartman
- Department of Psychiatry, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - A K Henders
- Genetic Epidemiology, Molecular Epidemiology and Neurogenetics Laboratories, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - A C Heath
- Department of Psychiatry, Washington University School of Medicine, St Louis, MO, USA
| | - I B Hickie
- Brain and Mind Research Institute, University of Sydney, Sydney, NSW, Australia
| | - M Hickman
- School of Social and Community Medicine, University of Bristol, Bristol, UK
| | - C J Hopfer
- Department of Psychiatry, University of Colorado Denver, Aurora, CO, USA
| | - J J Hottenga
- Department of Biological Psychology/Netherlands Twin Register, VU University, Amsterdam, The Netherlands
| | - A C Huizink
- Department of Developmental Psychology and EMGO Institute for Health and Care Research, VU University, Amsterdam, The Netherlands
| | - D E Irons
- Department of Psychology, University of Minnesota, Minneapolis, MN, USA
| | - R S Kahn
- Department of Human Neurogenetics, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
| | - T Korhonen
- Department of Public Health, Hjelt Institute, University of Helsinki, Helsinki, Finland
- Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland
- Department of Mental Health and Substance Abuse Services, National Institute for Health and Welfare, Helsinki, Finland
| | - H R Kranzler
- Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - K Krauter
- Department of Molecular, Cellular and Developmental Biology, University of Colorado Boulder, Boulder, CO, USA
| | - P A C van Lier
- Department of Developmental Psychology and EMGO Institute for Health and Care Research, VU University, Amsterdam, The Netherlands
| | - G H Lubke
- Department of Biological Psychology/Netherlands Twin Register, VU University, Amsterdam, The Netherlands
- Department of Psychology, University of Notre Dame, Notre Dame, IN, USA
| | - P A F Madden
- Department of Psychiatry, Washington University School of Medicine, St Louis, MO, USA
| | - R Mägi
- Estonian Genome Center, University of Tartu, Tartu, Estonia
| | - M K McGue
- Department of Psychology, University of Minnesota, Minneapolis, MN, USA
| | - S E Medland
- Genetic Epidemiology, Molecular Epidemiology and Neurogenetics Laboratories, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - W H J Meeus
- Research Centre Adolescent Development, Utrecht University, Utrecht, The Netherlands
- Developmental Psychology, Tilburg University, Tilburg, The Netherlands
| | - M B Miller
- Department of Psychology, University of Minnesota, Minneapolis, MN, USA
| | - G W Montgomery
- Genetic Epidemiology, Molecular Epidemiology and Neurogenetics Laboratories, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - M G Nivard
- Department of Biological Psychology/Netherlands Twin Register, VU University, Amsterdam, The Netherlands
| | - I M Nolte
- Department of Epidemiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - A J Oldehinkel
- Interdisciplinary Center for Pathology and Emotion Regulation, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Z Pausova
- The Hospital for Sick Children Research Institute, Toronto, Canada
- Department of Physiology and Nutritional Sciences, University of Toronto, Toronto, ON, Canada
| | - B Qaiser
- Department of Public Health, Hjelt Institute, University of Helsinki, Helsinki, Finland
| | - L Quaye
- Twin Research and Genetic Epidemiology, King's College London, London, UK
| | - J A Ramos-Quiroga
- Department of Psychiatry, Hospital Universitari Vall d'Hebron, Barcelona, Spain
- Biomedical Network Research Centre on Mental Health (CIBERSAM), Barcelona, Spain
- Department of Psychiatry and Legal Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - V Richarte
- Department of Psychiatry, Hospital Universitari Vall d'Hebron, Barcelona, Spain
| | - R J Rose
- Department of Psychological and Brain Sciences, Indiana University Bloomington, Bloomington, IN, USA
| | - J Shin
- The Hospital for Sick Children Research Institute, Toronto, Canada
| | - M C Stallings
- Department of Psychology and Neuroscience, Institute for Behavioral Genetics, University of Colorado Boulder, Boulder, CO, USA
| | - A I Stiby
- School of Social and Community Medicine, University of Bristol, Bristol, UK
| | - T L Wall
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA
| | - M J Wright
- Genetic Epidemiology, Molecular Epidemiology and Neurogenetics Laboratories, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - H M Koot
- Department of Developmental Psychology and EMGO Institute for Health and Care Research, VU University, Amsterdam, The Netherlands
| | - T Paus
- Rotman Research Institute, Baycrest, Toronto, ON, Canada
- Department of Psychology and Psychiatry, University of Toronto, Toronto, ON, Canada
- Center for the Developing Brain, Child Mind Institute, New York, NY, USA
| | - J K Hewitt
- Department of Psychology and Neuroscience, Institute for Behavioral Genetics, University of Colorado Boulder, Boulder, CO, USA
| | - M Ribasés
- Psychiatric Genetics Unit, Vall d'Hebron Research Institute (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
- Department of Psychiatry, Hospital Universitari Vall d'Hebron, Barcelona, Spain
- Biomedical Network Research Centre on Mental Health (CIBERSAM), Barcelona, Spain
| | - J Kaprio
- Department of Public Health, Hjelt Institute, University of Helsinki, Helsinki, Finland
- Department of Mental Health and Substance Abuse Services, National Institute for Health and Welfare, Helsinki, Finland
- Institute for Molecular Medicine Finland, University of Helsinki, Helsinki, Finland
| | - M P Boks
- Department of Human Neurogenetics, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
| | - H Snieder
- Department of Epidemiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - T Spector
- Twin Research and Genetic Epidemiology, King's College London, London, UK
| | - M R Munafò
- School of Social and Community Medicine, University of Bristol, Bristol, UK
- UK Centre for Tobacco and Alcohol Studies and School of Experimental Psychology, University of Bristol, Bristol, UK
| | - A Metspalu
- Estonian Genome Center, University of Tartu, Tartu, Estonia
| | - J Gelernter
- Department of Psychiatry, Genetics, and Neurobiology, Yale University School of Medicine and VA CT, West Haven, CT, USA
| | - D I Boomsma
- Department of Biological Psychology/Netherlands Twin Register, VU University, Amsterdam, The Netherlands
- Neuroscience Campus Amsterdam, Amsterdam, The Netherlands
| | - W G Iacono
- Department of Psychology, University of Minnesota, Minneapolis, MN, USA
| | - N G Martin
- Genetic Epidemiology, Molecular Epidemiology and Neurogenetics Laboratories, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - N A Gillespie
- Department of Psychiatry, Virginia Institute for Psychiatric and Behavior Genetics, Virginia Commonwealth University, Richmond, VA, USA
- Genetic Epidemiology, Molecular Epidemiology and Neurogenetics Laboratories, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - E M Derks
- Department of Psychiatry, Academic Medical Centre, Amsterdam, The Netherlands
| | - J M Vink
- Department of Biological Psychology/Netherlands Twin Register, VU University, Amsterdam, The Netherlands
- Behavioural Science Institute, Radboud University, Nijmegen, The Netherlands
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Tang QY, Zhang FF, Xu J, Wang R, Chen J, Logothetis DE, Zhang Z. Epilepsy-Related Slack Channel Mutants Lead to Channel Over-Activity by Two Different Mechanisms. Cell Rep 2015; 14:129-139. [PMID: 26725113 DOI: 10.1016/j.celrep.2015.12.019] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 08/11/2015] [Accepted: 11/23/2015] [Indexed: 01/07/2023] Open
Abstract
Twelve sodium-activated potassium channel (KCNT1, Slack) genetic mutants have been identified from severe early-onset epilepsy patients. The changes in biophysical properties of these mutants and the underlying mechanisms causing disease remain elusive. Here, we report that seven of the 12 mutations increase, whereas one mutation decreases, the channel's sodium sensitivity. Two of the mutants exhibit channel over-activity only when the intracellular Na(+) ([Na(+)]i) concentration is ∼80 mM. In contrast, single-channel data reveal that all 12 mutants increase the maximal open probability (Po). We conclude that these mutant channels lead to channel over-activity predominantly by increasing the ability of sodium binding to activate the channel, which is indicated by its maximal Po. The sodium sensitivity of these epilepsy causing mutants probably determines the [Na(+)]i concentration at which these mutants exert their pathological effects.
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Affiliation(s)
- Qiong-Yao Tang
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical College, Xuzhou, Jiangsu Province 221004, China; Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical College, Xuzhou, Jiangsu Province 221004, China
| | - Fei-Fei Zhang
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical College, Xuzhou, Jiangsu Province 221004, China; Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical College, Xuzhou, Jiangsu Province 221004, China
| | - Jie Xu
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical College, Xuzhou, Jiangsu Province 221004, China; Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical College, Xuzhou, Jiangsu Province 221004, China
| | - Ran Wang
- School of Anesthesiology, Xuzhou Medical College, Xuzhou, Jiangsu Province 221004, China
| | - Jian Chen
- School of Anesthesiology, Xuzhou Medical College, Xuzhou, Jiangsu Province 221004, China
| | - Diomedes E Logothetis
- Department of Physiology and Biophysics, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Zhe Zhang
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical College, Xuzhou, Jiangsu Province 221004, China; Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical College, Xuzhou, Jiangsu Province 221004, China.
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19
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Gururaj S, Fleites J, Bhattacharjee A. Slack sodium-activated potassium channel membrane expression requires p38 mitogen-activated protein kinase phosphorylation. Neuropharmacology 2015; 103:279-89. [PMID: 26721627 DOI: 10.1016/j.neuropharm.2015.12.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 12/11/2015] [Accepted: 12/15/2015] [Indexed: 01/14/2023]
Abstract
p38 MAPK has long been understood as an inducible kinase under conditions of cellular stress, but there is now increasing evidence to support its role in the regulation of neuronal function. Several phosphorylation targets have been identified, an appreciable number of which are ion channels, implicating the possible involvement of p38 MAPK in neuronal excitability. The KNa channel Slack is an important protein to be studied as it is highly and ubiquitously expressed in DRG neurons and is important in the maintenance of their firing accommodation. We sought to examine if the Slack channel could be a substrate of p38 MAPK activity. First, we found that the Slack C-terminus contains two putative p38 MAPK phosphorylation sites that are highly conserved across species. Second, we show via electrophysiology experiments that KNa currents and further, Slack currents, are subject to tonic modulation by p38 MAPK. Third, biochemical approaches revealed that Slack channel regulation by p38 MAPK occurs through direct phosphorylation at the two putative sites of interaction, and mutating both sites prevented surface expression of Slack channels. Based on these results, we conclude that p38 MAPK is an obligate regulator of Slack channel function via the trafficking of channels into the membrane. The present study identifies Slack KNa channels as p38 MAPK substrates.
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Affiliation(s)
- Sushmitha Gururaj
- Department of Pharmacology and Toxicology, The State University of New York, Buffalo, USA
| | - John Fleites
- Program in Neuroscience, The State University of New York, Buffalo, USA
| | - Arin Bhattacharjee
- Department of Pharmacology and Toxicology, The State University of New York, Buffalo, USA; Program in Neuroscience, The State University of New York, Buffalo, USA.
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20
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Gao SB, Wu Y, Lü CX, Guo ZH, Li CH, Ding JP. Slack and Slick KNa channels are required for the depolarizing afterpotential of acutely isolated, medium diameter rat dorsal root ganglion neurons. Acta Pharmacol Sin 2008; 29:899-905. [PMID: 18664322 DOI: 10.1111/j.1745-7254.2008.00842.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
AIM Na+-activated K+ (K(Na)) channels set and stabilize resting membrane potential in rat small dorsal root ganglion (DRG) neurons. However, whether K(Na) channels play the same role in other size DRG neurons is still elusive. The aim of this study is to identify the existence and potential physiological functions of K(Na) channels in medium diameter (25-35 microm) DRG neurons. METHODS Inside-out and whole-cell patch-clamp were used to study the electrophysiological characterizations of native K(Na) channels. RT-PCR was used to identify the existence of Slack and Slick genes. RESULTS We report that K(Na) channels are required for depolarizing afterpotential (DAP) in medium sized rat DRG neurons. In inside-out patches, K(Na) channels represented 201 pS unitary chord conductance and were activated by cytoplasmic Na+ [the half maximal effective concentration (EC50): 35 mmol/L] in 160 mmol/L symmetrical K+o/K+i solution. Additionally, these K(Na) channels also represented cytoplasmic Cl(-)-dependent activation. RT-PCR confirmed the existence of Slack and Slick genes in DRG neurons. Tetrodotoxin (TTX, 100 nmol/L) completely blocked the DRG inward Na+ currents, and the following outward currents which were thought to be K(Na) currents. The DAP was increased when extracellular Na+ was replaced by Li+. CONCLUSION We conclude that Slack and Slick K(Na) channels are required for DAP of medium diameter rat DRG neurons that regulate DRG action potential repolarization.
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Affiliation(s)
- Shang-bang Gao
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
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Berg AP, Sen N, Bayliss DA. TrpC3/C7 and Slo2.1 are molecular targets for metabotropic glutamate receptor signaling in rat striatal cholinergic interneurons. J Neurosci 2007; 27:8845-56. [PMID: 17699666 PMCID: PMC6672182 DOI: 10.1523/jneurosci.0551-07.2007] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Large aspiny cholinergic interneurons provide the sole source of striatal acetylcholine, a neurotransmitter critical for basal ganglia function; these tonically active interneurons receive excitatory inputs from corticostriatal glutamatergic afferents that act, in part, via metabotropic glutamate receptors (mGluRs). We combined electrophysiological recordings in brain slices with molecular neuroanatomy to identify distinct ion channel targets for mGluR1/5 receptors in striatal cholinergic interneurons: transient receptor potential channel 3/7 (TrpC3/C7) and Slo2.1. In recordings obtained with methanesulfonate-based internal solutions, we found an mGluR-activated current with voltage-dependent and pharmacological properties reminiscent of TrpC3 and TrpC7; expression of these TrpC subunits in cholinergic interneurons was verified by combined immunohistochemistry and in situ hybridization, and modulation of both TrpC channels was reconstituted in HEK293 (human embryonic kidney 293) cells cotransfected with mGluR1 or mGluR5. With a chloride-based internal solution, mGluR agonists did not activate interneuron TrpC-like currents. Instead, a time-dependent, outwardly rectifying K(+) current developed after whole-cell access, and this Cl(-)-activated K(+) current was strongly inhibited by volatile anesthetics and mGluR activation. This modulation was recapitulated in cells transfected with Slo2.1, a Na(+)- and Cl(-)-activated K(+) channel, and Slo2.1 expression was confirmed histochemically in striatal cholinergic interneurons. By using gramicidin perforated-patch recordings, we established that the predominant agonist-activated current was TrpC-like when ambient intracellular chloride was preserved, although a small K(+) current contribution was observed in some cells. Together, our data indicate that mGluR1/5-mediated glutamatergic excitation of cholinergic interneurons is primarily a result of activation of TrpC3/TrpC7-like cationic channels; under conditions when intracellular NaCl is elevated, a Slo2.1 background K(+) channel may also contribute.
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Affiliation(s)
- Allison P Berg
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia 22908, USA.
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22
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Abstract
The Slack (sequence like a calcium-activated K channel) and Slick (sequence like an intermediate conductance K channel) genes, which encode sodium-activated K+ (K(Na)) channels, are expressed at high levels in neurons of the medial nucleus of the trapezoid body (MNTB) in the auditory brainstem. These neurons lock their action potentials to incoming stimuli with a high degree of temporal precision. Channels with unitary properties similar to those of Slack and/or Slick channels, which are gated by [Na+]i and [Cl-]i and by changes in cytoplasmic ATP levels, are present in MNTB neurons. Manipulations of the level of K(Na) current in MNTB neurons, either by increasing levels of internal Na+ or by exposure to a pharmacological activator of Slack channels, significantly enhance the accuracy of timing of action potentials at high frequencies of stimulation. These findings suggest that such fidelity of timing at high frequencies may be attributed in part to high-conductance K(Na) channels.
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Affiliation(s)
- Bo Yang
- Departments of Pharmacology and
| | | | - Leonard K. Kaczmarek
- Departments of Pharmacology and
- Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut 06520
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23
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Santi CM, Ferreira G, Yang B, Gazula VR, Butler A, Wei A, Kaczmarek LK, Salkoff L. Opposite regulation of Slick and Slack K+ channels by neuromodulators. J Neurosci 2006; 26:5059-68. [PMID: 16687497 PMCID: PMC6674240 DOI: 10.1523/jneurosci.3372-05.2006] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Slick (Slo2.1) and Slack (Slo2.2) are two novel members of the mammalian Slo potassium channel gene family that may contribute to the resting potentials of cells and control their basal level of excitability. Slo2 channels have sensors that couple channel activity to the intracellular concentrations of Na+ and Cl- ions (Yuan et al., 2003). We now report that activity of both Slo2 channels is controlled by neuromodulators through Galphaq-protein coupled receptors (GqPCRs) (the M1 muscarinic receptor and the mGluR1 metabotropic glutamate receptor). Experiments coexpressing channels and receptors in Xenopus oocytes show that Slo2.1 and Slo2.2 channels are modulated in opposite ways: Slo2.1 is strongly inhibited, whereas Slo2.2 currents are strongly activated through GqPCR stimulation. Differential regulation involves protein kinase C (PKC); application of the PKC activator PMA, to cells expressing channels but not receptors, inhibits Slo2.1 whole-cell currents and increases Slo2.2 currents. Synthesis of a chimera showed that the distal carboxyl region of Slo2.1 controls the sensitivity of Slo2.1 to PMA. Slo2 channels have widespread expression in brain (Bhattacharjee et al., 2002, 2005). Using immunocytochemical techniques, we show coexpression of Slo2 channels with the GqPCRs in cortical and hippocampal brain sections and in cultured hippocampal neurons. The differential control of these novel channels by neurotransmitters may elicit long-lasting increases or decreases in neuronal excitability and, because of their widespread distribution, may provide a mechanism to activate or repress electrical activity in many systems of the brain.
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Abstract
This study investigates the presence and properties of Na+-activated K+ (K(Na)) channels in epithelial renal cells. Using real-time PCR on mouse microdissected nephron segments, we show that Slo2.2 mRNA, which encodes for the K(Na) channels of excitable cells, is expressed in the medullary and cortical thick ascending limbs of Henle's loop, but not in the other parts of the nephron. Patch-clamp analysis revealed the presence of a high conductance K+ channel in the basolateral membrane of both the medullary and cortical thick ascending limbs. This channel was highly K+ selective (P(K)/P(Na) approximately 20), its conductance ranged from 140 to 180 pS with subconductance levels, and its current/voltage relationship displayed intermediate, Na+-dependent, inward rectification. Internal Na+ and Cl- activated the channel with 50% effective concentrations (EC50) and Hill coefficients (nH) of 30 +/- 1 mM and 3.9 +/- 0.5 for internal Na+, and 35 +/- 10 mM and 1.3 +/- 0.25 for internal Cl-. Channel activity was unaltered by internal ATP (2 mM) and by internal pH, but clearly decreased when internal free Ca2+ concentration increased. This is the first demonstration of the presence in the epithelial cell membrane of a functional, Na+-activated, large-conductance K+ channel that closely resembles native K(Na) channels of excitable cells. This Slo2.2 type, Na+- and Cl--activated K+ channel is primarily located in the thick ascending limb, a major renal site of transcellular NaCl reabsorption.
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Affiliation(s)
- Marc Paulais
- UPMC, CNRS UMR7134, Institut Fédératif de Recherches 58, Paris, France.
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Lin YW, MacMullen C, Ganguly A, Stanley CA, Shyng SL. A novel KCNJ11 mutation associated with congenital hyperinsulinism reduces the intrinsic open probability of beta-cell ATP-sensitive potassium channels. J Biol Chem 2006; 281:3006-12. [PMID: 16332676 PMCID: PMC1479853 DOI: 10.1074/jbc.m511875200] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The beta-cell ATP-sensitive potassium (KATP) channel controls insulin secretion by linking glucose metabolism to membrane excitability. Loss of KATP channel function due to mutations in ABCC8 or KCNJ11, genes that encode the sulfonylurea receptor 1 or the inward rectifier Kir6.2 subunit of the channel, is a major cause of congenital hyperinsulinism. Here, we report identification of a novel KCNJ11 mutation associated with the disease that renders a missense mutation, F55L, in the Kir6.2 protein. Mutant channels reconstituted in COS cells exhibited a wild-type-like surface expression level and normal sensitivity to ATP, MgADP, and diazoxide. However, the intrinsic open probability of the mutant channel was greatly reduced, by approximately 10-fold. This low open probability defect could be reversed by application of phosphatidylinositol 4,5-bisphosphates or oleoyl-CoA to the cytoplasmic face of the channel, indicating that reduced channel response to membrane phospholipids and/or long chain acyl-CoAs underlies the low intrinsic open probability in the mutant. Our findings reveal a novel molecular mechanism for loss of KATP channel function and congenital hyperinsulinism and support the importance of phospholipids and/or long chain acyl-CoAs in setting the physiological activity of beta-cell KATP channels. The F55L mutation is located in the slide helix of Kir6.2. Several permanent neonatal diabetes-associated mutations found in the same structure have the opposite effect of increasing intrinsic channel open probability. Our results also highlight the critical role of the Kir6.2 slide helix in determining the intrinsic open probability of KATP channels.
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Affiliation(s)
- Yu-Wen Lin
- From the Center for Research on Occupational and Environmental Toxicology, Oregon Health & Science University, Portland, OR 97239, and
| | - Courtney MacMullen
- Division of Endocrinology/Diabetes, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, 19104
| | - Arupa Ganguly
- Division of Endocrinology/Diabetes, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, 19104
| | - Charles A. Stanley
- Division of Endocrinology/Diabetes, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, 19104
| | - Show-Ling Shyng
- From the Center for Research on Occupational and Environmental Toxicology, Oregon Health & Science University, Portland, OR 97239, and
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26
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Jo S, Lee KH, Song S, Jung YK, Park CS. Identification and functional characterization of cereblon as a binding protein for large-conductance calcium-activated potassium channel in rat brain. J Neurochem 2005; 94:1212-24. [PMID: 16045448 DOI: 10.1111/j.1471-4159.2005.03344.x] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Large-conductance Ca2+-activated K+ (BK(Ca)) channels are activated by membrane depolarization and modulated by intracellular Ca2+. Here, we report the direct interaction of cereblon (CRBN) with the cytosolic carboxy-terminus of the BK(Ca) channel alpha subunit (Slo). Rat CRBN contained the N-terminal domain of the Lon protease, a 'regulators of G protein-signaling' (RGS)-like domain, a leucine zipper (LZ) motif, and four putative protein kinase C (PKC) phosphorylation sites. RNA messages of rat cereblon (rCRBN) were widely distributed in different tissues with especially high-levels of expression in the brain. Direct association of rCRBN with the BK(Ca) channel was confirmed by immunoprecipitation in brain lysate, and the two proteins were co-localized in cultured rat hippocampal neurons. Ionic currents evoked by the rSlo channel were dramatically suppressed upon coexpression of rCRBN. rCRBN decreased the formation of the tetrameric rSlo complex thus reducing the surface expression of functional channels. Therefore, we suggest that CRBN may play an important role in assembly and surface expression of functional BK(Ca) channels by direct interaction with the cytosolic C-terminus of its alpha-subunit.
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Affiliation(s)
- Sooyeon Jo
- Department of Life Science, Gwangju Institute Science and Technology (GIST), Gwangju, Republic of Korea
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27
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Abstract
Na+-activated K+ currents (K(Na)) have been reported in multiple neuronal nuclei and the properties of K(Na) vary in different cell types. We have described previously the distribution of Slack, a Na+-activated K+ channel subunit. Another recently cloned Na+-activated K+ channel is Slick, which differs from Slack in its rapid activation and its sensitivity to intracellular ATP levels. We now report the localization of Slick in the rat central nervous system using in situ and immunohistochemical techniques. As for Slack, we find that Slick is widely distributed in the brain. Specifically, strong hybridization signals and immunoreactivity were found in the brainstem, including auditory neurons such as the medial nucleus of the trapezoid body. As has also been shown for Slack, Slick is expressed in the olfactory bulb, red nucleus, facial nucleus, pontine nucleus, oculomotor nucleus, substantia nigra, deep cerebellar nuclei, vestibular nucleus, and the thalamus. Slick mRNA and protein, however, also are found in certain neurons that do not express Slack. These neurons include those of the hippocampal CA1, CA2, and CA3 regions, the dentate gyrus, supraoptic nucleus, hypothalamus, and cortical layers II, III, and V. These data suggest that Slick may function independently of Slack in these regions. Computer simulations indicate that Slick currents can cause adaptation during prolonged stimuli. Such adaptation allows a neuron to respond to high-frequency stimulation with lower-frequency firing that remains temporally locked to individual stimuli, a property seen in many auditory neurons. Although it is not yet known if Slick and Slack subunits heteromultimerize, the existence of two genes that encode K(Na), that are widely expressed in the nervous system, with both overlapping and nonoverlapping distributions, provides the basis for the reported heterogeneity in the properties of K(Na) from various neurons.
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Affiliation(s)
- Arin Bhattacharjee
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520, USA
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28
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Zhang L, Sukhareva M, Barker JL, Maric D, Hao Y, Chang YH, Ma W, O'Shaughnessy T, Rubinow DR. Direct binding of estradiol enhances Slack (sequence like a calcium-activated potassium channel) channels’ activity. Neuroscience 2005; 131:275-82. [PMID: 15708472 DOI: 10.1016/j.neuroscience.2004.10.042] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/06/2004] [Indexed: 10/25/2022]
Abstract
17Beta-estradiol (E2) is a major neuroregulator, exerting both genomic and non-genomic actions. E2 regulation of Slack (sequence like a calcium-activated potassium channel) potassium channels has not been identified in the CNS. We demonstrate E2-induced activation of Slack channels, which display a unitary conductance of about 60 pS, are inhibited by intracellular calcium, and are abundantly expressed in the nervous system. In lipid bilayers derived from rat cortical neuronal membranes, E2 increases Slack open probability and appears to decrease channel inactivation. Additionally, E2 binds to the Slack channel and activates outward currents in human embryonic kidney-293 cells that express Slack channels but not classical estrogen receptors (i.e. ERalpha or ERbeta). Neither E2-induced activation nor the binding intensity of E2 to the Slack channel is blocked by tamoxifen, an ER antagonist/agonist. Thus, E2 activates a potassium channel, Slack, through a non-traditional membrane binding site, adding to known non-genomic mechanisms by which E2 exerts pharmacological and toxicological effects in the CNS.
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Affiliation(s)
- L Zhang
- Behavioral Endocrinology Branch, NIMH/NIH, Building 10, Room 65340, MSC 1276, Bethesda, MD 20892-1276, USA.
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29
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Lim HH, Park CS. Identification and functional characterization of ankyrin-repeat family protein ANKRA as a protein interacting with BKCa channel. Mol Biol Cell 2004; 16:1013-25. [PMID: 15616191 PMCID: PMC551470 DOI: 10.1091/mbc.e04-06-0537] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Ankyrin-repeat family A protein (ANKRA) was originally cloned in mouse as an interacting protein to megalin, a member of low-density lipoprotein receptor superfamily. Here, we report that the isolation of rat ANKRA as a new binding partner for the alpha-subunit of rat large-conductance Ca2+-activated K+ channel (rSlo). We mapped the binding region of each protein by using yeast two-hybrid and in vitro binding assays. ANKRA expressed together with rSlo channels were colocalized near the plasma membrane and coimmunoprecipitated in transfected cells. We also showed that BKCa channel in rat cerebral cortex coprecipitated with rANKRA and colocalized in cultured rat hippocampal neuron. Although the coexpression of ANKRA did not affect the surface expression of rSlo, the gating kinetics of rSlo channel was significantly altered and the effects were highly dependent on the intracellular calcium. These results indicate that ANKRA could modulate the excitability of neurons by binding directly to endogenous BKCa channel and altering its gating kinetics in a calcium-dependent manner.
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Affiliation(s)
- Hyun-Ho Lim
- Department of Life Science, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea
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Choisy SCM, Hancox JC, Arberry LA, Reynolds AM, Shattock MJ, James AF. Evidence for a Novel K+Channel Modulated by α1A-Adrenoceptors in Cardiac Myocytes. Mol Pharmacol 2004; 66:735-48. [PMID: 15322267 DOI: 10.1124/mol.104.000760] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Accumulating evidence suggests that steady-state K(+) currents modulate excitability and action potential duration, particularly in cardiac cell types with relatively abbreviated action potential plateau phases. Despite representing potential drug targets, at present these currents and their modulation are comparatively poorly characterized. Therefore, we investigated the effects of phenylephrine [PE; an alpha(1)-adrenoceptor (alpha(1)-AR) agonist] on a sustained outward K(+) current in rat ventricular myocytes. Under K(+) current-selective conditions at 35 degrees C and whole-cell patch clamp, membrane depolarization elicited transient (I(t)) and steady-state (I(ss)) outward current components. PE (10 microM) significantly decreased I(ss) amplitude, without significant effect on I(t). Preferential modulation of I(ss) by PE was confirmed by intracellular application of the voltage-gated K(+) channel blocker tetraethylammonium, which largely inhibited I(t) without affecting the PE-sensitive current (I(ss,PE)). I(ss,PE) had the properties of an outwardly rectifying steady-state K(+)-selective conductance. Acidification of the external solution or externally applied BaCl(2) or quinidine strongly inhibited I(ss,PE). However, I(ss,PE) was not abolished by anandamide, ruthenium red, or zinc, inhibitors of TASK acid-sensitive background K(+) channels. Furthermore, the PE-sensitive current was partially inhibited by external administration of high concentrations of tetraethylammonium and 4-aminopyridine, which are voltage-gated K(+) channel-blockers. Power spectrum analysis of I(ss,PE) yielded a large unitary conductance of 78 pS. I(ss,PE) resulted from PE activation of the alpha(1A)-AR subtype, involved a pertussis toxin-insensitive G-protein, and was independent of cytosolic Ca(2+). These results collectively demonstrate that alpha(1A)-AR activation results in the inhibition of an outwardly rectifying steady-state K(+) current with properties distinct from previously characterized cardiac K(+) channels.
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Affiliation(s)
- Stéphanie C M Choisy
- Department of Physiology and Cardiovascular Research Laboratories, School of Medical Sciences, University of Bristol, University Walk, Bristol, BS8 1TD, United Kingdom
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Bhattacharjee A, Joiner WJ, Wu M, Yang Y, Sigworth FJ, Kaczmarek LK. Slick (Slo2.1), a rapidly-gating sodium-activated potassium channel inhibited by ATP. J Neurosci 2003; 23:11681-91. [PMID: 14684870 PMCID: PMC6740956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023] Open
Abstract
Neuronal stressors such as hypoxia and firing of action potentials at very high frequencies cause intracellular Na+ to rise and ATP to be consumed faster than it can be regenerated. We report the cloning of a gene encoding a K+ channel, Slick, and demonstrate that functionally it is a hybrid between two classes of K+ channels, Na+-activated (KNa) and ATP-sensitive (KATP) K+ channels. The Slick channel is activated by intracellular Na+ and Cl- and is inhibited by intracellular ATP. Slick is widely expressed in the CNS and is detected in heart. We identify a consensus ATP binding site near the C terminus of the channel that is required for ATP and its nonhydrolyzable analogs to reduce open probability. The convergence of Na+, Cl-, and ATP sensitivity in one channel may endow Slick with the ability to integrate multiple indicators of the metabolic state of a cell and to adjust electrical activity appropriately.
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Affiliation(s)
- Arin Bhattacharjee
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520, USA
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32
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Uchino S, Wada H, Honda S, Hirasawa T, Yanai S, Nakamura Y, Ondo Y, Kohsaka S. Slo2 sodium-activated K+ channels bind to the PDZ domain of PSD-95. Biochem Biophys Res Commun 2003; 310:1140-7. [PMID: 14559234 DOI: 10.1016/j.bbrc.2003.09.133] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Slo2 channels are a type of sodium-activated K+ channels and possess a typical PDZ binding motif at the carboxy-terminal end. Thus, we investigated whether Slo2 channels bind to PSD-95, because it is well known that other types of K+ channels, voltage-gated and inward rectifier K+ channels, bind to PSD-95 via the PDZ binding motif and are involved in excitatory synaptic transmission. By using an extract prepared from cultured neocortical neurons, we demonstrated a biochemical interaction between mSlo2 channels and PSD-95, and a mutational analysis revealed that mSlo2 channels bound to the first PDZ domain of PSD-95 via the PDZ binding motif. To investigate the expression of mSlo2 protein in primary neocortical neurons, we raised anti-mSlo2 channel antibody and immunostained neocortical neurons. The immunocytochemical study showed that mSlo2 channels partly colocalized with PSD-95 in mouse neocortical neurons.
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Affiliation(s)
- Shigeo Uchino
- Department of Neurochemistry, National Institute of Neuroscience, 4-1-1 Ogawahigashi, Kodaira, Tokyo 187-8502, Japan
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33
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Yuan A, Santi CM, Wei A, Wang ZW, Pollak K, Nonet M, Kaczmarek L, Crowder CM, Salkoff L. The sodium-activated potassium channel is encoded by a member of the Slo gene family. Neuron 2003; 37:765-73. [PMID: 12628167 DOI: 10.1016/s0896-6273(03)00096-5] [Citation(s) in RCA: 191] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Na(+)-activated potassium channels (K(Na)) have been identified in cardiomyocytes and neurons where they may provide protection against ischemia. We now report that K(Na) is encoded by the rSlo2 gene (also called Slack), the mammalian ortholog of slo-2 in C. elegans. rSlo2, heterologously expressed, shares many properties of native K(Na) including activation by intracellular Na(+), high conductance, and prominent subconductance states. In addition to activation by Na(+), we report that rSLO-2 channels are cooperatively activated by intracellular Cl(-), similar to C. elegans SLO-2 channels. Since intracellular Na(+) and Cl(-) both rise in oxygen-deprived cells, coactivation may more effectively trigger the activity of rSLO-2 channels in ischemia. In C. elegans, mutational and physiological analysis revealed that the SLO-2 current is a major component of the delayed rectifier. We demonstrate in C. elegans that slo-2 mutants are hypersensitive to hypoxia, suggesting a conserved role for the slo-2 gene subfamily.
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Affiliation(s)
- Alex Yuan
- Department of Anatomy and Neurobiology, Washington University School of Medicine, 660 S. Euclid Avenue, Saint Louis, MO 63110, USA
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34
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Abstract
The Slack gene encodes a voltage-dependent K(+) channel that has a unitary conductance of approximately 60 pS. Evidence from heterologous expression studies suggests that Slack channel subunits can also combine with the Slo subunit to generate Ca(2+)-activated K(+) channels of larger conductances. Nonetheless, the function of Slack in the brain remains to be identified. We have now generated an affinity-purified antibody against the N-terminal of rat Slack, for biochemical and immunohistochemical studies. The antibody recognized Slack in transiently transfected CHO cells both by immunocytochemistry and by Western blot analysis. The antibody also detected a single band in rat brain membranes. The localization of Slack in rat brain slices was then determined using the antibody. Most prominent Slack immunoreactivity occurs in the brainstem, in particular the trigeminal system and reticular formation, where very intense staining was found in both cell bodies and axonal fibers of associated nuclei. Labeling was also very strong in the vestibular and oculomotor nuclei. Within the auditory system, the medial nucleus of the trapezoid had a robust signal consistent with staining of the giant presynaptic terminals. Strong Slack immunoreactivity was present in the olfactory bulb, red nucleus, and deep cerebellar nuclei. There was labeling also in the thalamus, substantia nigra, and amygdala. The only cortical region in which Slack immunoreactivity was detected was the frontal cortex. The subcellular and regional distribution of Slack differs from that previously reported for the Slo channel subunit and suggests that Slack may also have an autonomous role in regulating the firing properties of neurons.
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Affiliation(s)
- Arin Bhattacharjee
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520, USA
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35
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Abstract
Among the retroposons, the source of the endonuclease activity is known to be variable and can be provided as either a retroviral-like integrase or a protein similar to the cellular apurinic-apyrimidinic endonuclease. It has also been reported that other retroposon and retrointron sequences have limited similarity to various eubacterial endonucleases. We investigated whether any retroposon genomes possibly encode multiple endonuclease functions. Amino acid alignments were generated and analyzed for the presence of the characterized ordered-series-of-motifs (OSM) representative of four different endonuclease functions. The results indicate that SLACS, CZAR, CRE1, CRE2, and some Trypanosoma brucei retroposon sequences encode multiple putative endonuclease functions. Interestingly, one of the endonuclease functions is embedded within the potential ribonuclease H sequence found in SLACS, CZAR, CRE1, CRE2, and R2BM retroposons.
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Affiliation(s)
- Marcella A McClure
- Department of Microbiology, Montana State University, Bozeman, Montana 59717, USA.
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36
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Joiner WJ, Tang MD, Wang LY, Dworetzky SI, Boissard CG, Gan L, Gribkoff VK, Kaczmarek LK. Formation of intermediate-conductance calcium-activated potassium channels by interaction of Slack and Slo subunits. Nat Neurosci 1998; 1:462-9. [PMID: 10196543 DOI: 10.1038/2176] [Citation(s) in RCA: 138] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Large-conductance calcium-activated potassium channels (maxi-K channels) have an essential role in the control of excitability and secretion. Only one gene Slo is known to encode maxi-K channels, which are sensitive to both membrane potential and intracellular calcium. We have isolated a potassium channel gene called Slack that is abundantly expressed in the nervous system. Slack channels rectify outwardly with a unitary conductance of about 25-65 pS and are inhibited by intracellular calcium. However, when Slack is co-expressed with Slo, channels with pharmacological properties and single-channel conductances that do not match either Slack or Slo are formed. The Slack/Slo channels have intermediate conductances of about 60-180 pS and are activated by cytoplasmic calcium. Our findings indicate that some intermediate-conductance channels in the nervous system may result from an interaction between Slack and Slo channel subunits.
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Affiliation(s)
- W J Joiner
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520, USA
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