1
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Swan AH, Schindler RFR, Savarese M, Mayer I, Rinné S, Bleser F, Schänzer A, Hahn A, Sabatelli M, Perna F, Chapman K, Pfuhl M, Spivey AC, Decher N, Udd B, Tasca G, Brand T. Correction: Differential effects of mutations of POPDC proteins on heteromeric interaction and membrane trafficking. Acta Neuropathol Commun 2023; 11:114. [PMID: 37434226 DOI: 10.1186/s40478-023-01591-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/13/2023] Open
Affiliation(s)
- Alexander H Swan
- National Heart and Lung Institute (NHLI), Imperial College London, London, UK
- Department of Chemistry, Imperial College London, London, UK
| | - Roland F R Schindler
- National Heart and Lung Institute (NHLI), Imperial College London, London, UK
- Assay Biology, Domainex Ltd, Cambridge, CB10 1XL, UK
| | - Marco Savarese
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Isabelle Mayer
- National Heart and Lung Institute (NHLI), Imperial College London, London, UK
| | - Susanne Rinné
- Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Marburg, Germany
| | - Felix Bleser
- Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Marburg, Germany
| | - Anne Schänzer
- Institute of Neuropathology, Justus Liebig University Giessen, Giessen, Germany
| | - Andreas Hahn
- Department of Child Neurology, Justus Liebig University Giessen, Giessen, Germany
| | - Mario Sabatelli
- Department of Neurology, Universitá Cattolica del Sacro Cuore, Rome, Italy
| | - Francesco Perna
- Dipartimento Di Scienze Cardiovascolari, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | | | - Mark Pfuhl
- School of Cardiovascular Medicine and Sciences and Randall Centre, King's College London, London, UK
| | - Alan C Spivey
- Department of Chemistry, Imperial College London, London, UK
| | - Niels Decher
- Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Marburg, Germany
| | - Bjarne Udd
- Folkhälsan Research Center, University of Helsinki, Helsinki, Finland
| | - Giorgio Tasca
- Unità Operativa Complessa di Neurologia, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
- John Walton Muscular Dystrophy Research Centre, Newcastle University and Newcastle Hospitals NHS Foundation Trusts , Newcastle Upon Tyne, UK
| | - Thomas Brand
- National Heart and Lung Institute (NHLI), Imperial College London, London, UK.
- Imperial Centre of Translational and Experimental Medicine, Du Cane Road, London, W120NN, UK.
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2
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Vera-Zambrano A, Baena-Nuevo M, Rinné S, Villegas-Esguevillas M, Barreira B, Telli G, de Benito-Bueno A, Blázquez JA, Climent B, Pérez-Vizcaino F, Valenzuela C, Decher N, Gonzalez T, Cogolludo A. Sigma-1 receptor modulation fine-tunes K V1.5 channels and impacts pulmonary vascular function. Pharmacol Res 2023; 189:106684. [PMID: 36740150 DOI: 10.1016/j.phrs.2023.106684] [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] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 01/23/2023] [Accepted: 02/01/2023] [Indexed: 02/05/2023]
Abstract
KV1.5 channels are key players in the regulation of vascular tone and atrial excitability and their impairment is associated with cardiovascular diseases including pulmonary arterial hypertension (PAH) and atrial fibrillation (AF). Unfortunately, pharmacological strategies to improve KV1.5 channel function are missing. Herein, we aimed to study whether the chaperone sigma-1 receptor (S1R) is able to regulate these channels and represent a new strategy to enhance their function. By using different electrophysiological and molecular techniques in X. laevis oocytes and HEK293 cells, we demonstrate that S1R physically interacts with KV1.5 channels and regulate their expression and function. S1R induced a bimodal regulation of KV1.5 channel expression/activity, increasing it at low concentrations and decreasing it at high concentrations. Of note, S1R agonists (PRE084 and SKF10047) increased, whereas the S1R antagonist BD1047 decreased, KV1.5 expression and activity. Moreover, PRE084 markedly increased KV1.5 currents in pulmonary artery smooth muscle cells and attenuated vasoconstriction and proliferation in pulmonary arteries. We also show that both KV1.5 channels and S1R, at mRNA and protein levels, are clearly downregulated in samples from PAH and AF patients. Moreover, the expression of both genes showed a positive correlation. Finally, the ability of PRE084 to increase KV1.5 function was preserved under sustained hypoxic conditions, as an in vitro PAH model. Our study provides insight into the key role of S1R in modulating the expression and activity of KV1.5 channels and highlights the potential role of this chaperone as a novel pharmacological target for pathological conditions associated with KV1.5 channel dysfunction.
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Affiliation(s)
- Alba Vera-Zambrano
- Department of Biochemistry, School of Medicine, Universidad Autónoma de Madrid, Madrid, Spain; Instituto de Investigaciones Biomédicas "Alberto Sols" CSIC-UAM, Madrid, Spain; Department of Pharmacology and Toxicology, School of Medicine, University Complutense of Madrid, Madrid, Spain.
| | - Maria Baena-Nuevo
- Instituto de Investigaciones Biomédicas "Alberto Sols" CSIC-UAM, Madrid, Spain
| | - Susanne Rinné
- Institute of Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, 35043 Marburg, Germany
| | - Marta Villegas-Esguevillas
- Department of Pharmacology and Toxicology, School of Medicine, University Complutense of Madrid, Madrid, Spain; Ciber Enfermedades Respiratorias (CIBERES), Spain; Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain
| | - Bianca Barreira
- Department of Pharmacology and Toxicology, School of Medicine, University Complutense of Madrid, Madrid, Spain; Ciber Enfermedades Respiratorias (CIBERES), Spain; Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain
| | - Gokcen Telli
- Hacettepe University, Department of Pharmacology, Faculty of Pharmacy, Ankara, Turkey
| | | | | | - Belén Climent
- Department of Physiology, Faculty of Pharmacy, University Complutense of Madrid, Madrid, Spain
| | - Francisco Pérez-Vizcaino
- Department of Pharmacology and Toxicology, School of Medicine, University Complutense of Madrid, Madrid, Spain; Ciber Enfermedades Respiratorias (CIBERES), Spain; Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain
| | - Carmen Valenzuela
- Instituto de Investigaciones Biomédicas "Alberto Sols" CSIC-UAM, Madrid, Spain; Spanish Network for Biomedical Research in Cardiovascular Research (CIBERCV), Instituto de Salud Carlos III, Madrid, Spain
| | - Niels Decher
- Institute of Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, 35043 Marburg, Germany
| | - Teresa Gonzalez
- Department of Biochemistry, School of Medicine, Universidad Autónoma de Madrid, Madrid, Spain; Instituto de Investigaciones Biomédicas "Alberto Sols" CSIC-UAM, Madrid, Spain; Department of Physiology, Faculty of Pharmacy, University Complutense of Madrid, Madrid, Spain
| | - Angel Cogolludo
- Department of Pharmacology and Toxicology, School of Medicine, University Complutense of Madrid, Madrid, Spain; Ciber Enfermedades Respiratorias (CIBERES), Spain; Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain.
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3
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Rinné S, Oertli A, Nagel C, Tomsits P, Jenewein T, Kääb S, Kauferstein S, Loewe A, Beckmann BM, Decher N. Functional Characterization of a Spectrum of Novel Romano-Ward Syndrome KCNQ1 Variants. Int J Mol Sci 2023; 24:ijms24021350. [PMID: 36674868 PMCID: PMC9865342 DOI: 10.3390/ijms24021350] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 12/20/2022] [Accepted: 12/23/2022] [Indexed: 01/13/2023] Open
Abstract
The KCNQ1 gene encodes the α-subunit of the cardiac voltage-gated potassium (Kv) channel KCNQ1, also denoted as Kv7.1 or KvLQT1. The channel assembles with the ß-subunit KCNE1, also known as minK, to generate the slowly activating cardiac delayed rectifier current IKs, a key regulator of the heart rate dependent adaptation of the cardiac action potential duration (APD). Loss-of-function variants in KCNQ1 cause the congenital Long QT1 (LQT1) syndrome, characterized by delayed cardiac repolarization and a QT interval prolongation in the surface electrocardiogram (ECG). Autosomal dominant loss-of-function variants in KCNQ1 result in the LQT syndrome called Romano-Ward syndrome (RWS), while autosomal recessive variants affecting function, lead to Jervell and Lange-Nielsen syndrome (JLNS), associated with deafness. The aim of this study was the characterization of novel KCNQ1 variants identified in patients with RWS to widen the spectrum of known LQT1 variants, and improve the interpretation of the clinical relevance of variants in the KCNQ1 gene. We functionally characterized nine human KCNQ1 variants using the voltage-clamp technique in Xenopus laevis oocytes, from which we report seven novel variants. The functional data was taken as input to model surface ECGs, to subsequently compare the functional changes with the clinically observed QTc times, allowing a further interpretation of the severity of the different LQTS variants. We found that the electrophysiological properties of the variants correlate with the severity of the clinically diagnosed phenotype in most cases, however, not in all. Electrophysiological studies combined with in silico modelling approaches are valuable components for the interpretation of the pathogenicity of KCNQ1 variants, but assessing the clinical severity demands the consideration of other factors that are included, for example in the Schwartz score.
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Affiliation(s)
- Susanne Rinné
- Institute of Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, 35037 Marburg, Germany
| | - Annemarie Oertli
- Institute of Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, 35037 Marburg, Germany
| | - Claudia Nagel
- Institute of Biomedical Engineering, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
| | - Philipp Tomsits
- Department of Medicine I, University Hospital, LMU Munich, 80802 Munich, Germany
- Deutsches Zentrum für Herz-Kreislauferkrankungen (DZHK), Partner Site Munich, 80636 Munich, Germany
- Member of the European Reference Network for Rare, Low Prevalance and Complex Diseases of the Heart (ERN GUARD-Heart), 81377 Munich, Germany
- Institute of Surgical Research at the Walter-Brendel-Centre of Experimental Medicine, University Hospital, LMU Munich, Marchioninistrasse 27, 81377 Munich, Germany
| | - Tina Jenewein
- Institute of Legal Medicine, Goethe University, University Hospital Frankfurt, 60590 Frankfurt, Germany
- Institute for Transfusion Medicine and Immunohematology, German Red Cross Blood Service Baden-Württemberg-Hessen, Goethe University Frankfurt, 60528 Frankfurt, Germany
| | - Stefan Kääb
- Department of Medicine I, University Hospital, LMU Munich, 80802 Munich, Germany
- Deutsches Zentrum für Herz-Kreislauferkrankungen (DZHK), Partner Site Munich, 80636 Munich, Germany
- Member of the European Reference Network for Rare, Low Prevalance and Complex Diseases of the Heart (ERN GUARD-Heart), 81377 Munich, Germany
| | - Silke Kauferstein
- Institute of Legal Medicine, Goethe University, University Hospital Frankfurt, 60590 Frankfurt, Germany
- Deutsches Zentrum für Herz-Kreislauferkrankungen (DZHK), Partner Site Frankfurt, 60596 Frankfurt, Germany
| | - Axel Loewe
- Institute of Biomedical Engineering, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
| | - Britt Maria Beckmann
- Department of Medicine I, University Hospital, LMU Munich, 80802 Munich, Germany
- Institute of Legal Medicine, Goethe University, University Hospital Frankfurt, 60590 Frankfurt, Germany
| | - Niels Decher
- Institute of Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, 35037 Marburg, Germany
- Correspondence: ; Tel.: +49-(0)6421-28-62148
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Swan AH, Schindler RFR, Savarese M, Mayer I, Rinné S, Bleser F, Schänzer A, Hahn A, Sabatelli M, Perna F, Chapman K, Pfuhl M, Spivey AC, Decher N, Udd B, Tasca G, Brand T. Differential effects of mutations of POPDC proteins on heteromeric interaction and membrane trafficking. Acta Neuropathol Commun 2023; 11:4. [PMID: 36624536 PMCID: PMC9830914 DOI: 10.1186/s40478-022-01501-w] [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] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 12/22/2022] [Indexed: 01/11/2023] Open
Abstract
The Popeye domain containing (POPDC) genes encode sarcolemma-localized cAMP effector proteins. Mutations in blood vessel epicardial substance (BVES) also known as POPDC1 and POPDC2 have been associated with limb-girdle muscular dystrophy and cardiac arrhythmia. Muscle biopsies of affected patients display impaired membrane trafficking of both POPDC isoforms. Biopsy material of patients carrying mutations in BVES were immunostained with POPDC antibodies. The interaction of POPDC proteins was investigated by co-precipitation, proximity ligation, bioluminescence resonance energy transfer and bimolecular fluorescence complementation. Site-directed mutagenesis was utilised to map the domains involved in protein-protein interaction. Patients carrying a novel homozygous variant, BVES (c.547G > T, p.V183F) displayed only a skeletal muscle pathology and a mild impairment of membrane trafficking of both POPDC isoforms. In contrast, variants such as BVES p.Q153X or POPDC2 p.W188X were associated with a greater impairment of membrane trafficking. Co-transfection analysis in HEK293 cells revealed that POPDC proteins interact with each other through a helix-helix interface located at the C-terminus of the Popeye domain. Site-directed mutagenesis of an array of ultra-conserved hydrophobic residues demonstrated that some of them are required for membrane trafficking of the POPDC1-POPDC2 complex. Mutations in POPDC proteins that cause an impairment in membrane localization affect POPDC complex formation while mutations which leave protein-protein interaction intact likely affect some other essential function of POPDC proteins.
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Affiliation(s)
- Alexander H. Swan
- grid.7445.20000 0001 2113 8111National Heart and Lung Institute (NHLI), Imperial College London, London, UK ,grid.7445.20000 0001 2113 8111Department of Chemistry, Imperial College London, London, UK
| | - Roland F. R. Schindler
- grid.7445.20000 0001 2113 8111National Heart and Lung Institute (NHLI), Imperial College London, London, UK ,grid.434240.5Present Address: Assay Biology, Domainex Ltd, Cambridge, CB10 1XL UK
| | - Marco Savarese
- grid.7737.40000 0004 0410 2071Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Isabelle Mayer
- grid.7445.20000 0001 2113 8111National Heart and Lung Institute (NHLI), Imperial College London, London, UK
| | - Susanne Rinné
- grid.10253.350000 0004 1936 9756Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Marburg, Germany
| | - Felix Bleser
- grid.10253.350000 0004 1936 9756Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Marburg, Germany
| | - Anne Schänzer
- grid.8664.c0000 0001 2165 8627Institute of Neuropathology, Justus Liebig University Giessen, Giessen, Germany
| | - Andreas Hahn
- grid.8664.c0000 0001 2165 8627Department of Child Neurology, Justus Liebig University Giessen, Giessen, Germany
| | - Mario Sabatelli
- grid.8142.f0000 0001 0941 3192Department of Neurology, Universitá Cattolica del Sacro Cuore, Rome, Italy
| | - Francesco Perna
- grid.414603.4Dipartimento Di Scienze Cardiovascolari, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Kathryn Chapman
- grid.434240.5Present Address: Assay Biology, Domainex Ltd, Cambridge, CB10 1XL UK
| | - Mark Pfuhl
- grid.13097.3c0000 0001 2322 6764School of Cardiovascular Medicine and Sciences and Randall Centre, King’s College London, London, UK
| | - Alan C. Spivey
- grid.7445.20000 0001 2113 8111Department of Chemistry, Imperial College London, London, UK
| | - Niels Decher
- grid.8664.c0000 0001 2165 8627Institute of Neuropathology, Justus Liebig University Giessen, Giessen, Germany
| | - Bjarne Udd
- grid.7737.40000 0004 0410 2071Folkhälsan Research Center, University of Helsinki, Helsinki, Finland
| | - Giorgio Tasca
- grid.414603.4Unità Operativa Complessa di Neurologia, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy ,grid.1006.70000 0001 0462 7212Present Address: John Walton Muscular Dystrophy Research Centre, Newcastle University and Newcastle Hospitals NHS Foundation Trusts, Newcastle Upon Tyne, UK
| | - Thomas Brand
- grid.7445.20000 0001 2113 8111National Heart and Lung Institute (NHLI), Imperial College London, London, UK ,Imperial Centre of Translational and Experimental Medicine, Du Cane Road, London, W120NN UK
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5
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Rinné S, Stallmeyer B, Pinggera A, Netter MF, Matschke LA, Dittmann S, Kirchhefer U, Neudorf U, Opp J, Striessnig J, Decher N, Schulze-Bahr E. Whole Exome Sequencing Identifies a Heterozygous Variant in the Cav1.3 Gene CACNA1D Associated with Familial Sinus Node Dysfunction and Focal Idiopathic Epilepsy. Int J Mol Sci 2022; 23:ijms232214215. [PMID: 36430690 PMCID: PMC9693521 DOI: 10.3390/ijms232214215] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 11/04/2022] [Accepted: 11/11/2022] [Indexed: 11/18/2022] Open
Abstract
Cav1.3 voltage-gated L-type calcium channels (LTCCs) are involved in cardiac pacemaking, hearing and hormone secretion, but are also expressed postsynaptically in neurons. So far, homozygous loss of function mutations in CACNA1D encoding the Cav1.3 α1-subunit are described in congenital sinus node dysfunction and deafness. In addition, germline mutations in CACNA1D have been linked to neurodevelopmental syndromes including epileptic seizures, autism, intellectual disability and primary hyperaldosteronism. Here, a three-generation family with a syndromal phenotype of sinus node dysfunction, idiopathic epilepsy and attention deficit hyperactivity disorder (ADHD) is investigated. Whole genome sequencing and functional heterologous expression studies were used to identify the disease-causing mechanisms in this novel syndromal disorder. We identified a heterozygous non-synonymous variant (p.Arg930His) in the CACNA1D gene that cosegregated with the combined clinical phenotype in an autosomal dominant manner. Functional heterologous expression studies showed that the CACNA1D variant induces isoform-specific alterations of Cav1.3 channel gating: a gain of ion channel function was observed in the brain-specific short CACNA1D isoform (Cav1.3S), whereas a loss of ion channel function was seen in the long (Cav1.3L) isoform. The combined gain-of-function (GOF) and loss-of-function (LOF) induced by the R930H variant are likely to be associated with the rare combined clinical and syndromal phenotypes in the family. The GOF in the Cav1.3S variant with high neuronal expression is likely to result in epilepsy, whereas the LOF in the long Cav1.3L variant results in sinus node dysfunction.
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Affiliation(s)
- Susanne Rinné
- Institute of Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, 35037 Marburg, Germany
| | - Birgit Stallmeyer
- Institute for Genetics of Heart Diseases (IfGH), University Hospital Muenster, 48149 Muenster, Germany
| | - Alexandra Pinggera
- Department of Pharmacology and Toxicology, Center for Molecular Biosciences, University of Innsbruck, 6020 Innsbruck, Austria
| | - Michael F. Netter
- Institute of Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, 35037 Marburg, Germany
| | - Lina A. Matschke
- Institute of Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, 35037 Marburg, Germany
| | - Sven Dittmann
- Institute for Genetics of Heart Diseases (IfGH), University Hospital Muenster, 48149 Muenster, Germany
| | - Uwe Kirchhefer
- Institute of Pharmacology and Toxicology, University Hospital Muenster, 48149 Muenster, Germany
| | - Ulrich Neudorf
- Zentrum für Kinder-und Jugendmedizin, Klinik für Kinderheilkunde III-Bereich Kardiologie, University Hospital Essen, 45147 Essen, Germany
| | - Joachim Opp
- Ev. Krankenhaus Oberhausen, 46047 Oberhausen, Germany
| | - Jörg Striessnig
- Department of Pharmacology and Toxicology, Center for Molecular Biosciences, University of Innsbruck, 6020 Innsbruck, Austria
| | - Niels Decher
- Institute of Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, 35037 Marburg, Germany
- Correspondence: (N.D.); (E.S.-B.); Tel.: +49-(0)6421/28-62148 (N.D.); +49-(0)251/83-55326 (E.S.-B.)
| | - Eric Schulze-Bahr
- Institute for Genetics of Heart Diseases (IfGH), University Hospital Muenster, 48149 Muenster, Germany
- Correspondence: (N.D.); (E.S.-B.); Tel.: +49-(0)6421/28-62148 (N.D.); +49-(0)251/83-55326 (E.S.-B.)
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6
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Arévalo B, Bedoya M, Kiper AK, Vergara F, Ramírez D, Mazola Y, Bustos D, Zúñiga R, Cikutovic R, Cayo A, Rinné S, Ramirez-Apan MT, Sepúlveda FV, Cerda O, López-Collazo E, Decher N, Zúñiga L, Gutierrez M, González W. Selective TASK-1 Inhibitor with a Defined Structure–Activity Relationship Reduces Cancer Cell Proliferation and Viability. J Med Chem 2022; 65:15014-15027. [DOI: 10.1021/acs.jmedchem.1c00378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Bárbara Arévalo
- Centro de Estudios en Alimentos Procesados−CEAP, Conicyt, Programa Regional R19A10001, Gore Maule, 3460000 Talca, Chile
| | - Mauricio Bedoya
- Centro de Investigación de Estudios Avanzados del Maule (CIEAM), Vicerrectoría de Investigación y Postgrado, Universidad Católica del Maule, 3460000 Talca, Chile
- Laboratorio de Bioinformática y Química Computacional, Departamento de Medicina Traslacional, Facultad de Medicina, Universidad Católica del Maule, 3480094 Talca, Chile
| | - Aytug K. Kiper
- Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Deutschhausstraße 1-2, 35037 Marburg, Germany
| | - Fernando Vergara
- Centro de Bioinformática, Simulación y Modelado (CBSM), Facultad de Ingeniería, Universidad de Talca, 1 Poniente No. 1141, 3460000 Talca, Chile
| | - David Ramírez
- Departamento de Farmacología, Facultad de Ciencias Biológicas, Universidad de Concepción, 4030000 Concepción, Chile
| | - Yuliet Mazola
- Centro de Bioinformática, Simulación y Modelado (CBSM), Facultad de Ingeniería, Universidad de Talca, 1 Poniente No. 1141, 3460000 Talca, Chile
| | - Daniel Bustos
- Centro de Investigación de Estudios Avanzados del Maule (CIEAM), Vicerrectoría de Investigación y Postgrado, Universidad Católica del Maule, 3460000 Talca, Chile
- Laboratorio de Bioinformática y Química Computacional (LBQC), Escuela de Química y Farmacia, Facultad de Medicina, Universidad Católica del Maule, 3460000 Talca, Chile
| | - Rafael Zúñiga
- Centro de Nanomedicina, Diagnóstico y Desarrollo de Fármacos (ND3), Laboratorio de Fisiología Molecular, Escuela de Medicina, Universidad de Talca, Casilla, 3460000 Talca, Chile
- Instituto de Investigación Interdisciplinaria, Vicerrectoría Académica, Universidad de Talca, 3460000 Talca, Chile
| | - Rocio Cikutovic
- Centro de Nanomedicina, Diagnóstico y Desarrollo de Fármacos (ND3), Laboratorio de Fisiología Molecular, Escuela de Medicina, Universidad de Talca, Casilla, 3460000 Talca, Chile
| | - Angel Cayo
- Centro de Nanomedicina, Diagnóstico y Desarrollo de Fármacos (ND3), Laboratorio de Fisiología Molecular, Escuela de Medicina, Universidad de Talca, Casilla, 3460000 Talca, Chile
| | - Susanne Rinné
- Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Deutschhausstraße 1-2, 35037 Marburg, Germany
| | - M. Teresa Ramirez-Apan
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, 04510, Coyoacán, 04510 México, DF, México
| | - Francisco V. Sepúlveda
- Centro de Estudios Científicos (CECs), 5110466 Valdivia, Chile
- Facultad de Medicina y Ciencia, Universidad San Sebastián, 5110466 Valdivia, Chile
| | - Oscar Cerda
- Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, 8380453 Santiago, Chile
- Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Facultad de Medicina, Universidad de Chile, 8380453 Santiago, Chile
| | - Eduardo López-Collazo
- The Innate Immune Response Group and Tumor Immunology Laboratory, IdiPAZ, La Paz University Hospital, 8046 Madrid, Spain
| | - Niels Decher
- Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Deutschhausstraße 1-2, 35037 Marburg, Germany
- Marburg Center for Mind, Brain and Behavior−MCMBB, Philipps-University Marburg, 35037 Marburg, Germany
| | - Leandro Zúñiga
- Centro de Nanomedicina, Diagnóstico y Desarrollo de Fármacos (ND3), Laboratorio de Fisiología Molecular, Escuela de Medicina, Universidad de Talca, Casilla, 3460000 Talca, Chile
| | - Margarita Gutierrez
- Laboratorio de Síntesis y Actividad Biológica, Instituto de Química de Recursos Naturales, Universidad de Talca, 1 poniente No. 1141, 3460000 Talca, Chile
| | - Wendy González
- Centro de Bioinformática, Simulación y Modelado (CBSM), Facultad de Ingeniería, Universidad de Talca, 1 Poniente No. 1141, 3460000 Talca, Chile
- Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Talca, 1 Poniente No. 1141, 3460000 Talca, Chile
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7
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Baldwin TA, Li Y, Marsden AN, Rinné S, Garza‐Carbajal A, Schindler RFR, Zhang M, Garcia MA, Venna VR, Decher N, Brand T, Dessauer CW. POPDC1 scaffolds a complex of adenylyl cyclase 9 and the potassium channel TREK-1 in heart. EMBO Rep 2022; 23:e55208. [PMID: 36254885 PMCID: PMC9724675 DOI: 10.15252/embr.202255208] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 09/23/2022] [Accepted: 09/29/2022] [Indexed: 11/05/2022] Open
Abstract
The establishment of macromolecular complexes by scaffolding proteins is key to the local production of cAMP by anchored adenylyl cyclase (AC) and the subsequent cAMP signaling necessary for cardiac functions. We identify a novel AC scaffold, the Popeye domain-containing (POPDC) protein. The POPDC family of proteins is important for cardiac pacemaking and conduction, due in part to their cAMP-dependent binding and regulation of TREK-1 potassium channels. We show that TREK-1 binds the AC9:POPDC1 complex and copurifies in a POPDC1-dependent manner with AC9 activity in heart. Although the AC9:POPDC1 interaction is cAMP-independent, TREK-1 association with AC9 and POPDC1 is reduced upon stimulation of the β-adrenergic receptor (βAR). AC9 activity is required for βAR reduction of TREK-1 complex formation with AC9:POPDC1 and in reversing POPDC1 enhancement of TREK-1 currents. Finally, deletion of the gene-encoding AC9 (Adcy9) gives rise to bradycardia at rest and stress-induced heart rate variability, a milder phenotype than the loss of Popdc1 but similar to the loss of Kcnk2 (TREK-1). Thus, POPDC1 represents a novel adaptor for AC9 interactions with TREK-1 to regulate heart rate control.
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Affiliation(s)
- Tanya A Baldwin
- Department Integrative Biology and PharmacologyMcGovern Medical School, University of Texas Health Science CenterHoustonTXUSA
| | - Yong Li
- Department Integrative Biology and PharmacologyMcGovern Medical School, University of Texas Health Science CenterHoustonTXUSA
| | - Autumn N Marsden
- Department Integrative Biology and PharmacologyMcGovern Medical School, University of Texas Health Science CenterHoustonTXUSA
| | - Susanne Rinné
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior MCMBBPhilipps‐University of MarburgMarburgGermany
| | - Anibal Garza‐Carbajal
- Department Integrative Biology and PharmacologyMcGovern Medical School, University of Texas Health Science CenterHoustonTXUSA
| | | | - Musi Zhang
- Department Integrative Biology and PharmacologyMcGovern Medical School, University of Texas Health Science CenterHoustonTXUSA
| | - Mia A Garcia
- Department Integrative Biology and PharmacologyMcGovern Medical School, University of Texas Health Science CenterHoustonTXUSA
| | - Venugopal Reddy Venna
- Department NeurologyMcGovern Medical School, University of Texas Health Science CenterHoustonTXUSA
| | - Niels Decher
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior MCMBBPhilipps‐University of MarburgMarburgGermany
| | - Thomas Brand
- National Heart and Lung Institute, Imperial College LondonLondonUK
| | - Carmen W Dessauer
- Department Integrative Biology and PharmacologyMcGovern Medical School, University of Texas Health Science CenterHoustonTXUSA
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8
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Kummer S, Rinné S, Seemann G, Bachmann N, Timothy K, Thornton PS, Pillekamp F, Mayatepek E, Bergmann C, Meissner T, Decher N. Hyperinsulinemic Hypoglycemia Associated with a CaV1.2 Variant with Mixed Gain- and Loss-of-Function Effects. Int J Mol Sci 2022; 23:ijms23158097. [PMID: 35897673 PMCID: PMC9332183 DOI: 10.3390/ijms23158097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 06/30/2022] [Revised: 07/18/2022] [Accepted: 07/19/2022] [Indexed: 11/16/2022] Open
Abstract
The voltage-dependent L-type calcium channel isoform CaV1.2 is critically involved in many physiological processes, e.g., in cardiac action potential formation, electromechanical coupling and regulation of insulin secretion by beta cells. Gain-of-function mutations in the calcium voltage-gated channel subunit alpha 1 C (CACNA1C) gene, encoding the CaV1.2 α1-subunit, cause Timothy syndrome (TS), a multisystemic disorder that includes autism spectrum disorders and long QT (LQT) syndrome. Strikingly, TS patients frequently suffer from hypoglycemia of yet unproven origin. Using next-generation sequencing, we identified a novel heterozygous CACNA1C mutation in a patient with congenital hyperinsulinism (CHI) and associated hypoglycemic episodes. We characterized the electrophysiological phenotype of the mutated channel using voltage-clamp recordings and in silico action potential modeling experiments. The identified CaV1.2L566P mutation causes a mixed electrophysiological phenotype of gain- and loss-of-function effects. In silico action potential modeling supports that this mixed electrophysiological phenotype leads to a tissue-specific impact on beta cells compared to cardiomyocytes. Thus, CACNA1C variants may be associated with non-syndromic hyperinsulinemic hypoglycemia without long-QT syndrome, explained by very specific electrophysiological properties of the mutated channel. We discuss different biochemical characteristics and clinical impacts of hypoglycemia in the context of CACNA1C variants and show that these may be associated with significant morbidity for Timothy Syndrome patients. Our findings underline that the potential of hypoglycemia warrants careful attention in patients with CACNA1C variants, and such variants should be included in the differential diagnosis of non-syndromic congenital hyperinsulinism.
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Affiliation(s)
- Sebastian Kummer
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, University Children’s Hospital, 40225 Duesseldorf, Germany; (F.P.); (E.M.); (T.M.)
- Correspondence: (S.K.); (N.D.); Tel.: +49-211-81-17001 (S.K.); +49-6421-2862148 (N.D.)
| | - Susanne Rinné
- Institute of Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, 35043 Marburg, Germany;
| | - Gunnar Seemann
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg—Bad Krozingen, Medical Center—University of Freiburg, 79085 Freiburg im Breisgau, Germany;
| | - Nadine Bachmann
- Medizinische Genetik Mainz, Limbach Genetics, 55128 Mainz, Germany; (N.B.); (C.B.)
| | - Katherine Timothy
- Children’s Hospital Boston, Harvard Medical School, Boston, MA 02115, USA;
| | - Paul S. Thornton
- Division of Endocrinology and Diabetes, Cook Children’s Medical Center, Fort Worth, TX 76104, USA;
| | - Frank Pillekamp
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, University Children’s Hospital, 40225 Duesseldorf, Germany; (F.P.); (E.M.); (T.M.)
| | - Ertan Mayatepek
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, University Children’s Hospital, 40225 Duesseldorf, Germany; (F.P.); (E.M.); (T.M.)
| | - Carsten Bergmann
- Medizinische Genetik Mainz, Limbach Genetics, 55128 Mainz, Germany; (N.B.); (C.B.)
| | - Thomas Meissner
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, University Children’s Hospital, 40225 Duesseldorf, Germany; (F.P.); (E.M.); (T.M.)
| | - Niels Decher
- Institute of Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, 35043 Marburg, Germany;
- Correspondence: (S.K.); (N.D.); Tel.: +49-211-81-17001 (S.K.); +49-6421-2862148 (N.D.)
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9
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Valdés-Jiménez A, Jiménez-González D, Kiper AK, Rinné S, Decher N, González W, Reyes-Parada M, Núñez-Vivanco G. A New Strategy for Multitarget Drug Discovery/Repositioning Through the Identification of Similar 3D Amino Acid Patterns Among Proteins Structures: The Case of Tafluprost and its Effects on Cardiac Ion Channels. Front Pharmacol 2022; 13:855792. [PMID: 35370665 PMCID: PMC8971525 DOI: 10.3389/fphar.2022.855792] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Accepted: 02/21/2022] [Indexed: 01/01/2023] Open
Abstract
The identification of similar three-dimensional (3D) amino acid patterns among different proteins might be helpful to explain the polypharmacological profile of many currently used drugs. Also, it would be a reasonable first step for the design of novel multitarget compounds. Most of the current computational tools employed for this aim are limited to the comparisons among known binding sites, and do not consider several additional important 3D patterns such as allosteric sites or other conserved motifs. In the present work, we introduce Geomfinder2.0, which is a new and improved version of our previously described algorithm for the deep exploration and discovery of similar and druggable 3D patterns. As compared with the original version, substantial improvements that have been incorporated to our software allow: (i) to compare quaternary structures, (ii) to deal with a list of pairs of structures, (iii) to know how druggable is the zone where similar 3D patterns are detected and (iv) to significantly reduce the execution time. Thus, the new algorithm achieves up to 353x speedup as compared to the previous sequential version, allowing the exploration of a significant number of quaternary structures in a reasonable time. In order to illustrate the potential of the updated Geomfinder version, we show a case of use in which similar 3D patterns were detected in the cardiac ions channels NaV1.5 and TASK-1. These channels are quite different in terms of structure, sequence and function and both have been regarded as important targets for drugs aimed at treating atrial fibrillation. Finally, we describe the in vitro effects of tafluprost (a drug currently used to treat glaucoma, which was identified as a novel putative ligand of NaV1.5 and TASK-1) upon both ion channels’ activity and discuss its possible repositioning as a novel antiarrhythmic drug.
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Affiliation(s)
- Alejandro Valdés-Jiménez
- Center for Bioinformatics, Simulations and Modelling, Faculty of Engineering, University of Talca, Talca, Chile
- Computer Architecture Department, Universitat Politécnica de Catalunya, Barcelona, Spain
| | - Daniel Jiménez-González
- Computer Architecture Department, Universitat Politécnica de Catalunya, Barcelona, Spain
- Barcelona Supercomputing Center, Barcelona, Spain
| | - Aytug K. Kiper
- Institute for Physiology and Pathophysiology, Philipps-University Marburg, Marburg, Germany
| | - Susanne Rinné
- Institute for Physiology and Pathophysiology, Philipps-University Marburg, Marburg, Germany
| | - Niels Decher
- Institute for Physiology and Pathophysiology, Philipps-University Marburg, Marburg, Germany
| | - Wendy González
- Center for Bioinformatics, Simulations and Modelling, Faculty of Engineering, University of Talca, Talca, Chile
- Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Talca, Talca, Chile
- *Correspondence: Wendy González, ; Miguel Reyes-Parada, ; Gabriel Núñez-Vivanco,
| | - Miguel Reyes-Parada
- Centro de Investigación Biomédica y Aplicada (CIBAP), Escuela de Medicina, Facultad de Ciencias Médicas, Universidad de Santiago de Chile, Santiago, Chile
- Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Talca, Chile
- *Correspondence: Wendy González, ; Miguel Reyes-Parada, ; Gabriel Núñez-Vivanco,
| | - Gabriel Núñez-Vivanco
- Departamento de Ciencias Naturales y Tecnología, Universidad de Aysén, Coyhaique, Chile
- *Correspondence: Wendy González, ; Miguel Reyes-Parada, ; Gabriel Núñez-Vivanco,
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10
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Matschke LA, Komadowski MA, Stöhr A, Lee B, Henrich MT, Griesbach M, Rinné S, Geibl FF, Chiu WH, Koprich JB, Brotchie JM, Kiper AK, Dolga AM, Oertel WH, Decher N. Enhanced firing of locus coeruleus neurons and SK channel dysfunction are conserved in distinct models of prodromal Parkinson's disease. Sci Rep 2022; 12:3180. [PMID: 35210472 PMCID: PMC8873463 DOI: 10.1038/s41598-022-06832-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 02/07/2022] [Indexed: 12/21/2022] Open
Abstract
Parkinson's disease (PD) is clinically defined by the presence of the cardinal motor symptoms, which are associated with a loss of dopaminergic nigrostriatal neurons in the substantia nigra pars compacta (SNpc). While SNpc neurons serve as the prototypical cell-type to study cellular vulnerability in PD, there is an unmet need to extent our efforts to other neurons at risk. The noradrenergic locus coeruleus (LC) represents one of the first brain structures affected in Parkinson's disease (PD) and plays not only a crucial role for the evolving non-motor symptomatology, but it is also believed to contribute to disease progression by efferent noradrenergic deficiency. Therefore, we sought to characterize the electrophysiological properties of LC neurons in two distinct PD models: (1) in an in vivo mouse model of focal α-synuclein overexpression; and (2) in an in vitro rotenone-induced PD model. Despite the fundamental differences of these two PD models, α-synuclein overexpression as well as rotenone exposure led to an accelerated autonomous pacemaker frequency of LC neurons, accompanied by severe alterations of the afterhyperpolarization amplitude. On the mechanistic side, we suggest that Ca2+-activated K+ (SK) channels are mediators of the increased LC neuronal excitability, as pharmacological activation of these channels is sufficient to prevent increased LC pacemaking and subsequent neuronal loss in the LC following in vitro rotenone exposure. These findings suggest a role of SK channels in PD by linking α-synuclein- and rotenone-induced changes in LC firing rate to SK channel dysfunction.
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Affiliation(s)
- Lina A Matschke
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior - MCMBB, Philipps-University Marburg, 35037, Marburg, Germany.,Clinic for Neurology, Philipps-University Marburg, 35043, Marburg, Germany
| | - Marlene A Komadowski
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior - MCMBB, Philipps-University Marburg, 35037, Marburg, Germany
| | - Annette Stöhr
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior - MCMBB, Philipps-University Marburg, 35037, Marburg, Germany
| | - Bolam Lee
- Clinic for Neurology, Philipps-University Marburg, 35043, Marburg, Germany
| | - Martin T Henrich
- Clinic for Neurology, Philipps-University Marburg, 35043, Marburg, Germany
| | - Markus Griesbach
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior - MCMBB, Philipps-University Marburg, 35037, Marburg, Germany
| | - Susanne Rinné
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior - MCMBB, Philipps-University Marburg, 35037, Marburg, Germany
| | - Fanni F Geibl
- Clinic for Neurology, Philipps-University Marburg, 35043, Marburg, Germany
| | - Wei-Hua Chiu
- Clinic for Neurology, Philipps-University Marburg, 35043, Marburg, Germany
| | - James B Koprich
- Krembil Research Institute, Toronto Western Hospital, University Health Network, 8KD402, Toronto, ON, M5T 2S8, Canada
| | - Jonathan M Brotchie
- Krembil Research Institute, Toronto Western Hospital, University Health Network, 8KD402, Toronto, ON, M5T 2S8, Canada
| | - Aytug K Kiper
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior - MCMBB, Philipps-University Marburg, 35037, Marburg, Germany
| | - Amalia M Dolga
- Faculty of Science and Engineering, Groningen Research Institute of Pharmacy, Department of Molecular Pharmacology, University of Groningen, 9713 AV, Groningen, The Netherlands
| | - Wolfgang H Oertel
- Clinic for Neurology, Philipps-University Marburg, 35043, Marburg, Germany.,Hertie Senior Research Professor of the Charitable Hertie Foundation, 60323, Frankfurt am Main, Germany
| | - Niels Decher
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior - MCMBB, Philipps-University Marburg, 35037, Marburg, Germany.
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11
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Vera Zambrano A, Rinné S, Baena-Nuevo M, Morales-Cano D, Barreira B, Decher N, Cogolludo A, Gonzalez Gallego T. Modulation of Kv1.5 channel expression and function by the sigma 1 receptor. Biophys J 2022. [DOI: 10.1016/j.bpj.2021.11.814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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12
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Ramírez D, Mejia-Gutierrez M, Insuasty B, Rinné S, Kiper AK, Platzk M, Müller T, Decher N, Quiroga J, De-la-Torre P, González W. 5-(Indol-2-yl)pyrazolo[3,4- b]pyridines as a New Family of TASK-3 Channel Blockers: A Pharmacophore-Based Regioselective Synthesis. Molecules 2021; 26:molecules26133897. [PMID: 34202296 PMCID: PMC8271858 DOI: 10.3390/molecules26133897] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 06/16/2021] [Accepted: 06/18/2021] [Indexed: 11/16/2022] Open
Abstract
TASK channels belong to the two-pore-domain potassium (K2P) channels subfamily. These channels modulate cellular excitability, input resistance, and response to synaptic stimulation. TASK-channel inhibition led to membrane depolarization. TASK-3 is expressed in different cancer cell types and neurons. Thus, the discovery of novel TASK-3 inhibitors makes these bioactive compounds very appealing to explore new cancer and neurological therapies. TASK-3 channel blockers are very limited to date, and only a few heterofused compounds have been reported in the literature. In this article, we combined a pharmacophore hypothesis with molecular docking to address for the first time the rational design, synthesis, and evaluation of 5-(indol-2-yl)pyrazolo[3,4-b]pyridines as a novel family of human TASK-3 channel blockers. Representative compounds of the synthesized library were assessed against TASK-3 using Fluorometric imaging plate reader-Membrane Potential assay (FMP). Inhibitory properties were validated using two-electrode voltage-clamp (TEVC) methods. We identified one active hit compound (MM-3b) with our systematic pipeline, exhibiting an IC50 ≈ 30 μM. Molecular docking models suggest that compound MM-3b binds to TASK-3 at the bottom of the selectivity filter in the central cavity, similar to other described TASK-3 blockers such as A1899 and PK-THPP. Our in silico and experimental studies provide a new tool to predict and design novel TASK-3 channel blockers.
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Affiliation(s)
- David Ramírez
- Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Llano Subercaseaux 2801-Piso 5, Santiago 8900000, Chile
- Correspondence: (D.R.); (P.D.-l.-T.); (W.G.)
| | - Melissa Mejia-Gutierrez
- Heterocyclic Compounds Research Group, Department of Chemistry, Universidad del Valle, A.A, Cali 760031, Colombia; (M.M.-G.); (B.I.); (J.Q.)
| | - Braulio Insuasty
- Heterocyclic Compounds Research Group, Department of Chemistry, Universidad del Valle, A.A, Cali 760031, Colombia; (M.M.-G.); (B.I.); (J.Q.)
| | - Susanne Rinné
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Center for Mind, Brain and Behavior (CMBB), Philipps-University of Marburg, Deutschhausstraße 2, 35037 Marburg, Germany; (S.R.); (A.K.K.); (N.D.)
| | - Aytug K. Kiper
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Center for Mind, Brain and Behavior (CMBB), Philipps-University of Marburg, Deutschhausstraße 2, 35037 Marburg, Germany; (S.R.); (A.K.K.); (N.D.)
| | - Magdalena Platzk
- Joint Pulmonary Drug Discovery Lab Bayer-MGH, Boston, MA 02114, USA;
| | - Thomas Müller
- Bayer AG, Research & Development, Pharmaceuticals, D-42096 Wuppertal, Germany;
| | - Niels Decher
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Center for Mind, Brain and Behavior (CMBB), Philipps-University of Marburg, Deutschhausstraße 2, 35037 Marburg, Germany; (S.R.); (A.K.K.); (N.D.)
| | - Jairo Quiroga
- Heterocyclic Compounds Research Group, Department of Chemistry, Universidad del Valle, A.A, Cali 760031, Colombia; (M.M.-G.); (B.I.); (J.Q.)
| | - Pedro De-la-Torre
- Department of Otolaryngology, Harvard Medical School and Massachusetts Eye and Ear, 243 Charles St, Boston, MA 02114, USA
- Caribe Therapeutics, Vía 40 No. 69-111, Oficina 804 A, Barranquilla 080002, Colombia
- Correspondence: (D.R.); (P.D.-l.-T.); (W.G.)
| | - Wendy González
- Centro de Bioinformática, Simulación y Modelado (CBSM), Facultad de Ingeniería, Universidad de Talca, Poniente No. 1141, Talca 3460000, Chile
- Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Talca, Talca 3460000, Chile
- Correspondence: (D.R.); (P.D.-l.-T.); (W.G.)
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13
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Wiedmann F, Beyersdorf C, Zhou XB, Kraft M, Paasche A, Jávorszky N, Rinné S, Sutanto H, Büscher A, Foerster KI, Blank A, El-Battrawy I, Li X, Lang S, Tochtermann U, Kremer J, Arif R, Karck M, Decher N, van Loon G, Akin I, Borggrefe M, Kallenberger S, Heijman J, Haefeli WE, Katus HA, Schmidt C. Treatment of atrial fibrillation with doxapram: TASK-1 potassium channel inhibition as a novel pharmacological strategy. Cardiovasc Res 2021; 118:1728-1741. [PMID: 34028533 DOI: 10.1093/cvr/cvab177] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Indexed: 12/20/2022] Open
Abstract
AIMS TASK-1 (K2P3.1) two-pore domain potassium channels are atrial-specific and significantly upregulated in atrial fibrillation (AF) patients, contributing to AF-related electrical remodelling. Inhibition of TASK-1 in cardiomyocytes of AF patients was shown to counteract AF-related action potential duration shortening. Doxapram was identified as a potent inhibitor of the TASK-1 channel. In the present study, we investigated the antiarrhythmic efficacy of doxapram in a porcine model of AF. METHODS AND RESULTS Doxapram successfully cardioverted pigs with artificially induced episodes of AF. We established a porcine model of persistent AF in domestic pigs via intermittent atrial burst stimulation using implanted pacemakers. All pigs underwent catheter-based electrophysiological investigations prior to and after 14 d of doxapram treatment. Pigs in the treatment group received intravenous administration of doxapram once per day. In doxapram-treated AF pigs, the AF burden was significantly reduced. After 14 d of treatment with doxapram, TASK-1 currents were still similar to values of sinus rhythm animals. Doxapram significantly suppressed AF episodes and normalized cellular electrophysiology by inhibition of the TASK-1 channel. Patch-clamp experiments on human atrial cardiomyocytes, isolated from patients with and without AF could reproduce the TASK-1 inhibitory effect of doxapram. CONCLUSIONS Repurposing doxapram might yield a promising new antiarrhythmic drug to treat AF in patients. TRANSLATIONAL PERSPECTIVE Pharmacological suppression of atrial TASK 1 potassium currents prolongs atrial refractoriness with no effects on ventricular repolarization, resulting in atrial-specific class III antiarrhythmic effects. In our preclinical pilot study the respiratory stimulant doxapram was successfully administered for cardioversion of acute AF as well as rhythm control of persistent AF in a clinically relevant porcine animal model.
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Affiliation(s)
- Felix Wiedmann
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany.,HCR, Heidelberg Center for Heart Rhythm Disorders, University of Heidelberg, Heidelberg, Germany
| | - Christoph Beyersdorf
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany.,HCR, Heidelberg Center for Heart Rhythm Disorders, University of Heidelberg, Heidelberg, Germany
| | - Xiao-Bo Zhou
- DZHK (German Center for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany.,First Department of Medicine, University Medical Center Mannheim, Mannheim, Germany
| | - Manuel Kraft
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany.,HCR, Heidelberg Center for Heart Rhythm Disorders, University of Heidelberg, Heidelberg, Germany
| | - Amelie Paasche
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany.,HCR, Heidelberg Center for Heart Rhythm Disorders, University of Heidelberg, Heidelberg, Germany
| | - Natasa Jávorszky
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany.,HCR, Heidelberg Center for Heart Rhythm Disorders, University of Heidelberg, Heidelberg, Germany
| | - Susanne Rinné
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior MCMBB, University of Marburg, Marburg, Germany
| | - Henry Sutanto
- Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Antonius Büscher
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany.,HCR, Heidelberg Center for Heart Rhythm Disorders, University of Heidelberg, Heidelberg, Germany
| | - Kathrin I Foerster
- Department of Clinical Pharmacology and Pharmacoepidemiology, University Hospital Heidelberg, Heidelberg, Germany
| | - Antje Blank
- Department of Clinical Pharmacology and Pharmacoepidemiology, University Hospital Heidelberg, Heidelberg, Germany
| | - Ibrahim El-Battrawy
- DZHK (German Center for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany.,First Department of Medicine, University Medical Center Mannheim, Mannheim, Germany
| | - Xin Li
- First Department of Medicine, University Medical Center Mannheim, Mannheim, Germany
| | - Siegfried Lang
- DZHK (German Center for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany.,First Department of Medicine, University Medical Center Mannheim, Mannheim, Germany
| | - Ursula Tochtermann
- Department of Cardiac Surgery, University Hospital Heidelberg, Heidelberg, Germany
| | - Jamila Kremer
- Department of Cardiac Surgery, University Hospital Heidelberg, Heidelberg, Germany
| | - Rawa Arif
- Department of Cardiac Surgery, University Hospital Heidelberg, Heidelberg, Germany
| | - Matthias Karck
- Department of Cardiac Surgery, University Hospital Heidelberg, Heidelberg, Germany
| | - Niels Decher
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior MCMBB, University of Marburg, Marburg, Germany
| | - Gunther van Loon
- Department of Large Animal Internal Medicine, Equine Cardioteam, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Ibrahim Akin
- DZHK (German Center for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany.,First Department of Medicine, University Medical Center Mannheim, Mannheim, Germany
| | - Martin Borggrefe
- DZHK (German Center for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany.,First Department of Medicine, University Medical Center Mannheim, Mannheim, Germany
| | - Stefan Kallenberger
- Digital Health Center, Berlin Institute of Health (BIH) and Charité, Berlin, Germany and Health Data Science Unit, University Hospital Heidelberg, Heidelberg, Germany
| | - Jordi Heijman
- Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Walter E Haefeli
- Department of Clinical Pharmacology and Pharmacoepidemiology, University Hospital Heidelberg, Heidelberg, Germany
| | - Hugo A Katus
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany.,HCR, Heidelberg Center for Heart Rhythm Disorders, University of Heidelberg, Heidelberg, Germany
| | - Constanze Schmidt
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany.,HCR, Heidelberg Center for Heart Rhythm Disorders, University of Heidelberg, Heidelberg, Germany
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14
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Kiper AK, Bedoya M, Stalke S, Marzian S, Ramírez D, de la Cruz A, Peraza DA, Vera-Zambrano A, Márquez Montesinos JCE, Arévalo Ramos BA, Rinné S, Gonzalez T, Valenzuela C, Gonzalez W, Decher N. Identification of a critical binding site for local anaesthetics in the side pockets of K v 1 channels. Br J Pharmacol 2021; 178:3034-3048. [PMID: 33817777 DOI: 10.1111/bph.15480] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 02/24/2021] [Accepted: 03/10/2021] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND AND PURPOSE Local anaesthetics block sodium and a variety of potassium channels. Although previous studies identified a residue in the pore signature sequence together with three residues in the S6 segment as a putative binding site, the precise molecular basis of inhibition of Kv channels by local anaesthetics remained unknown. Crystal structures of Kv channels predict that some of these residues point away from the central cavity and face into a drug binding site called side pockets. Thus, the question arises whether the binding site of local anaesthetics is exclusively located in the central cavity or also involves the side pockets. EXPERIMENTAL APPROACH A systematic functional alanine mutagenesis approach, scanning 58 mutants, together with in silico docking experiments and molecular dynamics simulations was utilized to elucidate the binding site of bupivacaine and ropivacaine. KEY RESULTS Inhibition of Kv 1.5 channels by local anaesthetics requires binding to the central cavity and the side pockets, and the latter requires interactions with residues of the S5 and the back of the S6 segments. Mutations in the side pockets remove stereoselectivity of inhibition of Kv 1.5 channels by bupivacaine. Although binding to the side pockets is conserved for different local anaesthetics, the binding mode in the central cavity and the side pockets shows considerable variations. CONCLUSION AND IMPLICATIONS Local anaesthetics bind to the central cavity and the side pockets, which provide a crucial key to the molecular understanding of their Kv channel affinity and stereoselectivity, as well as their spectrum of side effects.
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Affiliation(s)
- Aytug K Kiper
- Institute for Physiology and Pathophysiology, Philipps-University Marburg, Marburg, Germany
| | - Mauricio Bedoya
- Centro de Bioinformática y Simulación Molecular, Universidad de Talca, Talca, Chile.,Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Talca, Talca, Chile
| | - Sarah Stalke
- Institute for Physiology and Pathophysiology, Philipps-University Marburg, Marburg, Germany
| | - Stefanie Marzian
- Institute for Physiology and Pathophysiology, Philipps-University Marburg, Marburg, Germany
| | - David Ramírez
- Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago, Chile
| | - Alicia de la Cruz
- Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas (CSIC) and Universidad Autónoma de Madrid (UAM), Madrid, Spain.,Spanish Network for Biomedical Research in Cardiovascular Research (CIBERCV), Instituto de Salud Carlos III, Madrid, Spain
| | - Diego A Peraza
- Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas (CSIC) and Universidad Autónoma de Madrid (UAM), Madrid, Spain.,Spanish Network for Biomedical Research in Cardiovascular Research (CIBERCV), Instituto de Salud Carlos III, Madrid, Spain
| | - Alba Vera-Zambrano
- Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas (CSIC) and Universidad Autónoma de Madrid (UAM), Madrid, Spain.,Spanish Network for Biomedical Research in Cardiovascular Research (CIBERCV), Instituto de Salud Carlos III, Madrid, Spain.,Biochemistry Department, School of Medicine, Universidad Autónoma de Madrid, Madrid, Spain
| | | | | | - Susanne Rinné
- Institute for Physiology and Pathophysiology, Philipps-University Marburg, Marburg, Germany
| | - Teresa Gonzalez
- Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas (CSIC) and Universidad Autónoma de Madrid (UAM), Madrid, Spain.,Spanish Network for Biomedical Research in Cardiovascular Research (CIBERCV), Instituto de Salud Carlos III, Madrid, Spain.,Biochemistry Department, School of Medicine, Universidad Autónoma de Madrid, Madrid, Spain
| | - Carmen Valenzuela
- Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas (CSIC) and Universidad Autónoma de Madrid (UAM), Madrid, Spain.,Spanish Network for Biomedical Research in Cardiovascular Research (CIBERCV), Instituto de Salud Carlos III, Madrid, Spain
| | - Wendy Gonzalez
- Centro de Bioinformática y Simulación Molecular, Universidad de Talca, Talca, Chile.,Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Talca, Talca, Chile
| | - Niels Decher
- Institute for Physiology and Pathophysiology, Philipps-University Marburg, Marburg, Germany
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15
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Schewe M, Riel EB, Rinné S, Kopec W, Langer J, Lindemann P, Jürs BC, Nazaré M, Groot BLD, Decher N, Baukrowitz T. Structural Basis for Gating of the Two-Pore Domain K+ (K2P) Channels TASK-1 and TALK-2. Biophys J 2021. [DOI: 10.1016/j.bpj.2020.11.1850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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16
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Endres D, Decher N, Röhr I, Vowinkel K, Domschke K, Komlosi K, Tzschach A, Gläser B, Schiele MA, Runge K, Süß P, Schuchardt F, Nickel K, Stallmeyer B, Rinné S, Schulze-Bahr E, Tebartz van Elst L. New Cav1.2 Channelopathy with High-Functioning Autism, Affective Disorder, Severe Dental Enamel Defects, a Short QT Interval, and a Novel CACNA1C Loss-Of-Function Mutation. Int J Mol Sci 2020; 21:ijms21228611. [PMID: 33203140 PMCID: PMC7696251 DOI: 10.3390/ijms21228611] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 11/04/2020] [Accepted: 11/07/2020] [Indexed: 12/12/2022] Open
Abstract
Complex neuropsychiatric-cardiac syndromes can be genetically determined. For the first time, the authors present a syndromal form of short QT syndrome in a 34-year-old German male patient with extracardiac features with predominant psychiatric manifestation, namely a severe form of secondary high-functioning autism spectrum disorder (ASD), along with affective and psychotic exacerbations, and severe dental enamel defects (with rapid wearing off his teeth) due to a heterozygous loss-of-function mutation in the CACNA1C gene (NM_000719.6: c.2399A > C; p.Lys800Thr). This mutation was found only once in control databases; the mutated lysine is located in the Cav1.2 calcium channel, is highly conserved during evolution, and is predicted to affect protein function by most pathogenicity prediction algorithms. L-type Cav1.2 calcium channels are widely expressed in the brain and heart. In the case presented, electrophysiological studies revealed a prominent reduction in the current amplitude without changes in the gating behavior of the Cav1.2 channel, most likely due to a trafficking defect. Due to the demonstrated loss of function, the p.Lys800Thr variant was finally classified as pathogenic (ACMG class 4 variant) and is likely to cause a newly described Cav1.2 channelopathy.
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Affiliation(s)
- Dominique Endres
- Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (K.R.); (K.N.); (L.T.v.E.)
- Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (K.D.); (M.A.S.)
- Correspondence: ; Tel.: +49-761-270-66360
| | - Niels Decher
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior-Philipps-University Marburg, 35037 Marburg, Germany; (N.D.); (I.R.); (K.V.); (S.R.)
| | - Isabell Röhr
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior-Philipps-University Marburg, 35037 Marburg, Germany; (N.D.); (I.R.); (K.V.); (S.R.)
| | - Kirsty Vowinkel
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior-Philipps-University Marburg, 35037 Marburg, Germany; (N.D.); (I.R.); (K.V.); (S.R.)
| | - Katharina Domschke
- Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (K.D.); (M.A.S.)
- Center for Basics in Neuromodulation, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Katalin Komlosi
- Institute of Human Genetics, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany; (K.K.); (A.T.); (B.G.)
| | - Andreas Tzschach
- Institute of Human Genetics, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany; (K.K.); (A.T.); (B.G.)
| | - Birgitta Gläser
- Institute of Human Genetics, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany; (K.K.); (A.T.); (B.G.)
| | - Miriam A. Schiele
- Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (K.D.); (M.A.S.)
| | - Kimon Runge
- Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (K.R.); (K.N.); (L.T.v.E.)
- Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (K.D.); (M.A.S.)
| | - Patrick Süß
- Department of Molecular Neurology, University Hospital Erlangen, 91054 Erlangen, Germany;
| | - Florian Schuchardt
- Department of Neurology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany;
| | - Kathrin Nickel
- Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (K.R.); (K.N.); (L.T.v.E.)
- Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (K.D.); (M.A.S.)
| | - Birgit Stallmeyer
- Institute for Genetics of Heart Diseases, Department of Cardiovascular Medicine, University Hospital Münster, 48149 Münster, Germany; (B.S.); (E.S.-B.)
| | - Susanne Rinné
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior-Philipps-University Marburg, 35037 Marburg, Germany; (N.D.); (I.R.); (K.V.); (S.R.)
| | - Eric Schulze-Bahr
- Institute for Genetics of Heart Diseases, Department of Cardiovascular Medicine, University Hospital Münster, 48149 Münster, Germany; (B.S.); (E.S.-B.)
| | - Ludger Tebartz van Elst
- Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (K.R.); (K.N.); (L.T.v.E.)
- Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (K.D.); (M.A.S.)
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17
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Wiedmann F, Rinné S, Donner B, Decher N, Katus HA, Schmidt C. Mechanosensitive TREK-1 two-pore-domain potassium (K 2P) channels in the cardiovascular system. Prog Biophys Mol Biol 2020; 159:126-135. [PMID: 32553901 DOI: 10.1016/j.pbiomolbio.2020.05.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 04/01/2020] [Accepted: 05/11/2020] [Indexed: 12/12/2022]
Abstract
TWIK-related K+ channel (TREK-1) two-pore-domain potassium (K2P) channels mediate background potassium currents and regulate cellular excitability in many different types of cells. Their functional activity is controlled by a broad variety of different physiological stimuli, such as temperature, extracellular or intracellular pH, lipids and mechanical stress. By linking cellular excitability to mechanical stress, TREK-1 currents might be important to mediate parts of the mechanoelectrical feedback described in the heart. Furthermore, TREK-1 currents might contribute to the dysregulation of excitability in the heart in pathophysiological situations, such as those caused by abnormal stretch or ischaemia-associated cell swelling, thereby contributing to arrhythmogenesis. In this review, we focus on the functional role of TREK-1 in the heart and its putative contribution to cardiac mechanoelectrical coupling. Its cardiac expression among different species is discussed, alongside with functional evidence for TREK-1 currents in cardiomyocytes. In addition, evidence for the involvement of TREK-1 currents in different cardiac arrhythmias, such as atrial fibrillation or ventricular tachycardia, is summarized. Furthermore, the role of TREK-1 and its interaction partners in the regulation of the cardiac heart rate is reviewed. Finally, we focus on the significance of TREK-1 in the development of cardiac hypertrophy, cardiac fibrosis and heart failure.
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Affiliation(s)
- Felix Wiedmann
- Department of Cardiology, University Hospital Heidelberg, Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany; HCR, Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Heidelberg, Germany
| | - Susanne Rinné
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior - Philipps-University Marburg, Marburg, Germany
| | - Birgit Donner
- Pediatric Cardiology, University Children's Hospital Basel (UKBB), University of Basel, Basel, Switzerland
| | - Niels Decher
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior - Philipps-University Marburg, Marburg, Germany
| | - Hugo A Katus
- Department of Cardiology, University Hospital Heidelberg, Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany; HCR, Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Heidelberg, Germany
| | - Constanze Schmidt
- Department of Cardiology, University Hospital Heidelberg, Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany; HCR, Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Heidelberg, Germany.
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18
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Kuß J, Stallmeyer B, Goldstein M, Rinné S, Pees C, Zumhagen S, Seebohm G, Decher N, Pott L, Kienitz MC, Schulze-Bahr E. Familial Sinus Node Disease Caused by a Gain of GIRK (G-Protein Activated Inwardly Rectifying K + Channel) Channel Function. Circ Genom Precis Med 2020; 12:e002238. [PMID: 30645171 DOI: 10.1161/circgen.118.002238] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Inherited forms of sinus node dysfunction (SND) clinically include bradycardia, sinus arrest, and chronotropic incompetence and may serve as disease models to understand sinus node physiology and impulse generation. Recently, a gain-of-function mutation in the G-protein gene GNB2 led to enhanced activation of the GIRK (G-protein activated inwardly rectifying K+ channel). Thus, human cardiac GIRK channels are important for heart rate regulation and subsequently, genes encoding their subunits Kir3.1 and Kir3.4 ( KCNJ3 and KCNJ5) are potential candidates for inherited SND in human. METHODS We performed a combined approach of targeted sequencing of KCNJ3 and KCNJ5 in 52 patients with idiopathic SND and subsequent whole exome sequencing of additional family members in a genetically affected patient. A putative novel disease-associated gene variant was functionally analyzed by voltage-clamp experiments using various heterologous cell expression systems (Xenopus oocytes, CHO cells, and rat atrial cardiomyocytes). RESULTS In a 3-generation family with SND we identified a novel variant in KCNJ5 which leads to an amino acid substitution (p.Trp101Cys) in the first transmembrane domain of the Kir3.4 subunit of the cardiac GIRK channel. The identified variant cosegregated with the disease in the family and was absent in the Exome Variant Server and Exome Aggregation Consortium databases. Expression of mutant Kir3.4 (±native Kir3.1) in different heterologous cell expression systems resulted in increased GIRK currents ( IK,ACh) and a reduced inward rectification which was not compensated by intracellular spermidine. Moreover, in silico modeling of heterotetrameric mutant GIRK channels indicates a structurally altered binding site for spermine. CONCLUSIONS For the first time, an inherited gain-of-function mutation in the human GIRK3.4 causes familial human SND. The increased activity of GIRK channels is likely to lead to a sustained hyperpolarization of pacemaker cells and thereby reduces heart rate. Modulation of human GIRK channels may pave a way for further treatment of cardiac pacemaking.
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Affiliation(s)
- Johanna Kuß
- Department of Cardiovascular Medicine, Institute for Genetics of Heart Diseases (IfGH), University Hospital Münster, Germany (J.K., B.S., S.Z., G.S., E.S.-B.)
| | - Birgit Stallmeyer
- Department of Cardiovascular Medicine, Institute for Genetics of Heart Diseases (IfGH), University Hospital Münster, Germany (J.K., B.S., S.Z., G.S., E.S.-B.)
| | - Matthias Goldstein
- Institute of Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, Germany (M.G., S.R., N.D.)
| | - Susanne Rinné
- Institute of Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, Germany (M.G., S.R., N.D.)
| | - Christiane Pees
- Department of Pediatric Cardiology, University Children's Hospital Vienna, Austria (C.P.)
| | - Sven Zumhagen
- Department of Cardiovascular Medicine, Institute for Genetics of Heart Diseases (IfGH), University Hospital Münster, Germany (J.K., B.S., S.Z., G.S., E.S.-B.)
| | - Guiscard Seebohm
- Department of Cardiovascular Medicine, Institute for Genetics of Heart Diseases (IfGH), University Hospital Münster, Germany (J.K., B.S., S.Z., G.S., E.S.-B.)
| | - Niels Decher
- Institute of Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, Germany (M.G., S.R., N.D.)
| | - Lutz Pott
- Department of Cardiovascular Medicine, Institute of Physiology, Ruhr-University Bochum, Germany (L.P., M.-C.K.)
| | - Marie-Cécile Kienitz
- Department of Cardiovascular Medicine, Institute of Physiology, Ruhr-University Bochum, Germany (L.P., M.-C.K.)
| | - Eric Schulze-Bahr
- Department of Cardiovascular Medicine, Institute for Genetics of Heart Diseases (IfGH), University Hospital Münster, Germany (J.K., B.S., S.Z., G.S., E.S.-B.)
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19
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Vissing J, Johnson K, Töpf A, Nafissi S, Díaz-Manera J, French VM, Schindler RF, Sarathchandra P, Løkken N, Rinné S, Freund M, Decher N, Müller T, Duno M, Krag T, Brand T, Straub V. POPDC3 Gene Variants Associate with a New Form of Limb Girdle Muscular Dystrophy. Ann Neurol 2019; 86:832-843. [PMID: 31610034 DOI: 10.1002/ana.25620] [Citation(s) in RCA: 20] [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] [Received: 08/16/2018] [Revised: 10/07/2019] [Accepted: 10/07/2019] [Indexed: 12/26/2022]
Abstract
OBJECTIVE The Popeye domain containing 3 (POPDC3) gene encodes a membrane protein involved in cyclic adenosine monophosphate (cAMP) signaling. Besides gastric cancer, no disease association has been described. We describe a new muscular dystrophy associated with this gene. METHODS We screened 1,500 patients with unclassified limb girdle weakness or hyperCKemia for pathogenic POPDC3 variants. Five patients carrying POPDC3 variants were examined by muscle magnetic resonance imaging (MRI), muscle biopsy, and cardiac examination. We performed functional analyses in a zebrafish popdc3 knockdown model and heterologous expression of the mutant proteins in Xenopus laevis oocytes to measure TREK-1 current. RESULTS We identified homozygous POPDC3 missense variants (p.Leu155His, p.Leu217Phe, and p.Arg261Gln) in 5 patients from 3 ethnically distinct families. Variants affected highly conserved residues in the Popeye (p.Leu155 and p.Leu217) and carboxy-terminal (p.Arg261) domains. The variants were almost absent from control populations. Probands' muscle biopsies were dystrophic, and serum creatine kinase levels were 1,050 to 9,200U/l. Muscle weakness was proximal with adulthood onset in most patients and affected lower earlier than upper limbs. Muscle MRI revealed fat replacement of paraspinal and proximal leg muscles; cardiac investigations were unremarkable. Knockdown of popdc3 in zebrafish, using 2 different splice-site blocking morpholinos, resulted in larvae with tail curling and dystrophic muscle features. All 3 mutants cloned in Xenopus oocytes caused an aberrant modulation of the mechano-gated potassium channel, TREK-1. INTERPRETATION Our findings point to an important role of POPDC3 for skeletal muscle function and suggest that pathogenic variants in POPDC3 are responsible for a novel type of autosomal recessive limb girdle muscular dystrophy. ANN NEUROL 2019;86:832-843.
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Affiliation(s)
- John Vissing
- Copenhagen Neuromuscular Center, Rigshospitalet, University of Copenhagen, Denmark
| | - Katherine Johnson
- John Walton Muscular Dystrophy Research Centre, Institute of Genetic Medicine, Newcastle University and Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne, United Kingdom
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Ana Töpf
- John Walton Muscular Dystrophy Research Centre, Institute of Genetic Medicine, Newcastle University and Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - Shahriar Nafissi
- Department of Neurology, Iranian Center of Neurological Research, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Jordi Díaz-Manera
- Unitat de Malalties Neuromusculars, Servei de Neurologia, Hospital de la Santa Creu i Sant Pau de Barcelona and CIBERER, Madrid, Spain
| | - Vanessa M French
- Developmental Dynamics, Myocardial Function, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Roland F Schindler
- Developmental Dynamics, Myocardial Function, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Padmini Sarathchandra
- Heart Science Centre, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Nicoline Løkken
- Copenhagen Neuromuscular Center, Rigshospitalet, University of Copenhagen, Denmark
| | - Susanne Rinné
- Institute for Physiology and Pathophysiology, AG Vegetative Physiology, Philipps-University of Marburg, Marburg, Germany
| | - Max Freund
- Institute for Physiology and Pathophysiology, AG Vegetative Physiology, Philipps-University of Marburg, Marburg, Germany
| | - Niels Decher
- Institute for Physiology and Pathophysiology, AG Vegetative Physiology, Philipps-University of Marburg, Marburg, Germany
| | - Thomas Müller
- Institute for Molecular Plant Physiology and Biophysics, Julius-von-Sachs Platz 2, 97082, Würzburg, Germany
| | - Morten Duno
- Department of Clinical Genetics, Rigshospitalet, University of Copenhagen, Denmark
| | - Thomas Krag
- Copenhagen Neuromuscular Center, Rigshospitalet, University of Copenhagen, Denmark
| | - Thomas Brand
- Developmental Dynamics, Myocardial Function, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Volker Straub
- John Walton Muscular Dystrophy Research Centre, Institute of Genetic Medicine, Newcastle University and Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne, United Kingdom
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
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20
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Abstract
Rational drug design targeting ion channels is an exciting and always evolving research field. New medicinal chemistry strategies are being implemented to explore the wild chemical space and unravel the molecular basis of the ion channels modulators binding mechanisms. TASK channels belong to the two-pore domain potassium channel family and are modulated by extracellular acidosis. They are extensively distributed along the cardiovascular and central nervous systems, and their expression is up- and downregulated in different cancer types, which makes them an attractive therapeutic target. However, TASK channels remain unexplored, and drugs designed to target these channels are poorly selective. Here, we review TASK channels properties and their known blockers and activators, considering the new challenges in ion channels drug design and focusing on the implementation of computational methodologies in the drug discovery process.
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Affiliation(s)
- Mauricio Bedoya
- Centro de Bioinformática y Simulación Molecular (CBSM) , Universidad de Talca , 1 Poniente No. 1141 , 3460000 Talca , Chile
| | - Susanne Rinné
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior, MCMBB , Philipps-University of Marburg , Deutschhausstraße 2 , Marburg 35037 , Germany
| | - Aytug K Kiper
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior, MCMBB , Philipps-University of Marburg , Deutschhausstraße 2 , Marburg 35037 , Germany
| | - Niels Decher
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior, MCMBB , Philipps-University of Marburg , Deutschhausstraße 2 , Marburg 35037 , Germany
| | - Wendy González
- Centro de Bioinformática y Simulación Molecular (CBSM) , Universidad de Talca , 1 Poniente No. 1141 , 3460000 Talca , Chile.,Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD) , Universidad de Talca , 1 Poniente No. 1141 , 3460000 Talca , Chile
| | - David Ramírez
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud , Universidad Autónoma de Chile , El Llano Subercaseaux 2801, Piso 6 , 8900000 Santiago , Chile
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21
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Ramírez D, Bedoya M, Kiper AK, Rinné S, Morales-Navarro S, Hernández-Rodríguez EW, Sepúlveda FV, Decher N, González W. Structure/Activity Analysis of TASK-3 Channel Antagonists Based on a 5,6,7,8 tetrahydropyrido[4,3-d]pyrimidine. Int J Mol Sci 2019; 20:ijms20092252. [PMID: 31067753 PMCID: PMC6539479 DOI: 10.3390/ijms20092252] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 04/18/2019] [Accepted: 04/20/2019] [Indexed: 11/16/2022] Open
Abstract
TASK-3 potassium (K+) channels are highly expressed in the central nervous system, regulating the membrane potential of excitable cells. TASK-3 is involved in neurotransmitter action and has been identified as an oncogenic K+ channel. For this reason, the understanding of the action mechanism of pharmacological modulators of these channels is essential to obtain new therapeutic strategies. In this study we describe the binding mode of the potent antagonist PK-THPP into the TASK-3 channel. PK-THPP blocks TASK-1, the closest relative channel of TASK-3, with almost nine-times less potency. Our results confirm that the binding is influenced by the fenestrations state of TASK-3 channels and occurs when they are open. The binding is mainly governed by hydrophobic contacts between the blocker and the residues of the binding site. These interactions occur not only for PK-THPP, but also for the antagonist series based on 5,6,7,8 tetrahydropyrido[4,3-d]pyrimidine scaffold (THPP series). However, the marked difference in the potency of THPP series compounds such as 20b, 21, 22 and 23 (PK-THPP) respect to compounds such as 17b, inhibiting TASK-3 channels in the micromolar range is due to the presence of a hydrogen bond acceptor group that can establish interactions with the threonines of the selectivity filter.
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Affiliation(s)
- David Ramírez
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile. El Llano Subercaseaux 2801-Piso 6, 7500912 Santiago, Chile.
| | - Mauricio Bedoya
- Centro de Bioinformática y Simulación Molecular (CBSM), Universidad de Talca. 1 Poniente No. 1141, 3460000 Talca, Chile.
| | - Aytug K Kiper
- Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Deutschhausstraße 2, 35037 Marburg, Germany.
| | - Susanne Rinné
- Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Deutschhausstraße 2, 35037 Marburg, Germany.
| | - Samuel Morales-Navarro
- Bachillerato en Ciencias, Facultad de Ciencias, Universidad Santo Tomás, Av. Circunvalación Poniente #1855, 3460000 Talca, Chile.
| | - Erix W Hernández-Rodríguez
- Centro de Bioinformática y Simulación Molecular (CBSM), Universidad de Talca. 1 Poniente No. 1141, 3460000 Talca, Chile.
- Escuela de Química y Farmacia. Facultad de Medicina. Universidad Católica del Maule, 3460000 Talca, Chile.
| | | | - Niels Decher
- Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Deutschhausstraße 2, 35037 Marburg, Germany.
| | - Wendy González
- Centro de Bioinformática y Simulación Molecular (CBSM), Universidad de Talca. 1 Poniente No. 1141, 3460000 Talca, Chile.
- Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Talca, 3460000 Talca, Chile.
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22
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Rinné S, Kiper AK, Vowinkel KS, Ramírez D, Schewe M, Bedoya M, Aser D, Gensler I, Netter MF, Stansfeld PJ, Baukrowitz T, Gonzalez W, Decher N. The molecular basis for an allosteric inhibition of K +-flux gating in K 2P channels. eLife 2019; 8:39476. [PMID: 30803485 PMCID: PMC6391080 DOI: 10.7554/elife.39476] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 02/06/2019] [Indexed: 01/05/2023] Open
Abstract
Two-pore-domain potassium (K2P) channels are key regulators of many physiological and pathophysiological processes and thus emerged as promising drug targets. As for other potassium channels, there is a lack of selective blockers, since drugs preferentially bind to a conserved binding site located in the central cavity. Thus, there is a high medical need to identify novel drug-binding sites outside the conserved lipophilic central cavity and to identify new allosteric mechanisms of channel inhibition. Here, we identified a novel binding site and allosteric inhibition mechanism, disrupting the recently proposed K+-flux gating mechanism of K2P channels, which results in an unusual voltage-dependent block of leak channels belonging to the TASK subfamily. The new binding site and allosteric mechanism of inhibition provide structural and mechanistic insights into the gating of TASK channels and the basis for the drug design of a new class of potent blockers targeting specific types of K2P channels.
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Affiliation(s)
- Susanne Rinné
- Institute for Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, Marburg, Germany
| | - Aytug K Kiper
- Institute for Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, Marburg, Germany
| | - Kirsty S Vowinkel
- Institute for Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, Marburg, Germany
| | - David Ramírez
- Centro de Bioinformática y Simulación Molecular, Universidad de Talca, Talca, Chile.,Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Talca, Chile
| | - Marcus Schewe
- Institute of Physiology, University of Kiel, Kiel, Germany
| | - Mauricio Bedoya
- Centro de Bioinformática y Simulación Molecular, Universidad de Talca, Talca, Chile
| | - Diana Aser
- Institute for Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, Marburg, Germany
| | - Isabella Gensler
- Institute for Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, Marburg, Germany
| | - Michael F Netter
- Institute for Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, Marburg, Germany
| | - Phillip J Stansfeld
- Structural Bioinformatics and Computational Biochemistry Unit, Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | | | - Wendy Gonzalez
- Centro de Bioinformática y Simulación Molecular, Universidad de Talca, Talca, Chile.,Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Talca, Talca, Chile
| | - Niels Decher
- Institute for Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, Marburg, Germany
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23
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Soufi M, Ruppert V, Rinné S, Mueller T, Kurt B, Pilz G, Maieron A, Dodel R, Decher N, Schaefer JR. Increased KCNJ18 promoter activity as a mechanism in atypical normokalemic periodic paralysis. Neurol Genet 2018; 4:e274. [PMID: 30338294 PMCID: PMC6186026 DOI: 10.1212/nxg.0000000000000274] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 07/02/2018] [Indexed: 11/21/2022]
Abstract
Objective To identify the genetic basis of a patient with symptoms of normokalemic sporadic periodic paralysis (PP) and to study the effect of KCNJ18 mutations. Methods A candidate gene approach was used to identify causative gene mutations, using Sanger sequencing. KCNJ18 promoter activity was analyzed in transfected HEK293 cells with a luciferase assay, and functional analysis of Kir2.6 channels was performed with the two-electrode voltage-clamp technique. Results Although we did not identify harmful mutations in SCN4A, CACNA1S, KCNJ2 and KCNE3, we detected a monoallelic four-fold variant in KCNJ18 (R39Q/R40H/A56E/I249V), together with a variant in the respective promoter of this channel (c.-542T/A). The exonic variants in Kir2.6 did not alter the channel function; however, luciferase assays revealed a 10-fold higher promoter activity of the c.-542A promoter construct, which is likely to cause a gain-of-function by increased expression of Kir2.6. We found that reducing extracellular K+ levels causes a paradoxical reduction in outward currents, similar to that described for other inward rectifying K+ channels. Thus, reducing the extracellular K+ levels might be a therapeutic strategy to antagonize the transcriptionally increased KCNJ18 currents. Consistently, treatment of the patient with K+ reducing drugs dramatically improved the health situation and prevented PP attacks. Conclusions We show that a promoter defect in the KCNJ18 gene is likely to cause periodic paralysis, as the observed transcriptional upregulation will be linked to increased Kir2.6 function. This concept is further supported by our observation that most of the PP attacks in our patient disappeared on medical treatment with K+ reducing drugs.
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Affiliation(s)
- Muhidien Soufi
- Center for Undiagnosed and Rare Diseases (ZusE) (M.S., T.M., B.K., J.R.S.); Department of Cardiology (V.R.) and Department of Neurology (R.D.), University Hospital Giessen and Marburg; Vegetative Physiology (S.R., N.D.), Philipps-University Marburg, Institute of Physiology and Pathophysiology, & Marburg Center for Mind, Brain and Behavior, Marburg, Germany; Institute for Algebra (G.P.), Johannes Kepler University Linz; and Department of Gastroenterology (A.M.), Hospital Elisabethinen, Linz, Austria
| | - Volker Ruppert
- Center for Undiagnosed and Rare Diseases (ZusE) (M.S., T.M., B.K., J.R.S.); Department of Cardiology (V.R.) and Department of Neurology (R.D.), University Hospital Giessen and Marburg; Vegetative Physiology (S.R., N.D.), Philipps-University Marburg, Institute of Physiology and Pathophysiology, & Marburg Center for Mind, Brain and Behavior, Marburg, Germany; Institute for Algebra (G.P.), Johannes Kepler University Linz; and Department of Gastroenterology (A.M.), Hospital Elisabethinen, Linz, Austria
| | - Susanne Rinné
- Center for Undiagnosed and Rare Diseases (ZusE) (M.S., T.M., B.K., J.R.S.); Department of Cardiology (V.R.) and Department of Neurology (R.D.), University Hospital Giessen and Marburg; Vegetative Physiology (S.R., N.D.), Philipps-University Marburg, Institute of Physiology and Pathophysiology, & Marburg Center for Mind, Brain and Behavior, Marburg, Germany; Institute for Algebra (G.P.), Johannes Kepler University Linz; and Department of Gastroenterology (A.M.), Hospital Elisabethinen, Linz, Austria
| | - Tobias Mueller
- Center for Undiagnosed and Rare Diseases (ZusE) (M.S., T.M., B.K., J.R.S.); Department of Cardiology (V.R.) and Department of Neurology (R.D.), University Hospital Giessen and Marburg; Vegetative Physiology (S.R., N.D.), Philipps-University Marburg, Institute of Physiology and Pathophysiology, & Marburg Center for Mind, Brain and Behavior, Marburg, Germany; Institute for Algebra (G.P.), Johannes Kepler University Linz; and Department of Gastroenterology (A.M.), Hospital Elisabethinen, Linz, Austria
| | - Bilgen Kurt
- Center for Undiagnosed and Rare Diseases (ZusE) (M.S., T.M., B.K., J.R.S.); Department of Cardiology (V.R.) and Department of Neurology (R.D.), University Hospital Giessen and Marburg; Vegetative Physiology (S.R., N.D.), Philipps-University Marburg, Institute of Physiology and Pathophysiology, & Marburg Center for Mind, Brain and Behavior, Marburg, Germany; Institute for Algebra (G.P.), Johannes Kepler University Linz; and Department of Gastroenterology (A.M.), Hospital Elisabethinen, Linz, Austria
| | - Guenter Pilz
- Center for Undiagnosed and Rare Diseases (ZusE) (M.S., T.M., B.K., J.R.S.); Department of Cardiology (V.R.) and Department of Neurology (R.D.), University Hospital Giessen and Marburg; Vegetative Physiology (S.R., N.D.), Philipps-University Marburg, Institute of Physiology and Pathophysiology, & Marburg Center for Mind, Brain and Behavior, Marburg, Germany; Institute for Algebra (G.P.), Johannes Kepler University Linz; and Department of Gastroenterology (A.M.), Hospital Elisabethinen, Linz, Austria
| | - Andreas Maieron
- Center for Undiagnosed and Rare Diseases (ZusE) (M.S., T.M., B.K., J.R.S.); Department of Cardiology (V.R.) and Department of Neurology (R.D.), University Hospital Giessen and Marburg; Vegetative Physiology (S.R., N.D.), Philipps-University Marburg, Institute of Physiology and Pathophysiology, & Marburg Center for Mind, Brain and Behavior, Marburg, Germany; Institute for Algebra (G.P.), Johannes Kepler University Linz; and Department of Gastroenterology (A.M.), Hospital Elisabethinen, Linz, Austria
| | - Richard Dodel
- Center for Undiagnosed and Rare Diseases (ZusE) (M.S., T.M., B.K., J.R.S.); Department of Cardiology (V.R.) and Department of Neurology (R.D.), University Hospital Giessen and Marburg; Vegetative Physiology (S.R., N.D.), Philipps-University Marburg, Institute of Physiology and Pathophysiology, & Marburg Center for Mind, Brain and Behavior, Marburg, Germany; Institute for Algebra (G.P.), Johannes Kepler University Linz; and Department of Gastroenterology (A.M.), Hospital Elisabethinen, Linz, Austria
| | - Niels Decher
- Center for Undiagnosed and Rare Diseases (ZusE) (M.S., T.M., B.K., J.R.S.); Department of Cardiology (V.R.) and Department of Neurology (R.D.), University Hospital Giessen and Marburg; Vegetative Physiology (S.R., N.D.), Philipps-University Marburg, Institute of Physiology and Pathophysiology, & Marburg Center for Mind, Brain and Behavior, Marburg, Germany; Institute for Algebra (G.P.), Johannes Kepler University Linz; and Department of Gastroenterology (A.M.), Hospital Elisabethinen, Linz, Austria
| | - Juergen R Schaefer
- Center for Undiagnosed and Rare Diseases (ZusE) (M.S., T.M., B.K., J.R.S.); Department of Cardiology (V.R.) and Department of Neurology (R.D.), University Hospital Giessen and Marburg; Vegetative Physiology (S.R., N.D.), Philipps-University Marburg, Institute of Physiology and Pathophysiology, & Marburg Center for Mind, Brain and Behavior, Marburg, Germany; Institute for Algebra (G.P.), Johannes Kepler University Linz; and Department of Gastroenterology (A.M.), Hospital Elisabethinen, Linz, Austria
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24
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Möller M, Silbernagel N, Wrobel E, Stallmayer B, Amedonu E, Rinné S, Peischard S, Meuth SG, Wünsch B, Strutz-Seebohm N, Decher N, Schulze-Bahr E, Seebohm G. In Vitro Analyses of Novel HCN4 Gene Mutations. Cell Physiol Biochem 2018; 49:1197-1207. [PMID: 30196304 DOI: 10.1159/000493301] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 08/28/2018] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS The hyperpolarization-activated cyclic nucleotide-gated cation channel HCN4 contributes significantly to the generation of basic cardiac electrical activity in the sinus node and is a mediator of modulation by β-adrenergic stimulation. Heterologous expression of sick sinus syndrome (SSS) and bradycardia associated mutations within the human HCN4 gene results in altered channel function. The main aim was to describe the functional characterization of three (two novel and one known) missense mutations of HCN4 identified in families with SSS. METHODS Here, the two-electrode voltage clamp technique on Xenopus laevis oocytes and confocal imaging on transfected COS7 cells respectively, were used to analyze the functional effects of three HCN4 mutations; R378C, R550H, and E1193Q. Membrane surface expressions of wild type and the mutant channels were assessed by confocal microscopy, chemiluminescence assay, and Western blot in COS7 and HeLa cells. RESULTS The homomeric mutant channels R550H and E1193Q showed loss of function through increased rates of deactivation and distinctly reduced surface expression in all three homomeric mutant channels. HCN4 channels containing R550H and E1193Q mutant subunits only showed minor effects on the voltage dependence and rates of activation/deactivation. In contrast, homomeric R378C exerted a left-shifted activation curve and slowed activation kinetics. These effects were reduced in heteromeric co-expression of R378C with wild-type (WT) channels. CONCLUSION Dysfunction of homomeric/heteromeric mutant HCN4-R378C, R550H, and E1193Q channels in the present study was primarily caused by loss of function due to decreased channel surface expression.
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Affiliation(s)
- Melina Möller
- Myocellular Electrophysiology and Molecular Biology, Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Muenster, Muenster, Germany
| | - Nicole Silbernagel
- Institute of Physiology and Pathophysiology, Vegetative Physiology Group, Philipps University of Marburg, Marburg, Germany
| | - Eva Wrobel
- Myocellular Electrophysiology and Molecular Biology, Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Muenster, Muenster, Germany
| | - Birgit Stallmayer
- Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Muenster, Muenster, Germany
| | - Elsie Amedonu
- Myocellular Electrophysiology and Molecular Biology, Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Muenster, Muenster, Germany.,Department of Neurology, University Hospital Muenster, Muenster, Germany
| | - Susanne Rinné
- Institute of Physiology and Pathophysiology, Vegetative Physiology Group, Philipps University of Marburg, Marburg, Germany
| | - Stefan Peischard
- Myocellular Electrophysiology and Molecular Biology, Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Muenster, Muenster, Germany
| | - Sven G Meuth
- Department of Neurology, University Hospital Muenster, Muenster, Germany
| | - Bernhard Wünsch
- Institute of Pharmaceutical and Medical Chemistry, University of Muenster, Muenster, Germany
| | - Nathalie Strutz-Seebohm
- Myocellular Electrophysiology and Molecular Biology, Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Muenster, Muenster, Germany
| | - Niels Decher
- Institute of Physiology and Pathophysiology, Vegetative Physiology Group, Philipps University of Marburg, Marburg, Germany
| | - Eric Schulze-Bahr
- Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Muenster, Muenster, Germany
| | - Guiscard Seebohm
- Myocellular Electrophysiology and Molecular Biology, Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Muenster, Muenster, Germany
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25
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Silbernagel N, Walecki M, Schäfer MKH, Kessler M, Zobeiri M, Rinné S, Kiper AK, Komadowski MA, Vowinkel KS, Wemhöner K, Fortmüller L, Schewe M, Dolga AM, Scekic-Zahirovic J, Matschke LA, Culmsee C, Baukrowitz T, Monassier L, Ullrich ND, Dupuis L, Just S, Budde T, Fabritz L, Decher N. The VAMP-associated protein VAPB is required for cardiac and neuronal pacemaker channel function. FASEB J 2018; 32:6159-6173. [PMID: 29879376 PMCID: PMC6629115 DOI: 10.1096/fj.201800246r] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels encode neuronal and cardiac pacemaker currents. The composition of pacemaker channel complexes in different tissues is poorly understood, and the presence of additional HCN modulating subunits was speculated. Here we show that vesicle-associated membrane protein-associated protein B (VAPB), previously associated with a familial form of amyotrophic lateral sclerosis 8, is an essential HCN1 and HCN2 modulator. VAPB significantly increases HCN2 currents and surface expression and has a major influence on the dendritic neuronal distribution of HCN2. Severe cardiac bradycardias in VAPB-deficient zebrafish and VAPB-/- mice highlight that VAPB physiologically serves to increase cardiac pacemaker currents. An altered T-wave morphology observed in the ECGs of VAPB-/- mice supports the recently proposed role of HCN channels for ventricular repolarization. The critical function of VAPB in native pacemaker channel complexes will be relevant for our understanding of cardiac arrhythmias and epilepsies, and provides an unexpected link between these diseases and amyotrophic lateral sclerosis.-Silbernagel, N., Walecki, M., Schäfer, M.-K. H., Kessler, M., Zobeiri, M., Rinné, S., Kiper, A. K., Komadowski, M. A., Vowinkel, K. S., Wemhöner, K., Fortmüller, L., Schewe, M., Dolga, A. M., Scekic-Zahirovic, J., Matschke, L. A., Culmsee, C., Baukrowitz, T., Monassier, L., Ullrich, N. D., Dupuis, L., Just, S., Budde, T., Fabritz, L., Decher, N. The VAMP-associated protein VAPB is required for cardiac and neuronal pacemaker channel function.
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Affiliation(s)
- Nicole Silbernagel
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Phillips University, Marburg, Germany
| | - Magdalena Walecki
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Phillips University, Marburg, Germany
| | - Martin K-H Schäfer
- Institute of Anatomy and Cell Biology, Philipps University, Marburg, Germany
| | - Mirjam Kessler
- Molecular Cardiology, Department of Internal Medicine II, University Hospital Ulm, Ulm, Germany
| | | | - Susanne Rinné
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Phillips University, Marburg, Germany
| | - Aytug K Kiper
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Phillips University, Marburg, Germany
| | - Marlene A Komadowski
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Phillips University, Marburg, Germany.,Institute of Anatomy and Cell Biology, Philipps University, Marburg, Germany
| | - Kirsty S Vowinkel
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Phillips University, Marburg, Germany
| | - Konstantin Wemhöner
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Phillips University, Marburg, Germany
| | - Lisa Fortmüller
- Department of Cardiology II - Electrophysiology, University Hospital Münster, University of Münster, Munster, Germany
| | - Marcus Schewe
- Institute of Physiology, Christian-Albrechts University, Kiel, Germany
| | - Amalia M Dolga
- Institute of Pharmacology and Clinical Pharmacy, Phillips University, Marburg, Germany
| | - Jelena Scekic-Zahirovic
- Laboratoire de Pharmacologie et Toxicologie NeuroCardiovasculaire, Faculté de Médecine, Université de Strasbourg, Strasbourg, France
| | - Lina A Matschke
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Phillips University, Marburg, Germany
| | - Carsten Culmsee
- Institute of Pharmacology and Clinical Pharmacy, Phillips University, Marburg, Germany
| | - Thomas Baukrowitz
- Institute of Physiology, Christian-Albrechts University, Kiel, Germany
| | - Laurent Monassier
- Laboratoire de Pharmacologie et Toxicologie NeuroCardiovasculaire, Faculté de Médecine, Université de Strasbourg, Strasbourg, France
| | - Nina D Ullrich
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Luc Dupuis
- Laboratoire de Neurobiologie et Pharmacologie Cardiovasculaire, Faculté de Médecine, Université de Strasbourg, Strasbourg, France.,INSERM, Faculté de Médecine, Université de Strasbourg, Strasbourg, France
| | - Steffen Just
- Molecular Cardiology, Department of Internal Medicine II, University Hospital Ulm, Ulm, Germany
| | - Thomas Budde
- Institute for Physiology I, University of Münster, Munster, Germany
| | - Larissa Fabritz
- Department of Cardiology II - Electrophysiology, University Hospital Münster, University of Münster, Munster, Germany.,Institute of Cardiovascular Sciences, University Hospital Birmingham, University of Birmingham, Birmingham, United Kingdom.,Department of Cardiology, University Hospital Birmingham, University of Birmingham, Birmingham, United Kingdom.,Division of Rhythmology, Department of Genetic Epidemiology, University Hospital Münster, University of Münster, Munster, Germany.,Institute of Human Genetics, Department of Genetic Epidemiology, University Hospital Münster, University of Münster, Munster, Germany
| | - Niels Decher
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Phillips University, Marburg, Germany
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26
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Pott A, Bock S, Berger IM, Frese K, Dahme T, Keßler M, Rinné S, Decher N, Just S, Rottbauer W. Mutation of the Na +/K +-ATPase Atp1a1a.1 causes QT interval prolongation and bradycardia in zebrafish. J Mol Cell Cardiol 2018; 120:42-52. [PMID: 29750993 DOI: 10.1016/j.yjmcc.2018.05.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 04/24/2018] [Accepted: 05/07/2018] [Indexed: 02/01/2023]
Abstract
The genetic underpinnings that orchestrate the vertebrate heart rate are not fully understood yet, but of high clinical importance, since diseases of cardiac impulse formation and propagation are common and severe human arrhythmias. To identify novel regulators of the vertebrate heart rate, we deciphered the pathogenesis of the bradycardia in the homozygous zebrafish mutant hiphop (hip) and identified a missense-mutation (N851K) in Na+/K+-ATPase α1-subunit (atp1a1a.1). N851K affects zebrafish Na+/K+-ATPase ion transport capacity, as revealed by in vitro pump current measurements. Inhibition of the Na+/K+-ATPase in vivo indicates that hip rather acts as a hypomorph than being a null allele. Consequently, reduced Na+/K+-ATPase function leads to prolonged QT interval and refractoriness in the hip mutant heart, as shown by electrocardiogram and in vivo electrical stimulation experiments. We here demonstrate for the first time that Na+/K+-ATPase plays an essential role in heart rate regulation by prolonging myocardial repolarization.
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Affiliation(s)
- Alexander Pott
- Department of Internal Medicine II, Ulm University Medical Center, Ulm, Germany
| | - Sarah Bock
- Molecular Cardiology, Department of Internal Medicine II, Ulm University Medical Center, Ulm, Germany
| | - Ina M Berger
- Molecular Cardiology, Department of Internal Medicine II, Ulm University Medical Center, Ulm, Germany
| | - Karen Frese
- Department of Internal Medicine III, Heidelberg University Medical Center, Heidelberg, Germany
| | - Tillman Dahme
- Department of Internal Medicine II, Ulm University Medical Center, Ulm, Germany
| | - Mirjam Keßler
- Department of Internal Medicine II, Ulm University Medical Center, Ulm, Germany
| | - Susanne Rinné
- Institute for Physiology and Pathophysiology, AG Vegetative Physiology, Philipps-University of Marburg, Marburg, Germany
| | - Niels Decher
- Institute for Physiology and Pathophysiology, AG Vegetative Physiology, Philipps-University of Marburg, Marburg, Germany
| | - Steffen Just
- Molecular Cardiology, Department of Internal Medicine II, Ulm University Medical Center, Ulm, Germany.
| | - Wolfgang Rottbauer
- Department of Internal Medicine II, Ulm University Medical Center, Ulm, Germany.
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27
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Rinné S, Kiper A, Schmidt C, Ortiz-Bonnin B, Zwiener S, Seebohm G, Decher N. Stress-Kinase Regulation of TASK-1 and TASK-3. Cell Physiol Biochem 2017; 44:1024-1037. [DOI: 10.1159/000485402] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 10/17/2017] [Indexed: 11/19/2022] Open
Abstract
Background/Aims: TASK channels belong to the two-pore-domain potassium (K2P) channel family. TASK-1 is discussed to contribute to chronic atrial fibrillation (AFib) and has been together with uncoupling protein 1 found as a marker protein of brown adipose tissue (BAT) fat. In addition, TASK-1 was linked in a genome-wide association study to an increased body mass index. A recent study showed that TASK-1 inhibition is causing obesity in mice by a BAT whitening and that these effects are linked to the mineralocorticoid receptor pathway, albeit the mechanism remained elusive. Therefore, we aimed to probe whether K2P channels are regulated by serum- and glucocorticoid-inducible kinases (SGKs) which are known to modify many cellular functions by modulating ion channels. Methods: To this end we used functional co-expression studies and chemiluminescence-assays in Xenopus oocytes, together with fluorescence imaging and quantitative PCR experiments. Results: SGKs and proteinkinase B (PKB) induced a strong, dose- and time-dependent current reduction of TASK-1 and TASK-3. SGK co-expression reduced the surface expression of TASK-1/3, leading to a predominant localization of the channels into late endosomes. The down regulation of TASK-3 channels was abrogated by the dynamin inhibitor dynasore, confirming a role of SGKs in TASK-1/3 channel endocytosis. Conclusion: Stress-mediated changes in SGK expression pattern or activation is likely to alter TASK-1/3 expression at the surface membrane. The observed TASK-1 regulation might contribute to the pathogenesis of chronic AFib and provide a mechanistic link between increased mineralocorticoid levels and TASK-1 reduction, both linked to BAT whitening.
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Decher N, Ortiz-Bonnin B, Friedrich C, Schewe M, Kiper AK, Rinné S, Seemann G, Peyronnet R, Zumhagen S, Bustos D, Kockskämper J, Kohl P, Just S, González W, Baukrowitz T, Stallmeyer B, Schulze-Bahr E. Sodium permeable and "hypersensitive" TREK-1 channels cause ventricular tachycardia. EMBO Mol Med 2017; 9:403-414. [PMID: 28242754 PMCID: PMC5376757 DOI: 10.15252/emmm.201606690] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
In a patient with right ventricular outflow tract (RVOT) tachycardia, we identified a heterozygous point mutation in the selectivity filter of the stretch-activated K2P potassium channel TREK-1 (KCNK2 or K2P2.1). This mutation introduces abnormal sodium permeability to TREK-1. In addition, mutant channels exhibit a hypersensitivity to stretch-activation, suggesting that the selectivity filter is directly involved in stretch-induced activation and desensitization. Increased sodium permeability and stretch-sensitivity of mutant TREK-1 channels may trigger arrhythmias in areas of the heart with high physical strain such as the RVOT We present a pharmacological strategy to rescue the selectivity defect of the TREK-1 pore. Our findings provide important insights for future studies of K2P channel stretch-activation and the role of TREK-1 in mechano-electrical feedback in the heart.
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Affiliation(s)
- Niels Decher
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Marburg, Germany
| | - Beatriz Ortiz-Bonnin
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Marburg, Germany
| | - Corinna Friedrich
- Department of Cardiovascular Medicine, Institute for Genetics of Heart Diseases (IfGH), University Hospital Münster, Münster, Germany
| | - Marcus Schewe
- Institute of Physiology, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Aytug K Kiper
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Marburg, Germany
| | - Susanne Rinné
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Marburg, Germany
| | - Gunnar Seemann
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen, Medical Center - University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Rémi Peyronnet
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen, Medical Center - University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Sven Zumhagen
- Department of Cardiovascular Medicine, Institute for Genetics of Heart Diseases (IfGH), University Hospital Münster, Münster, Germany
| | - Daniel Bustos
- Center for Bioinformatics and Molecular Simulation, University of Talca, Talca, Chile
| | - Jens Kockskämper
- Institute of Pharmacology and Clinical Pharmacy, Biochemical and Pharmacological Center (BPC) Philipps-University of Marburg, Marburg, Germany
| | - Peter Kohl
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen, Medical Center - University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Steffen Just
- Molecular Cardiology, University Hospital Ulm, Ulm, Germany
| | - Wendy González
- Center for Bioinformatics and Molecular Simulation, University of Talca, Talca, Chile
| | - Thomas Baukrowitz
- Institute of Physiology, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Birgit Stallmeyer
- Department of Cardiovascular Medicine, Institute for Genetics of Heart Diseases (IfGH), University Hospital Münster, Münster, Germany
| | - Eric Schulze-Bahr
- Department of Cardiovascular Medicine, Institute for Genetics of Heart Diseases (IfGH), University Hospital Münster, Münster, Germany
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Leist M, Rinné S, Datunashvili M, Aissaoui A, Pape HC, Decher N, Meuth SG, Budde T. Acetylcholine-dependent upregulation of TASK-1 channels in thalamic interneurons by a smooth muscle-like signalling pathway. J Physiol 2017; 595:5875-5893. [PMID: 28714121 DOI: 10.1113/jp274527] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 07/10/2017] [Indexed: 12/13/2022] Open
Abstract
KEY POINTS The ascending brainstem transmitter acetylcholine depolarizes thalamocortical relay neurons while it induces hyperpolarization in local circuit inhibitory interneurons. Sustained K+ currents are modulated in thalamic neurons to control their activity modes; for the interneurons the molecular nature of the underlying ion channels is as yet unknown. Activation of TASK-1 K+ channels results in hyperpolarization of interneurons and suppression of their action potential firing. The modulation cascade involves a non-receptor tyrosine kinase, c-Src. The present study identifies a novel pathway for the activation of TASK-1 channels in CNS neurons that resembles cholinergic signalling and TASK-1 current modulation during hypoxia in smooth muscle cells. ABSTRACT The dorsal part of the lateral geniculate nucleus (dLGN) is the main thalamic site for state-dependent transmission of visual information. Non-retinal inputs from the ascending arousal system and inhibition provided by γ-aminobutyric acid (GABA)ergic local circuit interneurons (INs) control neuronal activity within the dLGN. In particular, acetylcholine (ACh) depolarizes thalamocortical relay neurons by inhibiting two-pore domain potassium (K2P ) channels. Conversely, ACh also hyperpolarizes INs via an as-yet-unknown mechanism. By using whole cell patch-clamp recordings in brain slices and appropriate pharmacological tools we here report that stimulation of type 2 muscarinic ACh receptors induces IN hyperpolarization by recruiting the G-protein βγ subunit (Gβγ), class-1A phosphatidylinositol-4,5-bisphosphate 3-kinase, and cellular and sarcoma (c-Src) tyrosine kinase, leading to activation of two-pore domain weakly inwardly rectifying K+ channel (TWIK)-related acid-sensitive K+ (TASK)-1 channels. The latter was confirmed by the use of TASK-1-deficient mice. Furthermore inhibition of phospholipase Cβ as well as an increase in the intracellular level of phosphatidylinositol-3,4,5-trisphosphate facilitated the muscarinic effect. Our results have uncovered a previously unknown role of c-Src tyrosine kinase in regulating IN function in the brain and identified a novel mechanism by which TASK-1 channels are activated in neurons.
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Affiliation(s)
- Michael Leist
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149, Münster, Germany
| | - Susanne Rinné
- Institut für Physiologie und Pathophysiologie, AG Vegetative Physiologie, Philipps-Universität, Deutschhausstraße 1-2, D-35037, Marburg, Germany
| | - Maia Datunashvili
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149, Münster, Germany
| | - Ania Aissaoui
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149, Münster, Germany
| | - Hans-Christian Pape
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149, Münster, Germany
| | - Niels Decher
- Institut für Physiologie und Pathophysiologie, AG Vegetative Physiologie, Philipps-Universität, Deutschhausstraße 1-2, D-35037, Marburg, Germany
| | - Sven G Meuth
- Department of Neurology, Westfälische Wilhelms-Universität, Albert-Schweitzer-Campus 1, D-48149, Münster, Germany
| | - Thomas Budde
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149, Münster, Germany
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Ramírez D, Arévalo B, Martínez G, Rinné S, Sepúlveda FV, Decher N, González W. Side Fenestrations Provide an "Anchor" for a Stable Binding of A1899 to the Pore of TASK-1 Potassium Channels. Mol Pharm 2017; 14:2197-2208. [PMID: 28494157 DOI: 10.1021/acs.molpharmaceut.7b00005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A1899 is a potent and selective inhibitor of the two-pore domain potassium (K2P) channel TASK-1. It was previously reported that A1899 acts as an open-channel blocker and binds to residues of the P1 and P2 regions, the M2 and M4 segments, and the halothane response element. The recently described crystal structures of K2P channels together with the newly identified side fenestrations indicate that residues relevant for TASK-1 inhibition are not purely facing the central cavity as initially proposed. Accordingly, the TASK-1 binding site and the mechanism of inhibition might need a re-evaluation. We have used TASK-1 homology models based on recently crystallized K2P channels and molecular dynamics simulation to demonstrate that the highly potent TASK-1 blocker A1899 requires binding to residues located in the side fenestrations. Unexpectedly, most of the previously described residues that interfere with TASK-1 blockade by A1899 project their side chains toward the fenestration lumina, underlining the relevance of these structures for drug binding in K2P channels. Despite its hydrophobicity, A1899 does not seem to use the fenestrations to gain access to the central cavity from the lipid bilayer. In contrast, binding of A1899 to residues of the side fenestrations might provide a physical "anchor", reflecting an energetically favorable binding mode that after pore occlusion stabilizes the closed state of the channels.
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Affiliation(s)
- David Ramírez
- Centro de Bioinformática y Simulación Molecular, Universidad de Talca , 1 poniente No. 1141, 3460000 Talca, Chile.,Instituto de Ciencias Biomédicas, Universidad Autonoma de Chile , 5 Poniente No. 1670, 3460000 Talca, Chile
| | - Bárbara Arévalo
- Centro de Bioinformática y Simulación Molecular, Universidad de Talca , 1 poniente No. 1141, 3460000 Talca, Chile
| | - Gonzalo Martínez
- Centro de Bioinformática y Simulación Molecular, Universidad de Talca , 1 poniente No. 1141, 3460000 Talca, Chile
| | - Susanne Rinné
- Institute for Physiology and Pathophysiology, Vegetative Physiology Group, University of Marburg , 35037 Marburg, Germany
| | | | - Niels Decher
- Institute for Physiology and Pathophysiology, Vegetative Physiology Group, University of Marburg , 35037 Marburg, Germany
| | - Wendy González
- Centro de Bioinformática y Simulación Molecular, Universidad de Talca , 1 poniente No. 1141, 3460000 Talca, Chile
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Decher N, Kiper AK, Rinné S. Stretch-activated potassium currents in the heart: Focus on TREK-1 and arrhythmias. Prog Biophys Mol Biol 2017; 130:223-232. [PMID: 28526352 DOI: 10.1016/j.pbiomolbio.2017.05.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 05/09/2017] [Accepted: 05/15/2017] [Indexed: 12/26/2022]
Abstract
This review focuses on the role and the molecular candidates of the cardiac stretch-activated potassium current (SAK). The functional properties of the two-pore domain potassium (K2P) channel TREK-1, a major candidate for the cardiac SAK, are analyzed and the molecular mechanism of stretch-activation in K2P potassium channels is discussed. Furthermore, the functional modulation of TREK-1 by different cardiac interaction partners, as well as evidence for the functional role of the stretch-dependent TREK-1 and its putative subunits in the heart is reviewed. In addition, we summarize the recent evidence that TREK-1 is involved in the pathogenesis of human cardiac arrhythmias.
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Affiliation(s)
- Niels Decher
- Institute for Physiology and Pathophysiology, AG Vegetative Physiology, Deutschhausstrasse 1-2, 35037 Marburg, Germany.
| | - Aytug K Kiper
- Institute for Physiology and Pathophysiology, AG Vegetative Physiology, Deutschhausstrasse 1-2, 35037 Marburg, Germany
| | - Susanne Rinné
- Institute for Physiology and Pathophysiology, AG Vegetative Physiology, Deutschhausstrasse 1-2, 35037 Marburg, Germany
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Stallmeyer B, Kuß J, Kotthoff S, Zumhagen S, Vowinkel K, Rinné S, Matschke LA, Friedrich C, Schulze-Bahr E, Rust S, Seebohm G, Decher N, Schulze-Bahr E. A Mutation in the G-Protein Gene GNB2 Causes Familial Sinus Node and Atrioventricular Conduction Dysfunction. Circ Res 2017; 120:e33-e44. [PMID: 28219978 DOI: 10.1161/circresaha.116.310112] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 02/16/2017] [Accepted: 02/20/2017] [Indexed: 11/16/2022]
Abstract
RATIONALE Familial sinus node and atrioventricular conduction dysfunction is a rare disorder that leads to paroxysmal dizziness, fatigue, and syncope because of a temporarily or permanently reduced heart rate. To date, only a few genes for familial sinus and atrioventricular conduction dysfunction are known, and the majority of cases remain pathogenically unresolved. OBJECTIVE We aim to identify the disease gene in a large 3-generation family (n=25) with autosomal dominant sinus node dysfunction (SND) and atrioventricular block (AVB) and to characterize the mutation-related pathomechanisms in familial SND+AVB. METHODS AND RESULTS Genome-wide linkage analysis mapped the SND+AVB disease locus to chromosome 7q21.1-q31.1 (2-point logarithm of the odds score: 4.64; θ=0); in this region, targeted exome sequencing identified a novel heterozygous mutation (p.Arg52Leu) in the GNB2 gene that strictly cosegregated with the SND+AVB phenotype. GNB2 encodes the β2 subunit (Gβ2) of the heterotrimeric G-protein complex that is being released from G-protein-coupled receptors on vagal stimulation. In 2 heterologous expression systems (HEK-293T cells and Xenopus laevis oocytes), an enhanced activation of the G-protein-activated K+ channel (GIRK; Kir3.1/Kir3.4) was shown when mutant Gβ2 was coexpressed with Gγ2; this was in contrast to coexpression of mutant Gβ2-Gγ2 with other cardiac ion channels (HCN4, HCN2, and Cav1.2). Molecular dynamics simulations suggested a reduced binding property of mutant Gβ2 to cardiac GIRK channels when compared with native Gβ2. CONCLUSIONS A GNB2 gene mutation is associated with familial SND+AVB and leads to a sustained activation of cardiac GIRK channels, which is likely to hyperpolarize the myocellular membrane potential and thus reduces their spontaneous activity. Our findings describe for the first time a role of a mutant G-protein in the nonsyndromic pacemaker disease because of GIRK channel activation.
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Affiliation(s)
- Birgit Stallmeyer
- From the Institute for Genetics of Heart Diseases, Department of Cardiology and Angiology, University Hospital Muenster, Germany (B.S., J.K., S.Z., C.F., E.S.-B., G.S., E.S.-B.); Department of Pediatric Cardiology (S.K.) and Department of General Pediatrics (S.R.), University Children's Hospital Muenster, Germany; and Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps University of Marburg, Germany (K.V., S.R., L.A.M., N.D.)
| | - Johanna Kuß
- From the Institute for Genetics of Heart Diseases, Department of Cardiology and Angiology, University Hospital Muenster, Germany (B.S., J.K., S.Z., C.F., E.S.-B., G.S., E.S.-B.); Department of Pediatric Cardiology (S.K.) and Department of General Pediatrics (S.R.), University Children's Hospital Muenster, Germany; and Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps University of Marburg, Germany (K.V., S.R., L.A.M., N.D.)
| | - Stefan Kotthoff
- From the Institute for Genetics of Heart Diseases, Department of Cardiology and Angiology, University Hospital Muenster, Germany (B.S., J.K., S.Z., C.F., E.S.-B., G.S., E.S.-B.); Department of Pediatric Cardiology (S.K.) and Department of General Pediatrics (S.R.), University Children's Hospital Muenster, Germany; and Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps University of Marburg, Germany (K.V., S.R., L.A.M., N.D.)
| | - Sven Zumhagen
- From the Institute for Genetics of Heart Diseases, Department of Cardiology and Angiology, University Hospital Muenster, Germany (B.S., J.K., S.Z., C.F., E.S.-B., G.S., E.S.-B.); Department of Pediatric Cardiology (S.K.) and Department of General Pediatrics (S.R.), University Children's Hospital Muenster, Germany; and Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps University of Marburg, Germany (K.V., S.R., L.A.M., N.D.)
| | - Kirsty Vowinkel
- From the Institute for Genetics of Heart Diseases, Department of Cardiology and Angiology, University Hospital Muenster, Germany (B.S., J.K., S.Z., C.F., E.S.-B., G.S., E.S.-B.); Department of Pediatric Cardiology (S.K.) and Department of General Pediatrics (S.R.), University Children's Hospital Muenster, Germany; and Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps University of Marburg, Germany (K.V., S.R., L.A.M., N.D.)
| | - Susanne Rinné
- From the Institute for Genetics of Heart Diseases, Department of Cardiology and Angiology, University Hospital Muenster, Germany (B.S., J.K., S.Z., C.F., E.S.-B., G.S., E.S.-B.); Department of Pediatric Cardiology (S.K.) and Department of General Pediatrics (S.R.), University Children's Hospital Muenster, Germany; and Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps University of Marburg, Germany (K.V., S.R., L.A.M., N.D.)
| | - Lina A Matschke
- From the Institute for Genetics of Heart Diseases, Department of Cardiology and Angiology, University Hospital Muenster, Germany (B.S., J.K., S.Z., C.F., E.S.-B., G.S., E.S.-B.); Department of Pediatric Cardiology (S.K.) and Department of General Pediatrics (S.R.), University Children's Hospital Muenster, Germany; and Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps University of Marburg, Germany (K.V., S.R., L.A.M., N.D.)
| | - Corinna Friedrich
- From the Institute for Genetics of Heart Diseases, Department of Cardiology and Angiology, University Hospital Muenster, Germany (B.S., J.K., S.Z., C.F., E.S.-B., G.S., E.S.-B.); Department of Pediatric Cardiology (S.K.) and Department of General Pediatrics (S.R.), University Children's Hospital Muenster, Germany; and Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps University of Marburg, Germany (K.V., S.R., L.A.M., N.D.)
| | - Ellen Schulze-Bahr
- From the Institute for Genetics of Heart Diseases, Department of Cardiology and Angiology, University Hospital Muenster, Germany (B.S., J.K., S.Z., C.F., E.S.-B., G.S., E.S.-B.); Department of Pediatric Cardiology (S.K.) and Department of General Pediatrics (S.R.), University Children's Hospital Muenster, Germany; and Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps University of Marburg, Germany (K.V., S.R., L.A.M., N.D.)
| | - Stephan Rust
- From the Institute for Genetics of Heart Diseases, Department of Cardiology and Angiology, University Hospital Muenster, Germany (B.S., J.K., S.Z., C.F., E.S.-B., G.S., E.S.-B.); Department of Pediatric Cardiology (S.K.) and Department of General Pediatrics (S.R.), University Children's Hospital Muenster, Germany; and Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps University of Marburg, Germany (K.V., S.R., L.A.M., N.D.)
| | - Guiscard Seebohm
- From the Institute for Genetics of Heart Diseases, Department of Cardiology and Angiology, University Hospital Muenster, Germany (B.S., J.K., S.Z., C.F., E.S.-B., G.S., E.S.-B.); Department of Pediatric Cardiology (S.K.) and Department of General Pediatrics (S.R.), University Children's Hospital Muenster, Germany; and Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps University of Marburg, Germany (K.V., S.R., L.A.M., N.D.)
| | - Niels Decher
- From the Institute for Genetics of Heart Diseases, Department of Cardiology and Angiology, University Hospital Muenster, Germany (B.S., J.K., S.Z., C.F., E.S.-B., G.S., E.S.-B.); Department of Pediatric Cardiology (S.K.) and Department of General Pediatrics (S.R.), University Children's Hospital Muenster, Germany; and Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps University of Marburg, Germany (K.V., S.R., L.A.M., N.D.)
| | - Eric Schulze-Bahr
- From the Institute for Genetics of Heart Diseases, Department of Cardiology and Angiology, University Hospital Muenster, Germany (B.S., J.K., S.Z., C.F., E.S.-B., G.S., E.S.-B.); Department of Pediatric Cardiology (S.K.) and Department of General Pediatrics (S.R.), University Children's Hospital Muenster, Germany; and Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps University of Marburg, Germany (K.V., S.R., L.A.M., N.D.).
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Ortiz-Bonnin B, Rinné S, Moss R, Streit AK, Scharf M, Richter K, Stöber A, Pfeufer A, Seemann G, Kääb S, Beckmann BM, Decher N. Electrophysiological characterization of a large set of novel variants in the SCN5A-gene: identification of novel LQTS3 and BrS mutations. Pflugers Arch 2016; 468:1375-87. [PMID: 27287068 DOI: 10.1007/s00424-016-1844-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 05/16/2016] [Accepted: 05/29/2016] [Indexed: 01/08/2023]
Abstract
SCN5A encodes for the α-subunit of the cardiac voltage-gated sodium channel Nav1.5. Gain-of-function mutations in SCN5A are related to congenital long QT syndrome (LQTS3) characterized by delayed cardiac repolarization, leading to a prolonged QT interval in the ECG. Loss-of-function mutations in SCN5A are related to Brugada syndrome (BrS), characterized by an ST-segment elevation in the right precordial leads (V1-V3). The aim of this study was the characterization of a large set of novel SCN5A variants found in patients with different cardiac phenotypes, mainly LQTS and BrS. SCN5A variants of 13 families were functionally characterized in Xenopus laevis oocytes using the two-electrode voltage-clamp technique. We found in most of the cases, but not all, that the electrophysiology of the variants correlated with the clinically diagnosed phenotype. A susceptibility to develop LQTS can be suggested in patients carrying the variants S216L, K480N, A572D, F816Y, and G983D. However, taking the phenotype into account, the presence of the variants in genomic data bases, the mutational segregation, combined with our in vitro and in silico experiments, the variants S216L, S262G, K480N, A572D, F816Y, G983D, and T1526P remain as variants of unknown significance. However, the SCN5A variants R568H and A993T can be classified as pathogenic LQTS3 causing mutations, while R222stop and R2012H are novel BrS causing mutations.
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Affiliation(s)
- Beatriz Ortiz-Bonnin
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Deutschhausstraße 1-2, 35037, Marburg, Germany
| | - Susanne Rinné
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Deutschhausstraße 1-2, 35037, Marburg, Germany
| | - Robin Moss
- Institute for Experimental Cardiovascular Medicine, University Heart Centre Freiburg - Bad Krozingen, Medical Center, University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Anne K Streit
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Deutschhausstraße 1-2, 35037, Marburg, Germany
| | - Michael Scharf
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Deutschhausstraße 1-2, 35037, Marburg, Germany
| | - Katrin Richter
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Deutschhausstraße 1-2, 35037, Marburg, Germany
| | - Anika Stöber
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Deutschhausstraße 1-2, 35037, Marburg, Germany
| | - Arne Pfeufer
- Helmholtz Zentrum München GmbH, Deutsches Forschungszentrum für Gesundheit und Umwelt, Institut für Humangenetik, Oberschleißheim, Germany
| | - Gunnar Seemann
- Institute for Experimental Cardiovascular Medicine, University Heart Centre Freiburg - Bad Krozingen, Medical Center, University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Stefan Kääb
- Department of Medicine, University Hospital of the Ludwig Maximilians University-Campus Innenstadt and Großhadern, Munich, Germany
| | - Britt-Maria Beckmann
- Department of Medicine, University Hospital of the Ludwig Maximilians University-Campus Innenstadt and Großhadern, Munich, Germany
| | - Niels Decher
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Deutschhausstraße 1-2, 35037, Marburg, Germany.
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Schindler RFR, Scotton C, Zhang J, Passarelli C, Ortiz-Bonnin B, Simrick S, Schwerte T, Poon KL, Fang M, Rinné S, Froese A, Nikolaev VO, Grunert C, Müller T, Tasca G, Sarathchandra P, Drago F, Dallapiccola B, Rapezzi C, Arbustini E, Di Raimo FR, Neri M, Selvatici R, Gualandi F, Fattori F, Pietrangelo A, Li W, Jiang H, Xu X, Bertini E, Decher N, Wang J, Brand T, Ferlini A. POPDC1(S201F) causes muscular dystrophy and arrhythmia by affecting protein trafficking. J Clin Invest 2015; 126:239-53. [PMID: 26642364 DOI: 10.1172/jci79562] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 10/29/2015] [Indexed: 01/16/2023] Open
Abstract
The Popeye domain-containing 1 (POPDC1) gene encodes a plasma membrane-localized cAMP-binding protein that is abundantly expressed in striated muscle. In animal models, POPDC1 is an essential regulator of structure and function of cardiac and skeletal muscle; however, POPDC1 mutations have not been associated with human cardiac and muscular diseases. Here, we have described a homozygous missense variant (c.602C>T, p.S201F) in POPDC1, identified by whole-exome sequencing, in a family of 4 with cardiac arrhythmia and limb-girdle muscular dystrophy (LGMD). This allele was absent in known databases and segregated with the pathological phenotype in this family. We did not find the allele in a further screen of 104 patients with a similar phenotype, suggesting this mutation to be family specific. Compared with WT protein, POPDC1(S201F) displayed a 50% reduction in cAMP affinity, and in skeletal muscle from patients, both POPDC1(S201F) and WT POPDC2 displayed impaired membrane trafficking. Forced expression of POPDC1(S201F) in a murine cardiac muscle cell line (HL-1) increased hyperpolarization and upstroke velocity of the action potential. In zebrafish, expression of the homologous mutation (popdc1(S191F)) caused heart and skeletal muscle phenotypes that resembled those observed in patients. Our study therefore identifies POPDC1 as a disease gene causing a very rare autosomal recessive cardiac arrhythmia and LGMD, expanding the genetic causes of this heterogeneous group of inherited rare diseases.
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Wemhöner K, Kanyshkova T, Silbernagel N, Fernandez-Orth J, Bittner S, Kiper AK, Rinné S, Netter MF, Meuth SG, Budde T, Decher N. An N-terminal deletion variant of HCN1 in the epileptic WAG/Rij strain modulates HCN current densities. Front Mol Neurosci 2015; 8:63. [PMID: 26578877 PMCID: PMC4630678 DOI: 10.3389/fnmol.2015.00063] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 10/13/2015] [Indexed: 11/26/2022] Open
Abstract
Rats of the Wistar Albino Glaxo/Rij (WAG/Rij) strain show symptoms resembling human absence epilepsy. Thalamocortical neurons of WAG/Rij rats are characterized by an increased HCN1 expression, a negative shift in Ih activation curve, and an altered responsiveness of Ih to cAMP. We cloned HCN1 channels from rat thalamic cDNA libraries of the WAG/Rij strain and found an N-terminal deletion of 37 amino acids. In addition, WAG-HCN1 has a stretch of six amino acids, directly following the deletion, where the wild-type sequence (GNSVCF) is changed to a polyserine motif. These alterations were found solely in thalamus mRNA but not in genomic DNA. The truncated WAG-HCN1 was detected late postnatal in WAG/Rij rats and was not passed on to rats obtained from pairing WAG/Rij and non-epileptic August Copenhagen Irish rats. Heterologous expression in Xenopus oocytes revealed 2.2-fold increased current amplitude of WAG-HCN1 compared to rat HCN1. While WAG-HCN1 channels did not have altered current kinetics or changed regulation by protein kinases, fluorescence imaging revealed a faster and more pronounced surface expression of WAG-HCN1. Using co-expression experiments, we found that WAG-HCN1 channels suppress heteromeric HCN2 and HCN4 currents. Moreover, heteromeric channels of WAG-HCN1 with HCN2 have a reduced cAMP sensitivity. Functional studies revealed that the gain-of-function of WAG-HCN1 is not caused by the N-terminal deletion alone, thus requiring a change of the N-terminal GNSVCF motif. Our findings may help to explain previous observations in neurons of the WAG/Rij strain and indicate that WAG-HCN1 may contribute to the genesis of absence seizures in WAG/Rij rats.
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Affiliation(s)
- Konstantin Wemhöner
- Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg Marburg, Germany
| | - Tatyana Kanyshkova
- Institute for Physiology I, Westfälische Wilhelms-Universität Münster, Germany
| | - Nicole Silbernagel
- Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg Marburg, Germany
| | | | - Stefan Bittner
- Department of Neurology, University Medical Center, Johannes Gutenberg-University Mainz Mainz, Germany
| | - Aytug K Kiper
- Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg Marburg, Germany
| | - Susanne Rinné
- Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg Marburg, Germany
| | - Michael F Netter
- Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg Marburg, Germany
| | - Sven G Meuth
- Department of Neurology, Westfälische Wilhelms-Universität Münster, Germany
| | - Thomas Budde
- Institute for Physiology I, Westfälische Wilhelms-Universität Münster, Germany
| | - Niels Decher
- Institute for Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg Marburg, Germany
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Rinné S, Kiper AK, Schlichthörl G, Dittmann S, Netter MF, Limberg SH, Silbernagel N, Zuzarte M, Moosdorf R, Wulf H, Schulze-Bahr E, Rolfes C, Decher N. TASK-1 and TASK-3 may form heterodimers in human atrial cardiomyocytes. J Mol Cell Cardiol 2015; 81:71-80. [DOI: 10.1016/j.yjmcc.2015.01.017] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 12/30/2014] [Accepted: 01/27/2015] [Indexed: 11/29/2022]
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Friedrich C, Rinné S, Zumhagen S, Kiper AK, Silbernagel N, Netter MF, Stallmeyer B, Schulze-Bahr E, Decher N. Gain-of-function mutation in TASK-4 channels and severe cardiac conduction disorder. EMBO Mol Med 2015; 6:937-51. [PMID: 24972929 PMCID: PMC4119356 DOI: 10.15252/emmm.201303783] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Analyzing a patient with progressive and severe cardiac conduction disorder combined with idiopathic ventricular fibrillation (IVF), we identified a splice site mutation in the sodium channel gene SCN5A. Due to the severe phenotype, we performed whole-exome sequencing (WES) and identified an additional mutation in the KCNK17 gene encoding the K2P potassium channel TASK-4. The heterozygous change (c.262G>A) resulted in the p.Gly88Arg mutation in the first extracellular pore loop. Mutant TASK-4 channels generated threefold increased currents, while surface expression was unchanged, indicating enhanced conductivity. When co-expressed with wild-type channels, the gain-of-function by G88R was conferred in a dominant-active manner. We demonstrate that KCNK17 is strongly expressed in human Purkinje cells and that overexpression of G88R leads to a hyperpolarization and strong slowing of the upstroke velocity of spontaneously beating HL-1 cells. Thus, we propose that a gain-of-function by TASK-4 in the conduction system might aggravate slowed conductivity by the loss of sodium channel function. Moreover, WES supports a second hit-hypothesis in severe arrhythmia cases and identified KCNK17 as a novel arrhythmia gene.
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Affiliation(s)
- Corinna Friedrich
- Department of Cardiovascular Medicine, Institute for Genetics of Heart Diseases (IfGH), University Hospital Münster, Münster, Germany
| | - Susanne Rinné
- Institute of Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, Marburg, Germany
| | - Sven Zumhagen
- Department of Cardiovascular Medicine, Institute for Genetics of Heart Diseases (IfGH), University Hospital Münster, Münster, Germany
| | - Aytug K Kiper
- Institute of Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, Marburg, Germany
| | - Nicole Silbernagel
- Institute of Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, Marburg, Germany
| | - Michael F Netter
- Institute of Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, Marburg, Germany
| | - Birgit Stallmeyer
- Department of Cardiovascular Medicine, Institute for Genetics of Heart Diseases (IfGH), University Hospital Münster, Münster, Germany
| | - Eric Schulze-Bahr
- Department of Cardiovascular Medicine, Institute for Genetics of Heart Diseases (IfGH), University Hospital Münster, Münster, Germany
| | - Niels Decher
- Institute of Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, Marburg, Germany
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Wemhöner K, Friedrich C, Stallmeyer B, Coffey AJ, Grace A, Zumhagen S, Seebohm G, Ortiz-Bonnin B, Rinné S, Sachse FB, Schulze-Bahr E, Decher N. Gain-of-function mutations in the calcium channel CACNA1C (Cav1.2) cause non-syndromic long-QT but not Timothy syndrome. J Mol Cell Cardiol 2015; 80:186-95. [PMID: 25633834 DOI: 10.1016/j.yjmcc.2015.01.002] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 12/20/2014] [Accepted: 01/05/2015] [Indexed: 11/24/2022]
Abstract
Gain-of-function mutations in CACNA1C, encoding the L-type Ca(2+) channel Cav1.2, cause Timothy syndrome (TS), a multi-systemic disorder with dysmorphic features, long-QT syndrome (LQTS) and autism spectrum disorders. TS patients have heterozygous mutations (G402S and G406R) located in the alternatively spliced exon 8, causing a gain-of-function by reduced voltage-dependence of inactivation. Screening 540 unrelated patients with non-syndromic forms of LQTS, we identified six functional relevant CACNA1C mutations in different regions of the channel. All these mutations caused a gain-of-function combining different mechanisms, including changes in current amplitude, rate of inactivation and voltage-dependence of activation or inactivation, similar as in TS. Computer simulations support the theory that the novel CACNA1C mutations prolong action potential duration. We conclude that genotype-negative LQTS patients should be investigated for mutations in CACNA1C, as a gain-of-function in Cav1.2 is likely to cause LQTS and only specific and rare mutations, i.e. in exon 8, cause the multi-systemic TS.
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Affiliation(s)
- Konstantin Wemhöner
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Deutschhausstr. 1-2, 35037 Marburg, Germany
| | - Corinna Friedrich
- Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Münster, Domagkstr. 3, 48149 Münster, Germany
| | - Birgit Stallmeyer
- Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Münster, Domagkstr. 3, 48149 Münster, Germany
| | - Alison J Coffey
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK
| | - Andrew Grace
- Department of Biochemistry, University of Cambridge, Hopkins Building, Tennis Court Road, Cambridge CB2 1QW, UK; Papworth Hospital, Cambridge CB23 3RE, UK
| | - Sven Zumhagen
- Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Münster, Domagkstr. 3, 48149 Münster, Germany
| | - Guiscard Seebohm
- Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Münster, Domagkstr. 3, 48149 Münster, Germany
| | - Beatriz Ortiz-Bonnin
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Deutschhausstr. 1-2, 35037 Marburg, Germany
| | - Susanne Rinné
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Deutschhausstr. 1-2, 35037 Marburg, Germany
| | - Frank B Sachse
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, 95 South 2000 East, Salt Lake City, UT 84112, USA; Department of Bioengineering, James LeVoy Sorenson Molecular Biotechnology Building, 36 S. Wasatch Drive, Salt Lake City, UT 84112, USA
| | - Eric Schulze-Bahr
- Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Münster, Domagkstr. 3, 48149 Münster, Germany
| | - Niels Decher
- Institute of Physiology and Pathophysiology, Vegetative Physiology, Philipps-University of Marburg, Deutschhausstr. 1-2, 35037 Marburg, Germany.
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Streit AK, Matschke LA, Dolga AM, Rinné S, Decher N. RNA editing in the central cavity as a mechanism to regulate surface expression of the voltage-gated potassium channel Kv1.1. J Biol Chem 2014; 289:26762-26771. [PMID: 25100718 DOI: 10.1074/jbc.m113.545731] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Voltage-gated potassium (Kv) 1.1 channels undergo a specific enzymatic RNA deamination, generating a channel with a single amino acid exchange located in the inner pore cavity (Kv1.1(I400V)). We studied I400V-edited Kv1.1 channels in more detail and found that Kv1.1(I400V) gave rise to much smaller whole-cell currents than Kv1.1. To elucidate the mechanism behind this current reduction, we conducted electrophysiological recordings on single-channel level and did not find any differences. Next we examined channel surface expression in Xenopus oocytes and HeLa cells using a chemiluminescence assay and found the edited channels to be less readily expressed at the surface membrane. This reduction in surface expression was verified by fluorescence imaging experiments. Western blot analysis for comparison of protein abundances and glycosylation patterns did not show any difference between Kv1.1 and Kv1.1(I400V), further indicating that changed trafficking of Kv1.1(I400V) is causing the current reduction. Block of endocytosis by dynasore or AP180C did not abolish the differences in current amplitudes between Kv1.1 and Kv1.1(I400V), suggesting that backward trafficking is not affected. Therefore, our data suggest that I400V RNA editing of Kv1.1 leads to a reduced current size by a decreased forward trafficking of the channel to the surface membrane. This effect is specific for Kv1.1 because coexpression of Kv1.4 channel subunits with Kv1.1(I400V) abolishes these trafficking effects. Taken together, we identified RNA editing as a novel mechanism to regulate homomeric Kv1.1 channel trafficking. Fine-tuning of Kv1.1 surface expression by RNA editing might contribute to the complexity of neuronal Kv channel regulation.
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Affiliation(s)
- Anne K Streit
- Institut für Physiologie und Pathophysiologie, Fachbereich Medizin, and Philipps-Universität Marburg, 35037 Marburg, Germany
| | - Lina A Matschke
- Institut für Physiologie und Pathophysiologie, Fachbereich Medizin, and Philipps-Universität Marburg, 35037 Marburg, Germany
| | - Amalia M Dolga
- Institut für Pharmakologie und Klinische Pharmazie, Fachbereich Pharmazie, Philipps-Universität Marburg, 35037 Marburg, Germany
| | - Susanne Rinné
- Institut für Physiologie und Pathophysiologie, Fachbereich Medizin, and Philipps-Universität Marburg, 35037 Marburg, Germany
| | - Niels Decher
- Institut für Physiologie und Pathophysiologie, Fachbereich Medizin, and Philipps-Universität Marburg, 35037 Marburg, Germany.
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40
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Renigunta V, Fischer T, Zuzarte M, Kling S, Zou X, Siebert K, Limberg MM, Rinné S, Decher N, Schlichthörl G, Daut J. Cooperative endocytosis of the endosomal SNARE protein syntaxin-8 and the potassium channel TASK-1. Mol Biol Cell 2014; 25:1877-91. [PMID: 24743596 PMCID: PMC4055267 DOI: 10.1091/mbc.e13-10-0592] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
SNARE proteins can have functions unrelated to membrane fusion. The unassembled form of the SNARE protein syntaxin-8 interacts with the K+ channel TASK-1; both proteins are internalized via clathrin-mediated endocytosis in a cooperative manner. This is a novel mechanism for the control of endocytosis by cargo proteins. The endosomal SNARE protein syntaxin-8 interacts with the acid-sensitive potassium channel TASK-1. The functional relevance of this interaction was studied by heterologous expression of these proteins (and mutants thereof) in Xenopus oocytes and in mammalian cell lines. Coexpression of syntaxin-8 caused a fourfold reduction in TASK-1 current, a corresponding reduction in the expression of TASK-1 at the cell surface, and a marked increase in the rate of endocytosis of the channel. TASK-1 and syntaxin-8 colocalized in the early endosomal compartment, as indicated by the endosomal markers 2xFYVE and rab5. The stimulatory effect of the SNARE protein on the endocytosis of the channel was abolished when both an endocytosis signal in TASK-1 and an endocytosis signal in syntaxin-8 were mutated. A syntaxin-8 mutant that cannot assemble with other SNARE proteins had virtually the same effect as wild-type syntaxin-8. Total internal reflection fluorescence microscopy showed formation and endocytosis of vesicles containing fluorescence-tagged clathrin, TASK-1, and/or syntaxin-8. Our results suggest that the unassembled form of syntaxin-8 and the potassium channel TASK-1 are internalized via clathrin-mediated endocytosis in a cooperative manner. This implies that syntaxin-8 regulates the endocytosis of TASK-1. Our study supports the idea that endosomal SNARE proteins can have functions unrelated to membrane fusion.
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Affiliation(s)
- Vijay Renigunta
- Institute of Physiology and Pathophysiology, Marburg University, 35037 Marburg, Germany
| | - Thomas Fischer
- Institute of Physiology and Pathophysiology, Marburg University, 35037 Marburg, Germany
| | - Marylou Zuzarte
- Institute of Physiology and Pathophysiology, Marburg University, 35037 Marburg, Germany
| | - Stefan Kling
- Institute of Physiology and Pathophysiology, Marburg University, 35037 Marburg, Germany
| | - Xinle Zou
- Institute of Physiology and Pathophysiology, Marburg University, 35037 Marburg, Germany
| | - Kai Siebert
- Institute of Physiology and Pathophysiology, Marburg University, 35037 Marburg, Germany
| | - Maren M Limberg
- Institute of Physiology and Pathophysiology, Marburg University, 35037 Marburg, Germany
| | - Susanne Rinné
- Institute of Physiology and Pathophysiology, Marburg University, 35037 Marburg, Germany
| | - Niels Decher
- Institute of Physiology and Pathophysiology, Marburg University, 35037 Marburg, Germany
| | - Günter Schlichthörl
- Institute of Physiology and Pathophysiology, Marburg University, 35037 Marburg, Germany
| | - Jürgen Daut
- Institute of Physiology and Pathophysiology, Marburg University, 35037 Marburg, Germany
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Marzian S, Stansfeld PJ, Rapedius M, Rinné S, Nematian-Ardestani E, Abbruzzese JL, Steinmeyer K, Sansom MSP, Sanguinetti MC, Baukrowitz T, Decher N. Side pockets provide the basis for a new mechanism of Kv channel-specific inhibition. Nat Chem Biol 2013; 9:507-13. [PMID: 23728494 DOI: 10.1038/nchembio.1271] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Accepted: 04/29/2013] [Indexed: 01/09/2023]
Abstract
Most known small-molecule inhibitors of voltage-gated ion channels have poor subtype specificity because they interact with a highly conserved binding site in the central cavity. Using alanine-scanning mutagenesis, electrophysiological recordings and molecular modeling, we have identified a new drug-binding site in Kv1.x channels. We report that Psora-4 can discriminate between related Kv channel subtypes because, in addition to binding the central pore cavity, it binds a second, less conserved site located in side pockets formed by the backsides of S5 and S6, the S4-S5 linker, part of the voltage sensor and the pore helix. Simultaneous drug occupation of both binding sites results in an extremely stable nonconducting state that confers high affinity, cooperativity, use-dependence and selectivity to Psora-4 inhibition of Kv1.x channels. This new mechanism of inhibition represents a molecular basis for the development of a new class of allosteric and selective voltage-gated channel inhibitors.
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Affiliation(s)
- Stefanie Marzian
- Institute for Physiology and Pathophysiology, University of Marburg, Marburg, Germany
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42
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Limberg MM, Zumhagen S, Netter MF, Coffey AJ, Grace A, Rogers J, Böckelmann D, Rinné S, Stallmeyer B, Decher N, Schulze-Bahr E. Non dominant-negative KCNJ2 gene mutations leading to Andersen-Tawil syndrome with an isolated cardiac phenotype. Basic Res Cardiol 2013; 108:353. [DOI: 10.1007/s00395-013-0353-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Revised: 04/12/2013] [Accepted: 04/18/2013] [Indexed: 11/25/2022]
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Wemhöner K, Silbernagel N, Marzian S, Netter MF, Rinné S, Stansfeld PJ, Decher N. A leucine zipper motif essential for gating of hyperpolarization-activated channels. J Biol Chem 2012; 287:40150-60. [PMID: 23048023 DOI: 10.1074/jbc.m112.378513] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND It is poorly understood how hyperpolarization-activated cyclic nucleotide-gated channels (HCNs) function. RESULTS We have identified a leucine zipper in the S5 segment of HCNs, regulating hyperpolarization-activated and instantaneous current components. CONCLUSION The leucine zipper is essential for HCN channel gating. SIGNIFICANCE The identification and functional characterization of the leucine zipper is an important step toward the understanding of HCN channel function. Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are pacemakers in cardiac myocytes and neurons. Although their membrane topology closely resembles that of voltage-gated K(+) channels, the mechanism of their unique gating behavior in response to hyperpolarization is still poorly understood. We have identified a highly conserved leucine zipper motif in the S5 segment of HCN family members. In order to study the role of this motif for channel function, the leucine residues of the zipper were individually mutated to alanine, arginine, or glutamine residues. Leucine zipper mutants traffic to the plasma membrane, but the channels lose their sensitivity to open upon hyperpolarization. Thus, our data indicate that the leucine zipper is an important molecular determinant for hyperpolarization-activated channel gating. Residues of the leucine zipper interact with the adjacent S6 segment of the channel. This interaction is essential for voltage-dependent gating of the channel. The lower part of the leucine zipper, at the intracellular mouth of the channel, is important for stabilizing the closed state. Mutations at these sites increase current amplitudes or result in channels with deficient closing and increased min-P(o). Our data are further supported by homology models of the open and closed state of the HCN2 channel pore. Thus, we conclude that the leucine zipper of HCN channels is a major determinant for hyperpolarization-activated channel gating.
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Affiliation(s)
- Konstantin Wemhöner
- Institute for Physiology, Vegetative Physiology Group, University of Marburg, Deutschhausstrasse 1-2, 35037 Marburg, Germany
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Froese A, Breher SS, Waldeyer C, Schindler RFR, Nikolaev VO, Rinné S, Wischmeyer E, Schlueter J, Becher J, Simrick S, Vauti F, Kuhtz J, Meister P, Kreissl S, Torlopp A, Liebig SK, Laakmann S, Müller TD, Neumann J, Stieber J, Ludwig A, Maier SK, Decher N, Arnold HH, Kirchhof P, Fabritz L, Brand T. Popeye domain containing proteins are essential for stress-mediated modulation of cardiac pacemaking in mice. J Clin Invest 2012; 122:1119-30. [PMID: 22354168 DOI: 10.1172/jci59410] [Citation(s) in RCA: 112] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Accepted: 12/21/2011] [Indexed: 01/04/2023] Open
Abstract
Cardiac pacemaker cells create rhythmic pulses that control heart rate; pacemaker dysfunction is a prevalent disorder in the elderly, but little is known about the underlying molecular causes. Popeye domain containing (Popdc) genes encode membrane proteins with high expression levels in cardiac myocytes and specifically in the cardiac pacemaking and conduction system. Here, we report the phenotypic analysis of mice deficient in Popdc1 or Popdc2. ECG analysis revealed severe sinus node dysfunction when freely roaming mutant animals were subjected to physical or mental stress. In both mutants, bradyarrhythmia developed in an age-dependent manner. Furthermore, we found that the conserved Popeye domain functioned as a high-affinity cAMP-binding site. Popdc proteins interacted with the potassium channel TREK-1, which led to increased cell surface expression and enhanced current density, both of which were negatively modulated by cAMP. These data indicate that Popdc proteins have an important regulatory function in heart rate dynamics that is mediated, at least in part, through cAMP binding. Mice with mutant Popdc1 and Popdc2 alleles are therefore useful models for the dissection of the mechanisms causing pacemaker dysfunction and could aid in the development of strategies for therapeutic intervention.
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Affiliation(s)
- Alexander Froese
- Cell and Developmental Biology, University of Würzburg, Würzburg, Germany
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45
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Limberg SH, Netter MF, Rolfes C, Rinné S, Schlichthörl G, Zuzarte M, Vassiliou T, Moosdorf R, Wulf H, Daut J, Sachse FB, Decher N. TASK-1 channels may modulate action potential duration of human atrial cardiomyocytes. Cell Physiol Biochem 2011; 28:613-24. [PMID: 22178873 DOI: 10.1159/000335757] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/28/2011] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND/AIMS Atrial fibrillation is the most common arrhythmia in the elderly, and potassium channels with atrium-specific expression have been discussed as targets to treat atrial fibrillation. Our aim was to characterize TASK-1 channels in human heart and to functionally describe the role of the atrial whole cell current I(TASK-1). METHODS AND RESULTS Using quantitative PCR, we show that TASK-1 is predominantly expressed in the atria, auricles and atrio-ventricular node of the human heart. Single channel recordings show the functional expression of TASK-1 in right human auricles. In addition, we describe for the first time the whole cell current carried by TASK-1 channels (I(TASK-1)) in human atrial tissue. We show that I(TASK-1) contributes to the sustained outward current I(Ksus) and that I(TASK-1) is a major component of the background conductance in human atrial cardiomyocytes. Using patch clamp recordings and mathematical modeling of action potentials, we demonstrate that modulation of I(TASK-1) can alter human atrial action potential duration. CONCLUSION Due to the lack of ventricular expression and the ability to alter human atrial action potential duration, TASK-1 might be a drug target for the treatment of atrial fibrillation.
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Affiliation(s)
- Sven H Limberg
- Institut für Physiologie und Pathophysiologie, Abteilung vegetative Physiologie, Universität Marburg, Deutschhausstraße 1-2, Marburg, Germany
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Streit AK, Netter MF, Kempf F, Walecki M, Rinné S, Bollepalli MK, Preisig-Müller R, Renigunta V, Daut J, Baukrowitz T, Sansom MSP, Stansfeld PJ, Decher N. A specific two-pore domain potassium channel blocker defines the structure of the TASK-1 open pore. J Biol Chem 2011; 286:13977-84. [PMID: 21362619 PMCID: PMC3077598 DOI: 10.1074/jbc.m111.227884] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Two-pore domain potassium (K(2P)) channels play a key role in setting the membrane potential of excitable cells. Despite their role as putative targets for drugs and general anesthetics, little is known about the structure and the drug binding site of K(2P) channels. We describe A1899 as a potent and highly selective blocker of the K(2P) channel TASK-1. As A1899 acts as an open-channel blocker and binds to residues forming the wall of the central cavity, the drug was used to further our understanding of the channel pore. Using alanine mutagenesis screens, we have identified residues in both pore loops, the M2 and M4 segments, and the halothane response element to form the drug binding site of TASK-1. Our experimental data were used to validate a K(2P) open-pore homology model of TASK-1, providing structural insights for future rational design of drugs targeting K(2P) channels.
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Affiliation(s)
- Anne K Streit
- Institute for Physiology and Pathophysiology, Vegetative Physiology Group, University of Marburg, 35037 Marburg, Germany
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Decher N, Wemhöner K, Rinné S, Netter MF, Zuzarte M, Aller MI, Kaufmann SG, Li XT, Meuth SG, Daut J, Sachse FB, Maier SK. Knock-Out of the Potassium Channel TASK-1 Leads to a Prolonged QT Interval and a Disturbed QRS Complex. Cell Physiol Biochem 2011; 28:77-86. [DOI: 10.1159/000331715] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/07/2011] [Indexed: 01/13/2023] Open
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Gao YD, Hanley PJ, Rinné S, Zuzarte M, Daut J. Calcium-activated K(+) channel (K(Ca)3.1) activity during Ca(2+) store depletion and store-operated Ca(2+) entry in human macrophages. Cell Calcium 2010; 48:19-27. [PMID: 20630587 DOI: 10.1016/j.ceca.2010.06.002] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2010] [Revised: 06/16/2010] [Accepted: 06/18/2010] [Indexed: 01/23/2023]
Abstract
STIM1 'senses' decreases in endoplasmic reticular (ER) luminal Ca(2+) and induces store-operated Ca(2+) (SOC) entry through plasma membrane Orai channels. The Ca(2+)/calmodulin-activated K(+) channel K(Ca)3.1 (previously known as SK4) has been implicated as an 'amplifier' of the Ca(2+)-release activated Ca(2+) (CRAC) current, especially in T lymphocytes. We have previously shown that human macrophages express K(Ca)3.1, and here we used the whole-cell patch-clamp technique to investigate the activity of these channels during Ca(2+) store depletion and store-operated Ca(2+) influx. Using RT-PCR, we found that macrophages express the elementary CRAC channel components Orai1 and STIM1, as well as Orai2, Orai3 and STIM2, but not the putatively STIM1-activated channels TRPC1, TRPC3-7 or TRPV6. In whole-cell configuration, a robust Ca(2+)-induced outwardly rectifying K(+) current inhibited by clotrimazole and augmented by DC-EBIO could be detected, consistent with K(Ca)3.1 channel current (also known as intermediate-conductance IK1). Introduction of extracellular Ca(2+) following Ca(2+) store depletion via P2Y(2) receptors induced a robust charybdotoxin (CTX)- and 2-APB-sensitive outward K(+) current and hyperpolarization. We also found that SOC entry induced by thapsigargin treatment induced CTX-sensitive K(+) current in HEK293 cells transiently expressing K(Ca)3.1. Our data suggest that SOC and K(Ca)3.1 channels are tightly coupled, such that a small Ca(2+) influx current induces a much large K(Ca)3.1 channel current and hyperpolarization, providing the necessary electrochemical driving force for prolonged Ca(2+) signaling and store repletion.
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Affiliation(s)
- Ya-dong Gao
- Institut für Physiologie und Pathophysiologie, Universität Marburg, Deutschhausstr. 2, 35037 Marburg, Germany.
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49
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Zuzarte M, Heusser K, Renigunta V, Schlichthörl G, Rinné S, Wischmeyer E, Daut J, Schwappach B, Preisig-Müller R. Intracellular traffic of the K+ channels TASK-1 and TASK-3: role of N- and C-terminal sorting signals and interaction with 14-3-3 proteins. J Physiol 2009; 587:929-52. [PMID: 19139046 DOI: 10.1113/jphysiol.2008.164756] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The two-pore-domain potassium channels TASK-1 (KCNK3) and TASK-3 (KCNK9) modulate the electrical activity of neurons and many other cell types. We expressed TASK-1, TASK-3 and related reporter constructs in Xenopus oocytes, mammalian cell lines and various yeast strains to study the mechanisms controlling their transport to the surface membrane and the role of 14-3-3 proteins. We measured potassium currents with the voltage-clamp technique and fused N- and C-terminal fragments of the channels to various reporter proteins to study changes in subcellular localisation and surface expression. Mutational analysis showed that binding of 14-3-3 proteins to the extreme C-terminus of TASK-1 and TASK-3 masks a tri-basic motif, KRR, which differs in several important aspects from canonical arginine-based (RxR) or lysine-based (KKxx) retention signals. Pulldown experiments with GST fusion proteins showed that the KRR motif in the C-terminus of TASK-3 channels was able to bind to COPI coatomer. Disabling the binding of 14-3-3, which exposes the KRR motif, caused localisation of the GFP-tagged channel protein mainly to the Golgi complex. TASK-1 and TASK-3 also possess a di-basic N-terminal retention signal, KR, whose function was found to be independent of the binding of 14-3-3. Suppression of channel surface expression with dominant-negative channel mutants revealed that interaction with 14-3-3 has no significant effect on the dimeric assembly of the channels. Our results give a comprehensive description of the mechanisms by which 14-3-3 proteins, together with N- and C-terminal sorting signals, control the intracellular traffic of TASK-1 and TASK-3.
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Affiliation(s)
- Marylou Zuzarte
- Institute of Physiology, Marburg University, Deutschhausstrasse 2, 35037 Marburg, Germany
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Mederos Y Schnitzler M, Rinné S, Skrobek L, Renigunta V, Schlichthörl G, Derst C, Gudermann T, Daut J, Preisig-Müller R. Mutation of histidine 105 in the T1 domain of the potassium channel Kv2.1 disrupts heteromerization with Kv6.3 and Kv6.4. J Biol Chem 2008; 284:4695-704. [PMID: 19074135 DOI: 10.1074/jbc.m808786200] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The voltage-activated K(+) channel subunit Kv2.1 can form heterotetramers with members of the Kv6 subfamily, generating channels with biophysical properties different from homomeric Kv2.1 channels. The N-terminal tetramerization domain (T1) has been shown previously to play a role in Kv channel assembly, but the mechanisms controlling specific heteromeric assembly are still unclear. In Kv6.x channels the histidine residue of the zinc ion-coordinating C3H1 motif of Kv2.1 is replaced by arginine or valine. Using a yeast two-hybrid assay, we found that substitution of the corresponding histidine 105 in Kv2.1 by valine (H105V) or arginine (H105R) disrupted the interaction of the T1 domain of Kv2.1 with the T1 domains of both Kv6.3 and Kv6.4, whereas interaction of the T1 domain of Kv2.1 with itself was unaffected by this mutation. Using fluorescence resonance energy transfer (FRET), interaction could be detected between the subunits Kv2.1/Kv2.1, Kv2.1/Kv6.3, and Kv2.1/Kv6.4. Reduced FRET signals were obtained after co-expression of Kv2.1(H105V) or Kv2.1(H105R) with Kv6.3 or Kv6.4. Wild-type Kv2.1 but not Kv2.1(H105V) could be co-immunoprecipitated with Kv6.4. Co-expression of dominant-negative mutants of Kv6.3 reduced the current produced Kv2.1, but not of Kv2.1(H105R) mutants. Co-expression of Kv6.3 or Kv6.4 with wt Kv2.1 but not with Kv2.1(H105V) or Kv2.1(H105R) changed the voltage dependence of activation of the channels. Our results suggest that His-105 in the T1 domain of Kv2.1 is required for functional heteromerization with members of the Kv6 subfamily. We conclude from our findings that Kv2.1 and Kv6.x subunits have complementary T1 domains that control selective heteromerization.
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