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Lei P, Zhu Q, Dong W. Investigation of a novel TBC1D24 variation causing autosomal dominant non-syndromic hearing loss. Sci Rep 2024; 14:4734. [PMID: 38413761 PMCID: PMC10899226 DOI: 10.1038/s41598-024-55435-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 02/23/2024] [Indexed: 02/29/2024] Open
Abstract
Hearing loss is considered one of the most common sensory neurological defects, with approximately 60% of cases attributed to genetic factors. Human pathogenic variants in the TBC1D24 gene are associated with various clinical phenotypes, including dominant nonsyndromic hearing loss DFNA65, characterized by progressive hearing loss after the development of language. This study provides an in-depth analysis of the causative gene and mutations in a family with hereditary deafness. We recruited a three-generation family with autosomal dominant nonsyndromic hearing loss (ADNSHL) and conducted detailed medical histories and relevant examinations. Next-generation sequencing (NGS) was used to identify genetic variants in the proband, which were then validated using Sanger sequencing. Multiple computational software tools were employed to predict the impact of the variant on the function and structure of the TBC1D24 protein. A series of bioinformatics tools were applied to determine the conservation characteristics of the sequence, establish a three-dimensional structural model, and investigate changes in molecular dynamics. A detailed genotype and phenotype analysis were carried out. The family exhibited autosomal dominant, progressive, postlingual, and nonsyndromic sensorineural hearing loss. A novel heterozygous variant, c.1459C>T (p.His487Tyr), in the TBC1D24 gene was identified and confirmed to be associated with the hearing loss phenotype in this family. Conservation analysis revealed high conservation of the amino acid affected by this variant across different species. The mutant protein showed alterations in thermodynamic stability, elasticity, and conformational dynamics. Molecular dynamics simulations indicated changes in RMSD, RMSF, Rg, and SASA of the mutant structure. We computed the onset age of non-syndromic hearing loss associated with mutations in the TBC1D24 gene and identified variations in the hearing progression time and annual threshold deterioration across different frequencies. The identification of a new variant associated with rare autosomal dominant nonsyndromic hereditary hearing loss in this family broadens the range of mutations in the TBC1D24 gene. This variant has the potential to influence the interaction between the TLDc domain and TBC domain, thereby affecting the protein's biological function.
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Affiliation(s)
- Peiliang Lei
- Department of Otolaryngology Head & Neck Surgery, The Second Hospital of Hebei Medical University, Heping West Road No. 215, Shijiazhuang, 050000, Hebei, China
- Department of Otolaryngology Head & Neck Surgery, The Third Hospital of Shijiazhuang, Tiyu South Street No.15, Shijiazhuang, 050011, Hebei, China
| | - Qingwen Zhu
- Department of Otolaryngology Head & Neck Surgery, The Second Hospital of Hebei Medical University, Heping West Road No. 215, Shijiazhuang, 050000, Hebei, China.
| | - Wenrong Dong
- Department of Otolaryngology Head & Neck Surgery, The Third Hospital of Shijiazhuang, Tiyu South Street No.15, Shijiazhuang, 050011, Hebei, China
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2
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Wilmes S, Kümmel D. Insights into the role of the membranes in Rab GTPase regulation. Curr Opin Cell Biol 2023; 83:102177. [PMID: 37327649 DOI: 10.1016/j.ceb.2023.102177] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 05/15/2023] [Accepted: 05/19/2023] [Indexed: 06/18/2023]
Abstract
Rab GTPases are molecular switches with essential roles in mediating vesicular trafficking and establishing organelle identity. The conversion from the inactive, cytosolic to the membrane-bound, active species and back is tightly controlled by regulatory proteins. Recently, the roles of membrane properties and lipid composition of different target organelles in determining the activity state of Rabs have come to light. The investigation of several Rab guanine nucleotide exchange factors (GEFs) has revealed principles of how the recruitment via lipid interactions and the spatial confinement on the membrane surface contribute to spatiotemporal specificity in the Rab GTPase network. This paints an intricate picture of the control mechanisms in Rab activation and highlights the importance of the membrane lipid code in the organization of the endomembrane system.
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Affiliation(s)
- Stephan Wilmes
- University of Münster, Institute of Biochemistry, Corrensstraße 36, 48149 Münster, Germany
| | - Daniel Kümmel
- University of Münster, Institute of Biochemistry, Corrensstraße 36, 48149 Münster, Germany.
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3
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Mackrill JJ. Non-inositol 1,4,5-trisphosphate (IP3) receptor IP3-binding proteins. BIOCHIMICA ET BIOPHYSICA ACTA (BBA) - MOLECULAR CELL RESEARCH 2023; 1870:119470. [PMID: 37011730 DOI: 10.1016/j.bbamcr.2023.119470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 03/23/2023] [Accepted: 03/23/2023] [Indexed: 04/03/2023]
Abstract
Conventionally, myo-D-inositol 1, 4,5-trisphosphate (IP3) is thought to exert its second messenger effects through the gating of IP3R Ca2+ release channels, located in Ca2+-storage organelles like the endoplasmic reticulum. However, there is considerable indirect evidence to support the concept that IP3 might interact with other, non-IP3R proteins within cells. To explore this possibility further, the Protein Data Bank was searched using the term "IP3". This resulted in the retrieval of 203 protein structures, the majority of which were members of the IP3R/ryanodine receptor superfamily of channels. Only 49 of these structures were complexed with IP3. These were inspected for their ability to interact with the carbon-1 phosphate of IP3, since this is the least accessible phosphate group of its precursor, phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2). This reduced the number of structures retrieved to 35, of which 9 were IP3Rs. The remaining 26 structures represent a diverse range of proteins, including inositol-lipid metabolizing enzymes, signal transducers, PH domain containing proteins, cytoskeletal anchor proteins, the TRPV4 ion channel, a retroviral Gag protein and fibroblast growth factor 2. Such proteins may impact on IP3 signalling and its effects on cell-biology. This represents an area open for exploration in the field of IP3 signalling.
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Affiliation(s)
- John James Mackrill
- Department of Physiology, University College Cork, Western Gateway Building, Western Road, Cork T12 XF62, Ireland.
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4
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Jacquemyn J, Kuenen S, Swerts J, Pavie B, Vijayan V, Kilic A, Chabot D, Wang YC, Schoovaerts N, Corthout N, Verstreken P. Parkinsonism mutations in DNAJC6 cause lipid defects and neurodegeneration that are rescued by Synj1. NPJ Parkinsons Dis 2023; 9:19. [PMID: 36739293 PMCID: PMC9899244 DOI: 10.1038/s41531-023-00459-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 01/16/2023] [Indexed: 02/06/2023] Open
Abstract
Recent evidence links dysfunctional lipid metabolism to the pathogenesis of Parkinson's disease, but the mechanisms are not resolved. Here, we generated a new Drosophila knock-in model of DNAJC6/Auxilin and find that the pathogenic mutation causes synaptic dysfunction, neurological defects and neurodegeneration, as well as specific lipid metabolism alterations. In these mutants, membrane lipids containing long-chain polyunsaturated fatty acids, including phosphatidylinositol lipid species that are key for synaptic vesicle recycling and organelle function, are reduced. Overexpression of another protein mutated in Parkinson's disease, Synaptojanin-1, known to bind and metabolize specific phosphoinositides, rescues the DNAJC6/Auxilin lipid alterations, the neuronal function defects and neurodegeneration. Our work reveals a functional relation between two proteins mutated in Parkinsonism and implicates deregulated phosphoinositide metabolism in the maintenance of neuronal integrity and neuronal survival.
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Affiliation(s)
- Julie Jacquemyn
- grid.511015.1VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium ,grid.5596.f0000 0001 0668 7884KU Leuven, Department of Neurosciences, Leuven Brain Institute, Mission Lucidity, 3000 Leuven, Belgium ,grid.17089.370000 0001 2190 316XPresent Address: Neuroscience and Mental Health Institute, University of Alberta, Department of Physiology, Department of Cell Biology, Group on Molecular and Cell Biology of Lipids, Edmonton, Alberta Canada
| | - Sabine Kuenen
- grid.511015.1VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium ,grid.5596.f0000 0001 0668 7884KU Leuven, Department of Neurosciences, Leuven Brain Institute, Mission Lucidity, 3000 Leuven, Belgium
| | - Jef Swerts
- grid.511015.1VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium ,grid.5596.f0000 0001 0668 7884KU Leuven, Department of Neurosciences, Leuven Brain Institute, Mission Lucidity, 3000 Leuven, Belgium
| | - Benjamin Pavie
- grid.511015.1VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium ,grid.5596.f0000 0001 0668 7884KU Leuven, Department of Neurosciences, Leuven Brain Institute, Mission Lucidity, 3000 Leuven, Belgium ,VIB-Bioimaging Core, 3000 Leuven, Belgium
| | - Vinoy Vijayan
- grid.511015.1VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium ,grid.5596.f0000 0001 0668 7884KU Leuven, Department of Neurosciences, Leuven Brain Institute, Mission Lucidity, 3000 Leuven, Belgium
| | - Ayse Kilic
- grid.511015.1VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium ,grid.5596.f0000 0001 0668 7884KU Leuven, Department of Neurosciences, Leuven Brain Institute, Mission Lucidity, 3000 Leuven, Belgium
| | - Dries Chabot
- grid.511015.1VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium ,grid.5596.f0000 0001 0668 7884KU Leuven, Department of Neurosciences, Leuven Brain Institute, Mission Lucidity, 3000 Leuven, Belgium
| | - Yu-Chun Wang
- grid.511015.1VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium ,grid.5596.f0000 0001 0668 7884KU Leuven, Department of Neurosciences, Leuven Brain Institute, Mission Lucidity, 3000 Leuven, Belgium ,grid.11486.3a0000000104788040Present Address: VIB Technology Watch, Technology Innovation Laboratory, VIB, Gent, Belgium
| | - Nils Schoovaerts
- grid.511015.1VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium ,grid.5596.f0000 0001 0668 7884KU Leuven, Department of Neurosciences, Leuven Brain Institute, Mission Lucidity, 3000 Leuven, Belgium
| | - Nikky Corthout
- grid.511015.1VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium ,grid.5596.f0000 0001 0668 7884KU Leuven, Department of Neurosciences, Leuven Brain Institute, Mission Lucidity, 3000 Leuven, Belgium ,VIB-Bioimaging Core, 3000 Leuven, Belgium
| | - Patrik Verstreken
- grid.511015.1VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium ,grid.5596.f0000 0001 0668 7884KU Leuven, Department of Neurosciences, Leuven Brain Institute, Mission Lucidity, 3000 Leuven, Belgium
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Yang JY, Wang WQ, Han MY, Huang SS, Wang GJ, Su Y, Xu JC, Fu Y, Kang DY, Yang K, Zhang X, Liu X, Gao X, Yuan YY, Dai P. Addition of an affected family member to a previously ascertained autosomal recessive nonsyndromic hearing loss pedigree and systematic phenotype-genotype analysis of splice-site variants in MYO15A. BMC Med Genomics 2022; 15:241. [PMCID: PMC9673454 DOI: 10.1186/s12920-022-01368-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 09/29/2022] [Indexed: 11/19/2022] Open
Abstract
Pathogenic variants in MYO15A are known to cause autosomal recessive nonsyndromic hearing loss (ARNSHL), DFNB3. We have previously reported on one ARNSHL family including two affected siblings and identified MYO15A c.5964+3G > A and c.8375 T > C (p.Val2792Ala) as the possible deafness-causing variants. Eight year follow up identified one new affected individual in this family, who also showed congenital, severe to profound sensorineural hearing loss. By whole exome sequencing, we identified a new splice-site variant c.5531+1G > C (maternal allele), in a compound heterozygote with previously identified missense variant c.8375 T > C (p.Val2792Ala) (paternal allele) in MYO15A as the disease-causing variants. The new affected individual underwent unilateral cochlear implantation at the age of 1 year, and 5 year follow-up showed satisfactory speech and language outcomes. Our results further indicate that MYO15A-associated hearing loss is good candidates for cochlear implantation, which is in accordance with previous report. In light of our findings and review of the literatures, 58 splice-site variants in MYO15A are correlated with a severe deafness phenotype, composed of 46 canonical splice-site variants and 12 non-canonical splice-site variants.
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Affiliation(s)
- Jin-Yuan Yang
- grid.488137.10000 0001 2267 2324College of Otolaryngology Head and Neck Surgery, Chinese PLA General Hospital, Chinese PLA Medical School, 28 Fuxing Road, Beijing, 100853 People’s Republic of China ,grid.419897.a0000 0004 0369 313XNational Clinical Research Center for Otolaryngologic Diseases, State Key Lab of Hearing Science, Ministry of Education, Beijing, People’s Republic of China ,Beijing Key Lab of Hearing Impairment Prevention and Treatment, Beijing, People’s Republic of China
| | - Wei-Qian Wang
- grid.488137.10000 0001 2267 2324College of Otolaryngology Head and Neck Surgery, Chinese PLA General Hospital, Chinese PLA Medical School, 28 Fuxing Road, Beijing, 100853 People’s Republic of China ,grid.419897.a0000 0004 0369 313XNational Clinical Research Center for Otolaryngologic Diseases, State Key Lab of Hearing Science, Ministry of Education, Beijing, People’s Republic of China ,Beijing Key Lab of Hearing Impairment Prevention and Treatment, Beijing, People’s Republic of China ,grid.488137.10000 0001 2267 2324Department of Otolaryngology, PLA Rocket Force Characteristic Medical Center, 16# XinWai Da Jie, Beijing, 100088 People’s Republic of China
| | - Ming-Yu Han
- grid.488137.10000 0001 2267 2324College of Otolaryngology Head and Neck Surgery, Chinese PLA General Hospital, Chinese PLA Medical School, 28 Fuxing Road, Beijing, 100853 People’s Republic of China ,grid.419897.a0000 0004 0369 313XNational Clinical Research Center for Otolaryngologic Diseases, State Key Lab of Hearing Science, Ministry of Education, Beijing, People’s Republic of China ,Beijing Key Lab of Hearing Impairment Prevention and Treatment, Beijing, People’s Republic of China
| | - Sha-Sha Huang
- grid.488137.10000 0001 2267 2324College of Otolaryngology Head and Neck Surgery, Chinese PLA General Hospital, Chinese PLA Medical School, 28 Fuxing Road, Beijing, 100853 People’s Republic of China ,grid.419897.a0000 0004 0369 313XNational Clinical Research Center for Otolaryngologic Diseases, State Key Lab of Hearing Science, Ministry of Education, Beijing, People’s Republic of China ,Beijing Key Lab of Hearing Impairment Prevention and Treatment, Beijing, People’s Republic of China
| | - Guo-Jian Wang
- grid.488137.10000 0001 2267 2324College of Otolaryngology Head and Neck Surgery, Chinese PLA General Hospital, Chinese PLA Medical School, 28 Fuxing Road, Beijing, 100853 People’s Republic of China ,grid.419897.a0000 0004 0369 313XNational Clinical Research Center for Otolaryngologic Diseases, State Key Lab of Hearing Science, Ministry of Education, Beijing, People’s Republic of China ,Beijing Key Lab of Hearing Impairment Prevention and Treatment, Beijing, People’s Republic of China
| | - Yu Su
- Department of Otolaryngology, Head and Neck Surgery, Chinese PLA General Hospital Affiliated Hainan Hospital, Jianglin Road, Sanya, 572013 People’s Republic of China ,Hainan Province Clinical Research Center for Otolaryngologic and Head and Neck Diseases, Jianglin Road, Sanya, 572013 People’s Republic of China
| | - Jin-Cao Xu
- grid.488137.10000 0001 2267 2324Department of Otolaryngology, PLA Rocket Force Characteristic Medical Center, 16# XinWai Da Jie, Beijing, 100088 People’s Republic of China
| | - Ying Fu
- grid.27255.370000 0004 1761 1174Department of Otorhinolaryngology, Qilu Hospital (Qingdao), Cheeloo College of Medicine, Shandong University, 758 Hefei Road, Qingdao, 266035 Shandong People’s Republic of China
| | - Dong-Yang Kang
- grid.488137.10000 0001 2267 2324College of Otolaryngology Head and Neck Surgery, Chinese PLA General Hospital, Chinese PLA Medical School, 28 Fuxing Road, Beijing, 100853 People’s Republic of China ,grid.419897.a0000 0004 0369 313XNational Clinical Research Center for Otolaryngologic Diseases, State Key Lab of Hearing Science, Ministry of Education, Beijing, People’s Republic of China ,Beijing Key Lab of Hearing Impairment Prevention and Treatment, Beijing, People’s Republic of China
| | - Kun Yang
- grid.488137.10000 0001 2267 2324Postgraduate Training Base of Jinzhou Medical University, The PLA Rocket Force Characteristic Medical Center, 16# XinWai Da Jie, Beijing, 100088 People’s Republic of China
| | - Xin Zhang
- grid.488137.10000 0001 2267 2324College of Otolaryngology Head and Neck Surgery, Chinese PLA General Hospital, Chinese PLA Medical School, 28 Fuxing Road, Beijing, 100853 People’s Republic of China ,grid.419897.a0000 0004 0369 313XNational Clinical Research Center for Otolaryngologic Diseases, State Key Lab of Hearing Science, Ministry of Education, Beijing, People’s Republic of China ,Beijing Key Lab of Hearing Impairment Prevention and Treatment, Beijing, People’s Republic of China
| | - Xing Liu
- grid.488137.10000 0001 2267 2324Department of Otolaryngology, PLA Rocket Force Characteristic Medical Center, 16# XinWai Da Jie, Beijing, 100088 People’s Republic of China
| | - Xue Gao
- grid.488137.10000 0001 2267 2324College of Otolaryngology Head and Neck Surgery, Chinese PLA General Hospital, Chinese PLA Medical School, 28 Fuxing Road, Beijing, 100853 People’s Republic of China ,grid.419897.a0000 0004 0369 313XNational Clinical Research Center for Otolaryngologic Diseases, State Key Lab of Hearing Science, Ministry of Education, Beijing, People’s Republic of China ,Beijing Key Lab of Hearing Impairment Prevention and Treatment, Beijing, People’s Republic of China ,grid.488137.10000 0001 2267 2324Department of Otolaryngology, PLA Rocket Force Characteristic Medical Center, 16# XinWai Da Jie, Beijing, 100088 People’s Republic of China
| | - Yong-Yi Yuan
- grid.488137.10000 0001 2267 2324College of Otolaryngology Head and Neck Surgery, Chinese PLA General Hospital, Chinese PLA Medical School, 28 Fuxing Road, Beijing, 100853 People’s Republic of China ,grid.419897.a0000 0004 0369 313XNational Clinical Research Center for Otolaryngologic Diseases, State Key Lab of Hearing Science, Ministry of Education, Beijing, People’s Republic of China ,Beijing Key Lab of Hearing Impairment Prevention and Treatment, Beijing, People’s Republic of China
| | - Pu Dai
- grid.488137.10000 0001 2267 2324College of Otolaryngology Head and Neck Surgery, Chinese PLA General Hospital, Chinese PLA Medical School, 28 Fuxing Road, Beijing, 100853 People’s Republic of China ,grid.419897.a0000 0004 0369 313XNational Clinical Research Center for Otolaryngologic Diseases, State Key Lab of Hearing Science, Ministry of Education, Beijing, People’s Republic of China ,Beijing Key Lab of Hearing Impairment Prevention and Treatment, Beijing, People’s Republic of China
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Michetti C, Falace A, Benfenati F, Fassio A. Synaptic genes and neurodevelopmental disorders: From molecular mechanisms to developmental strategies of behavioral testing. Neurobiol Dis 2022; 173:105856. [PMID: 36070836 DOI: 10.1016/j.nbd.2022.105856] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 08/29/2022] [Accepted: 08/30/2022] [Indexed: 10/14/2022] Open
Abstract
Synaptopathies are a class of neurodevelopmental disorders caused by modification in genes coding for synaptic proteins. These proteins oversee the process of neurotransmission, mainly controlling the fusion and recycling of synaptic vesicles at the presynaptic terminal, the expression and localization of receptors at the postsynapse and the coupling between the pre- and the postsynaptic compartments. Murine models, with homozygous or heterozygous deletion for several synaptic genes or knock-in for specific pathogenic mutations, have been developed. They have proved to be extremely informative for understanding synaptic physiology, as well as for clarifying the patho-mechanisms leading to developmental delay, epilepsy and motor, cognitive and social impairments that are the most common clinical manifestations of neurodevelopmental disorders. However, the onset of these disorders emerges during infancy and adolescence while the behavioral phenotyping is often conducted in adult mice, missing important information about the impact of synaptic development and maturation on the manifestation of the behavioral phenotype. Here, we review the main achievements obtained by behavioral testing in murine models of synaptopathies and propose a battery of behavioral tests to improve classification, diagnosis and efficacy of potential therapeutic treatments. Our aim is to underlie the importance of studying behavioral development and better focusing on disease onset and phenotypes.
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Affiliation(s)
- Caterina Michetti
- Department of Experimental Medicine, University of Genoa, Genoa, Italy; Center for Synaptic Neuroscience, Istituto Italiano di Tecnologia, Genoa, Italy.
| | - Antonio Falace
- Pediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories, Children's Hospital A. Meyer-University of Florence, Florence, Italy
| | - Fabio Benfenati
- Center for Synaptic Neuroscience, Istituto Italiano di Tecnologia, Genoa, Italy; IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Anna Fassio
- Department of Experimental Medicine, University of Genoa, Genoa, Italy; IRCCS Ospedale Policlinico San Martino, Genoa, Italy.
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Shao Q, Shi X, Ma B, Zeng J, Zheng A, Xie W. TBC1D24-related familial infantile multifocal myoclonus: Description of a new Chinese pedigree with a 20 year follow up. Epilepsy Res 2022; 182:106923. [DOI: 10.1016/j.eplepsyres.2022.106923] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 03/24/2022] [Accepted: 04/05/2022] [Indexed: 11/26/2022]
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8
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Cho TS, Beigaitė E, Klein NE, Sweeney ST, Bhattacharya MRC. The Putative Drosophila TMEM184B Ortholog Tmep Ensures Proper Locomotion by Restraining Ectopic Firing at the Neuromuscular Junction. Mol Neurobiol 2022; 59:2605-2619. [PMID: 35107803 PMCID: PMC9018515 DOI: 10.1007/s12035-022-02760-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 01/20/2022] [Indexed: 11/29/2022]
Abstract
TMEM184B is a putative seven-pass membrane protein that promotes axon degeneration after injury. TMEM184B mutation causes aberrant neuromuscular architecture and sensory and motor behavioral defects in mice. The mechanism through which TMEM184B causes neuromuscular defects is unknown. We employed Drosophila melanogaster to investigate the function of the closely related gene, Tmep (CG12004), at the neuromuscular junction. We show that Tmep is required for full adult viability and efficient larval locomotion. Tmep mutant larvae have a reduced body contraction rate compared to controls, with stronger deficits in females. In recordings from body wall muscles, Tmep mutants show substantial hyperexcitability, with many postsynaptic potentials fired in response to a single stimulation, consistent with a role for Tmep in restraining synaptic excitability. Additional branches and satellite boutons at Tmep mutant neuromuscular junctions are consistent with an activity-dependent synaptic overgrowth. Tmep is expressed in endosomes and synaptic vesicles within motor neurons, suggesting a possible role in synaptic membrane trafficking. Using RNAi knockdown, we show that Tmep is required in motor neurons for proper larval locomotion and excitability, and that its reduction increases levels of presynaptic calcium. Locomotor defects can be rescued by presynaptic knockdown of endoplasmic reticulum calcium channels or by reducing evoked release probability, further suggesting that excess synaptic activity drives behavioral deficiencies. Our work establishes a critical function for Tmep in the regulation of synaptic transmission and locomotor behavior.
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Affiliation(s)
- Tiffany S Cho
- Department of Neuroscience, University of Arizona, 1040 E 4th Street, Tucson, AZ, 85721, USA
| | - Eglė Beigaitė
- Department of Biology, University of York, York, YO10 5DD, UK.,York Biomedical Research Institute, University of York, York, YO10 5DD, UK
| | - Nathaniel E Klein
- Department of Neuroscience, University of Arizona, 1040 E 4th Street, Tucson, AZ, 85721, USA
| | - Sean T Sweeney
- Department of Biology, University of York, York, YO10 5DD, UK.,York Biomedical Research Institute, University of York, York, YO10 5DD, UK
| | - Martha R C Bhattacharya
- Department of Neuroscience, University of Arizona, 1040 E 4th Street, Tucson, AZ, 85721, USA.
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Overduin M, Kervin TA. The phosphoinositide code is read by a plethora of protein domains. Expert Rev Proteomics 2021; 18:483-502. [PMID: 34351250 DOI: 10.1080/14789450.2021.1962302] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
INTRODUCTION The proteins that decipher nucleic acid- and protein-based information are well known, however, those that read membrane-encoded information remain understudied. Here we report 70 different human, microbial and viral protein folds that recognize phosphoinositides (PIs), comprising the readers of a vast membrane code. AREAS COVERED Membrane recognition is best understood for FYVE, PH and PX domains, which exemplify hundreds of PI code readers. Comparable lipid interaction mechanisms may be mediated by kinases, adjacent C1 and C2 domains, trafficking arrestin, GAT and VHS modules, membrane-perturbing annexin, BAR, CHMP, ENTH, HEAT, syntaxin and Tubby helical bundles, multipurpose FERM, EH, MATH, PHD, PDZ, PROPPIN, PTB and SH2 domains, as well as systems that regulate receptors, GTPases and actin filaments, transfer lipids and assembled bacterial and viral particles. EXPERT OPINION The elucidation of how membranes are recognized has extended the genetic code to the PI code. Novel discoveries include PIP-stop and MET-stop residues to which phosphates and metabolites are attached to block phosphatidylinositol phosphate (PIP) recognition, memteins as functional membrane protein apparatuses, and lipidons as lipid "codons" recognized by membrane readers. At least 5% of the human proteome senses such membrane signals and allows eukaryotic organelles and pathogens to operate and replicate.
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Affiliation(s)
- Michael Overduin
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Troy A Kervin
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
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10
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Arnaud-Arnould M, Tauziet M, Moncorgé O, Goujon C, Blaise M. Crystal structure of the TLDc domain of human NCOA7-AS. Acta Crystallogr F Struct Biol Commun 2021; 77:230-237. [PMID: 34341188 PMCID: PMC8329711 DOI: 10.1107/s2053230x21006853] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 07/02/2021] [Indexed: 11/15/2022] Open
Abstract
The TLDc [Tre2/Bub2/Cdc16 (TBC), lysin motif (LysM), domain catalytic] domain is associated with oxidation-resistance related functions and is well conserved among eukaryotes. Seven proteins possess a TLDc domain in humans, notably proteins belonging to the oxidation resistance protein (OXR), nuclear receptor coactivator 7 (NCOA7) and TBC1 domain family member 24 (TBC1D24) families. Although the mechanism is unknown, a protective role of TLDc proteins against oxidative stress, notably in the brain, has been demonstrated. Neurobiological disorders caused by mutations in the TLDc domain have also been reported. The human NCOA7 gene encodes several mRNA isoforms; among these, isoform 4, named NCOA7-AS, is up-regulated by type 1 interferon in response to viral infection. NCOA7 and NCOA7-AS both interact with several subunits of the vacuolar proton pump V-ATPase, which leads to increased acidification of the endolysosomal system and consequently impairs infection by viruses that enter their host cells through the endosomal pathway, such as influenza A virus and hepatitis C virus. Similarly to full-length NCOA7, NCOA7-AS possesses a TLDc domain in its C-terminus. Structures of TLDc domains have been reported from zebrafish and fly but not from humans. Here, the expression, purification and crystallization of the TLDc domain from NCOA7 and NCOA7-AS is reported. The crystal structure solved at 1.8 Å resolution is compared with previously solved three-dimensional structures of TLDc domains.
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11
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TBC1D24 emerges as an important contributor to progressive postlingual dominant hearing loss. Sci Rep 2021; 11:10300. [PMID: 33986365 PMCID: PMC8119487 DOI: 10.1038/s41598-021-89645-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 04/29/2021] [Indexed: 11/08/2022] Open
Abstract
Several TBC1D24 variants are causally involved in the development of profound, prelingual hearing loss (HL) and different epilepsy syndromes inherited in an autosomal recessive manner. Only two TBC1D24 pathogenic variants have been linked with postlingual progressive autosomal dominant HL (ADHL). To determine the role of TBC1D24 in the development of ADHL and to characterize the TBC1D24-related ADHL, clinical exome sequencing or targeted multigene (n = 237) panel were performed for probands (n = 102) from multigenerational ADHL families. In four families, TBC1D24-related HL was found based on the identification of three novel, likely pathogenic (c.553G>A, p.Asp185Asn; c.1460A>T, p. His487Leu or c.1461C>G, p.His487Gln) and one known (c.533C>T, p.Ser178Leu) TBC1D24 variant. Functional consequences of these variants were characterized by analyzing the proposed homology models of the human TBC1D24 protein. Variants not only in the TBC (p.Ser178Leu, p.Asp185Asn) but also in the TLDc domain (p.His487Gln, p.His487Leu) are involved in ADHL development, the latter two mutations probably affecting interactions between the domains. Clinically, progressive HL involving mainly mid and high frequencies was observed in the patients (n = 29). The progression of HL was calculated by constructing age-related typical audiograms. TBC1D24-related ADHL originates from the cochlear component of the auditory system, becomes apparent usually in the second decade of life and accounts for approximately 4% of ADHL cases. Given the high genetic heterogeneity of ADHL, TBC1D24 emerges as an important contributor to this type of HL.
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12
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Morimune T, Tano A, Tanaka Y, Yukiue H, Yamamoto T, Tooyama I, Maruo Y, Nishimura M, Mori M. Gm14230 controls Tbc1d24 cytoophidia and neuronal cellular juvenescence. PLoS One 2021; 16:e0248517. [PMID: 33886577 PMCID: PMC8062039 DOI: 10.1371/journal.pone.0248517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Accepted: 02/28/2021] [Indexed: 11/19/2022] Open
Abstract
It is not fully understood how enzymes are regulated in the tiny reaction field of a cell. Several enzymatic proteins form cytoophidia, a cellular macrostructure to titrate enzymatic activities. Here, we show that the epileptic encephalopathy-associated protein Tbc1d24 forms cytoophidia in neuronal cells both in vitro and in vivo. The Tbc1d24 cytoophidia are distinct from previously reported cytoophidia consisting of inosine monophosphate dehydrogenase (Impdh) or cytidine-5'-triphosphate synthase (Ctps). Tbc1d24 cytoophidia is induced by loss of cellular juvenescence caused by depletion of Gm14230, a juvenility-associated lncRNA (JALNC) and zeocin treatment. Cytoophidia formation is associated with impaired enzymatic activity of Tbc1d24. Thus, our findings reveal the property of Tbc1d24 to form cytoophidia to maintain neuronal cellular juvenescence.
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Affiliation(s)
- Takao Morimune
- Molecular Neuroscience Research Center (MNRC), Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga, Japan
- Department of Pediatrics, Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga, Japan
- Department of Vascular Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan
| | - Ayami Tano
- Molecular Neuroscience Research Center (MNRC), Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga, Japan
- Department of Vascular Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan
| | - Yuya Tanaka
- Molecular Neuroscience Research Center (MNRC), Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga, Japan
- Department of Vascular Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan
| | - Haruka Yukiue
- Molecular Neuroscience Research Center (MNRC), Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga, Japan
| | - Takefumi Yamamoto
- Central Research Laboratory, Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga, Japan
| | - Ikuo Tooyama
- Molecular Neuroscience Research Center (MNRC), Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga, Japan
| | - Yoshihiro Maruo
- Department of Pediatrics, Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga, Japan
| | - Masaki Nishimura
- Molecular Neuroscience Research Center (MNRC), Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga, Japan
| | - Masaki Mori
- Molecular Neuroscience Research Center (MNRC), Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga, Japan
- Department of Vascular Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan
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13
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Castroflorio E, den Hoed J, Svistunova D, Finelli MJ, Cebrian-Serrano A, Corrochano S, Bassett AR, Davies B, Oliver PL. The Ncoa7 locus regulates V-ATPase formation and function, neurodevelopment and behaviour. Cell Mol Life Sci 2021; 78:3503-3524. [PMID: 33340069 PMCID: PMC8038996 DOI: 10.1007/s00018-020-03721-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 11/08/2020] [Accepted: 11/24/2020] [Indexed: 02/08/2023]
Abstract
Members of the Tre2/Bub2/Cdc16 (TBC), lysin motif (LysM), domain catalytic (TLDc) protein family are associated with multiple neurodevelopmental disorders, although their exact roles in disease remain unclear. For example, nuclear receptor coactivator 7 (NCOA7) has been associated with autism, although almost nothing is known regarding the mode-of-action of this TLDc protein in the nervous system. Here we investigated the molecular function of NCOA7 in neurons and generated a novel mouse model to determine the consequences of deleting this locus in vivo. We show that NCOA7 interacts with the cytoplasmic domain of the vacuolar (V)-ATPase in the brain and demonstrate that this protein is required for normal assembly and activity of this critical proton pump. Neurons lacking Ncoa7 exhibit altered development alongside defective lysosomal formation and function; accordingly, Ncoa7 deletion animals exhibited abnormal neuronal patterning defects and a reduced expression of lysosomal markers. Furthermore, behavioural assessment revealed anxiety and social defects in mice lacking Ncoa7. In summary, we demonstrate that NCOA7 is an important V-ATPase regulatory protein in the brain, modulating lysosomal function, neuronal connectivity and behaviour; thus our study reveals a molecular mechanism controlling endolysosomal homeostasis that is essential for neurodevelopment.
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Affiliation(s)
| | - Joery den Hoed
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, UK
| | - Daria Svistunova
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, UK
| | - Mattéa J Finelli
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, UK
| | | | - Silvia Corrochano
- MRC Harwell Institute, Harwell Campus, Oxfordshire, OX11 0RD, UK
- Hospital Clínico San Carlos, Instituto de Investigación Sanitaria San Carlos, Calle del Prof Martín Lagos s/n, 28040, Madrid, Spain
| | - Andrew R Bassett
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SA, UK
| | - Benjamin Davies
- Wellcome Centre for Human Genetics, Roosevelt Drive, Oxford, OX3 7BN, UK
| | - Peter L Oliver
- MRC Harwell Institute, Harwell Campus, Oxfordshire, OX11 0RD, UK.
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, UK.
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14
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Abstract
One in three epilepsy cases is drug resistant, and seizures often begin in infancy, when they are life-threatening and when therapeutic options are highly limited. An important tool for prioritizing and validating genes associated with epileptic conditions, which is suitable for large-scale screening, is disease modeling in Drosophila. Approximately two-thirds of disease genes are conserved in Drosophila, and gene-specific fly models exhibit behavioral changes that are related to symptoms of epilepsy. Models are based on behavior readouts, seizure-like attacks and paralysis following stimulation, and neuronal, cell-biological readouts that are in the majority based on changes in nerve cell activity or morphology. In this review, we focus on behavioral phenotypes. Importantly, Drosophila modeling is independent of, and complementary to, other approaches that are computational and based on systems analysis. The large number of known epilepsy-associated gene variants indicates a need for efficient research strategies. We will discuss the status quo of epilepsy disease modelling in Drosophila and describe promising steps towards the development of new drugs to reduce seizure rates and alleviate other epileptic symptoms.
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Affiliation(s)
- Paul Lasko
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, Netherlands
- Department of Biology, McGill University, Montréal, Québec, Canada
| | - Kevin Lüthy
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, Netherlands
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15
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Martín‐González J, Montero‐Bullón J, Lacal J. Dictyostelium discoideum as a non-mammalian biomedical model. Microb Biotechnol 2021; 14:111-125. [PMID: 33124755 PMCID: PMC7888446 DOI: 10.1111/1751-7915.13692] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 10/06/2020] [Accepted: 10/11/2020] [Indexed: 02/06/2023] Open
Abstract
Dictyostelium discoideum is one of eight non-mammalian model organisms recognized by the National Institute of Health for the study of human pathology. The use of this slime mould is possible owing to similarities in cell structure, behaviour and intracellular signalling with mammalian cells. Its haploid set of chromosomes completely sequenced amenable to genetic manipulation, its unique and short life cycle with unicellular and multicellular stages, and phenotypic richness encoding many human orthologues, make Dictyostelium a representative and simple model organism to unveil cellular processes in human disease. Dictyostelium studies within the biomedical field have provided fundamental knowledge in the areas of bacterial infection, immune cell chemotaxis, autophagy/phagocytosis and mitochondrial and neurological disorders. Consequently, Dictyostelium has been used to the development of related pharmacological treatments. Herein, we review the utilization of Dictyostelium as a model organism in biomedicine.
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Affiliation(s)
- Javier Martín‐González
- Molecular Genetics of Human Diseases GroupDepartment of Microbiology and GeneticsFaculty of BiologyUniversity of SalamancaCampus Miguel de UnamunoSalamancaE‐37007Spain
| | - Javier‐Fernando Montero‐Bullón
- Metabolic Engineering GroupDepartment of Microbiology and GeneticsUniversity of SalamancaCampus Miguel de UnamunoSalamancaE‐37007Spain
| | - Jesus Lacal
- Molecular Genetics of Human Diseases GroupDepartment of Microbiology and GeneticsFaculty of BiologyUniversity of SalamancaCampus Miguel de UnamunoSalamancaE‐37007Spain
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16
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Garcia-Rosa S, de Freitas Brenha B, Felipe da Rocha V, Goulart E, Araujo BHS. Personalized Medicine Using Cutting Edge Technologies for Genetic Epilepsies. Curr Neuropharmacol 2021; 19:813-831. [PMID: 32933463 PMCID: PMC8686309 DOI: 10.2174/1570159x18666200915151909] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 08/08/2020] [Accepted: 08/28/2020] [Indexed: 11/22/2022] Open
Abstract
Epilepsy is the most common chronic neurologic disorder in the world, affecting 1-2% of the population. Besides, 30% of epilepsy patients are drug-resistant. Genomic mutations seem to play a key role in its etiology and knowledge of strong effect mutations in protein structures might improve prediction and the development of efficacious drugs to treat epilepsy. Several genetic association studies have been undertaken to examine the effect of a range of candidate genes for resistance. Although, few studies have explored the effect of the mutations into protein structure and biophysics in the epilepsy field. Much work remains to be done, but the plans made for exciting developments will hold therapeutic potential for patients with drug-resistance. In summary, we provide a critical review of the perspectives for the development of individualized medicine for epilepsy based on genetic polymorphisms/mutations in light of core elements such as transcriptomics, structural biology, disease model, pharmacogenomics and pharmacokinetics in a manner to improve the success of trial designs of antiepileptic drugs.
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Affiliation(s)
- Sheila Garcia-Rosa
- Brazilian Biosciences National Laboratory (LNBio), Center for Research in Energy and Material (CNPEM), Campinas, SP, Brazil
| | - Bianca de Freitas Brenha
- Laboratory of Embryonic Genetic Regulation, Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas, Campinas, SP, Brazil
| | - Vinicius Felipe da Rocha
- Brazilian Biosciences National Laboratory (LNBio), Center for Research in Energy and Material (CNPEM), Campinas, SP, Brazil
| | - Ernesto Goulart
- Human Genome and Stem-Cell Research Center (HUG-CEL), Department of Genetics and Evolutionary Biology, Institute of Biosciences, University of São Paulo, SP, Brazil
| | - Bruno Henrique Silva Araujo
- Brazilian Biosciences National Laboratory (LNBio), Center for Research in Energy and Material (CNPEM), Campinas, SP, Brazil
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17
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Paesmans J, Martin E, Deckers B, Berghmans M, Sethi R, Loeys Y, Pardon E, Steyaert J, Verstreken P, Galicia C, Versées W. A structure of substrate-bound Synaptojanin1 provides new insights in its mechanism and the effect of disease mutations. eLife 2020; 9:64922. [PMID: 33349335 PMCID: PMC7781601 DOI: 10.7554/elife.64922] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Accepted: 12/16/2020] [Indexed: 12/13/2022] Open
Abstract
Synaptojanin1 (Synj1) is a phosphoinositide phosphatase, important in clathrin uncoating during endocytosis of presynaptic vesicles. It was identified as a potential drug target for Alzheimer's disease, Down syndrome, and TBC1D24-associated epilepsy, while also loss-of-function mutations in Synj1 are associated with epilepsy and Parkinson's disease. Despite its involvement in a range of disorders, structural, and detailed mechanistic information regarding the enzyme is lacking. Here, we report the crystal structure of the 5-phosphatase domain of Synj1. Moreover, we also present a structure of this domain bound to the substrate diC8-PI(3,4,5)P3, providing the first image of a 5-phosphatase with a trapped substrate in its active site. Together with an analysis of the contribution of the different inositide phosphate groups to catalysis, these structures provide new insights in the Synj1 mechanism. Finally, we analysed the effect of three clinical missense mutations (Y793C, R800C, Y849C) on catalysis, unveiling the molecular mechanisms underlying Synj1-associated disease.
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Affiliation(s)
- Jone Paesmans
- VIB-VUB Center for Structural Biology, Brussels, Belgium.,Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Ella Martin
- VIB-VUB Center for Structural Biology, Brussels, Belgium.,Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Babette Deckers
- VIB-VUB Center for Structural Biology, Brussels, Belgium.,Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Marjolijn Berghmans
- VIB-VUB Center for Structural Biology, Brussels, Belgium.,Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Ritika Sethi
- VIB-VUB Center for Structural Biology, Brussels, Belgium.,Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Yannick Loeys
- VIB-VUB Center for Structural Biology, Brussels, Belgium.,Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Els Pardon
- VIB-VUB Center for Structural Biology, Brussels, Belgium.,Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Jan Steyaert
- VIB-VUB Center for Structural Biology, Brussels, Belgium.,Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Patrik Verstreken
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,KU Leuven, Department of Neurosciences, Leuven Brain Institute, Leuven, Belgium
| | - Christian Galicia
- VIB-VUB Center for Structural Biology, Brussels, Belgium.,Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Wim Versées
- VIB-VUB Center for Structural Biology, Brussels, Belgium.,Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
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18
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Wang M, Lin Y, Zhou S, Cui Y, Feng Q, Yan W, Xiang H. Genetic Mapping of Climbing and Mimicry: Two Behavioral Traits Degraded During Silkworm Domestication. Front Genet 2020; 11:566961. [PMID: 33391338 PMCID: PMC7773896 DOI: 10.3389/fgene.2020.566961] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 11/17/2020] [Indexed: 11/13/2022] Open
Abstract
Behavioral changes caused by domestication in animals are an important issue in evolutionary biology. The silkworm, Bombyx mori, is an ideal fully domesticated insect model for studying both convergent domestication and behavior evolution. We explored the genetic basis of climbing for foraging and mimicry, two degraded behaviors during silkworm domestication, in combination of bulked segregant analysis (BSA) and selection sweep screening. One candidate gene, ASNA1, located in the 3-5 Mb on chromosome 19, harboring a specific non-synonymous mutation in domestic silkworm, might be involved in climbing ability. This mutation was under positive selection in Lepidoptera, strongly suggesting its potential function in silkworm domestication. Nine candidate domesticated genes related to mimicry were identified on chromosomes 13, 21, and 27. Most of the candidate domesticated genes were generally expressed at higher levels in the brain of the wild silkworm. This study provides valuable information for deciphering the molecular basis of behavioral changes associated with silkworm domestication.
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Affiliation(s)
- Man Wang
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Yongjian Lin
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Shiyi Zhou
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Yong Cui
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Qili Feng
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Wei Yan
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Hui Xiang
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
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19
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Parzefall T, Frohne A, Koenighofer M, Neesen J, Laccone F, Eckl-Dorna J, Waters JJ, Schreiner M, Amr SS, Ashton E, Schoefer C, Gstœttner W, Frei K, Lucas T. A Novel Variant in the TBC1D24 Lipid-Binding Pocket Causes Autosomal Dominant Hearing Loss: Evidence for a Genotype-Phenotype Correlation. Front Cell Neurosci 2020; 14:585669. [PMID: 33281559 PMCID: PMC7689082 DOI: 10.3389/fncel.2020.585669] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 10/13/2020] [Indexed: 12/23/2022] Open
Abstract
Background: Hereditary hearing loss is a disorder with high genetic and allelic heterogeneity. Diagnostic screening of candidate genes commonly yields novel variants of unknown clinical significance. TBC1D24 is a pleiotropic gene associated with recessive DOORS syndrome, epileptic encephalopathy, myoclonic epilepsy, and both recessive and dominant hearing impairment. Genotype-phenotype correlations have not been established to date but could facilitate diagnostic variant assessment and elucidation of pathomechanisms. Methods and Results: Whole-exome and gene panel screening identified a novel (c.919A>C; p.Asn307His) causative variant in TBC1D24 in two unrelated Caucasian families with Autosomal dominant (AD) nonsyndromic late-onset hearing loss. Protein modeling on the Drosophila TBC1D24 ortholog Skywalker crystal structure showed close interhelix proximity (6.8Å) between the highly conserved residue p.Asn307 in α18 and the position of the single known pathogenic dominant variation (p.Ser178Leu) in α11 that causes a form of deafness with similar clinical characteristics. Conclusion: Genetic variants affecting two polar hydrophilic residues in neighboring helices of TBC1D24 cause AD nonsyndromic late-onset hearing loss. The spatial proximity of the affected residues suggests the first genotype-phenotype association in TBC1D24-related disorders. Three conserved residues in α18 contribute to the formation of a functionally relevant cationic phosphoinositide binding pocket that regulates synaptic vesicle trafficking which may be involved in the molecular mechanism of disease.
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Affiliation(s)
- Thomas Parzefall
- Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna, Austria
| | - Alexandra Frohne
- Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna, Austria.,Department for Cell and Developmental Biology, Orphan Disease Genetics Group, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Martin Koenighofer
- Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna, Austria
| | - Juergen Neesen
- Institute of Medical Genetics, Center for Pathobiochemistry and Genetics, Medical University of Vienna, Vienna, Austria
| | - Franco Laccone
- Institute of Medical Genetics, Center for Pathobiochemistry and Genetics, Medical University of Vienna, Vienna, Austria
| | - Julia Eckl-Dorna
- Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna, Austria
| | - Jonathan J Waters
- Rare and Inherited Disease Laboratory, London North Genomic Laboratory Hub, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
| | - Markus Schreiner
- Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Sami Samir Amr
- Laboratory for Molecular Medicine, Partners Healthcare Personalized Medicine, Cambridge, MA, United States.,Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, United States
| | - Emma Ashton
- Rare and Inherited Disease Laboratory, London North Genomic Laboratory Hub, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
| | - Christian Schoefer
- Department for Cell and Developmental Biology, Orphan Disease Genetics Group, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Wolfgang Gstœttner
- Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna, Austria
| | - Klemens Frei
- Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna, Austria
| | - Trevor Lucas
- Department for Cell and Developmental Biology, Orphan Disease Genetics Group, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
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20
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Mouse Models of Human Pathogenic Variants of TBC1D24 Associated with Non-Syndromic Deafness DFNB86 and DFNA65 and Syndromes Involving Deafness. Genes (Basel) 2020; 11:genes11101122. [PMID: 32987832 PMCID: PMC7598720 DOI: 10.3390/genes11101122] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 09/16/2020] [Accepted: 09/21/2020] [Indexed: 01/08/2023] Open
Abstract
Human pathogenic variants of TBC1D24 are associated with clinically heterogeneous phenotypes, including recessive nonsyndromic deafness DFNB86, dominant nonsyndromic deafness DFNA65, seizure accompanied by deafness, a variety of isolated seizure phenotypes and DOORS syndrome, characterized by deafness, onychodystrophy, osteodystrophy, intellectual disability and seizures. Thirty-five pathogenic variants of human TBC1D24 associated with deafness have been reported. However, functions of TBC1D24 in the inner ear and the pathophysiology of TBC1D24-related deafness are unknown. In this study, a novel splice-site variant of TBC1D24 c.965 + 1G > A in compound heterozygosity with c.641G > A p.(Arg214His) was found to be segregating in a Pakistani family. Affected individuals exhibited, either a deafness-seizure syndrome or nonsyndromic deafness. In human temporal bones, TBC1D24 immunolocalized in hair cells and spiral ganglion neurons, whereas in mouse cochlea, Tbc1d24 expression was detected only in spiral ganglion neurons. We engineered mouse models of DFNB86 p.(Asp70Tyr) and DFNA65 p.(Ser178Leu) nonsyndromic deafness and syndromic forms of deafness p.(His336Glnfs*12) that have the same pathogenic variants that were reported for human TBC1D24. Unexpectedly, no auditory dysfunction was detected in Tbc1d24 mutant mice, although homozygosity for some of the variants caused seizures or lethality. We provide some insightful supporting data to explain the phenotypic differences resulting from equivalent pathogenic variants of mouse Tbc1d24 and human TBC1D24.
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21
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Takai A, Yamaguchi M, Yoshida H, Chiyonobu T. Investigating Developmental and Epileptic Encephalopathy Using Drosophila melanogaster. Int J Mol Sci 2020; 21:ijms21176442. [PMID: 32899411 PMCID: PMC7503973 DOI: 10.3390/ijms21176442] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 08/30/2020] [Accepted: 09/01/2020] [Indexed: 12/16/2022] Open
Abstract
Developmental and epileptic encephalopathies (DEEs) are the spectrum of severe epilepsies characterized by early-onset, refractory seizures occurring in the context of developmental regression or plateauing. Early infantile epileptic encephalopathy (EIEE) is one of the earliest forms of DEE, manifesting as frequent epileptic spasms and characteristic electroencephalogram findings in early infancy. In recent years, next-generation sequencing approaches have identified a number of monogenic determinants underlying DEE. In the case of EIEE, 85 genes have been registered in Online Mendelian Inheritance in Man as causative genes. Model organisms are indispensable tools for understanding the in vivo roles of the newly identified causative genes. In this review, we first present an overview of epilepsy and its genetic etiology, especially focusing on EIEE and then briefly summarize epilepsy research using animal and patient-derived induced pluripotent stem cell (iPSC) models. The Drosophila model, which is characterized by easy gene manipulation, a short generation time, low cost and fewer ethical restrictions when designing experiments, is optimal for understanding the genetics of DEE. We therefore highlight studies with Drosophila models for EIEE and discuss the future development of their practical use.
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Affiliation(s)
- Akari Takai
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan;
| | - Masamitsu Yamaguchi
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 603-8585, Japan; (M.Y.); (H.Y.)
- Kansai Gakken Laboratory, Kankyo Eisei Yakuhin Co. Ltd., Kyoto 619-0237, Japan
| | - Hideki Yoshida
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 603-8585, Japan; (M.Y.); (H.Y.)
| | - Tomohiro Chiyonobu
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan;
- Correspondence:
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22
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Beauregard-Lacroix E, Pacheco-Cuellar G, Ajeawung NF, Tardif J, Dieterich K, Dabir T, Vind-Kezunovic D, White SM, Zadori D, Castiglioni C, Tranebjærg L, Tørring PM, Blair E, Wisniewska M, Camurri MV, van Bever Y, Molidperee S, Taylor J, Dionne-Laporte A, Sisodiya SM, Hennekam RCM, Campeau PM. DOORS syndrome and a recurrent truncating ATP6V1B2 variant. Genet Med 2020; 23:149-154. [PMID: 32873933 DOI: 10.1038/s41436-020-00950-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 08/12/2020] [Accepted: 08/12/2020] [Indexed: 12/31/2022] Open
Abstract
PURPOSE Biallelic variants in TBC1D24, which encodes a protein that regulates vesicular transport, are frequently identified in patients with DOORS (deafness, onychodystrophy, osteodystrophy, intellectual disability [previously referred to as mental retardation], and seizures) syndrome. The aim of the study was to identify a genetic cause in families with DOORS syndrome and without a TBC1D24 variant. METHODS Exome or Sanger sequencing was performed in individuals with a clinical diagnosis of DOORS syndrome without TBC1D24 variants. RESULTS We identified the same truncating variant in ATP6V1B2 (NM_001693.4:c.1516C>T; p.Arg506*) in nine individuals from eight unrelated families with DOORS syndrome. This variant was already reported in individuals with dominant deafness onychodystrophy (DDOD) syndrome. Deafness was present in all individuals, along with onychodystrophy and abnormal fingers and/or toes. All families but one had developmental delay or intellectual disability and five individuals had epilepsy. We also describe two additional families with DDOD syndrome in whom the same variant was found. CONCLUSION We expand the phenotype associated with ATP6V1B2 and propose another causal gene for DOORS syndrome. This finding suggests that DDOD and DOORS syndromes might lie on a spectrum of clinically and molecularly related conditions.
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Affiliation(s)
- Eliane Beauregard-Lacroix
- Medical Genetics Division, Department of Pediatrics, Sainte-Justine University Hospital Center, Montreal, QC, Canada
| | - Guillermo Pacheco-Cuellar
- Medical Genetics Division, Department of Pediatrics, Sainte-Justine University Hospital Center, Montreal, QC, Canada
| | - Norbert F Ajeawung
- CHU Sainte Justine Research Center, Université de Montréal, Montreal, QC, Canada
| | - Jessica Tardif
- Medical Genetics Division, Department of Pediatrics, Sainte-Justine University Hospital Center, Montreal, QC, Canada
| | - Klaus Dieterich
- Univ. Grenoble Alpes, Inserm, U1216, CHU Grenoble Alpes, Grenoble Institut Neurosciences (GIN), Grenoble, France
| | - Tabib Dabir
- Department of Genetic Medicine, Belfast City Hospital, Belfast, Northern Ireland, UK
| | - Dina Vind-Kezunovic
- Department of Dermatology, Copenhagen University Hospital Bispebjerg, Copenhagen, NV, Denmark
| | - Susan M White
- Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Melbourne, Australia
| | - Denes Zadori
- Department of Neurology, Interdisciplinary Excellence Center, Faculty of Medicine, Albert Szent-Györgyi Clinical Center, University of Szeged, Szeged, Hungary
| | | | - Lisbeth Tranebjærg
- The Kennedy Center, Department of Clinical Genetics, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.,Institute of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | | | - Ed Blair
- Oxford Regional Genetics Service, Oxford University Hospitals, Oxford, UK
| | - Marzena Wisniewska
- Department of Medical Genetics, Poznañ University of Medical Sciences, Poznañ, Poland
| | - Maria Vittoria Camurri
- Medical Genetics Division, Department of Pediatrics, Sainte-Justine University Hospital Center, Montreal, QC, Canada
| | - Yolande van Bever
- Department of Clinical Genetics, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Sirinart Molidperee
- CHU Sainte Justine Research Center, Université de Montréal, Montreal, QC, Canada
| | - Juliet Taylor
- Genetic Health Service New Zealand-Northern Hub, Auckland, New Zealand
| | - Alexandre Dionne-Laporte
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Sanjay M Sisodiya
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.,Chalfont Centre for Epilepsy, Bucks, UK
| | - Raoul C M Hennekam
- Department of Pediatrics, Amsterdam University Medical Center, Amsterdam, Netherlands
| | - Philippe M Campeau
- Medical Genetics Division, Department of Pediatrics, Sainte-Justine University Hospital Center, Montreal, QC, Canada.
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23
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Suresh NT, E R V, U K. Multi-scale top-down approach for modelling epileptic protein-protein interaction network analysis to identify driver nodes and pathways. Comput Biol Chem 2020; 88:107323. [PMID: 32653778 DOI: 10.1016/j.compbiolchem.2020.107323] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 06/04/2020] [Accepted: 06/23/2020] [Indexed: 12/23/2022]
Abstract
Protein - Protein Interaction Network (PPIN) analysis unveils molecular level mechanisms involved in disease condition. To explore the complex regulatory mechanisms behind epilepsy and to address the clinical and biological issues of epilepsy, in silico techniques are feasible in a cost- effective manner. In this work, a hierarchical procedure to identify influential genes and regulatory pathways in epilepsy prognosis is proposed. To obtain key genes and pathways causing epilepsy, integration of two benchmarked datasets which are exclusively devoted for complex disorders is done as an initial step. Using STRING database, PPIN is constructed for modelling protein-protein interactions. Further, key interactions are obtained from the established PPIN using network centrality measures followed by network propagation algorithm -Random Walk with Restart (RWR). The outcome of the method reveals some influential genes behind epilepsy prognosis, along with their associated pathways like PI3 kinase, VEGF signaling, Ras, Wnt signaling etc. In comparison with similar works, our results have shown improvement in identifying unique molecular functions, biological processes, gene co-occurrences etc. Also, CORUM provides an annotation for approximately 60% of similarity in human protein complexes with the obtained result. We believe that the formulated strategy can put-up the vast consideration of indigenous drugs towards meticulous identification of genes encoded by protein against several combinatorial disorders.
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Affiliation(s)
- Nikhila T Suresh
- Department of Computer Science and IT, Amrita School of Arts and Sciences, Amrita Vishwa Vidyapeetham, Kochi Campus, India
| | - Vimina E R
- Department of Computer Science and IT, Amrita School of Arts and Sciences, Amrita Vishwa Vidyapeetham, Kochi Campus, India.
| | - Krishnakumar U
- Department of Computer Science and IT, Amrita School of Arts and Sciences, Amrita Vishwa Vidyapeetham, Kochi Campus, India
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24
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Bonnycastle K, Davenport EC, Cousin MA. Presynaptic dysfunction in neurodevelopmental disorders: Insights from the synaptic vesicle life cycle. J Neurochem 2020; 157:179-207. [PMID: 32378740 DOI: 10.1111/jnc.15035] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/14/2020] [Accepted: 04/22/2020] [Indexed: 12/11/2022]
Abstract
The activity-dependent fusion, retrieval and recycling of synaptic vesicles is essential for the maintenance of neurotransmission. Until relatively recently it was believed that most mutations in genes that were essential for this process would be incompatible with life, because of this fundamental role. However, an ever-expanding number of mutations in this very cohort of genes are being identified in individuals with neurodevelopmental disorders, including autism, intellectual disability and epilepsy. This article will summarize the current state of knowledge linking mutations in presynaptic genes to neurodevelopmental disorders by sequentially covering the various stages of the synaptic vesicle life cycle. It will also discuss how perturbations of specific stages within this recycling process could translate into human disease. Finally, it will also provide perspectives on the potential for future therapy that are targeted to presynaptic function.
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Affiliation(s)
- Katherine Bonnycastle
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.,Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, UK.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK
| | - Elizabeth C Davenport
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.,Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, UK.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK
| | - Michael A Cousin
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.,Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, UK.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK
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25
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Lüthy K, Mei D, Fischer B, De Fusco M, Swerts J, Paesmans J, Parrini E, Lubarr N, Meijer IA, Mackenzie KM, Lee WT, Cittaro D, Aridon P, Schoovaerts N, Versées W, Verstreken P, Casari G, Guerrini R. TBC1D24-TLDc-related epilepsy exercise-induced dystonia: rescue by antioxidants in a disease model. Brain 2020; 142:2319-2335. [PMID: 31257402 DOI: 10.1093/brain/awz175] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 04/08/2019] [Accepted: 04/25/2019] [Indexed: 11/13/2022] Open
Abstract
Genetic mutations in TBC1D24 have been associated with multiple phenotypes, with epilepsy being the main clinical manifestation. The TBC1D24 protein consists of the unique association of a Tre2/Bub2/Cdc16 (TBC) domain and a TBC/lysin motif domain/catalytic (TLDc) domain. More than 50 missense and loss-of-function mutations have been described and are spread over the entire protein. Through whole genome/exome sequencing we identified compound heterozygous mutations, R360H and G501R, within the TLDc domain, in an index family with a Rolandic epilepsy exercise-induced dystonia phenotype (http://omim.org/entry/608105). A 20-year long clinical follow-up revealed that epilepsy was self-limited in all three affected patients, but exercise-induced dystonia persisted into adulthood in two. Furthermore, we identified three additional sporadic paediatric patients with a remarkably similar phenotype, two of whom had compound heterozygous mutations consisting of an in-frame deletion I81_K84 and an A500V mutation, and the third carried T182M and G511R missense mutations, overall revealing that all six patients harbour a missense mutation in the subdomain of TLDc between residues 500 and 511. We solved the crystal structure of the conserved Drosophila TLDc domain. This allowed us to predict destabilizing effects of the G501R and G511R mutations and, to a lesser degree, of R360H and potentially A500V. Next, we characterized the functional consequences of a strong and a weak TLDc mutation (TBC1D24G501R and TBC1D24R360H) using Drosophila, where TBC1D24/Skywalker regulates synaptic vesicle trafficking. In a Drosophila model neuronally expressing human TBC1D24, we demonstrated that the TBC1D24G501R TLDc mutation causes activity-induced locomotion and synaptic vesicle trafficking defects, while TBC1D24R360H is benign. The neuronal phenotypes of the TBC1D24G501R mutation are consistent with exacerbated oxidative stress sensitivity, which is rescued by treating TBC1D24G501R mutant animals with antioxidants N-acetylcysteine amide or α-tocopherol as indicated by restored synaptic vesicle trafficking levels and sustained behavioural activity. Our data thus show that mutations in the TLDc domain of TBC1D24 cause Rolandic-type focal motor epilepsy and exercise-induced dystonia. The humanized TBC1D24G501R fly model exhibits sustained activity and vesicle transport defects. We propose that the TBC1D24/Sky TLDc domain is a reactive oxygen species sensor mediating synaptic vesicle trafficking rates that, when dysfunctional, causes a movement disorder in patients and flies. The TLDc and TBC domain mutations' response to antioxidant treatment we observed in the animal model suggests a potential for combining antioxidant-based therapeutic approaches to TBC1D24-associated disorders with previously described lipid-altering strategies for TBC domain mutations.
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Affiliation(s)
- Kevin Lüthy
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,KU Leuven, Department of Neurosciences, Leuven Brain Institute, Leuven, Belgium
| | - Davide Mei
- Pediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories, Children's Hospital A. Meyer-University of Florence, Florence, Italy
| | - Baptiste Fischer
- VIB-VUB Center for Structural Biology, Brussels, Belgium.,Vrije Universiteit Brussel, Structural Biology Brussels, Brussels, Belgium
| | | | - Jef Swerts
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,KU Leuven, Department of Neurosciences, Leuven Brain Institute, Leuven, Belgium
| | - Jone Paesmans
- VIB-VUB Center for Structural Biology, Brussels, Belgium.,Vrije Universiteit Brussel, Structural Biology Brussels, Brussels, Belgium
| | - Elena Parrini
- Pediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories, Children's Hospital A. Meyer-University of Florence, Florence, Italy
| | - Naomi Lubarr
- Mount Sinai Beth Israel, Department of Neurology, New York, NY, USA
| | - Inge A Meijer
- Department of Pediatrics and Neurosciences, CHU Sainte-Justine and University of Montreal, Montreal, Canada
| | | | - Wang-Tso Lee
- Department of Pediatrics, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
| | | | - Paolo Aridon
- Department of Experimental Biomedicine and Clinical Neurosciences, University of Palermo, Palermo, Italy
| | - Nils Schoovaerts
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,KU Leuven, Department of Neurosciences, Leuven Brain Institute, Leuven, Belgium
| | - Wim Versées
- VIB-VUB Center for Structural Biology, Brussels, Belgium.,Vrije Universiteit Brussel, Structural Biology Brussels, Brussels, Belgium
| | - Patrik Verstreken
- VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium.,KU Leuven, Department of Neurosciences, Leuven Brain Institute, Leuven, Belgium
| | - Giorgio Casari
- San Raffaele University, Milan, Italy.,Telethon Institute of Genetics and Medicine, Naples, Italy
| | - Renzo Guerrini
- Pediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories, Children's Hospital A. Meyer-University of Florence, Florence, Italy.,IRCCS Fondazione Stella Maris, Pisa, Italy
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26
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Tona R, Chen W, Nakano Y, Reyes LD, Petralia RS, Wang YX, Starost MF, Wafa TT, Morell RJ, Cravedi KD, du Hoffmann J, Miyoshi T, Munasinghe JP, Fitzgerald TS, Chudasama Y, Omori K, Pierpaoli C, Banfi B, Dong L, Belyantseva IA, Friedman TB. The phenotypic landscape of a Tbc1d24 mutant mouse includes convulsive seizures resembling human early infantile epileptic encephalopathy. Hum Mol Genet 2020; 28:1530-1547. [PMID: 30602030 DOI: 10.1093/hmg/ddy445] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2018] [Revised: 12/02/2018] [Accepted: 12/11/2018] [Indexed: 12/19/2022] Open
Abstract
Epilepsy, deafness, onychodystrophy, osteodystrophy and intellectual disability are associated with a spectrum of mutations of human TBC1D24. The mechanisms underlying TBC1D24-associated disorders and the functions of TBC1D24 are not well understood. Using CRISPR-Cas9 genome editing, we engineered a mouse with a premature translation stop codon equivalent to human S324Tfs*3, a recessive mutation of TBC1D24 associated with early infantile epileptic encephalopathy (EIEE). Homozygous S324Tfs*3 mice have normal auditory and vestibular functions but show an abrupt onset of spontaneous seizures at postnatal day 15 recapitulating human EIEE. The S324Tfs*3 variant is located in an alternatively spliced micro-exon encoding six perfectly conserved amino acids incorporated postnatally into TBC1D24 protein due to a micro-exon utilization switch. During embryonic and early postnatal development, S324Tfs*3 homozygotes produce predominantly the shorter wild-type TBC1D24 protein isoform that omits the micro-exon. S324Tfs*3 homozygotes show an abrupt onset of seizures at P15 that correlates with a developmental switch to utilization of the micro-exon. A mouse deficient for alternative splice factor SRRM3 impairs incorporation of the Tbc1d24 micro-exon. Wild-type Tbc1d24 mRNA is abundantly expressed in the hippocampus using RNAscope in situ hybridization. Immunogold electron microscopy using a TBC1D24-specific antibody revealed that TBC1D24 is associated with clathrin-coated vesicles and synapses of hippocampal neurons, suggesting a crucial role of TBC1D24 in vesicle trafficking important for neuronal signal transmission. This is the first characterization of a mouse model of human TBC1D24-associated EIEE that can now be used to screen for antiepileptogenic drugs ameliorating TBCID24 seizure disorders.
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Affiliation(s)
- Risa Tona
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, Porter Neuroscience Research Center, National Institutes of Health, Bethesda, MD, USA.,Department of Otolaryngology, Head and Neck Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Wenqian Chen
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, Porter Neuroscience Research Center, National Institutes of Health, Bethesda, MD, USA
| | - Yoko Nakano
- Department of Anatomy and Cell Biology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Laura D Reyes
- Quantitative Medical Imaging Section, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - Ronald S Petralia
- Advanced Imaging Core, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
| | - Ya-Xian Wang
- Advanced Imaging Core, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
| | - Matthew F Starost
- Division of Veterinary Resources, National Institutes of Health, Bethesda, MD, USA
| | - Talah T Wafa
- Mouse Auditory Testing Core Facility, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
| | - Robert J Morell
- Genomics and Computational Biology Core, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
| | - Kevin D Cravedi
- Rodent Behavioral Core, National Institute of Mental Health, Porter Neuroscience Research Center, National Institutes of Health, Bethesda, MD, USA
| | - Johann du Hoffmann
- Rodent Behavioral Core, National Institute of Mental Health, Porter Neuroscience Research Center, National Institutes of Health, Bethesda, MD, USA
| | - Takushi Miyoshi
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, Porter Neuroscience Research Center, National Institutes of Health, Bethesda, MD, USA
| | - Jeeva P Munasinghe
- Mouse Imaging Facility, In vivo NMR Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Tracy S Fitzgerald
- Mouse Auditory Testing Core Facility, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
| | - Yogita Chudasama
- Rodent Behavioral Core, National Institute of Mental Health, Porter Neuroscience Research Center, National Institutes of Health, Bethesda, MD, USA.,Section on Behavioral Neuroscience, National Institute of Mental Health, Porter Neuroscience Research Center, National Institutes of Health, Bethesda, MD, USA
| | - Koichi Omori
- Department of Otolaryngology, Head and Neck Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Carlo Pierpaoli
- Quantitative Medical Imaging Section, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - Botond Banfi
- Department of Anatomy and Cell Biology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Lijin Dong
- Genetic Engineering Core, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Inna A Belyantseva
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, Porter Neuroscience Research Center, National Institutes of Health, Bethesda, MD, USA
| | - Thomas B Friedman
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, Porter Neuroscience Research Center, National Institutes of Health, Bethesda, MD, USA
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27
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Lin L, Lyu Q, Kwan PY, Zhao J, Fan R, Chai A, Lai CSW, Chan YS, Shen X, Lai KO. The epilepsy and intellectual disability-associated protein TBC1D24 regulates the maintenance of excitatory synapses and animal behaviors. PLoS Genet 2020; 16:e1008587. [PMID: 32004315 PMCID: PMC7015432 DOI: 10.1371/journal.pgen.1008587] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 02/12/2020] [Accepted: 12/29/2019] [Indexed: 12/27/2022] Open
Abstract
Perturbation of synapse development underlies many inherited neurodevelopmental disorders including intellectual disability (ID). Diverse mutations on the human TBC1D24 gene are strongly associated with epilepsy and ID. However, the physiological function of TBC1D24 in the brain is not well understood, and there is a lack of genetic mouse model that mimics TBC1D24 loss-of-function for the study of animal behaviors. Here we report that TBC1D24 is present at the postsynaptic sites of excitatory synapses, where it is required for the maintenance of dendritic spines through inhibition of the small GTPase ARF6. Mice subjected to viral-mediated knockdown of TBC1D24 in the adult hippocampus display dendritic spine loss, deficits in contextual fear memory, as well as abnormal behaviors including hyperactivity and increased anxiety. Interestingly, we show that the protein stability of TBC1D24 is diminished by the disease-associated missense mutation that leads to F251L amino acid substitution. We further generate the F251L knock-in mice, and the homozygous mutants show increased neuronal excitability, spontaneous seizure and pre-mature death. Moreover, the heterozygous F251L knock-in mice survive into adulthood but display dendritic spine defects and impaired memory. Our findings therefore uncover a previously uncharacterized postsynaptic function of TBC1D24, and suggest that impaired dendritic spine maintenance contributes to the pathophysiology of individuals harboring TBC1D24 gene mutations. The F251L knock-in mice represent a useful animal model for investigation of the mechanistic link between TBC1D24 loss-of-function and neurodevelopmental disorders.
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Affiliation(s)
- Lianfeng Lin
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Quanwei Lyu
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Pui-Yi Kwan
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Junjun Zhao
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Ruolin Fan
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Anping Chai
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Cora Sau Wan Lai
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China
| | - Ying-Shing Chan
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China
| | - Xuting Shen
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
| | - Kwok-On Lai
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China
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28
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Zhang J, Chen J, Zeng Q, Zhang L, Tian X, Yang X, Yang Z, Wu Y, Wu X, Zhang Y. Infantile epilepsy with multifocal myoclonus caused by TBC1D24 mutations. Seizure 2019; 69:228-234. [DOI: 10.1016/j.seizure.2019.05.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 05/09/2019] [Accepted: 05/11/2019] [Indexed: 11/16/2022] Open
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29
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Finelli MJ, Aprile D, Castroflorio E, Jeans A, Moschetta M, Chessum L, Degiacomi MT, Grasegger J, Lupien-Meilleur A, Bassett A, Rossignol E, Campeau PM, Bowl MR, Benfenati F, Fassio A, Oliver PL. The epilepsy-associated protein TBC1D24 is required for normal development, survival and vesicle trafficking in mammalian neurons. Hum Mol Genet 2019; 28:584-597. [PMID: 30335140 PMCID: PMC6360273 DOI: 10.1093/hmg/ddy370] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 10/09/2018] [Indexed: 12/16/2022] Open
Abstract
Mutations in the Tre2/Bub2/Cdc16 (TBC)1 domain family member 24 (TBC1D24) gene are associated with a range of inherited neurological disorders, from drug-refractory lethal epileptic encephalopathy and DOORS syndrome (deafness, onychodystrophy, osteodystrophy, mental retardation, seizures) to non-syndromic hearing loss. TBC1D24 has been implicated in neuronal transmission and maturation, although the molecular function of the gene and the cause of the apparently complex disease spectrum remain unclear. Importantly, heterozygous TBC1D24 mutation carriers have also been reported with seizures, suggesting that haploinsufficiency for TBC1D24 is significant clinically. Here we have systematically investigated an allelic series of disease-associated mutations in neurons alongside a new mouse model to investigate the consequences of TBC1D24 haploinsufficiency to mammalian neurodevelopment and synaptic physiology. The cellular studies reveal that disease-causing mutations that disrupt either of the conserved protein domains in TBC1D24 are implicated in neuronal development and survival and are likely acting as loss-of-function alleles. We then further investigated TBC1D24 haploinsufficiency in vivo and demonstrate that TBC1D24 is also crucial for normal presynaptic function: genetic disruption of Tbc1d24 expression in the mouse leads to an impairment of endocytosis and an enlarged endosomal compartment in neurons with a decrease in spontaneous neurotransmission. These data reveal the essential role for TBC1D24 at the mammalian synapse and help to define common synaptic mechanisms that could underlie the varied effects of TBC1D24 mutations in neurological disease.
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Affiliation(s)
- Mattéa J Finelli
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, UK
| | - Davide Aprile
- Department of Experimental Medicine, University of Genoa, Genoa, Italy
| | - Enrico Castroflorio
- Center of Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 9, Genoa, Italy
| | - Alexander Jeans
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, UK
| | - Matteo Moschetta
- Department of Experimental Medicine, University of Genoa, Genoa, Italy.,Center of Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 9, Genoa, Italy
| | | | | | - Julia Grasegger
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, UK
| | - Alexis Lupien-Meilleur
- CHU Ste-Justine, Departments of Neurosciences and Pediatrics, Université de Montréal, Montreal, QC, Canada
| | - Andrew Bassett
- Cellular Operations, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK
| | - Elsa Rossignol
- CHU Ste-Justine, Departments of Neurosciences and Pediatrics, Université de Montréal, Montreal, QC, Canada
| | - Philippe M Campeau
- CHU Ste-Justine, Departments of Neurosciences and Pediatrics, Université de Montréal, Montreal, QC, Canada
| | | | - Fabio Benfenati
- Center of Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 9, Genoa, Italy.,IRCCS Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, Genoa, Italy
| | - Anna Fassio
- Department of Experimental Medicine, University of Genoa, Genoa, Italy.,IRCCS Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, Genoa, Italy
| | - Peter L Oliver
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, UK.,MRC Harwell Institute, Harwell, Oxfordshire, UK
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30
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Baba T, Toth DJ, Sengupta N, Kim YJ, Balla T. Phosphatidylinositol 4,5-bisphosphate controls Rab7 and PLEKHM1 membrane cycling during autophagosome-lysosome fusion. EMBO J 2019; 38:e100312. [PMID: 31368593 PMCID: PMC6463214 DOI: 10.15252/embj.2018100312] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 01/02/2019] [Accepted: 01/23/2019] [Indexed: 12/12/2022] Open
Abstract
The small GTPase Rab7 is a key organizer of receptor sorting and lysosomal degradation by recruiting of a variety of effectors depending on its GDP/GTP-bound state. However, molecular mechanisms that trigger Rab7 inactivation remain elusive. Here we find that, among the endosomal pools, Rab7-positive compartments possess the highest level of PI4P, which is primarily produced by PI4K2A kinase. Acute conversion of this endosomal PI4P to PI(4,5)P2 causes Rab7 dissociation from late endosomes and releases a regulator of autophagosome-lysosome fusion, PLEKHM1, from the membrane. Rab7 effectors Vps35 and RILP are not affected by acute PI(4,5)P2 production. Deletion of PI4K2A greatly reduces PIP5Kγ-mediated PI(4,5)P2 production in Rab7-positive endosomes leading to impaired Rab7 inactivation and increased number of LC3-positive structures with defective autophagosome-lysosome fusion. These results reveal a late endosomal PI4P-PI(4,5)P2 -dependent regulatory loop that impacts autophagosome flux by affecting Rab7 cycling and PLEKHM1 association.
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Affiliation(s)
- Takashi Baba
- Section on Molecular Signal TransductionProgram for Developmental NeuroscienceEunice Kennedy Shriver National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMDUSA
| | - Daniel J Toth
- Section on Molecular Signal TransductionProgram for Developmental NeuroscienceEunice Kennedy Shriver National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMDUSA
| | - Nivedita Sengupta
- Section on Molecular Signal TransductionProgram for Developmental NeuroscienceEunice Kennedy Shriver National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMDUSA
| | - Yeun Ju Kim
- Section on Molecular Signal TransductionProgram for Developmental NeuroscienceEunice Kennedy Shriver National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMDUSA
| | - Tamas Balla
- Section on Molecular Signal TransductionProgram for Developmental NeuroscienceEunice Kennedy Shriver National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMDUSA
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31
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Aprile D, Fruscione F, Baldassari S, Fadda M, Ferrante D, Falace A, Buhler E, Sartorelli J, Represa A, Baldelli P, Benfenati F, Zara F, Fassio A. TBC1D24 regulates axonal outgrowth and membrane trafficking at the growth cone in rodent and human neurons. Cell Death Differ 2019; 26:2464-2478. [PMID: 30858606 DOI: 10.1038/s41418-019-0313-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 01/25/2019] [Accepted: 02/20/2019] [Indexed: 01/04/2023] Open
Abstract
Mutations in TBC1D24 are described in patients with a spectrum of neurological diseases, including mild and severe epilepsies and complex syndromic phenotypes such as Deafness, Onycodystrophy, Osteodystrophy, Mental Retardation and Seizure (DOORS) syndrome. The product of TBC1D24 is a multifunctional protein involved in neuronal development, regulation of synaptic vesicle trafficking, and protection from oxidative stress. Although pathogenic mutations in TBC1D24 span the entire coding sequence, no clear genotype/phenotype correlations have emerged. However most patients bearing predicted loss of function mutations exhibit a severe neurodevelopmental disorder. Aim of the study is to investigate the impact of TBC1D24 knockdown during the first stages of neuronal differentiation when axonal specification and outgrowth take place. In rat cortical primary neurons silenced for TBC1D24, we found defects in axonal specification, the maturation of axonal initial segment and action potential firing. The axonal phenotype was accompanied by an impairment of endocytosis at the growth cone and an altered activation of the TBC1D24 molecular partner ADP ribosylation factor 6. Accordingly, acute knockdown of TBC1D24 in cerebrocortical neurons in vivo analogously impairs callosal projections. The axonal defect was also investigated in human induced pluripotent stem cell-derived neurons from patients carrying TBC1D24 mutations. Reprogrammed neurons from a patient with severe developmental encephalopathy show significant axon formation defect that were absent from reprogrammed neurons of a patient with mild early onset epilepsy. Our data reveal that alterations of membrane trafficking at the growth cone induced by TBC1D24 loss of function cause axonal and excitability defects. The axonal phenotype correlates with the disease severity and highlight an important role for TBC1D24 in connectivity during brain development.
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Affiliation(s)
- Davide Aprile
- Department of Experimental Medicine, University of Genoa, Genoa, Italy
| | - Floriana Fruscione
- Laboratory of Neurogenetics and Neuroscience, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Simona Baldassari
- Laboratory of Neurogenetics and Neuroscience, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Manuela Fadda
- Department of Experimental Medicine, University of Genoa, Genoa, Italy
| | - Daniele Ferrante
- Department of Experimental Medicine, University of Genoa, Genoa, Italy
| | - Antonio Falace
- Pediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories, Children's Hospital A. Meyer-University of Florence, Florence, Italy
| | | | - Jacopo Sartorelli
- Laboratory of Neurogenetics and Neuroscience, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Alfonso Represa
- INMED, Aix-Marseille University, INSERM U1249, Marseille, France
| | - Pietro Baldelli
- Department of Experimental Medicine, University of Genoa, Genoa, Italy.,IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Fabio Benfenati
- IRCCS Ospedale Policlinico San Martino, Genoa, Italy.,Center of Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Federico Zara
- Laboratory of Neurogenetics and Neuroscience, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Anna Fassio
- Department of Experimental Medicine, University of Genoa, Genoa, Italy. .,IRCCS Ospedale Policlinico San Martino, Genoa, Italy.
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32
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Mucha BE, Banka S, Ajeawung NF, Molidperee S, Chen GG, Koenig MK, Adejumo RB, Till M, Harbord M, Perrier R, Lemyre E, Boucher RM, Skotko BG, Waxler JL, Thomas MA, Hodge JC, Gecz J, Nicholl J, McGregor L, Linden T, Sisodiya SM, Sanlaville D, Cheung SW, Ernst C, Campeau PM. A new microdeletion syndrome involving TBC1D24, ATP6V0C, and PDPK1 causes epilepsy, microcephaly, and developmental delay. Genet Med 2018; 21:1058-1064. [DOI: 10.1038/s41436-018-0290-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 08/17/2018] [Indexed: 12/17/2022] Open
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33
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Madigan JP, Hou F, Ye L, Hu J, Dong A, Tempel W, Yohe ME, Randazzo PA, Jenkins LMM, Gottesman MM, Tong Y. The tuberous sclerosis complex subunit TBC1D7 is stabilized by Akt phosphorylation-mediated 14-3-3 binding. J Biol Chem 2018; 293:16142-16159. [PMID: 30143532 DOI: 10.1074/jbc.ra118.003525] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 08/13/2018] [Indexed: 01/19/2023] Open
Abstract
The tuberous sclerosis complex (TSC) is a negative regulator of mTOR complex 1, a signaling node promoting cellular growth in response to various nutrients and growth factors. However, several regulators in TSC signaling still await discovery and characterization. Using pulldown and MS approaches, here we identified the TSC complex member, TBC1 domain family member 7 (TBC1D7), as a binding partner for PH domain and leucine-rich repeat protein phosphatase 1 (PHLPP1), a negative regulator of Akt kinase signaling. Most TBC domain-containing proteins function as Rab GTPase-activating proteins (RabGAPs), but the crystal structure of TBC1D7 revealed that it lacks residues critical for RabGAP activity. Sequence analysis identified a putative site for both Akt-mediated phosphorylation and 14-3-3 binding at Ser-124, and we found that Akt phosphorylates TBC1D7 at Ser-124. However, this phosphorylation had no effect on the binding of TBC1D7 to TSC1, but stabilized TBC1D7. Moreover, 14-3-3 protein both bound and stabilized TBC1D7 in a growth factor-dependent manner, and a phospho-deficient substitution, S124A, prevented this interaction. The crystal structure of 14-3-3ζ in complex with a phospho-Ser-124 TBC1D7 peptide confirmed the direct interaction between 14-3-3 and TBC1D7. The sequence immediately upstream of Ser-124 aligned with a canonical β-TrCP degron, and we found that the E3 ubiquitin ligase β-TrCP2 ubiquitinates TBC1D7 and decreases its stability. Our findings reveal that Akt activity determines the phosphorylation status of TBC1D7 at the phospho-switch Ser-124, which governs binding to either 14-3-3 or β-TrCP2, resulting in increased or decreased stability of TBC1D7, respectively.
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Affiliation(s)
| | - Feng Hou
- the Structural Genomics Consortium and
| | - Linlei Ye
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario M5G 1L7, Canada, and
| | | | | | | | | | - Paul A Randazzo
- Laboratory of Cell and Molecular Biology, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland 20892
| | | | | | - Yufeng Tong
- the Structural Genomics Consortium and .,the Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario N9B 3P4, Canada
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34
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Danial-Farran N, Brownstein Z, Gulsuner S, Tammer L, Khayat M, Aleme O, Chervinsky E, Zoubi OA, Walsh T, Ast G, King MC, Avraham KB, Shalev SA. Genetics of hearing loss in the Arab population of Northern Israel. Eur J Hum Genet 2018; 26:1840-1847. [PMID: 30139988 PMCID: PMC6244407 DOI: 10.1038/s41431-018-0218-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 06/18/2018] [Accepted: 06/26/2018] [Indexed: 01/04/2023] Open
Abstract
For multiple generations, much of the Arab population of Northern Israel has lived in communities with consanguineous marriages and large families. These communities have been particularly cooperative and informative for understanding the genetics of recessive traits. We studied the genetics of hearing loss in this population, evaluating 168 families from 46 different villages. All families were screened for founder variants by Sanger sequencing and 13 families were further evaluated by sequencing all known genes for hearing loss using our targeted gene panel HEar-Seq. Deafness in 34 of 168 families (20%) was explained by founder variants in GJB2, SLC26A4, or OTOF. In 6 of 13 families (46%) evaluated using HEar-Seq, deafness was explained by damaging alleles of SLC26A4, MYO15A, OTOG, LOXHD1, and TBC1D24. In some genes critical to hearing, it is particularly difficult to interpret variants that might affect splicing, because the genes are not expressed in accessible tissue. To address this problem for possible splice-altering variants of MYO15A, we evaluated minigenes transfected into HEK293 cells. Results revealed exon skipping in the message of MYO15A c.9083+6T>A, and intron retention in the message of MYO15A c.8340G>A, in each case leading to a premature stop and consistent with co-segregation of homozygosity for each variant with hearing loss. The profile of genetics of hearing loss in this population reflects the genetic heterogeneity of hearing loss and the usefulness of synthetic technologies to evaluate potentially causal variants in genes not expressed in accessible tissues.
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Affiliation(s)
- Nada Danial-Farran
- Genetics Institute, Emek Medical Center, Afula, Israel.,Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.,Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Zippora Brownstein
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Suleyman Gulsuner
- Department of Medicine, Division of Medical Genetics, University of Washington, Seattle, WA, USA
| | - Luna Tammer
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Morad Khayat
- Genetics Institute, Emek Medical Center, Afula, Israel
| | - Ola Aleme
- Genetics Institute, Emek Medical Center, Afula, Israel
| | | | | | - Tom Walsh
- Department of Medicine, Division of Medical Genetics, University of Washington, Seattle, WA, USA
| | - Gil Ast
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Mary-Claire King
- Department of Medicine, Division of Medical Genetics, University of Washington, Seattle, WA, USA
| | - Karen B Avraham
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.
| | - Stavit A Shalev
- Genetics Institute, Emek Medical Center, Afula, Israel. .,Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.
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35
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Soukup SF, Vanhauwaert R, Verstreken P. Parkinson's disease: convergence on synaptic homeostasis. EMBO J 2018; 37:embj.201898960. [PMID: 30065071 DOI: 10.15252/embj.201898960] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 05/07/2018] [Accepted: 07/06/2018] [Indexed: 01/01/2023] Open
Abstract
Parkinson's disease, the second most common neurodegenerative disorder, affects millions of people globally. There is no cure, and its prevalence will double by 2030. In recent years, numerous causative genes and risk factors for Parkinson's disease have been identified and more than half appear to function at the synapse. Subtle synaptic defects are thought to precede blunt neuronal death, but the mechanisms that are dysfunctional at synapses are only now being unraveled. Here, we review recent work and propose a model where different Parkinson proteins interact in a cell compartment-specific manner at the synapse where these proteins regulate endocytosis and autophagy. While this field is only recently emerging, the work suggests that the loss of synaptic homeostasis may contribute to neurodegeneration and is a key player in Parkinson's disease.
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Affiliation(s)
- Sandra-Fausia Soukup
- VIB-KU Leuven Center for Brain& Disease Research, Leuven, Belgium .,Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Roeland Vanhauwaert
- VIB-KU Leuven Center for Brain& Disease Research, Leuven, Belgium.,Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Patrik Verstreken
- VIB-KU Leuven Center for Brain& Disease Research, Leuven, Belgium .,Department of Neurosciences, KU Leuven, Leuven, Belgium
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36
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Li J, Liu R, Feng H, Zhang J, Wang D, Wang Y, Zeng J, Fan Y. Novel TBC1D24 Mutations in a Case of Nonconvulsive Status Epilepticus. Front Neurol 2018; 9:623. [PMID: 30108545 PMCID: PMC6079244 DOI: 10.3389/fneur.2018.00623] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 07/10/2018] [Indexed: 01/19/2023] Open
Abstract
Objective: Nonconvulsive status epilepticus (NCSE) is an uncommon clinical manifestation in patients with TBC1D24 mutations. In addition, NCSE has not been reported as a syndrome together with cerebellar ataxia and ophthalmoplegia. Methods: We herein report the clinical and genetic features of a four-year-old patient with NCSE, cerebellar ataxia, and ophthalmoplegia caused by hitherto unidentified TBC1D24 mutations. We performed 24-h video electroencephalogram (EEG), magnetic resonance imaging, and gene sequencing on the patient and her parents to determine the diagnosis. Results: We identified a novel c.1416_1437del (p.Ser473Argfs*43) mutation, as well as the previously identified c.1499C>T (p.Ala500Val) mutation in TBC1D24, by using targeted next-generation sequencing. The novel mutation (inherited from the mother) is the first reported deletion mutation longer than 20 bp in TBC1D24. The p.Ala500Val mutation inherited from father has been reported in a German patient with infantile myoclonic, for whom results from the EEG and neuroimaging were normal. These two mutations resulted in the severe phenotypes observed in our patient Conclusions: The identification of the novel TBC1D24 mutation and consequent complicated clinical manifestations suggest that patients with NCSE and ataxia demand more attention. We further recommend that genetic test should be administered to these patients to avoid genetic inheritance of this mutation.
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Affiliation(s)
- Jingjing Li
- Department of Neurology and Stroke Center, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Ruihong Liu
- Fifth Affiliated Hospital, Sun Yat-sen University-BGI Laboratory, Department of Experimental Medicine, Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, China
| | - Huiyu Feng
- Department of Neurology and Stroke Center, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Jian Zhang
- Department of Neurology and Stroke Center, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Dilong Wang
- Department of Neurology and Stroke Center, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Yiming Wang
- Fifth Affiliated Hospital, Sun Yat-sen University-BGI Laboratory, Department of Experimental Medicine, Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, China.,Xinhua College, Sun Yat-sen University, Guangzhou, China
| | - Jinsheng Zeng
- Department of Neurology and Stroke Center, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Yuhua Fan
- Department of Neurology and Stroke Center, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
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37
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Abstract
Background The protein kinase Target Of Rapamycin (TOR) is a nexus for the regulation of eukaryotic cell growth. TOR assembles into one of two distinct signalling complexes, TOR complex 1 (TORC1) and TORC2 (mTORC1/2 in mammals), with a set of largely non-overlapping protein partners. (m)TORC1 activation occurs in response to a series of stimuli relevant to cell growth, including nutrient availability, growth factor signals and stress, and regulates much of the cell's biosynthetic activity, from proteins to lipids, and recycling through autophagy. mTORC1 regulation is of great therapeutic significance, since in humans many of these signalling complexes, alongside subunits of mTORC1 itself, are implicated in a wide variety of pathophysiologies, including multiple types of cancer, neurological disorders, neurodegenerative diseases and metabolic disorders including diabetes. Methodology Recent years have seen numerous structures determined of (m)TOR, which have provided mechanistic insight into (m)TORC1 activation in particular, however the integration of cellular signals occurs upstream of the kinase and remains incompletely understood. Here we have collected and analysed in detail as many as possible of the molecular and structural studies which have shed light on (m)TORC1 repression, activation and signal integration. Conclusions A molecular understanding of this signal integration pathway is required to understand how (m)TORC1 activation is reconciled with the many diverse and contradictory stimuli affecting cell growth. We discuss the current level of molecular understanding of the upstream components of the (m)TORC1 signalling pathway, recent progress on this key biochemical frontier, and the future studies necessary to establish a mechanistic understanding of this master-switch for eukaryotic cell growth.
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Affiliation(s)
- Kailash Ramlaul
- Section of Structural Biology, Department of Medicine, Imperial College London, SW7 2AZ, UK
| | - Christopher H S Aylett
- Section of Structural Biology, Department of Medicine, Imperial College London, SW7 2AZ, UK
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38
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Patent Highlights February-March 2018. Pharm Pat Anal 2018; 7:147-154. [PMID: 29882729 DOI: 10.4155/ppa-2018-0014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A snapshot of noteworthy recent developments in the patent literature of relevance to pharmaceutical and medical research development.
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39
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Farhan SMK, Nixon KCJ, Everest M, Edwards TN, Long S, Segal D, Knip MJ, Arts HH, Chakrabarti R, Wang J, Robinson JF, Lee D, Mirsattari SM, Rupar CA, Siu VM, Poulter MO, Hegele RA, Kramer JM. Identification of a novel synaptic protein, TMTC3, involved in periventricular nodular heterotopia with intellectual disability and epilepsy. Hum Mol Genet 2018; 26:4278-4289. [PMID: 28973161 PMCID: PMC5886076 DOI: 10.1093/hmg/ddx316] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 08/08/2017] [Indexed: 12/30/2022] Open
Abstract
Defects in neuronal migration cause brain malformations, which are associated with intellectual disability (ID) and epilepsy. Using exome sequencing, we identified compound heterozygous variants (p.Arg71His and p. Leu729ThrfsTer6) in TMTC3, encoding transmembrane and tetratricopeptide repeat containing 3, in four siblings with nocturnal seizures and ID. Three of the four siblings have periventricular nodular heterotopia (PVNH), a common brain malformation caused by failure of neurons to migrate from the ventricular zone to the cortex. Expression analysis using patient-derived cells confirmed reduced TMTC3 transcript levels and loss of the TMTC3 protein compared to parental and control cells. As TMTC3 function is currently unexplored in the brain, we gathered support for a neurobiological role for TMTC3 by generating flies with post-mitotic neuron-specific knockdown of the highly conserved Drosophila melanogaster TMTC3 ortholog, CG4050/tmtc3. Neuron-specific knockdown of tmtc3 in flies resulted in increased susceptibility to induced seizures. Importantly, this phenotype was rescued by neuron-specific expression of human TMTC3, suggesting a role for TMTC3 in seizure biology. In addition, we observed co-localization of TMTC3 in the rat brain with vesicular GABA transporter (VGAT), a presynaptic marker for inhibitory synapses. TMTC3 is localized at VGAT positive pre-synaptic terminals and boutons in the rat hypothalamus and piriform cortex, suggesting a role for TMTC3 in the regulation of GABAergic inhibitory synapses. TMTC3 did not co-localize with Vglut2, a presynaptic marker for excitatory neurons. Our data identified TMTC3 as a synaptic protein that is involved in PVNH with ID and epilepsy, in addition to its previously described association with cobblestone lissencephaly.
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Affiliation(s)
- Sali M K Farhan
- Molecular Medicine Research Group, Robarts Research Institute, London, ON, Canada, N6A 5B7.,Department of Biochemistry
| | - Kevin C J Nixon
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1
| | - Michelle Everest
- Molecular Medicine Research Group, Robarts Research Institute, London, ON, Canada, N6A 5B7.,Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1
| | - Tara N Edwards
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1
| | - Shirley Long
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1
| | - Dmitri Segal
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1
| | - Maria J Knip
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1
| | - Heleen H Arts
- Molecular Medicine Research Group, Robarts Research Institute, London, ON, Canada, N6A 5B7.,Division of Genetics and Development, Children's Health Research Institute, London, ON, Canada, N6A 5W9.,Department of Human Genetics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre Nijmegen, The Netherlands
| | - Rana Chakrabarti
- Division of Genetics and Development, Children's Health Research Institute, London, ON, Canada, N6A 5W9.,Department of Pediatrics
| | - Jian Wang
- Molecular Medicine Research Group, Robarts Research Institute, London, ON, Canada, N6A 5B7
| | - John F Robinson
- Molecular Medicine Research Group, Robarts Research Institute, London, ON, Canada, N6A 5B7
| | | | - Seyed M Mirsattari
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1.,Departments of Clinical Neurological Sciences, Medical Biophysics, Medical Imaging and Psychology
| | - C Anthony Rupar
- Department of Biochemistry.,Division of Genetics and Development, Children's Health Research Institute, London, ON, Canada, N6A 5W9.,Department of Pediatrics.,Department of Pathology and Laboratory Medicine, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1
| | - Victoria M Siu
- Department of Biochemistry.,Division of Genetics and Development, Children's Health Research Institute, London, ON, Canada, N6A 5W9.,Department of Pediatrics
| | | | - Michael O Poulter
- Molecular Medicine Research Group, Robarts Research Institute, London, ON, Canada, N6A 5B7.,Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1
| | - Robert A Hegele
- Molecular Medicine Research Group, Robarts Research Institute, London, ON, Canada, N6A 5B7.,Department of Biochemistry
| | - Jamie M Kramer
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1.,Division of Genetics and Development, Children's Health Research Institute, London, ON, Canada, N6A 5W9.,Department of Biology, Faculty of Science, Western University, London, ON, Canada, N6A 5B7
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40
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Jin EJ, Kiral FR, Hiesinger PR. The where, what, and when of membrane protein degradation in neurons. Dev Neurobiol 2018; 78:283-297. [PMID: 28884504 PMCID: PMC5816708 DOI: 10.1002/dneu.22534] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 09/01/2017] [Accepted: 09/04/2017] [Indexed: 12/20/2022]
Abstract
Membrane protein turnover and degradation are required for the function and health of all cells. Neurons may live for the entire lifetime of an organism and are highly polarized cells with spatially segregated axonal and dendritic compartments. Both longevity and morphological complexity represent challenges for regulated membrane protein degradation. To investigate how neurons cope with these challenges, an increasing number of recent studies investigated local, cargo-specific protein sorting, and degradation at axon terminals and in dendritic processes. In this review, we explore the current answers to the ensuing questions of where, what, and when membrane proteins are degraded in neurons. © 2017 The Authors Developmental Neurobiology Published by Wiley Periodicals, Inc. Develop Neurobiol 78: 283-297, 2018.
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Affiliation(s)
- Eugene Jennifer Jin
- Division of NeurobiologyInstitute for Biology, Freie Universität Berlin14195 BerlinGermany
- Graduate School of Biomedical SciencesUniversity of Texas Southwestern Medical CenterDallasTX75390USA
| | - Ferdi Ridvan Kiral
- Division of NeurobiologyInstitute for Biology, Freie Universität Berlin14195 BerlinGermany
| | - Peter Robin Hiesinger
- Division of NeurobiologyInstitute for Biology, Freie Universität Berlin14195 BerlinGermany
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41
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Zhou Q, Lin Y, Ye J, Li L, Hu N, Wang D, Wang Y. Homozygous TBC1D24 Mutation in a Case of Epilepsia Partialis Continua. Front Neurol 2018; 8:750. [PMID: 29416524 PMCID: PMC5787533 DOI: 10.3389/fneur.2017.00750] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 12/28/2017] [Indexed: 11/13/2022] Open
Abstract
TBC1D24 mutation-related epileptic syndrome includes a wide spectrum of epilepsies. We describe a case with a homozygous TBC1D24 mutation inherited from consanguineous parents. The patient manifested epilepsia partialis continua (EPC) and rare secondary generalized tonic-clonic seizure without intellectual disability or developmental delay. EPC, which involved focal limbs, came with waking and went with sleep. The genetic analysis reported a novel mutation in the TBC1D24 gene, c.229_240del (p.82_84del). The homozygous mutation was inherited from her healthy parents who were heterozygous. Morphometric analysis program (MAP), an MRI post-processing technique, was used and detected a subtle abnormality of the brain. A comprehensive analysis based on semiology, electroencephalogram, somatosensory-evoked potential, and MAP suggested a potential focal structural abnormality. This case indicates a possible correlation between the TBC1D24 mutation and brain development abnormality.
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Affiliation(s)
- Qilin Zhou
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Yicong Lin
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Jing Ye
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Liping Li
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Ningning Hu
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Di Wang
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Yuping Wang
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
- The Beijing Key Laboratory of Neuromodulation, Beijing, China
- Center of Epilepsy, Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China
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42
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The membrane strikes back: phosphoinositide binding regulates Skywalker function. Nat Struct Mol Biol 2017; 23:956-957. [PMID: 27814349 DOI: 10.1038/nsmb.3313] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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43
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Finelli MJ, Oliver PL. TLDc proteins: new players in the oxidative stress response and neurological disease. Mamm Genome 2017; 28:395-406. [PMID: 28707022 PMCID: PMC5614904 DOI: 10.1007/s00335-017-9706-7] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 07/03/2017] [Indexed: 12/14/2022]
Abstract
Oxidative stress (OS) arises from an imbalance in the cellular redox state, which can lead to intracellular damage and ultimately cell death. OS occurs as a result of normal ageing, but it is also implicated as a common etiological factor in neurological disease; thus identifying novel proteins that modulate the OS response may facilitate the design of new therapeutic approaches applicable to many disorders. In this review, we describe the recent progress that has been made using a range of genetic approaches to understand a family of proteins that share the highly conserved TLDc domain. We highlight their shared ability to prevent OS-related cell death and their unique functional characteristics, as well as discussing their potential application as new neuroprotective factors. Furthermore, with an increasing number of pathogenic mutations leading to epilepsy and hearing loss being discovered in the TLDc protein TBC1D24, understanding the function of this family has important implications for a range of inherited neurological diseases.
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Affiliation(s)
- Mattéa J Finelli
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, UK
| | - Peter L Oliver
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, UK.
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44
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Banuelos E, Ramsey K, Belnap N, Krishnan M, Balak C, Szelinger S, Siniard AL, Russell M, Richholt R, De Both M, Piras I, Naymik M, Claasen AM, Rangasamy S, Huentelman MJ, Craig DW, Campeau PM, Narayanan V, Schrauwen I. Case Report: Novel mutations in TBC1D24 are associated with autosomal dominant tonic-clonic and myoclonic epilepsy and recessive Parkinsonism, psychosis, and intellectual disability. F1000Res 2017; 6:553. [PMID: 28663785 PMCID: PMC5473401 DOI: 10.12688/f1000research.10588.1] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/22/2017] [Indexed: 12/27/2022] Open
Abstract
Mutations disrupting presynaptic protein TBC1D24 are associated with a variable neurological phenotype, including DOORS syndrome, myoclonic epilepsy, early-infantile epileptic encephalopathy, and non-syndromic hearing loss. In this report, we describe a family segregating autosomal dominant epilepsy, and a 37-year-old Caucasian female with a severe neurological phenotype including epilepsy, Parkinsonism, psychosis, visual and auditory hallucinations, gait ataxia and intellectual disability. Whole exome sequencing revealed two missense mutations in the TBC1D24 gene segregating within this family (c.1078C>T; p.Arg360Cys and c.404C>T; p.Pro135Leu). The female proband who presents with a severe neurological phenotype carries both of these mutations in a compound heterozygous state. The p.Pro135Leu variant, however, is present in the proband's mother and sibling as well, and is consistent with an autosomal dominant pattern linked to tonic-clonic and myoclonic epilepsy. In conclusion, we describe a single family in which TBC1D24 mutations cause expanded dominant and recessive phenotypes. In addition, we discuss and highlight that some variants in TBC1D24 might cause a dominant susceptibility to epilepsy.
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Affiliation(s)
- Erika Banuelos
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA.,Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA
| | - Keri Ramsey
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA.,Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA
| | - Newell Belnap
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA.,Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA
| | - Malavika Krishnan
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA.,Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA
| | - Chris Balak
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA.,Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA
| | - Szabolcs Szelinger
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA.,Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA
| | - Ashley L Siniard
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA.,Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA
| | - Megan Russell
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA.,Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA
| | - Ryan Richholt
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA.,Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA
| | - Matt De Both
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA.,Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA
| | - Ignazio Piras
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA.,Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA
| | - Marcus Naymik
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA.,Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA
| | - Ana M Claasen
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA.,Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA
| | - Sampathkumar Rangasamy
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA.,Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA
| | - Matthew J Huentelman
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA.,Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA
| | - David W Craig
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA.,Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA
| | - Philippe M Campeau
- Department of Pediatrics, CHU Sainte-Justine Research Center and University of Montreal, Montreal, QC, H3T 1C5, Canada
| | - Vinodh Narayanan
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA.,Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA
| | - Isabelle Schrauwen
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA.,Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, 85004, USA
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Sheehan P, Waites CL. Coordination of synaptic vesicle trafficking and turnover by the Rab35 signaling network. Small GTPases 2017; 10:54-63. [PMID: 28129039 PMCID: PMC6343537 DOI: 10.1080/21541248.2016.1270392] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Rab35 and the Rab35 network of GAPs, GEFs, and effectors are important regulators of membrane trafficking for a variety of cellular processes, from cytokinesis and phagocytosis to neurite outgrowth. In the past five years, components of this signaling network have also been implicated as critical mediators of synaptic vesicle (SV) recycling and protein homeostasis. Recent studies by several groups, including our own, have demonstrated that Rab35-mediated endosomal sorting is required for the degradation of SV proteins via the ESCRT pathway, thereby eliminating old or damaged proteins from the SV pool. This sorting process is regulated by Rab35 activation in response to neuronal activity, and potentially by an antagonistic signaling relationship between Rab35 and the small GTPase Arf6 that directs SVs into distinct recycling pathways depending on neuronal activity levels. Furthermore, mutations in genes encoding Rab35 regulatory proteins are emerging as causative factors in human neurologic and neurodegenerative diseases, consistent with their important roles in synaptic and neuronal health. Here, we review these recent findings and offer our perspective on how the Rab35 signaling network functions to maintain neurotransmission and synaptic fitness.
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Affiliation(s)
- Patricia Sheehan
- a Department of Pathology and Cell Biology , Columbia University Medical Center , New York , NY , USA
| | - Clarissa L Waites
- a Department of Pathology and Cell Biology , Columbia University Medical Center , New York , NY , USA.,b Department of Neuroscience , Columbia University Medical Center , New York , NY , USA
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Tipping the scales: Lessons from simple model systems on inositol imbalance in neurological disorders. Eur J Cell Biol 2017; 96:154-163. [PMID: 28153412 DOI: 10.1016/j.ejcb.2017.01.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 01/18/2017] [Accepted: 01/21/2017] [Indexed: 11/20/2022] Open
Abstract
Inositol and inositol-containing compounds have signalling and regulatory roles in many cellular processes, suggesting that inositol imbalance may lead to wide-ranging changes in cellular functions. Indeed, changes in inositol-dependent signalling have been implicated in various diseases and cellular functions such as autophagy, and these changes have often been proposed as therapeutic targets. However, few studies have highlighted the links between inositol depletion and the downstream effects on inositol phosphates and phosphoinositides in disease states. For this research, many advances have employed simple model systems that include the social amoeba D. discoideum and the yeast S. cerevisiae, since these models enable a range of experimental approaches that are not possible in mammalian models. In this review, we discuss recent findings initiated in simple model systems and translated to higher model organisms where the effect of altered inositol, inositol phosphate and phosphoinositide levels impact on bipolar disorder, Alzheimer disease, epilepsy and autophagy.
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