Wang Zheng, Augustus J Lowry, Harper E Smith, Jiale Xie, Shaun Rawson, Chen Wang, Jin Ou, Marcos Sotomayor, Tian-Min Fu, Huanghe Yang, Jeffrey R Holt
{"title":"机械敏感性TMEM63通道病变的结构和功能基础。","authors":"Wang Zheng, Augustus J Lowry, Harper E Smith, Jiale Xie, Shaun Rawson, Chen Wang, Jin Ou, Marcos Sotomayor, Tian-Min Fu, Huanghe Yang, Jeffrey R Holt","doi":"10.1016/j.neuron.2025.05.009","DOIUrl":null,"url":null,"abstract":"<p><p>TMEM63A, -B, and -C constitute a mammalian family of mechanosensitive ion channels that are mutated in neurodevelopmental disorders. The molecular mechanisms underlying TMEM63 activation by force and the impact of disease-associated mutations have not been clarified. Here, we elucidate the structural and functional bases of a prevalent TMEM63B mutation p.V44M. We first found that TMEM63B p.V44M and the homologous TMEM63A p.V53M are gain-of-function mutations that do not enhance channel activity but instead evoke constitutive lipid scramblase activity. We then solved TMEM63A p.V53M mutant structures in both closed and lipid-open states, which revealed major rearrangements of pore-lining helices, creating a lateral cleft across the membrane. Simulation studies revealed lipid scrambling through this cleft. The structural rearrangements were triggered by disruption of a surface-proximal hydrophobic latch, a putative force-sensing module that includes a cluster of disease mutation sites. Our findings provide mechanistic insight into TMEM63 channelopathies and suggest a possible force-sensing mechanism.</p>","PeriodicalId":19313,"journal":{"name":"Neuron","volume":" ","pages":""},"PeriodicalIF":15.0000,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Structural and functional basis of mechanosensitive TMEM63 channelopathies.\",\"authors\":\"Wang Zheng, Augustus J Lowry, Harper E Smith, Jiale Xie, Shaun Rawson, Chen Wang, Jin Ou, Marcos Sotomayor, Tian-Min Fu, Huanghe Yang, Jeffrey R Holt\",\"doi\":\"10.1016/j.neuron.2025.05.009\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>TMEM63A, -B, and -C constitute a mammalian family of mechanosensitive ion channels that are mutated in neurodevelopmental disorders. The molecular mechanisms underlying TMEM63 activation by force and the impact of disease-associated mutations have not been clarified. Here, we elucidate the structural and functional bases of a prevalent TMEM63B mutation p.V44M. We first found that TMEM63B p.V44M and the homologous TMEM63A p.V53M are gain-of-function mutations that do not enhance channel activity but instead evoke constitutive lipid scramblase activity. We then solved TMEM63A p.V53M mutant structures in both closed and lipid-open states, which revealed major rearrangements of pore-lining helices, creating a lateral cleft across the membrane. Simulation studies revealed lipid scrambling through this cleft. The structural rearrangements were triggered by disruption of a surface-proximal hydrophobic latch, a putative force-sensing module that includes a cluster of disease mutation sites. Our findings provide mechanistic insight into TMEM63 channelopathies and suggest a possible force-sensing mechanism.</p>\",\"PeriodicalId\":19313,\"journal\":{\"name\":\"Neuron\",\"volume\":\" \",\"pages\":\"\"},\"PeriodicalIF\":15.0000,\"publicationDate\":\"2025-06-02\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Neuron\",\"FirstCategoryId\":\"3\",\"ListUrlMain\":\"https://doi.org/10.1016/j.neuron.2025.05.009\",\"RegionNum\":1,\"RegionCategory\":\"医学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"NEUROSCIENCES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Neuron","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1016/j.neuron.2025.05.009","RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"NEUROSCIENCES","Score":null,"Total":0}
Structural and functional basis of mechanosensitive TMEM63 channelopathies.
TMEM63A, -B, and -C constitute a mammalian family of mechanosensitive ion channels that are mutated in neurodevelopmental disorders. The molecular mechanisms underlying TMEM63 activation by force and the impact of disease-associated mutations have not been clarified. Here, we elucidate the structural and functional bases of a prevalent TMEM63B mutation p.V44M. We first found that TMEM63B p.V44M and the homologous TMEM63A p.V53M are gain-of-function mutations that do not enhance channel activity but instead evoke constitutive lipid scramblase activity. We then solved TMEM63A p.V53M mutant structures in both closed and lipid-open states, which revealed major rearrangements of pore-lining helices, creating a lateral cleft across the membrane. Simulation studies revealed lipid scrambling through this cleft. The structural rearrangements were triggered by disruption of a surface-proximal hydrophobic latch, a putative force-sensing module that includes a cluster of disease mutation sites. Our findings provide mechanistic insight into TMEM63 channelopathies and suggest a possible force-sensing mechanism.
期刊介绍:
Established as a highly influential journal in neuroscience, Neuron is widely relied upon in the field. The editors adopt interdisciplinary strategies, integrating biophysical, cellular, developmental, and molecular approaches alongside a systems approach to sensory, motor, and higher-order cognitive functions. Serving as a premier intellectual forum, Neuron holds a prominent position in the entire neuroscience community.