Combined clinical, structural and cellular studies discriminate pathogenic and benign TRPV4 variants

作者：Sarah H. Berth, Linh K. Vo, Do Hoon Kwon, Tiffany Grider, Yasmine S Damayanti, Gage P Kosmanopoulos, Andrew S. Fox, Alexander R. Lau, Patrice Carr, Jack K. Donohue, Maya Hoke, Simone Thomas, Chafic Karam, Alex J. Fay, Ethan Meltzer, Thomas O. Crawford, Rachelle Gaudet, Michael E. Shy, Ute A. Hellmich, Seok‐Yong Lee, Charlotte J. Sumner, Brett A. McCray · 发表于：Brain · 年份：2024 · DOI：10.1093/brain/awae243 · 被引用次数：7 · 研究领域：Ion Channels and Receptors、RNA regulation and disease、Hearing, Cochlea, Tinnitus, Genetics

Dominant mutations in the calcium-permeable ion channel TRPV4 (transient receptor potential vanilloid 4) cause diverse and largely distinct channelopathies, including inherited forms of neuromuscular disease, skeletal dysplasias and arthropathy. Pathogenic TRPV4 mutations cause gain of ion channel function and toxicity that can be rescued by small molecule TRPV4 antagonists in cellular and animal models, suggesting that TRPV4 antagonism could be therapeutic for patients. Numerous variants in TRPV4 have been detected with targeted and whole exome/genome sequencing, but for the vast majority, their pathogenicity remains unclear. Here, we used a combination of clinical information and experimental structure-function analyses to evaluate 30 TRPV4 variants across various functional protein domains. We report clinical features of seven patients with TRPV4 variants of unknown significance and provide extensive functional characterization of these and an additional 17 variants, including structural position, ion channel function, subcellular localization, expression level, cytotoxicity and protein-protein interactions. We find that gain-of-function mutations within the TRPV4 intracellular ankyrin repeat domain target charged amino acid residues important for RhoA interaction, whereas ankyrin repeat domain residues outside of the RhoA interface have normal or reduced ion channel activity. We further identify a cluster of gain-of-function variants within the intracellular intrinsically...