Download MendeleyFunctional and structural basis of a hypermorphic TRPC3 variant.
Bell, B., Jaramillo-Granada, A.M., Romero, L.O., Gutierrez, I.A., Mallampalli, V.K.P.S., Fan, G., Varma, S., Baker, M.L., Serysheva, I.I., Vasquez, V., Cordero-Morales, J.F.(2026) Sci Adv 12: eaec9284-eaec9284
- PubMed: 41880503 Search on PubMedSearch on PubMed Central
- DOI: https://doi.org/10.1126/sciadv.aec9284
- Primary Citation Related Structures:
9OLK, 9OLL, 9OLM, 9OLX, 9OPU - PubMed Abstract:
Cerebellar ataxias are characterized by impaired motor coordination resulting from neuronal dysfunction within the cerebellum. The mechanisms underlying this pathology and its cerebellar-specific neurodegeneration remain unknown. We uncover how a gain-of-function canonical transient receptor potential member 3 (TRPC3) mutation, coupled with a cerebellum-specific isoform, stabilizes the channel's open state, resists the leading inhibitor Pyr3, and drives calcium-dependent cell death. Restoring calcium homeostasis by expressing a Purkinje cell calcium pump improves cell viability. Transgenic expression of the TRPC3 hypermorphic variant in Caenorhabditis elegans induces neurodegeneration, confirming its pathogenicity across species. Cryo-electron microscopy and molecular simulations reveal the structural basis for the stabilization of the cerebellar-specific TRPC3 variant in its open state and uncover a druggable allosteric inhibitory binding site. These findings provide an explanation for the vulnerability of cerebellar neurons in TRPC3-associated ataxias and highlight a site for therapeutic intervention.
- Department of Biochemistry and Molecular Biology, Center for Membrane Biology, McGovern Medical School at the University of Texas Health Science Center at Houston, Houston, TX, USA.
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