6cud
Structure of the human TRPC3 in a lipid-occupied, closed state
Structural highlights
DiseaseTRPC3_HUMAN The disease is caused by mutations affecting the gene represented in this entry. FunctionTRPC3_HUMAN Thought to form a receptor-activated non-selective calcium permeant cation channel. Probably is operated by a phosphatidylinositol second messenger system activated by receptor tyrosine kinases or G-protein coupled receptors. Activated by diacylglycerol (DAG) in a membrane-delimited fashion, independently of protein kinase C, and by inositol 1,4,5-triphosphate receptors (ITPR) with bound IP3. May also be activated by internal calcium store depletion.[1] [2] [3] [4] Publication Abstract from PubMedThe TRPC channels are crucially involved in store-operated calcium entry and calcium homeostasis, and they are implicated in human diseases such as neurodegenerative disease, cardiac hypertrophy, and spinocerebellar ataxia. We present a structure of the full-length human TRPC3, a lipid-gated TRPC member, in a lipid-occupied, closed state at 3.3 Angstrom. TRPC3 has four elbow-like membrane reentrant helices prior to the first transmembrane helix. The TRP helix is perpendicular to, and thus disengaged from, the pore-lining S6, suggesting a different gating mechanism from other TRP subfamily channels. The third transmembrane helix S3 is remarkably long, shaping a unique transmembrane domain, and constituting an extracellular domain that may serve as a sensor of external stimuli. We identified two lipid binding sites, one being sandwiched between the pre-S1 elbow and the S4-S5 linker, and the other being close to the ion-conducting pore, where the conserved LWF motif of the TRPC family is located. Structure of the human lipid-gated cation channel TRPC3.,Fan C, Choi W, Sun W, Du J, Lu W Elife. 2018 May 4;7. pii: 36852. doi: 10.7554/eLife.36852. PMID:29726814[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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