7dxe

Structure of TRPC3 gain of function mutation R803C at 3.2 angstrom in 1340nM free calcium stateStructure of TRPC3 gain of function mutation R803C at 3.2 angstrom in 1340nM free calcium state

Structural highlights

7dxe is a 4 chain structure. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:	, , ,
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Disease

[TRPC3_HUMAN] The disease is caused by mutations affecting the gene represented in this entry.

Function

[TRPC3_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 PubMed

TRPC3 and TRPC6 channels are calcium-permeable non-selective cation channels that are involved in many physiological processes. The gain-of-function (GOF) mutations of TRPC6 lead to familial focal segmental glomerulosclerosis (FSGS) in humans, but their pathogenic mechanism remains elusive. Here, we report the cryo-EM structures of human TRPC3 in both high-calcium and low-calcium conditions. Based on these structures and accompanying electrophysiological studies, we identified both inhibitory and activating calcium-binding sites in TRPC3 that couple intracellular calcium concentrations to the basal channel activity. These calcium sensors are also structurally and functionally conserved in TRPC6. We uncovered that the GOF mutations of TRPC6 activate the channel by allosterically abolishing the inhibitory effects of intracellular calcium. Furthermore, structures of human TRPC6 in complex with two chemically distinct inhibitors bound at different ligand-binding pockets reveal different conformations of the transmembrane domain, providing templates for further structure-based drug design targeting TRPC6-related diseases such as FSGS.

Structural mechanism of human TRPC3 and TRPC6 channel regulation by their intracellular calcium-binding sites.,Guo W, Tang Q, Wei M, Kang Y, Wu JX, Chen L Neuron. 2022 Mar 16;110(6):1023-1035.e5. doi: 10.1016/j.neuron.2021.12.023. Epub , 2022 Jan 19. PMID:35051376^[5]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Woo JS, Hwang JH, Ko JK, Weisleder N, Kim DH, Ma J, Lee EH. S165F mutation of junctophilin 2 affects Ca2+ signalling in skeletal muscle. Biochem J. 2010 Mar 15;427(1):125-34. doi: 10.1042/BJ20091225. PMID:20095964 doi:http://dx.doi.org/10.1042/BJ20091225
↑ Zhu X, Jiang M, Peyton M, Boulay G, Hurst R, Stefani E, Birnbaumer L. trp, a novel mammalian gene family essential for agonist-activated capacitative Ca2+ entry. Cell. 1996 May 31;85(5):661-71. PMID:8646775
↑ Zhu X, Jiang M, Birnbaumer L. Receptor-activated Ca2+ influx via human Trp3 stably expressed in human embryonic kidney (HEK)293 cells. Evidence for a non-capacitative Ca2+ entry. J Biol Chem. 1998 Jan 2;273(1):133-42. PMID:9417057
↑ Hofmann T, Obukhov AG, Schaefer M, Harteneck C, Gudermann T, Schultz G. Direct activation of human TRPC6 and TRPC3 channels by diacylglycerol. Nature. 1999 Jan 21;397(6716):259-63. doi: 10.1038/16711. PMID:9930701 doi:http://dx.doi.org/10.1038/16711
↑ Guo W, Tang Q, Wei M, Kang Y, Wu JX, Chen L. Structural mechanism of human TRPC3 and TRPC6 channel regulation by their intracellular calcium-binding sites. Neuron. 2022 Mar 16;110(6):1023-1035.e5. doi: 10.1016/j.neuron.2021.12.023. Epub , 2022 Jan 19. PMID:35051376 doi:http://dx.doi.org/10.1016/j.neuron.2021.12.023

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OCA

[1] Woo JS, Hwang JH, Ko JK, Weisleder N, Kim DH, Ma J, Lee EH. S165F mutation of junctophilin 2 affects Ca2+ signalling in skeletal muscle. Biochem J. 2010 Mar 15;427(1):125-34. doi: 10.1042/BJ20091225. PMID:20095964 doi:http://dx.doi.org/10.1042/BJ20091225

[2] Zhu X, Jiang M, Peyton M, Boulay G, Hurst R, Stefani E, Birnbaumer L. trp, a novel mammalian gene family essential for agonist-activated capacitative Ca2+ entry. Cell. 1996 May 31;85(5):661-71. PMID:8646775

[3] Zhu X, Jiang M, Birnbaumer L. Receptor-activated Ca2+ influx via human Trp3 stably expressed in human embryonic kidney (HEK)293 cells. Evidence for a non-capacitative Ca2+ entry. J Biol Chem. 1998 Jan 2;273(1):133-42. PMID:9417057

[4] Hofmann T, Obukhov AG, Schaefer M, Harteneck C, Gudermann T, Schultz G. Direct activation of human TRPC6 and TRPC3 channels by diacylglycerol. Nature. 1999 Jan 21;397(6716):259-63. doi: 10.1038/16711. PMID:9930701 doi:http://dx.doi.org/10.1038/16711

[5] Guo W, Tang Q, Wei M, Kang Y, Wu JX, Chen L. Structural mechanism of human TRPC3 and TRPC6 channel regulation by their intracellular calcium-binding sites. Neuron. 2022 Mar 16;110(6):1023-1035.e5. doi: 10.1016/j.neuron.2021.12.023. Epub , 2022 Jan 19. PMID:35051376 doi:http://dx.doi.org/10.1016/j.neuron.2021.12.023

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