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. Interacts with ITPR1 (PubMed:9853757). Interacts with ITPR3 (PubMed:10611319). Interacts with MX1 (PubMed:15757897). Interacts with RNF24 (PubMed:17850865). Interacts with JPH2; the interaction is involved in maintaining Ca(2+) homeostasis in skeletal muscle and is mediated by JPH2 'Ser-165' phosphorylation (PubMed:20095964). Interacts with isoform short of TRPC1. Expressed predominantly in brain and at much lower levels in ovary, colon, small intestine, lung, prostate, placenta and testis. The disease is caused by variants affecting the gene represented in this entry. Belongs to the transient receptor (TC 1.A.4) family. STrpC subfamily. TRPC3 sub-subfamily.