TRPC3 channel
| Channel name | TRPC31,2,3,4,5,6 |
| Description | Diacylglycerol-Ca2+-activated TRP channel |
| Other names | mTRPC3 |
| Molecular information | Human unigene: Hs0.150981, chr. 4q27 |
| Mouse unigene: Mm0.74363, chr. 3 | |
| Associated subunits | TRPC6, TRPC7, FKBP12, VAMP2, syntaxin, SNAP, NCX1, TrkB |
| Functional assays | Patch-clamp, calcium imaging |
| Current | Inwardly and outwardly rectifying, nonselective cation current |
| Conductance | 66pS2 |
| Ion selectivity | PNa/PCa = 1:1.5 |
| Activation | Intracellular Ca2+ |
| Inactivation | Not established |
| Activators | Activated either by DAG or direct interaction with the IP3 receptor in vitro; activated through a BDNF, TrkB-mediated pathway in neurons |
| Gating inhibitors | None |
| Blockers | 2-APB, 1–25 μM Gd3+, La3+, RuR |
| Radioligands | None |
| Channel distribution | Brain, placenta, heart, muscle, smooth muscle |
| Physiological functions | Resistance artery myogenic tone, airway regulation |
| Mutations and pathophysiology | Not established |
| Pharmacological significance | Not established |
| Comments | DAG response is PKC-independent |
chr., chromosome; TrkB, tyrosine kinase B; BDNF, brain-derived neurotrophic factor; RuR, ruthenium red.
↵1. Hofmann T, Schaefer M, Schultz G, and Gudermann T (2002) Subunit composition of mammalian transient receptor potential channels in living cells. Proc Natl Acad Sci USA 99:7461-7466
↵2. Hofmann T, Obukhov AG, Schaefer M, Harteneck C, Gudermann T, and Schultz G (1999) Direct activation of human TRPC6 and TRPC3 channels by diacylglycerol. Nature (Lond) 397:259-263
↵3. Sinkins WG, Goel M, Estacion M, and Schilling WP (2004) Association of immunophilins with mammalian TRPC channels. J Biol Chem 279:34521-34529
↵4. Treves S, Franzini-Armstrong C, Moccagatta L, Arnoult C, Grasso C, Schrum A, Ducreux S, Zhu MX, Mikoshiba K, et al. (2004) Junctate is a key element in calcium entry induced by activation of InsP3receptors and/or calcium store depletion. J Cell Biol 166:537-548
↵5. Singh BB, Lockwich TP, Bandyopadhyay BC, Liu X, Bollimuntha S, Brazer SC, Combs C, Das S, Leenders AG, Sheng ZH, et al. (2004) VAMP2-dependent exocytosis regulates plasma membrane insertion of TRPC3 channels and contributes to agonist-stimulated Ca2+ influx. Mol Cell 15:635-646
↵6. Rosker C, Graziani A, Lukas M, Eder P, Zhu MX, Romanin C, and Groschner, K (2004) Ca2+ signaling by TRPC3 involves Na+ entry and local coupling to the Na+/Ca2+ exchanger. J Biol Chem 279:13696-13704