TRPC1 channel
| Channel name | TRPC11,2,3,4,5,6,7,8 |
| Description | Nonselective cation channel subunit |
| Other names | TRP1 |
| Molecular information | Human unigene: Hs0.250687, chr. 3q22–3q24 |
| Mouse unigene: Mm0.149633 | |
| Associated subunits | TRPC4, TRPC5 (TRPC3–embryo), calmodulin, IP3Rs, caveolin-1, Gq/11, PMCA, mGluR1 |
| Functional assays | Patch-clamp, calcium imaging |
| Current | Outwardly rectifying when coexpressed with TRPC4 and TRPC5 |
| Conductance | Not established |
| Ion selectivity | PNa/PCa ∼1:1 (when coexpressed with TRPC4 and TRPC5)5 |
| Activation | Stretch? |
| Inactivation | Not established |
| Activators | Recording of Gq-coupled receptor (heteromer TRPC1/TRPC5), whole cell current, augmented store-operated influx as presumed homomer; no direct agonists identified, gated in response to stimulation of the Gq-coupled receptors, augmented by La3+ (heteromer of TRPC1 with TRPC4 or TRPC5)5; it has been proposed that the mGluR1-evoked slow EPSC is mediated by the TRPC1 cation channel; TRPC1 is expressed in perisynaptic regions of the cerebellar parallel fiber-Purkinje cell synapse and may be physically associated with mGluR16 |
| Gating inhibitors | None |
| Blockers | Inhibited by 80 μM 2-APB (heteromer) and Gd3+ |
| Radioligands | None |
| Channel distribution | Widely expressed; highest levels in brain, heart, kidney, lung, skeletal muscle, prostate, skin testis, ovaries |
| Physiological functions | Putative role in receptor-mediated, Ca2+-dependent secretion and contraction |
| Mutations and pathophysiology | Not established |
| Pharmacological significance | Involved in Ca2+ entry induced by phospholipid hydrolysis (PI response) and Ca2+ store depletion |
| Comments | Splice variants in human and mouse |
chr., chromosome; PMCA, plasma membrane calcium pump; EPSC, excitatory postsynaptic current; PI, phosphatidylinositol.
↵1. Wes PD, Chevesich J, Jeromin A, Rosenberg C, Stettten G, and Montell C (1995) TRPC1, a human homolog of a Drosophila store-operated channel. Proc Natl Acad Sci USA 92:9652-9656
↵2. Zhu X, Jiang M, Peyton M, Boulay G, Hurst R, Stefani E, and Birnbaumer L (1996) trp, a novel mammalian gene family essential for agonist-activated capacitative Ca2+ entry. Cell 85:661-671
↵3. Zitt C, Zobel A, Obukhov AG, Harteneck C, Kalkbrenner F, Luckhoff A, and Schultz G (1996) Cloning and functional expression of a human Ca2+-permeable cation channel activated by calcium store depletion. Neuron 16:1189-1196
↵4. Lintschinger B, Balzer-Geldsetzer M, Baskaran T, Graier WF, Romanin C, Zhu MX, and Groschner K (2000) Coassembly of Trp1 and Trp3 proteins generates diacylglycerol- and Ca2+-sensitive cation channels. J Biol Chem 275:27799-27805
↵5. Strübing C, Krapivinsky G, Krapivinsky L, and Clapham DE (2001) TRPC1 and TRPC5 form a novel cation channel in mammalian brain. Neuron 29:645-655
↵6. Xu XZ, Li HS, Guggino WB, and Montell C (1997) Coassembly of TRP and TRPL produces a distinct store-operated conductance. Cell 89:1155-1164
↵7. Brazer SC, Singh BB, Liu X, Swaim W, and Ambudkar IS (2003) Caveolin-1 contributes to assembly of store-operated Ca2+ influx channels by regulating plasma membrane localization of TRPC1. J Biol Chem 278:27208-27215
↵8. Kim SJ, Kim YS, Yuan JP, Petralia RS, Worley PF, and Linden DJ (2003) Activation of the TRPC1 cation channel by metabotropic glutamate receptor mGluR1. Nature (Lond) 426:285–291</.>