TRPM5 channel
| Channel name | TRPM51,2,3 |
| Description | Nonselective, monovalent cation channel |
| Other names | Mtr1, LTRPC5 |
| Molecular information | Human unigene: Hs0.272287, chr. 11p15.5 |
| Mouse unigene: Mm0.286668, chr. 7 F5 | |
| Associated subunits | Not established |
| Functional assays | Patch-clamp, calcium imaging |
| Current | Steep outward rectification >0 mV |
| Conductance | 23pS (isotonic monovalent) |
| Ion selectivity | PNa/PCa = >20 (monovalent selective) |
| Activation | GPCR (T1R, T2R), Ggus-PLCβ2 [Ca2+]i 1—100 μM |
| Inactivation | Not established |
| Activators | [Ca2+]i |
| Gating inhibitors | None |
| Blockers | Not established |
| Radioligands | None |
| Channel distribution | Widely distributed, eye, liver, lung, tongue, stomach |
| Physiological functions | Sweet, bitter, umami taste transduction |
| Mutations and pathophysiology | Not established |
| Pharmacological significance | Not established |
| Comments | VMCA is an unusual feature; candidate gene for rhabdomyosarcomas, Wilms' tumor, and Beckwith-Wiedemann syndrome |
chr., chromosome; GPCR, G protein-coupled receptor; VMCA, voltage-modulated calcium-activated.
↵1. Hofmann T, Chubanov V, Gudermann T, and Montell C (2003) TRPM5 is a voltage-modulated and Ca2+-activated monovalent selective cation channel. Curr Biol 13:1153-1158
↵2. Liu D and Liman ER (2003) Intracellular Ca2+ and the phospholipid PIP2 regulate the taste transduction ion channel TRPM5. Proc Natl Acad Sci USA 100:15160-15165
↵3. Prawitt D, Monteilh-Zoller MK, Brixel L, Spangenberg C, Zabel B, Fleig A, and Penner R (2003) TRPM5 is a transient Ca2+-activated cation channel responding to rapid changes in [Ca2+]i. Proc Natl Acad Sci USA 100:15166-15171