transient receptor potential cation channel subfamily M member 5; long transient receptor potential channel 5; LTrpC5, MLSN1- & TRP- related gene 1 protein (RPM5, LTRPC5, MTR1)

Function: - voltage-modulated Ca⁺²-activated, monovalent cation channel (VCAM) - mediates a transient membrane depolarization - plays a central role in taste transduction - monovalent-specific, non-selective cation channel - mediates transport of Na⁺, K⁺ & Cs+ ions equally well - activated directly by increases in intracellular Ca⁺², but is impermeable to it - gating is voltage-dependent & displays rapid activation & deactivation kinetics upon channel stimulation even during sustained elevations in Ca⁺² - also activated by a fast intracellular Ca⁺² increase in response to inositol 1,4,5-triphosphate-producing receptor agonists. - the channel is blocked by extracellular acidification - external acidification has 2 effects 1) a fast reversible block of the current 2) a slower irreversible enhancement of current inactivation - highly temperature-sensitive, heat activated channel showing a steep increase of inward currents at temperatures between 15-35 degrees C - heat activation is due to a shift of the voltage-dependent activation curve to negative potentials - activated by arachidonic acid in vitro - may be involved in perception of bitter, sweet & umami tastes - may also be involved in sensing semiochemicals Structure: - belongs to the transient receptor family, LTrpC subfamily Compartment: cell membrane; multi-pass membrane protein Alternative splicing: named isoforms=3 Expression: - strongly expressed in fetal brain, liver & kidney, & in adult prostate, testis, ovary, colon & peripheral blood leukocytes - in monochromosomal cell lines shows exclusive paternal expression Pathology: - expressed in a large proportion of Wilms' tumors & rhabdomyosarcomas

General

phosphoprotein receptor transmembrane 5 protein

Properties

SIZE: entity length = 1165 aa MW = 131 kD COMPARTMENT: cellular membrane MOTIF: exoplasmic domain {1-733} MOTIF: Tyr phosphorylation site {Y419} coiled coil {553-581} transmembrane domain {734-754} cytoplasmic loop {755-811} transmembrane domain {812-832} exoplasmic loop {833-835} transmembrane domain {836-856} cytoplasmic loop {857-872} transmembrane domain {873-893} exoplasmic loop {894-954} transmembrane domain {955-975} cytoplasmic domain {976-1165}

Database Correlations

OMIM 604600 UniProt Q9NZQ8 Pfam PF00520 Kegg hsa:2985

References

UniProt :accession Q9NZQ8