TRPM5

TRPM5 is a member of the transient receptor potential (TRP) protein family, which is a diverse group of proteins with structural features typical of ion channels. TRPM5 plays an important role in taste transduction, and has characteristics of a calcium-activated, non-selective cation channel that carries Na+, K+, and Cs+ ions equally well, but not Ca(2+) ions. TRPM5 is activated by lower concentrations of intracellular Ca(2+), and inhibited by higher concentrations. It is also a highly temperature-sensitive, heat activated channel showing a steep increase of inward currents at temperatures between 15 and 35 degrees Celsius.

Full Name

Transient Receptor Potential Cation Channel Subfamily M Member 5

Function

Voltage-modulated Ca2+-activated, monovalent cation channel (VCAM) that mediates a transient membrane depolarization and plays a central role in taste transduction. Monovalent-specific, non-selective cation channel that mediates the transport of Na+, K+ and Cs+ ions equally well. Activated directly by increases in intracellular Ca2+, but is impermeable to it. Gating is voltage-dependent and displays rapid activation and deactivation kinetics upon channel stimulation even during sustained elevations in Ca2+. Also activated by a fast intracellular Ca2+ increase in response to inositol 1,4,5-triphosphate-producing receptor agonists. The channel is blocked by extracellular acidification. External acidification has 2 effects, a fast reversible block of the current and a slower irreversible enhancement of current inactivation. Is a highly temperature-sensitive, heat activated channel showing a steep increase of inward currents at temperatures between 15 and 35 degrees Celsius. 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 and umami tastes. May also be involved in sensing semiochemicals.

Biological Process

Biological Process calcium ion transmembrane transport Source:GO_Central1 Publication
Biological Process cation transmembrane transport Source:GO_Central1 Publication
Biological Process regulation of ion transmembrane transport Source:UniProtKB-KW
Biological Process sensory perception of taste Source:InterPro

Cellular Location

Cell membrane

Topology

Cytoplasmic: 1-646
Helical: 647-667
Extracellular: 668-733
Helical: 734-754
Cytoplasmic: 755-811
Helical: 812-832
Extracellular: 833-835
Helical: 836-856
Cytoplasmic: 857-872
Helical: 873-893
Extracellular: 894-954
Helical: 955-975
Cytoplasmic: 976-1165