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)

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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
a fast reversible block of the current
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

strongly expressed in fetal brain, liver & kidney, & in adult prostate, testis, ovary, colon & peripheral blood leukocytes
in monochromosomal cell lines shows exclusive paternal expression