transient receptor potential cation channel subfamily M member 4 (long transient receptor potential channel 4,l hTRPM4, melastatin-4, Ca+2-activated non-selective cation channel 1, TRPM4)

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Function

Ca+2-activated non selective cation channel that mediates membrane depolarization
activated by an increase in intracellular Ca+2, but is impermeable to Ca+2
mediates transport of monovalent cations (Na+ > K+ > Cs+ > Li+), leading to depolarize the membrane
role in cadiomyocytes, neurons from entorhinal cortex, dorsal root & vomeronasal neurons, endocrine pancreas cells, kidney epithelial cells, cochlea hair cells etc.
role in T-cell activation by modulating Ca+2 oscillations after T lymphocyte activation, required for NFAT-dependent IL2 production
role in myogenic constriction of cerebral arteries
controls insulin secretion in pancreatic beta-cells
role in pacemaking
gating is voltage-dependent & repressed by decavanadate
calmodulin-binding confers the Ca+2 sensitivity
ATP is able to restore Ca+2 sensitivity after desensitization
phosphatidylinositol 4,5-biphosphate (PIP2)-binding strongly enhances activity, by increasing the channel's Ca+2 sensitivity & shifting its voltage dependence of activation towards negative potentials
activity is enhanced by 3,5- bis(trifluoromethyl)pyrazole derivative (BTP2)
phosphorylation by PKC leads to increase the sensitivity to Ca+2

widely expressed with a high expression in intestine & prostate
in brain, expressed in cerebral arteries & isolated vascular smooth muscle cells