The Transient Receptor Potential Melastatin (TRPM) subfamily of cation-permeable channels is ubiquitous in mammalian tissues. This family includes TRPM1-8. In addition to acting as a calcium-permeant channel, some TRPM family members, TRPM6 and TRPM7, possess serine/threonine kinase activity and autophosphorylation. TRPM8 is thermoactivated at mildly cold temperatures (>25oC), and can also be activated by compounds that cause a cooling sensation, such as menthol and icilin. TRPM8 is expressed in trigeminal and dorsal root ganglia neurons where it confers sensitivity to cold in the somatosensory system. In vascular smooth muscle, TRPM8 may alter blood flow by constricting or enlarging blood vessels. TRPM8 is also expressed in normal prostate epithelial cells, as well as overexpressed in several primary tumors including colon, lung, skin, breast, and prostate cancers.
