The Ca2+-Activated Monovalent Cation-Selective Channels TRPM4 and TRPM5

In this review we summarize the current data on the ion channels TRPM4 and TRPM5. These proteins are to date the only molecular candidates for the class of Ca²⁺ -activated cation channels (CAN channels). They form monovalent cation-selective and Ca-impermeable ion channels, which are activated by a rise of the cytosolic Ca²⁺ concentration. They have been described in a plethora of tissues, and their physiological importance is only now being explored since knockout mice have become available.