Calcium-activated potassium channel subunit alpha-1 (KCNMA1)

Potassium channel activated by both membrane depolarization or increase in cytosolic Ca(2+) which mediates export of K(+). Additionally it is activated by the concentration of cytosolic Mg(2+).

Its activation dampens the excitatory events which elevate the cytosolic Ca(2+) concentration and/or depolarize the cell membrane. Plays a key role in controlling excitability in several of systems, such as regulation of the contraction of smooth muscle, the tuning of hair cells in the cochlea, regulation of transmitter release, and innate immunity.