[Term]
id: PR:000000668
name: calcium-activated calmodulin-binding potassium channel alpha subunit
def: "A calcium-activated potassium channel protein that has amino- and carboxyl-terminal intracellular domains separated by a domain containing six transmembrane helices (S1-S6) in which the last two helices (S5 and S6) flank a loop, called the pore loop, which determines ion selectivity. They are subunits of the small conductance calcium-activated channels. SK channels are independent of voltage and gated solely by intracellular calcium. These membrane channels are heteromeric complexes that comprise pore-forming alpha-subunits and the calcium-binding protein calmodulin. Calmodulin binds to the SK channel through the Calmodulin binding domain (Pfam:PF02888), which is located in an intracellular region of the alpha-subunit immediately carboxy-terminal to the pore. Channel opening is triggered when calcium binds the EF hands in the N-lobe of calmodulin. These channels play a crucial role in hyperpolarizing the membrane potential of excitable and nonexcitable cells." [PMID:10026195, PMID:11323678]
comment: Category=family.
xref: PIRSF:PIRSF038511
is_a: PR:000044649 ! calcium-activated potassium channel protein