KCa2.1 is a member of the Ca2+-activated K+ channels family with small conductance that includes KCa2.2 (SK2) and KCa2.3 (SK3). The channel is voltage insensitive and is activated by intracellular Ca2+ in the submicromolar range. It has a similar topology to that of voltage-dependent K+ channels (KV channels), that is six transmembrane domains and intracellular N- and C-termini. KCa2.1 channel expression is roughly confined to neuronal tissue, although there are some indications that it may be present in non-neuronal tissues as well.
