KCa1.1 (BKCa, Maxi K+ or slo) is part of a structurally diverse group of K+ channels that are activated by an increase in intracellular Ca2+. KCa1.1 shows a large single channel conductance when recorded electrophysiologically and hence its name. It differs from the rest of the subfamily members in that it can be activated by both an increase in intracellular Ca2+ and by membrane depolarization.
KCa1.1 is expressed in virtually all cell types where it causes hyperpolarization and helps to connect between intracellular Ca2+ signaling pathways and membrane excitability.
Indeed, KCa1.1 channels have a crucial role in smooth muscle contractility, neuronal spike shaping and neurotransmitter release.
