Bkca Channels As Physiological Regulators: A Focused Review

Large-conductance Ca2+- and voltage-gated big K+ (BKCa, MaxiK, or Slo1) - channels are expressed in almost every cell of mammalian tissues and participate in a multitude of physiological processes such as vascular tone regulation, neuronal excitability, neurotransmitter release, neurovascular coupling, bladder tone regulation, urinary K+ excretion, and retinal circulation. BKCa channel is a tetramer of the pore-forming a-subunit encoded by a single gene, Slo. The BKCa-alpha-subunits are associated with the modulatory beta-subunits, which contribute to the functional diversity of the channel. BKCa channels sense and regulate membrane voltage and intracellular Ca2+, which then modulates several cell signaling and metabolic pathways. This review focuses on the main physiologic roles of BKCa channels and the pathogenesis of diseases associated with their loss or malfunction. The mechanistic information highlighted in this review is aimed to enhance the understanding of the unique and diverse roles of BKCa channels in various physiological and pathophysiological phenomena.