Abstract
Potassium channels represent a diverse family of ion channels whose members display the common property of being highly selectivity for potassium as the conducting ion. Support for the idea of the large diversity of potassium channels is gained from sequencing the Caenorhabditis elegans genome. It is predicted that about 100 K+ channel subunits exist in this organism. These K+ channel subunits belong to eight conserved K+ channel families (Wei et al., 1996), and the high-conductance, Ca2+-activated K+ (BKCa) channel is a representative member of one of these families. BKCa channels are widely distributed in both electrically excitable and nonexcitable cells (Latorre et al., 1989; McManus, 1991), are activated by both voltage and intracellular Ca2+, and display a high conductance, as well as a high selectivity for K+. They regulate excitation—contraction coupling processes in vascular, airway, bladder, and other types of smooth muscle and also control transmitter release from neuroendocrine tissue. In nonexcitable cells, BKCa channels regulate fluid secretion and cell volume. In various tissues, BKCa channels are modulated by exogenous ligands signaling through their respective membrane receptors. Regulatory mechanisms such as phosphorylation, interaction with GTP-binding proteins, or direct modulation by intracellular second messengers have been identified and charcterized.
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Garcia, M.L., Kaczorowski, G.J. (2001). Pharmacology of High-Conductance, Ca2+-Activated Potassium Channels. In: Archer, S.L., Rusch, N.J. (eds) Potassium Channels in Cardiovascular Biology. Springer, Boston, MA. https://doi.org/10.1007/978-1-4615-1303-2_13
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