Voltage-Gated Potassium Channels

Voltage-gated K⁺ (K_v) channels are K⁺ selective pores in the membrane that open or close with changes in the membrane potential. K_v channels constitute the largest family of K⁺ channels. K_v channels are expressed in most cell types and play diverse physiological roles that depend on the specific cell type. In neurons and muscle cells, K_v channels are responsible for the repolarization phase of the action potential. This chapter discusses the structure of K_v channels and describes key aspects of ionic selectivity, voltage gating and the mechanisms of inactivation that operate in these channels. The various families of K_v channels and key functional properties and pharmacology of these channel families are described. Aspects of K_v channels that are presently not well understood and represent avenues of future research are discussed.