Molecular mechanisms of cardiac voltage-gated potassium channelopathies.

Potassium channels form highly K+ ion-selective pores in the plasma membrane of excitable cells. Voltage-gated potassium (Kv) channels open in response to membrane depolarization to allow rapid diffusion of K+ ions out of the cell, thus repolarizing the cell to restore a negative resting membrane potential. Inherited mutations in Kv channel genes produce abnormal cellular repolarization and cause diseases of excitable tissues. Small molecule interactions with Kv channels can cause similar pathologies. During the last decade of research into Kv channels and associated diseases--termed 'channelopathies'--we have begun to understand Kv channel function and dysfunction at the molecular level. In this review, the molecular mechanisms of Kv channelopathies are discussed, with particular emphasis on the overlap between inherited and acquired disease, and the drive towards novel channel-targeted therapies.