Changing perspectives on how the permeation pathway through potassium channels is regulated.
Katrina A BlackRuitao JinSitong HeJacqueline M GulbisPublished in: The Journal of physiology (2019)
The primary means by which ion permeation through potassium channels is controlled, and the key to selective intervention in a range of pathophysiological conditions, is the process by which channels switch between non-conducting and conducting states. Conventionally, this has been explained by a steric mechanism in which the pore alternates between two conformations: a 'closed' state in which the conduction pathway is occluded and an 'open' state in which the pathway is sufficiently wide to accommodate fully hydrated ions. Recently, however, 'non-canonical' mechanisms have been proposed for some classes of K+ channels. The purpose of this review is to illuminate structural and dynamic relationships underpinning permeation control in K+ channels, indicating where additional data might resolve some of the remaining issues.