A Non-canonical Voltage-Sensing Mechanism Controls Gating in K2P K(+) Channels.

ABSTRACT: Two-pore domain (K2P) K(+) channels are major regulators of excitability that endow cells with an outwardly rectifying background "leak" conductance. In some K2P channels, strong voltage-dependent activation has been observed, but the mechanism remains unresolved because they lack a canonical voltage-sensing domain. Here, we show voltage-dependent gating is common to most K2P channels and that this voltage sensitivity originates from the movement of three to four ions into the high electric field of an inactive selectivity filter. Overall, this ion-flux gating mechanism generates a one-way "check valve" within the filter because outward movement of K(+) induces filter opening, whereas inward movement promotes inactivation. Furthermore, many physiological stimuli switch off this flux gating

SUBMITTER: Schewe M 

PROVIDER: S-EPMC4771873 | biostudies-literature | 2016 Feb

REPOSITORIES: biostudies-literature