National Health and Medical Research Council (NHMRC, Australia)
オーストラリア
引用
ジャーナル: Nat Commun / 年: 2024 タイトル: Potassium dependent structural changes in the selectivity filter of HERG potassium channels. 著者: Carus H Y Lau / Emelie Flood / Mark J Hunter / Billy J Williams-Noonan / Karen M Corbett / Chai-Ann Ng / James C Bouwer / Alastair G Stewart / Eduardo Perozo / Toby W Allen / Jamie I Vandenberg / 要旨: The fine tuning of biological electrical signaling is mediated by variations in the rates of opening and closing of gates that control ion flux through different ion channels. Human ether-a-go-go ...The fine tuning of biological electrical signaling is mediated by variations in the rates of opening and closing of gates that control ion flux through different ion channels. Human ether-a-go-go related gene (HERG) potassium channels have uniquely rapid inactivation kinetics which are critical to the role they play in regulating cardiac electrical activity. Here, we exploit the K sensitivity of HERG inactivation to determine structures of both a conductive and non-conductive selectivity filter structure of HERG. The conductive state has a canonical cylindrical shaped selectivity filter. The non-conductive state is characterized by flipping of the selectivity filter valine backbone carbonyls to point away from the central axis. The side chain of S620 on the pore helix plays a central role in this process, by coordinating distinct sets of interactions in the conductive, non-conductive, and transition states. Our model represents a distinct mechanism by which ion channels fine tune their activity and could explain the uniquely rapid inactivation kinetics of HERG.