Aromatic-aromatic interactions between residues in KCa3.1 pore helix and S5 transmembrane segment control the channel gating process.

ABSTRACT: The Ca(2+)-activated potassium channel KCa3.1 is emerging as a therapeutic target for a large variety of health disorders. One distinguishing feature of KCa3.1 is that the channel open probability at saturating Ca(2+) concentrations (Pomax) is low, typically 0.1-0.2 for KCa3.1 wild type. This observation argues for the binding of Ca(2+) to the calmodulin (CaM)-KCa3.1 complex, promoting the formation of a preopen closed-state configuration leading to channel opening. We have previously shown that the KCa3.1 active gate is most likely located at the level of the selectivity filter. As Ca(2+)-dependent gating of KCa3.1 originates from the binding of Ca(2+) to CaM in the C terminus, the hypothesis of a gate located at the level of the selectivity filter requires that the conformational change

SUBMITTER: Garneau L 

PROVIDER: S-EPMC4001770 | biostudies-literature | 2014 Feb

REPOSITORIES: biostudies-literature