Helical motion of an S4 voltage sensor revealed by gating pore currents.

The mechanism by which the voltage sensors of voltage-gated ion channels move gating charge during the activation process is a subject of active debate. In this issue of Channels, Gamal El-Din et al. probe the movements of the S4 voltage sensor of Shaker K(+) channels through clever use of omega gating pore currents generated by paired gating-charge mutations. Their results provide strong support for a sliding helix or helical screw mechanism of gating charge movement.