The Voltage Sensor Is Responsible For Aph Dependence In Hv1 Channels

Significance Acid extrusion in various types of cells and the reactive oxygen species production by the NADPH oxidase in phagocytes and microglia are mediated by the voltage-gated proton channel (H v 1). One of the biophysical properties essential for the H v 1 function is its ΔpH-dependent gating. Here, we measured the H v 1 gating currents’ pH dependence in the monomeric nonconducting D160N Ciona intestinalis H v 1 mutant. We demonstrated that H v 1 ΔpH-dependent gating is a consequence of voltage sensor modulation by direct gating currents recordings. Around 60% of the energy stored in the ΔpH is coupled to the H v 1 voltage sensor activation. Therefore, the proton chemical energy is transduced to the voltage sensor activation in H v 1 to produce ΔpH-dependent gating.