Direct Interaction between the Voltage Sensors Produces Cooperative Sustained Deactivation in Voltage-gated H+ Channel Dimers.

ABSTRACT: The voltage-gated H(+) channel (Hv) is a voltage sensor domain-like protein consisting of four transmembrane segments (S1-S4). The native Hv structure is a homodimer, with the two channel subunits functioning cooperatively. Here we show that the two voltage sensor S4 helices within the dimer directly cooperate via a π-stacking interaction between Trp residues at the middle of each segment. Scanning mutagenesis showed that Trp situated around the original position provides the slow gating kinetics characteristic of the dimer's cooperativity. Analyses of the Trp mutation on the dimeric and monomeric channel backgrounds and analyses with tandem channel constructs suggested that the two Trp residues within the dimer are functionally coupled during Hv deactivation but are less so during activat

SUBMITTER: Okuda H 

PROVIDER: S-EPMC4786727 | biostudies-literature | 2016 Mar

REPOSITORIES: biostudies-literature