Gating charge interactions with the S1 segment during activation of a Na+ channel voltage sensor.

ABSTRACT: Voltage-gated Na(+) channels initiate action potentials during electrical signaling in excitable cells. Opening and closing of the pore of voltage-gated ion channels are mechanically linked to voltage-driven outward movement of the positively charged S4 transmembrane segment in their voltage sensors. Disulfide locking of cysteine residues substituted for the outermost T0 and R1 gating-charge positions and a conserved negative charge (E43) at the extracellular end of the S1 segment of the bacterial Na(+) channel NaChBac detects molecular interactions that stabilize the resting state of the voltage sensor and define its conformation. Upon depolarization, the more inward gating charges R2 and R3 engage in these molecular interactions as the S4 segment moves outward to its intermediate and act

SUBMITTER: DeCaen PG 

PROVIDER: S-EPMC3219111 | biostudies-literature | 2011 Nov

REPOSITORIES: biostudies-literature