Voltage-sensor movements describe slow inactivation of voltage-gated sodium channels I: wild-type skeletal muscle Na(V)1.4.

ABSTRACT: The number of voltage-gated sodium (Na(V)) channels available to generate action potentials in muscles and nerves is adjusted over seconds to minutes by prior electrical activity, a process called slow inactivation (SI). The basis for SI is uncertain. Na(V) channels have four domains (DI-DIV), each with a voltage sensor that moves in response to depolarizing stimulation over milliseconds to activate the channels. Here, SI of the skeletal muscle channel Na(V)1.4 is induced by repetitive stimulation and is studied by recording of sodium currents, gating currents, and changes in the fluorescence of probes on each voltage sensor to assess their movements. The magnitude, voltage dependence, and time course of the onset and recovery of SI are observed to correlate with voltage-sensor movements 1

SUBMITTER: Silva JR 

PROVIDER: S-EPMC3581692 | biostudies-literature | 2013 Mar

REPOSITORIES: biostudies-literature