title: Built for speed: molecular properties of the voltage sensor domain underlie the rapid activation of voltage-gated Na(+) channels compared with Shaker-type K(+) channels.
abstract: Many of us were taught in high school biology that the action potential waveform in nerves and other excitable tissues was generated by an initial rapid influx of external Na(+) ions across the plasma membrane, followed by an outward movement of intracellular K(+) ions. The former event, mediated by voltage-gated Na(+) channels, is responsible for the fast depolarizing upstroke of the action potential, while voltage-gated K+ channels are responsible for the subsequent repolarizing phase, which largely controls action potential duration. Although Hodgkin and Huxley described the fundamental importance of this sequential activation process more than 60 y ago, the molecular and structural details underlying the faster activation of voltage-gated Na(+) (Nav) vs. K(+) (Kv) channels have yet to be fully resolved.
authors.affiliation: Faculty of Medicine; University of Calgary; Calgary, Alberta, Canada.
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Braun
mesh_terms: D000200:Action Potentials / Q000235:genetics*; D000818:Animals; D015640:Ion Channel Gating / Q000235:genetics*; D015221:Potassium Channels / Q000235:genetics*; D051637:Shaker Superfamily of Potassium Channels / Q000235:genetics*
chemical_list: D015221:Potassium Channels; D051637:Shaker Superfamily of Potassium Channels
keywords: Kv channel; Nav channel; gating current; hydrophobicity; voltage sensor domain