Human Kv1.6 current displays a C-type-like inactivation when re-expressed in cos-7 cells

Biochem Biophys Res Commun. 2003 Nov 7;311(1):83-9. doi: 10.1016/j.bbrc.2003.09.167.

Abstract

The human Kv1.6K(+) channel was functionally re-expressed in COS-7 cells at different levels. Voltage-activated K(+) currents are recorded upon cell membrane depolarization independently of the level of Kv1.6 expression. The current acquires a fast inactivation when Kv1.6 expression is increased. Inactivation was not affected by divalent cations or by extracellular tetraethylammonium. We have characterized the inactivation properties in biophysical terms. The fraction of inactivated current and the kinetics of inactivation are increased as the cell becomes more depolarized. Inactivated current can be reactivated according to a bi-exponential function of time. Additional experiments indicate that Kv1.6 inactivation properties are close to those of a conventional C-type inactivation. This work suggests that the concentration of Kv1.6 channel in the cell membrane strongly modulates the kinetic properties of Kv1.6-induced K(+) current. The physiological implications of these modifications are discussed.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptation, Physiological / drug effects
  • Adaptation, Physiological / physiology
  • Animals
  • COS Cells
  • Chlorocebus aethiops
  • Delayed Rectifier Potassium Channels
  • Electric Conductivity
  • Humans
  • Ion Channel Gating / drug effects
  • Ion Channel Gating / genetics
  • Ion Channel Gating / physiology*
  • Membrane Potentials / drug effects
  • Membrane Potentials / physiology*
  • Potassium Channels / drug effects
  • Potassium Channels / genetics
  • Potassium Channels / physiology*
  • Potassium Channels, Voltage-Gated*
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Tetraethylammonium / pharmacology
  • Transfection / methods*

Substances

  • Delayed Rectifier Potassium Channels
  • Potassium Channels
  • Potassium Channels, Voltage-Gated
  • Recombinant Proteins
  • Tetraethylammonium