Endogenous voltage-gated potassium channels in human embryonic kidney (HEK293) cells

J Neurosci Res. 1998 Jun 1;52(5):612-7. doi: 10.1002/(SICI)1097-4547(19980601)52:5<612::AID-JNR13>3.0.CO;2-3.


Endogenous voltage-gated potassium currents were investigated in human embryonic kidney (HEK293) and Chinese hamster ovary (CHO) cells using whole-cell voltage clamp recording. Depolarizing voltage steps from -70 mV triggered an outwardly rectified current in nontransfected HEK293 cells. This current had an amplitude of 296 pA at +40 mV and a current density of 19.2 pA/pF. The outward current was eliminated by replacing internal K+ with Cs+ and suppressed by the K+ channel blockers tetraethylammonium and 4-aminopyridine. Raising external K+ attenuated the outward current and shifted the reversal potential towards positive potentials as predicted by the Nernst equation. The current had a fast activation phase but inactivated slowly. These features implicate delayed rectifier (I(K))-like channels as mediators of the observed current, which was comparable in size to I(K) currents in many other cells. A small native inward rectifier current but no transient outward current I(A), the M current I(M), or Ca2+-dependent K+ currents were detected in HEK293 cells. In contrast to these findings in HEK293 cells, little or no I(K)-like current was detected in CHO cells. The difference in endogenous voltage-activated currents in HEK293 and CHO cells suggest that CHO cell lines are a preferred system for exogenous K+ channel expression.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • 4-Aminopyridine / pharmacology
  • Animals
  • CHO Cells / metabolism
  • Cell Line
  • Cricetinae
  • Delayed Rectifier Potassium Channels
  • Electrophysiology
  • Humans
  • Ion Channel Gating / physiology*
  • Kidney / cytology
  • Kidney / embryology
  • Kidney / metabolism*
  • Patch-Clamp Techniques
  • Potassium Channels / drug effects
  • Potassium Channels / metabolism
  • Potassium Channels / physiology*
  • Potassium Channels, Voltage-Gated*
  • Tetraethylammonium / pharmacology


  • Delayed Rectifier Potassium Channels
  • Potassium Channels
  • Potassium Channels, Voltage-Gated
  • Tetraethylammonium
  • 4-Aminopyridine