Premium
Endogenous voltage‐gated potassium channels in human embryonic kidney (HEK293) cells
Author(s) -
Yu Shan Ping,
Kerchner Geoffrey A.
Publication year - 1998
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/(sici)1097-4547(19980601)52:5<612::aid-jnr13>3.0.co;2-3
Subject(s) - hek 293 cells , embryonic stem cell , endogeny , potassium channel , voltage gated ion channel , microbiology and biotechnology , potassium , human kidney , voltage gated potassium channel , chemistry , neuroscience , kidney , biophysics , biology , ion channel , endocrinology , genetics , cell culture , biochemistry , gene , receptor , organic chemistry
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 Ca 2+ ‐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. J. Neurosci. Res. 52:612–617, 1998. © 1998 Wiley‐Liss, Inc.