Glutathione potentiates cloned rat brain large conductance Ca(2+)-activated K(+) channels (rSlo).
We have investigated the modulation of a cloned rat brain alpha-subunit of large conductance Ca(2+)-activated K(+) channels (rSlo K(+) channels) by glutathione (GSH), a physiological sulfhydryl-specific reducing reagent. The application of GSH to the intracellular side of excised inside-out macroscopic patches of rslo-transfected HEK293 cells reversibly activated the currents. The activation rate constants of the current were increased while the deactivation rate constants were decreased by GSH at all voltages tested without any change in the voltage dependence of the rate constants. GSH induced a leftward shift of the steady state conductance-voltage relationship curve of the current with no change in the slope of the curve. These results suggest that modulation by GSH may constitute an important regulatory mechanism of neuronal large conductance Ca(2+)-activated K(+) channels.
Chung
Sungkwon
S
Department of Physiology, Sungkyunkwan University, School of Medicine, 440-746, Suwon, South Korea. schung@yurim.skku.ac.kr
Jung
Wonyong
W
Uhm
Dae Yong
DY
Ha
Tal Soo
TS
Park
Chul Seung
CS
D000818:Animals; D002478:Cells, Cultured; D003001:Cloning, Molecular; D005978:Glutathione / Q000494:pharmacology*; D006801:Humans; D015640:Ion Channel Gating / Q000187:drug effects*; D007668:Kidney / Q000166:cytology; D051037:Large-Conductance Calcium-Activated Potassium Channel alpha Subunits; D051036:Large-Conductance Calcium-Activated Potassium Channels; D008564:Membrane Potentials / Q000187:drug effects; D010084:Oxidation-Reduction; D018408:Patch-Clamp Techniques; D024681:Potassium Channels, Calcium-Activated / Q000235:genetics* / Q000378:metabolism*; D051381:Rats; D014162:Transfection
D051037:Large-Conductance Calcium-Activated Potassium Channel alpha Subunits; D051036:Large-Conductance Calcium-Activated Potassium Channels; D024681:Potassium Channels, Calcium-Activated; D005978:Glutathione