Glutathione-gated K+ channels of Escherichia coli carry out K+ efflux controlled by the redox state of the cell.
The kinetics of K+ efflux across the membranes of i) wild-type Escherichia coli poisoned by the thiol reagent N-ethylmaleimide, ii) K+ retention mutants and iii) glutathione-deficient mutants, have revealed a common "K+ leaky phenotype"; it is characterized by a very high rate of K+ efflux. The results suggest that the products of kefB and kefC genes could encode two K+ channels, both gated by glutathione. The possible function of these K+ channels seems to be a K+ exit controlled by the redox state of the cell; indeed, it can be inferred from the effects of several oxidants and reductants that turning on and off of the K+ efflux mediated by the channels can be correlated with the redox state of glutathione.
Meury
J
J
Institut Jacques Monod, Paris, France.
Robin
A
A
D001693:Biological Transport, Active; D003470:Culture Media; D004926:Escherichia coli / Q000378:metabolism*; D005978:Glutathione / Q000378:metabolism*; D015640:Ion Channel Gating; D007700:Kinetics; D010084:Oxidation-Reduction; D011188:Potassium / Q000378:metabolism*; D015221:Potassium Channels / Q000378:metabolism*
D003470:Culture Media; D015221:Potassium Channels; D005978:Glutathione; D011188:Potassium