Activation of potassium channels during metabolite detoxification in Escherichia coli

Gail Patricia Ferguson, Alasdair Munro, Roseileen M. Douglas, Debbie McLaggan, Ian Rylance Booth

Research output: Contribution to journalArticle

63 Citations (Scopus)

Abstract

In bacteria the detoxification of compounds as diverse as methylglyoxal and chlorodinitrobenzene proceeds through the formation of a glutathione adduct. In the Gram-negative bacteria, e.g. Escherichia coli, such glutathione adducts activate one, or both, of a pair of potassium efflux systems KefB and KefC. These systems share many of the properties of cation-translocating channels in eukaryotes. The activity of these systems has been found to be present in a range of Gram-negative bacteria, but not in the glutathione-deficient species of Gram-positive organisms. The conservation of the activity of these systems in a diverse range of organisms suggested a physiological role for these systems. Here we demonstrate that in E. coli cells activation of the KefB efflux system is essential for the survival of exposure to methylglyoxal. Methylglyoxal can be added to the growth medium or its synthesis can be stimulated in the cytoplasm. Under both sets of conditions survival is aided by the activity of KefB. Inhibition of KefB activity by the addition of 10 mM potassium to the growth medium stimulates methylglyoxal-induced cell death. This establishes an essential physiological function for the KefB system.
Original languageEnglish
Pages (from-to)1297-1303
Number of pages7
JournalMolecular Microbiology
Volume9
Issue number6
DOIs
Publication statusPublished - 1 Sep 1993

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Keywords

  • Antiporters
  • Bacterial Proteins
  • Cell Death
  • Escherichia coli
  • Escherichia coli Proteins
  • Glutathione
  • Kinetics
  • Metabolic Detoxication, Drug
  • Potassium
  • Potassium Channels
  • Potassium-Hydrogen Antiporters
  • Pyruvaldehyde
  • Time Factors

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