Analysis of the kefA2 mutation suggests that KefA is a cation-specific channel involved in osmotic adaptation in Escherichia coli

Debbie McLaggan, M. A. Jones, N. Levina, Ian Rylance Booth, G. Gouesbet, S. Lindey, W. Epstein

Research output: Contribution to journalArticle

47 Citations (Scopus)

Abstract

Mechanosensitive channels play an essential role in the regulation of turgor pressure in bacteria. In Escherichia coli, there are multiple mechanosensitive channels that have been characterized genetically: MscL, YggB and KefA. In this report, we describe the cloning of the kefA gene, the organization of the KefA protein and the phenotype of a missense mutation, kefA, which affects the KefA mechanosensitive channel. The altered function of the channel is manifest through increased sensitivity to K+ during growth at low osmolarity and complete inhibition of growth in media containing high K+ concentrations (0.6 M) in the presence of betaine or proline. Growth in high Na+ medium (0.6 M NaCl plus 20 mM K+) is normal. Analysis of the cytoplasmic pools shows that the mutant cannot regulate the K+ content of the cytoplasm when grown in high K+ medium. However, regulation of pools of amino acids is essentially normal and the mutant can accumulate high pools of proline during growth inhibition. The mutant shows increased sensitivity to acid hypo-osmotic shock (transition from neutral to acid pH combined with a reduction in osmolarity). The data are consistent with abnormal regulation of KefA in the presence of high K+ concentrations and either betaine or proline.

Original languageEnglish
Pages (from-to)521-536
Number of pages15
JournalMolecular Microbiology
Volume43
Issue number2
DOIs
Publication statusPublished - 2002

Keywords

  • COMPATIBLE SOLUTE ACCUMULATION
  • POTASSIUM-TRANSPORT LOCI
  • MECHANOSENSITIVE CHANNEL
  • SALMONELLA-TYPHIMURIUM
  • ALKALINE-PHOSPHATASE
  • CYTOPLASMIC MEMBRANE
  • MULTIDRUG EFFLUX
  • ION CHANNELS
  • PROTEIN
  • MSCL

Cite this

Analysis of the kefA2 mutation suggests that KefA is a cation-specific channel involved in osmotic adaptation in Escherichia coli. / McLaggan, Debbie; Jones, M. A.; Levina, N.; Booth, Ian Rylance; Gouesbet, G.; Lindey, S.; Epstein, W.

In: Molecular Microbiology, Vol. 43, No. 2, 2002, p. 521-536.

Research output: Contribution to journalArticle

McLaggan, Debbie ; Jones, M. A. ; Levina, N. ; Booth, Ian Rylance ; Gouesbet, G. ; Lindey, S. ; Epstein, W. / Analysis of the kefA2 mutation suggests that KefA is a cation-specific channel involved in osmotic adaptation in Escherichia coli. In: Molecular Microbiology. 2002 ; Vol. 43, No. 2. pp. 521-536.
@article{10046cf2f75c408ea4edeafa3fe90034,
title = "Analysis of the kefA2 mutation suggests that KefA is a cation-specific channel involved in osmotic adaptation in Escherichia coli",
abstract = "Mechanosensitive channels play an essential role in the regulation of turgor pressure in bacteria. In Escherichia coli, there are multiple mechanosensitive channels that have been characterized genetically: MscL, YggB and KefA. In this report, we describe the cloning of the kefA gene, the organization of the KefA protein and the phenotype of a missense mutation, kefA, which affects the KefA mechanosensitive channel. The altered function of the channel is manifest through increased sensitivity to K+ during growth at low osmolarity and complete inhibition of growth in media containing high K+ concentrations (0.6 M) in the presence of betaine or proline. Growth in high Na+ medium (0.6 M NaCl plus 20 mM K+) is normal. Analysis of the cytoplasmic pools shows that the mutant cannot regulate the K+ content of the cytoplasm when grown in high K+ medium. However, regulation of pools of amino acids is essentially normal and the mutant can accumulate high pools of proline during growth inhibition. The mutant shows increased sensitivity to acid hypo-osmotic shock (transition from neutral to acid pH combined with a reduction in osmolarity). The data are consistent with abnormal regulation of KefA in the presence of high K+ concentrations and either betaine or proline.",
keywords = "COMPATIBLE SOLUTE ACCUMULATION, POTASSIUM-TRANSPORT LOCI, MECHANOSENSITIVE CHANNEL, SALMONELLA-TYPHIMURIUM, ALKALINE-PHOSPHATASE, CYTOPLASMIC MEMBRANE, MULTIDRUG EFFLUX, ION CHANNELS, PROTEIN, MSCL",
author = "Debbie McLaggan and Jones, {M. A.} and N. Levina and Booth, {Ian Rylance} and G. Gouesbet and S. Lindey and W. Epstein",
year = "2002",
doi = "10.1046/j.1365-2958.2002.02764.x",
language = "English",
volume = "43",
pages = "521--536",
journal = "Molecular Microbiology",
issn = "0950-382X",
publisher = "Wiley-Blackwell",
number = "2",

}

TY - JOUR

T1 - Analysis of the kefA2 mutation suggests that KefA is a cation-specific channel involved in osmotic adaptation in Escherichia coli

AU - McLaggan, Debbie

AU - Jones, M. A.

AU - Levina, N.

AU - Booth, Ian Rylance

AU - Gouesbet, G.

AU - Lindey, S.

AU - Epstein, W.

PY - 2002

Y1 - 2002

N2 - Mechanosensitive channels play an essential role in the regulation of turgor pressure in bacteria. In Escherichia coli, there are multiple mechanosensitive channels that have been characterized genetically: MscL, YggB and KefA. In this report, we describe the cloning of the kefA gene, the organization of the KefA protein and the phenotype of a missense mutation, kefA, which affects the KefA mechanosensitive channel. The altered function of the channel is manifest through increased sensitivity to K+ during growth at low osmolarity and complete inhibition of growth in media containing high K+ concentrations (0.6 M) in the presence of betaine or proline. Growth in high Na+ medium (0.6 M NaCl plus 20 mM K+) is normal. Analysis of the cytoplasmic pools shows that the mutant cannot regulate the K+ content of the cytoplasm when grown in high K+ medium. However, regulation of pools of amino acids is essentially normal and the mutant can accumulate high pools of proline during growth inhibition. The mutant shows increased sensitivity to acid hypo-osmotic shock (transition from neutral to acid pH combined with a reduction in osmolarity). The data are consistent with abnormal regulation of KefA in the presence of high K+ concentrations and either betaine or proline.

AB - Mechanosensitive channels play an essential role in the regulation of turgor pressure in bacteria. In Escherichia coli, there are multiple mechanosensitive channels that have been characterized genetically: MscL, YggB and KefA. In this report, we describe the cloning of the kefA gene, the organization of the KefA protein and the phenotype of a missense mutation, kefA, which affects the KefA mechanosensitive channel. The altered function of the channel is manifest through increased sensitivity to K+ during growth at low osmolarity and complete inhibition of growth in media containing high K+ concentrations (0.6 M) in the presence of betaine or proline. Growth in high Na+ medium (0.6 M NaCl plus 20 mM K+) is normal. Analysis of the cytoplasmic pools shows that the mutant cannot regulate the K+ content of the cytoplasm when grown in high K+ medium. However, regulation of pools of amino acids is essentially normal and the mutant can accumulate high pools of proline during growth inhibition. The mutant shows increased sensitivity to acid hypo-osmotic shock (transition from neutral to acid pH combined with a reduction in osmolarity). The data are consistent with abnormal regulation of KefA in the presence of high K+ concentrations and either betaine or proline.

KW - COMPATIBLE SOLUTE ACCUMULATION

KW - POTASSIUM-TRANSPORT LOCI

KW - MECHANOSENSITIVE CHANNEL

KW - SALMONELLA-TYPHIMURIUM

KW - ALKALINE-PHOSPHATASE

KW - CYTOPLASMIC MEMBRANE

KW - MULTIDRUG EFFLUX

KW - ION CHANNELS

KW - PROTEIN

KW - MSCL

U2 - 10.1046/j.1365-2958.2002.02764.x

DO - 10.1046/j.1365-2958.2002.02764.x

M3 - Article

VL - 43

SP - 521

EP - 536

JO - Molecular Microbiology

JF - Molecular Microbiology

SN - 0950-382X

IS - 2

ER -