Calcium ions are involved in Escherichia coli chemotaxis

Proc Natl Acad Sci U S A. 1992 Dec 15;89(24):11804-8. doi: 10.1073/pnas.89.24.11804.

Abstract

Escherichia coli regulates intracellular free Ca2+ at about 90 nM [Gangola, P. & Rosen, B. P. (1987) J. Biol. Chem. 262, 12570-12574]. To increase intracellular free Ca2+, nitr-5/Ca2+, a "caged" Ca2+ compound, was electroporated into cells and then its affinity for Ca2+ was reduced by exposure to 370-nm light. Upon release of the Ca2+ ions, the cells tumbled. Studies on mutant strains showed that the receptor proteins (methyl-accepting chemotaxis proteins, MCPs) were not required for the Ca(2+)-induced tumbling but that CheA, CheW, and CheY proteins were required. Similar results were obtained with DM-nitrophen/Ca2+, another caged calcium compound that releases Ca2+ upon illumination at 340 nm. Diazo-2, a caged Ca2+ chelator that takes up Ca2+ upon illumination at 340 nm, was used to decrease intracellular free Ca2+, and this caused smooth swimming.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Bacterial Proteins / metabolism
  • Calcium / metabolism*
  • Chemotactic Factors / physiology*
  • Chemotaxis*
  • Cytoplasm / physiology
  • Escherichia coli / physiology*
  • Escherichia coli Proteins*
  • Histidine Kinase
  • Membrane Proteins / physiology
  • Methyl-Accepting Chemotaxis Proteins

Substances

  • Bacterial Proteins
  • CheW protein, E coli
  • Chemotactic Factors
  • Escherichia coli Proteins
  • Membrane Proteins
  • Methyl-Accepting Chemotaxis Proteins
  • cheY protein, E coli
  • CheW protein, Bacteria
  • CheB protein, Bacteria
  • Histidine Kinase
  • cheA protein, E coli
  • Calcium