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.
Department
Molecular, Cellular and Biomedical Sciences
Publication Date
12-15-1992
Journal Title
Proceedings of the National Academy of Sciences
Publisher
National Academy of Sciences
Digital Object Identifier (DOI)
Document Type
Article
Recommended Citation
Tisa L.S. and J. Adler. 1992. Calcium ions are involved in Escherichia coli chemotaxis. Proc. Natl. Acad. Sci. USA 89:11804-11808. (DOI: 10.1073/pnas.89.24.11804)
Comments
This is an article published by National Academy of Sciences in Proceedings of the National Academy of Sciences in 1993, available online: https://dx.doi.org/10.1073/pnas.89.24.11804