https://dx.doi.org/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 Date

12-15-1992

Journal Title

Proceedings of the National Academy of Sciences

Publisher

National Academy of Sciences

Digital Object Identifier (DOI)

https://dx.doi.org/10.1073/pnas.89.24.11804

Document Type

Article

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

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