Journal
MOLECULAR MICROBIOLOGY
Volume 57, Issue 3, Pages 774-785Publisher
WILEY
DOI: 10.1111/j.1365-2958.2005.04728.x
Keywords
-
Categories
Funding
- NIGMS NIH HHS [GM072125, GM55984, R01 GM055984-09, R01 GM055984] Funding Source: Medline
Ask authors/readers for more resources
In bacterial chemotaxis, the chemoreceptors [methylaccepting chernotaxis proteins (MCPs)] transduce chemotactic signals through the two-component histidine kinase CheA. At low but not high attractant concentrations, chemotactic signals must be amplified. The MCPs are organized into a polar lattice, and this organization has been proposed to be critical for signal amplification. Although evidence in support of this model has emerged, an understanding of how signals are amplified and modulated is lacking. We probed the role of MCP localization under conditions wherein signal amplification must be inhibited. We tested whether a large increase in attractant concentration (a change that should alter receptor occupancy from c. 0% to > 95%) would elicit changes in the chemoreceptor localization. We treated Escherlchia coli or Bacillus subtilis with a high level of attractant, exposed cells to the cross-linking agent paraformaldehyde and visualized chemoreceptor location with an anti-MCP antibody. A marked increase in the percentage of cells displaying a diffuse staining pattern was obtained. In contrast, no increase in diffuse MCP staining is observed when cells are treated with a repellent or a low concentration of attractant. For B. subtilis mutants that do not undergo chernotaxis, the addition of a high concentration of attractant has no effect on MCP localization. Our data suggest that interactions between chemoreceptors are decreased when signal amplification is unnecessary.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available