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Investigating Flagella-Driven Motility in Escherichia coli by Applying Three Established Techniques in a Series
Published on: May 10, 2020
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A flagellar accessory protein links chemotaxis to surface sensing
Rachel I Salemi1, Ana K Cruz1, David M Hershey1
1Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA.
Journal of Bacteriology
|October 18, 2024
Summary
The FssF protein in Caulobacter crescentus is crucial for chemotaxis and surface adhesion. Deleting FssF disrupts chemotaxis, leading to increased bacterial adhesion and biofilm formation.
Area of Science:
- Microbiology
- Cell Biology
- Bacterial Physiology
Background:
- Bacteria utilize complex signaling to sense and colonize surfaces, with flagellar surface sensing being key.
- Caulobacter crescentus uses a holdfast adhesin for surface attachment, and flagellar disruption enhances this production.
- Previous work identified genes involved in flagellar surface sensing, including fssF.
Purpose of the Study:
- To investigate the role of the FssF protein in Caulobacter crescentus surface sensing and flagellar function.
- To determine the localization and interactions of FssF within the flagellar apparatus.
- To elucidate the relationship between chemotaxis, motility, and surface adhesion regulated by FssF.
Main Methods:
- Fluorescent tagging of FssF to determine its cellular localization.
- Genetic analysis, including gene deletion and epistasis experiments, to study fssF function.
- Assessment of motility, chemotaxis, and adhesion phenotypes in wild-type and mutant strains.
Main Results:
- FssF localizes to the flagellated cell pole, requiring flagellar C-ring components for proper localization.
- Deletion of fssF causes severe motility defects due to disrupted chemotaxis, not swimming.
- fssF promotes adhesion via a stator-dependent pathway and its absence leads to hyperadhesion, similar to other chemotaxis mutants.
Conclusions:
- The FssF protein is a novel component of the flagellar C-ring involved in regulating chemotaxis and surface adhesion.
- Flagellar stator subunits integrate mechanical and chemical signals to control bacterial adhesion.
- Chemotaxis is essential for a robust surface sensing response in Caulobacter crescentus, impacting biofilm formation.
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