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An alternative route to nitric oxide resistance
1Department of Molecular and Cell Biology, University of Texas at Dallas, Richardson, TX 75080, USA. stephen.spiro@utdallas.edu
Molecular Microbiology
|May 22, 2010
Summary
The bacterium Vibrio fischeri produces a nitric oxide (NO)-resistant alternative oxidase (Aox). This enzyme allows V. fischeri to respire in the presence of NO, which may regulate its symbiosis with the bobtail squid.
Area of Science:
- Microbiology
- Symbiotic relationships
- Biochemistry
Background:
- Vibrio fischeri and Euprymna scolopes form a bioluminescent symbiosis.
- Host nitric oxide (NO) is present during symbiont colonization.
- NO may regulate bacterial populations within the light organ.
Purpose of the Study:
- Investigate the response of V. fischeri to nitric oxide (NO).
- Determine the role of NO in the Vibrio-squid symbiosis.
- Identify mechanisms of NO resistance in V. fischeri.
Main Methods:
- Analysis of V. fischeri gene expression and enzyme activity.
- Respirometry experiments under varying NO concentrations.
- Biochemical characterization of alternative oxidase (Aox).
Main Results:
- V. fischeri upregulates an alternative oxidase (Aox) in response to NO.
- The identified Aox confers resistance to NO-mediated respiratory inhibition.
- This Aox allows V. fischeri to maintain respiration at inhibitory NO levels.
Conclusions:
- V. fischeri possesses an NO-inducible and NO-resistant alternative oxidase.
- This Aox is crucial for V. fischeri survival and function in the NO-rich light organ.
- The findings provide insight into NO's role in regulating bacterial symbiosis.
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