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DNA-affinity-purified Chip (DAP-chip) Method to Determine Gene Targets for Bacterial Two component Regulatory Systems
Published on: July 21, 2014
Multiple two-component systems modulate alkali generation in Streptococcus gordonii in response to environmental
1Department of Oral Biology, University of Florida, Gainesville, FL 32610, USA.
Journal of Bacteriology
|September 29, 2009
Summary
Two-component systems (TCS) like CiaRH, ComDE, and VicRK regulate the arginine deiminase system (ADS) in Streptococcus gordonii, crucial for acid tolerance and survival in the oral cavity.
Area of Science:
- Microbiology
- Molecular Biology
- Oral Health
Background:
- Streptococcus gordonii, an oral commensal, relies on the arginine deiminase system (ADS) for acid tolerance.
- ADS gene expression is influenced by environmental factors including pH, oxygen, and nutrient availability.
- Previous studies identified ArcR and CcpA as regulators of ADS, but the roles of other systems remained unclear.
Purpose of the Study:
- To investigate the roles of CiaRH, ComDE, and VicRK two-component systems (TCS) in regulating the arginine deiminase system (ADS) in Streptococcus gordonii.
- To understand how these TCS contribute to the organism's adaptation to environmental stresses in the oral cavity.
- To compare the regulatory mechanisms and stress tolerance conferred by these TCS in S. gordonii versus Streptococcus mutans.
Main Methods:
- Gene expression analysis of ADS genes under varying pH and oxygen conditions.
- Construction and characterization of S. gordonii mutants lacking components of CiaRH, ComDE, and VicRK TCS.
- Assessment of mutant growth in acidified media and sensitivity to lethal pH and oxidative stress.
Main Results:
- CiaRH and ComDE TCS are essential for low-pH-dependent ADS gene expression.
- VicRK TCS is required for optimal anaerobic ADS gene expression and oxygen sensitivity.
- Mutants lacking these TCS exhibited impaired growth in acid and increased sensitivity to stress, with notable differences compared to S. mutans.
Conclusions:
- The study identifies CiaRH, ComDE, and VicRK TCS as key regulators of the ADS in S. gordonii, responding to pH and oxygen.
- These TCS are critical for S. gordonii's viability and stress tolerance in the oral environment.
- The findings highlight distinct regulatory roles of these TCS in S. gordonii compared to S. mutans, offering insights into oral microbial ecology.
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