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Purification of a High Molecular Mass Protein in Streptococcus mutans
Published on: September 14, 2019
Regulation of gbpC expression in Streptococcus mutans
Indranil Biswas1, Laura Drake, Saswati Biswas
1Basic Biomedical Sciences, University of South Dakota, Lee Medical Building, 414 E. Clark Street, Vermillion, SD 57069, USA. ibiswas@usd.edu
Journal of Bacteriology
|July 10, 2007
Summary
The expression of the gbpC gene in Streptococcus mutans is regulated by stress conditions and the global regulator CovR. CovR directly binds to the gbpC promoter, repressing its transcription, which is crucial for dental caries development.
Area of Science:
- Microbiology
- Molecular Biology
- Genetics
Background:
- Streptococcus mutans is the primary cause of dental caries.
- The GbpC protein is vital for S. mutans adherence, biofilm formation, and pathogenesis.
- Understanding gbpC gene regulation is key to combating S. mutans-related diseases.
Purpose of the Study:
- To investigate the regulation of gbpC gene expression in S. mutans.
- To identify factors influencing gbpC expression under various stress conditions.
- To elucidate the role of the CovR regulator in gbpC transcription.
Main Methods:
- Transcriptional fusion reporter assay (PgbpC-gusA).
- Analysis under thermal, osmotic, and acid stress conditions.
- Semi-quantitative reverse transcription-PCR.
- DNase I protection assay to confirm CovR binding.
Main Results:
- gbpC expression peaks during the mid-exponential growth phase with a transcript half-life under 2 minutes.
- Thermal stress induces gbpC expression, while acid stress represses it; osmotic stress has no significant effect.
- The global regulator CovR directly binds to the PgbpC promoter region (-68 to +28), repressing gbpC transcription.
Conclusions:
- Stress conditions significantly modulate gbpC expression in S. mutans.
- CovR acts as a transcriptional repressor of gbpC.
- This regulatory mechanism is important for S. mutans virulence and pathogenesis.
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