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EpsR Negatively Regulates Streptococcus mutans Exopolysaccharide Synthesis
1Department of Operative Dentistry and Endodontics, State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
Journal of Dental Research
|March 22, 2021
Summary
Researchers identified EpsR, a transcription factor that controls exopolysaccharide (EPS) production and glucosyltransferase B (GtfB) expression in Streptococcus mutans. This finding offers new insights into preventing dental caries by targeting cariogenic biofilm formation.
Area of Science:
- Microbiology
- Molecular Biology
- Oral Health
Background:
- Streptococcus mutans is the primary cause of human dental caries.
- Glucosyltransferases (Gtfs) from S. mutans are crucial for cariogenic oral biofilm development.
- The regulation of gtf expression by transcription factors is not well understood.
Purpose of the Study:
- To identify and characterize transcription factors regulating gtf expression in S. mutans.
- To investigate the role of EpsR in controlling exopolysaccharide (EPS) production and GtfB expression.
Main Methods:
- In-frame deletion strain construction for epsR.
- Analysis of biofilm structure, EPS production, and GtfB activity.
- Global gene expression profiling using transcriptomics.
- Electrophoretic mobility shift assay (EMSA) and DNase I footprinting.
- Beta-galactosidase assays to assess transcriptional regulation.
Main Results:
- EpsR negatively regulates gtfB expression and exopolysaccharide (EPS) production.
- epsR deletion resulted in altered biofilm architecture, increased water-insoluble EPS, and upregulated GtfB.
- Global gene expression analysis showed marked upregulation of gtfB in the deletion strain.
- EpsR binds to a conserved DNA motif and acts as a repressor of gtfB expression.
Conclusions:
- EpsR is a key transcription factor regulating gtfB expression and EPS production in S. mutans.
- Understanding EpsR's role provides new insights into the regulation of S. mutans cariogenicity.
- These findings may lead to novel strategies for preventing dental caries by targeting biofilm formation.
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