Regulation of gtf Gene Expression in S mutans
Principal Investigator: Steven Goodman
Abstract: Streptococcus mutans is a causative agent of dental caries. It's ability to inflict damage is strongly linked to the production of long chain glucose polymers (glucans) derived from dietary sucrose which allow the bacteria possesses a family of genes that express enzymes called glucosyltransferases (GTF). There are three GTFs in S. mutans. They share 50 percent sequence identity and are encoded by the homologous gtfB, gtfC and gtfD genes. The gtfB and gtfC gene are found in direct repeat with a mere 198 base paries separation between coding sequences. Although mutations in either gtfB or gtfC produce a colonizing deficient phenotype, little is known about their regulation. Until recently, the only effector known to regulate these genes was sucrose, the substrate of the GTFs. Supplemented sucrose transiently induces a 3-fold increase in a gtfB transcriptional fusion. Now we have demonstrated that both gtfB and gtfC show coordinated growth phase- dependent expression. For both genes, expression peaks prior to exponential growth and falls over 100-fold by early stationary phase. In this proposal, we intend to further study this phenomenon including identifying critical cis and trans acting elements and through mutagenesis determine how these elements affect gtf gene expression. Since these gtf genes are involved in the colonization process, the genetic elements that are found here will need to be examined in terms of the bacteria's pathogenic mechanisms.
Funding Period: 2001-08-01 - 2007-06-30
more information: NIH RePORT
- A VicRK signal transduction system in Streptococcus mutans affects gtfBCD, gbpB, and ftf expression, biofilm formation, and genetic competence developmentM Dilani Senadheera
Dental Research Institute, University of Toronto, 124 Edward Street, Toronto ON M51G6, Canada
J Bacteriol 187:4064-76. 2005..001). Taken together, these findings support involvement of the vicRK signal transduction system in regulating several important physiological processes in S. mutans...
- Peptide pheromone induced cell death of Streptococcus mutansFengxia Qi
Division of Oral Biology and Medicine, UCLA School of Dentistry, Los Angeles, CA 90095, United States
FEMS Microbiol Lett 251:321-6. 2005..mutans in a ComDE-dependent manner. We also demonstrated that further increases of CSP stopped S. mutans cell division leading to cell death. Use of CSP as a possible therapeutic agent is discussed...
- The Streptococcus mutans vicX gene product modulates gtfB/C expression, biofilm formation, genetic competence, and oxidative stress toleranceM Dilani Senadheera
Dental Research Institute, University of Toronto, Toronto, ON, Canada
J Bacteriol 189:1451-8. 2007..05, as determined by ANOVA). Collectively, these findings provide insight into important phenotypes controlled by the vicX gene product that can impact S. mutans pathogenicity...
- Escherichia coli HU protein has a role in the repair of abasic sites in DNAYoke W Kow
Department of Radiation Oncology, Emory University School of Medicine, Clifton Road NE, Atlanta, GA 30322, USA
Nucleic Acids Res 35:6672-80. 2007..These data suggest, therefore, that HU protein plays a significant role in the repair of AP sites in E. coli...