| Title: | Regulation of the competence pathway as a novel role associated with a streptococcal bacteriocin |
| Author(s): | Dufour D; Cordova M; Cvitkovitch DG; Levesque CM; |
| Address: | "Dental Research Institute, Faculty of Dentistry, University of Toronto, 124 Edward St., Toronto, Ontario M5G 1G6, Canada" |
| ISSN/ISBN: | 1098-5530 (Electronic) 0021-9193 (Print) 0021-9193 (Linking) |
| Abstract: | "The oral biofilm organism Streptococcus mutans must face numerous environmental stresses to survive in its natural habitat. Under specific stresses, S. mutans expresses the competence-stimulating peptide (CSP) pheromone known to induce autolysis and facilitate the uptake and incorporation of exogenous DNA, a process called DNA transformation. We have previously demonstrated that the CSP-induced CipB bacteriocin (mutacin V) is a major factor involved in both cellular processes. Our objective in this work was to characterize the role of CipB bacteriocin during DNA transformation. Although other bacteriocin mutants were impaired in their ability to acquire DNA under CSP-induced conditions, the DeltacipB mutant was the only mutant showing a sharp decrease in transformation efficiency. The autolysis function of CipB bacteriocin does not participate in the DNA transformation process, as factors released via lysis of a subpopulation of cells did not contribute to the development of genetic competence in the surviving population. Moreover, CipB does not seem to participate in membrane depolarization to assist passage of DNA. Microarray-based expression profiling showed that under CSP-induced conditions, CipB regulated approximately 130 genes, among which are the comDE locus and comR and comX genes, encoding critical factors that influence competency development in S. mutans. We also discovered that the CipI protein conferring immunity to CipB-induced autolysis also prevented the transcriptional regulatory activity of CipB. Our data suggest that besides its role in cell lysis, the S. mutans CipB bacteriocin also functions as a peptide regulator for the transcriptional control of the competence regulon" |
| Keywords: | "Bacterial Proteins/genetics/metabolism Bacteriocins/*biosynthesis *Gene Expression Regulation, Bacterial Streptococcus mutans/*genetics/*metabolism *Transformation, Bacterial;" |
| Notes: | "MedlineDufour, Delphine Cordova, Martha Cvitkovitch, Dennis G Levesque, Celine M eng R01 DE013230/DE/NIDCR NIH HHS/ R01DE013230/DE/NIDCR NIH HHS/ MOP-93555/CAPMC/CIHR/Canada Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't 2011/10/11 J Bacteriol. 2011 Dec; 193(23):6552-9. doi: 10.1128/JB.05968-11. Epub 2011 Oct 7" |
