| Title: | The cryptic competence pathway in Streptococcus pyogenes is controlled by a peptide pheromone |
| Author(s): | Mashburn-Warren L; Morrison DA; Federle MJ; |
| Address: | "Center for Pharmaceutical Biotechnology, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois, USA" |
| ISSN/ISBN: | 1098-5530 (Electronic) 0021-9193 (Print) 0021-9193 (Linking) |
| Abstract: | "Horizontal gene transfer is an important means of bacterial evolution that is facilitated by transduction, conjugation, and natural genetic transformation. Transformation occurs after bacterial cells enter a state of competence, where naked DNA is acquired from the extracellular environment. Induction of the competent state relies on signals that activate master regulators, causing the expression of genes involved in DNA uptake, processing, and recombination. All streptococcal species contain the master regulator SigX and SigX-dependent effector genes required for natural genetic transformation; however, not all streptococcal species have been shown to be naturally competent. We recently demonstrated that competence development in Streptococcus mutans requires the type II ComRS quorum-sensing circuit, comprising an Rgg transcriptional activator and a novel peptide pheromone (L. Mashburn-Warren, D. A. Morrison, and M. J. Federle, Mol. Microbiol. 78:589-606, 2010). The type II ComRS system is shared by the pyogenic, mutans, and bovis streptococci, including the clinically relevant pathogen Streptococcus pyogenes. Here, we describe the activation of sigX by a small-peptide pheromone and an Rgg regulator of the type II ComRS class. We confirm previous reports that SigX is functional and able to activate sigX-dependent gene expression within the competence regulon, and that SigX stability is influenced by the cytoplasmic protease ClpP. Genomic analyses of available S. pyogenes genomes revealed the presence of intact genes within the competence regulon. While this is the first report to show natural induction of sigX, S. pyogenes remained nontransformable under laboratory conditions. Using radiolabeled DNA, we demonstrate that transformation is blocked at the stage of DNA uptake" |
| Keywords: | "Bacterial Proteins/genetics/metabolism *DNA Transformation Competence Endopeptidase Clp Gene Expression Regulation, Bacterial Gene Transfer, Horizontal Peptides/genetics/*metabolism Pheromones/genetics/*metabolism *Quorum Sensing Serine Endopeptidases/gen;" |
| Notes: | "MedlineMashburn-Warren, Lauren Morrison, Donald A Federle, Michael J eng R01 AI091779/AI/NIAID NIH HHS/ HHMI/Howard Hughes Medical Institute/ AI091779/AI/NIAID NIH HHS/ Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't 2012/06/26 J Bacteriol. 2012 Sep; 194(17):4589-600. doi: 10.1128/JB.00830-12. Epub 2012 Jun 22" |
