| Title: | Redundant group a streptococcus signaling peptides exhibit unique activation potentials |
| Author(s): | LaSarre B; Chang JC; Federle MJ; |
| Address: | "Department of Medicinal Chemistry and Pharmacognosy, Center for Pharmaceutical Biotechnology, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA" |
| ISSN/ISBN: | 1098-5530 (Electronic) 0021-9193 (Print) 0021-9193 (Linking) |
| Abstract: | "All bacterial quorum sensing (QS) systems are based on the production, secretion, and detection of small signaling molecules. Gram-positive bacteria typically use small peptides as QS effectors, and each QS circuit generally requires the interaction of a single signaling molecule with a single receptor protein. The recently described Rgg2 and Rgg3 (Rgg2/3) regulatory circuit of Streptococcus pyogenes (group A streptococcus [GAS]) is one of only a few QS circuits known to utilize multiple signaling peptides. In this system, two distinct, endogenously produced peptide pheromones (SHP2 and SHP3) both function to activate the QS circuit. The aim of this study was to further define the roles of SHP2 and SHP3 in activation of the Rgg2/3 QS system, specifically with regard to shp gene identity and dosage. Results from our studies using transcriptional reporters and isogenic GAS mutants demonstrate that shp gene dosage does contribute to Rgg2/3 system induction, as decreased gene dosage results in decreased or absent induction. Beyond this, however, data indicate that the shp genes possess distinct potentials for supporting system activation, with shp3 more readily able to support system activation than shp2. Studies using synthetic peptides and shp gene mutants indicate that the disparate activities of endogenous SHPs are due to production, rather than signaling, differences and are conferred by the N-terminal regions rather than the C-terminal signaling regions of the peptides. These data provide evidence that the N-terminal, noneffector sequences of SHP pheromones influence their production efficiencies and thereby the relative activation potentials of endogenous SHPs" |
| Keywords: | "Bacterial Proteins/chemistry/*drug effects/genetics/*metabolism *Gene Expression Regulation, Bacterial Pheromones/genetics/metabolism/*pharmacology Protein Sorting Signals/genetics/*physiology Quorum Sensing/*drug effects/genetics Signal Transduction Stre;" |
| Notes: | "MedlineLaSarre, Breah Chang, Jennifer C Federle, Michael J eng R01 AI091779/AI/NIAID NIH HHS/ AI091779/AI/NIAID NIH HHS/ Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't 2013/07/23 J Bacteriol. 2013 Sep; 195(18):4310-8. doi: 10.1128/JB.00684-13. Epub 2013 Jul 19" |
