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PepO , a CovRS ‐controlled endopeptidase, disrupts S treptococcus pyogenes quorum sensing
Author(s) -
Wilkening Reid V.,
Chang Jennifer C.,
Federle Michael J.
Publication year - 2016
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/mmi.13216
Subject(s) - virulence , quorum sensing , biology , streptococcus pyogenes , microbiology and biotechnology , pathogen , signal transduction , gene , genetics , bacteria , staphylococcus aureus
Summary Group A Streptococcus ( GAS , S treptococcus pyogenes ) is a human‐restricted pathogen with a capacity to both colonize asymptomatically and cause illnesses ranging from pharyngitis to necrotizing fasciitis. An understanding of how and when GAS switches between genetic programs governing these different lifestyles has remained an enduring mystery and likely requires carefully tuned environmental sensors to activate and silence genetic schemes when appropriate. Herein, we describe the relationship between the Control of Virulence ( CovRS , CsrRS ) two‐component system and the R gg2/3 quorum‐sensing pathway. We demonstrate that responses of CovRS to the stress signals Mg 2+ and a fragment of the antimicrobial peptide LL ‐37 result in modulated activity of pheromone signaling of the R gg2/3 pathway through a means of proteolysis of SHP peptide pheromones. This degradation is mediated by the cytoplasmic endopeptidase PepO , which is the first identified enzymatic silencer of an RRNPP ‐type quorum‐sensing pathway. These results suggest that under conditions in which the virulence potential of GAS is elevated (i.e. enhanced virulence gene expression), cellular responses mediated by the R gg2/3 pathway are abrogated and allow individuals to escape from group behavior. These results also indicate that R gg2/3 signaling is instead functional during non‐virulent GAS lifestyles.