title: Regulation of sagA, siaA and scpC by SilCR, a putative signaling peptide of Streptococcus pyogenes.
abstract: SilCR, a 17 amino acid putative signaling peptide, was proposed to modulate gene expression in Streptococcus pyogenes. We showed that SilCR added exogenously to an M1 serotype strain lacking the sil locus upregulates the in vitro expression of sagA, siaA, and scpC, genes associated with S. pyogenes pathogenesis. Interestingly, only sagA and siaA were upregulated by SilCR in vivo, whereas the expression of scpC remained unaltered. A previous report indicated that exogenously added SilCR protects mice to some degree from developing necrotic lesions caused by an invasive strain of S. pyogenes. In contrast to this report, we found that SilCR did not reduce lesion formation in a subcutaneous murine model of S. pyogenes infection but rather appeared to delay wound healing.
authors.affiliation: Department of Microbiology, Faculty of Dentistry, University of Toronto, Toronto, ON, Canada.
authors.forename: Kowthar Y
authors.initials: KY
authors.lastname: Salim
authors.forename: Joyce C
authors.initials: JC
authors.lastname: de Azavedo
authors.forename: Darrin J
authors.initials: DJ
authors.lastname: Bast
authors.forename: Dennis G
authors.initials: DG
authors.lastname: Cvitkovitch
mesh_terms: D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D005260:Female; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D051379:Mice; D008822:Mice, Transgenic; D021382:Protein Sorting Signals; D013290:Streptococcal Infections / Q000382:microbiology*; D013297:Streptococcus pyogenes / Q000235:genetics* / Q000378:metabolism
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D021382:Protein Sorting Signals; C523920:SiaA protein, Streptococcus pyogenes