title: Transcriptional Profiling of the Oral PathogenStreptococcus mutansin Response to Competence Signaling Peptide XIP.
abstract: In the cariogenicStreptococcus mutans, competence development is regulated by the ComRS signaling system comprised of the ComR regulator and the ComS prepeptide to the competence signaling peptide XIP (ComX-inducing peptide). Aside from competence development, XIP signaling has been demonstrated to regulate cell lysis, and recently, the expression of bacteriocins, small antimicrobial peptides used by bacteria to inhibit closely related species. Our study further explores the effect of XIP signaling on theS. mutanstranscriptome. RNA sequencing revealed that XIP induction resulted in a global change in gene expression that was consistent with a stress response. An increase in several membrane-bound regulators, including HdrRM and BrsRM, involved in bacteriocin production, and the VicRKX system, involved in acid tolerance and biofilm formation, was observed. Furthermore, global changes in gene expression corresponded to changes observed during the stringent response to amino acid starvation. Effects were also observed on genes involved in sugar transport and carbon catabolite repression and included thelevQRSTandlevDEFGoperons. Finally, our work identified a novel heat shock-responsive intergenic region, encoding a small RNA, with a potential role in competence shutoff.IMPORTANCEGenetic competence provides bacteria with an opportunity to increase genetic diversity or acquire novel traits conferring a survival advantage. In the cariogenic pathogenStreptococcus mutans, DNA transformation is regulated by the competence stimulating peptide XIP (ComX-inducing peptide). The present study utilizes high-throughput RNA sequencing (RNAseq) to provide a greater understanding of how global gene expression patterns change in response to XIP. Overall, our work demonstrates that inS. mutans, XIP signaling induces a response that resembles the stringent response to amino acid starvation. We further identify a novel heat shock-responsive intergenic region with a potential role in competence shutoff. Together, our results provide further evidence that multiple stress response mechanisms are linked through the genetic competence signaling pathway inS. mutans.
authors.affiliation: Dental Research Institute, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Iwona B
authors.initials: IB
authors.lastname: Wenderska
authors.affiliation: Dental Research Institute, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Andrew
authors.initials: A
authors.lastname: Latos
authors.affiliation: Department of Biology, Middlebury College, Middlebury, Vermont, USA.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Pruitt
authors.affiliation: College of Dentistry, Biosciences, Ohio State University, Columbus, Ohio, USA.
authors.forename: Sara
authors.initials: S
authors.lastname: Palmer
authors.affiliation: Department of Biology, Middlebury College, Middlebury, Vermont, USA.
authors.forename: Grace
authors.initials: G
authors.lastname: Spatafora
authors.affiliation: Dental Research Institute, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Dilani B
authors.initials: DB
authors.lastname: Senadheera
authors.affiliation: Dental Research Institute, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Dennis G
authors.initials: DG
authors.lastname: Cvitkovitch
keywords: ComRS; Streptococcus mutans; XIP; cell signaling; genetic competence; signaling peptides; transcriptome