title: Quorum Sensing Regulation of Competence and Bacteriocins in Streptococcus pneumoniae and mutans.
abstract: The human pathogensStreptococcus pneumoniaeandStreptococcus mutanshave both evolved complex quorum sensing (QS) systems that regulate the production of bacteriocins and the entry into the competent state, a requirement for natural transformation. Natural transformation provides bacteria with a mechanism to repair damaged genes or as a source of new advantageous traits. InS. pneumoniae, the competence pathway is controlled by the two-component signal transduction pathway ComCDE, which directly regulates SigX, the alternative sigma factor required for the initiation into competence. Over the past two decades, effectors of cellular killing (i.e., fratricides) have been recognized as important targets of the pneumococcal competence QS pathway. Recently, direct interactions between the ComCDE and the paralogous BlpRH pathway, regulating bacteriocin production, were identified, further strengthening the interconnections between these two QS systems. Interestingly, a similar theme is being revealed inS. mutans, the primary etiological agent of dental caries. This review compares the relationship between the bacteriocin and the competence QS pathways in bothS. pneumoniaeandS. mutans, and hopes to provide clues to regulatory pathways across the genusStreptococcusas a potential tool to efficiently investigate putative competence pathways in nontransformable streptococci.
authors.affiliation: Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, Chicago, IL 60607, USA. ebeisn2@uic.edu.
authors.forename: Erin
authors.initials: E
authors.lastname: Shanker
authors.affiliation: Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, Chicago, IL 60607, USA. mfederle@uic.edu.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Federle
keywords: bacteriocin; competence; fratricide; gene regulation; quorum sensing; transformation