title: The Rcs regulon in Proteus mirabilis: implications for motility, biofilm formation, and virulence.
abstract: The overall role of the Rcs phosphorelay in Proteus mirabilis is largely unknown. Previous work had demonstrated that the Rcs phosphorelay represses the flhDC operon and activates the minCDE cell division inhibition system. To identify additional cellular functions regulated by the Rcs phosphorelay, an analysis of RNA-seq data was undertaken. In this report, the results of the RNA-sequencing are discussed with an emphasis on the predicted roles of the Rcs phosphorelay in swarmer cell differentiation, motility, biofilm formation, and virulence. RcsB is shown to activate genes important for differentiation and fimbriae formation, while repressing the expression of genes important for motility and virulence. Additionally, to follow up on the RNA-Seq data, we demonstrate that an rcsB mutant is deficient in its ability to form biofilm and exhibits enhanced virulence in a Galleria mellonella waxworm model. Overall, these results indicate the Rcs regulon in P. mirabilis extends beyond flagellar genes to include those involved in biofilm formation and virulence. Furthermore, the information presented in this study may provide clues to additional roles of the Rcs phosphorelay in other members of the Enterobacteriaceae.
authors.affiliation: Department of Microbiology and Immunology, Emory University, 3001 Rollins Research Center, Atlanta, GA, USA.
authors.forename: Kristen E
authors.initials: KE
authors.lastname: Howery
authors.affiliation: Research Service, Atlanta VA Medical Center, Decatur, GA, USA.
authors.forename: Katy M
authors.initials: KM
authors.lastname: Clemmer
authors.affiliation: Department of Microbiology and Immunology, Emory University, 3001 Rollins Research Center, Atlanta, GA, USA. prather@emory.edu.|Research Service, Atlanta VA Medical Center, Decatur, GA, USA. prather@emory.edu.
authors.forename: Philip N
authors.identifier: http://orcid.org/0000-0001-9674-6250
authors.initials: PN
authors.lastname: Rather
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D018441:Biofilms; D002455:Cell Division; D015964:Gene Expression Regulation, Bacterial; D009154:Mutation; D009876:Operon; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D011513:Proteus mirabilis / Q000472:pathogenicity / Q000502:physiology*; D015398:Signal Transduction; D015533:Transcriptional Activation; D014774:Virulence / Q000235:genetics
chemical_list: D001426:Bacterial Proteins
keywords: Proteus; Rcs phosphorelay; Swarming