title: The pathogenicity island encoded PvrSR/RcsCB regulatory network controls biofilm formation and dispersal in Pseudomonas aeruginosa PA14.
abstract: Pseudomonas aeruginosa biofilm formation is linked to persistent infections in humans. Biofilm formation is facilitated by extracellular appendages, some of which are assembled by the Chaperone Usher Pathway (Cup). The cupD gene cluster is located on the PAPI-1 pathogenicity island of strain PA14 and has probably been acquired together with four genes encoding two-component signal transduction proteins. We have previously showed that the RcsB response regulator activates expression of the cupD genes, which leads to the production of CupD fimbriae and increased attachment. Here we show that RcsB activity is tightly modulated by two sensors, RcsC and PvrS. While PvrS acts as a kinase that enhances RcsB activity, RcsC has a dual function, first as a phosphorelay, and second as a phosphatase. We found that, under certain growth conditions, overexpression of RcsB readily induces biofilm dispersal. Microarray analysis shows that RcsB positively controls expression of pvrR that encodes the phosphodiesterase required for this dispersal process. Finally, in addition to the PAPI-1 encoded cupD genes, RcsB controls several genes on the core genome, some of which encode orphan response regulators. We thus discovered that RcsB is central to a large regulatory network that fine-tunes the switch between biofilm formation and dispersal.
authors.affiliation: Imperial College London, Department of Life Sciences, MRC Centre for Molecular Bacteriology and Infection, South Kensington Campus, Flowers Building, SW7 2AZ, London, UK.
authors.forename: Helga
authors.initials: H
authors.lastname: Mikkelsen
authors.forename: Kailyn
authors.initials: K
authors.lastname: Hui
authors.forename: Nicolas
authors.initials: N
authors.lastname: Barraud
authors.forename: Alain
authors.initials: A
authors.lastname: Filloux
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D018441:Biofilms / Q000254:growth & development*; D015964:Gene Expression Regulation, Bacterial; D053263:Gene Regulatory Networks; D044404:Genomic Islands; D005810:Multigene Family; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D010770:Phosphotransferases / Q000378:metabolism; D011401:Promoter Regions, Genetic; D025941:Protein Interaction Mapping; D011550:Pseudomonas aeruginosa / Q000201:enzymology / Q000235:genetics / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; C074889:RcsB protein, Bacteria; D010770:Phosphotransferases; D010744:Phosphoric Monoester Hydrolases; D010727:Phosphoric Diester Hydrolases