title: Global regulation in Pseudomonas aeruginosa: the regulatory protein AlgR2 (AlgQ) acts as a modulator of quorum sensing.
abstract: The Pseudomonas aeruginosa protein AlgR2 (AlgQ) was originally identified as a regulatory protein implicated in alginate production. It also regulates the synthesis of polyphosphate as well as of a variety of secretable virulence factors, upregulating neuraminidase and siderophore synthesis and downregulating rhamnolipid biosurfactant and extracellular protease synthesis. In this study, we show that the regulatory effect of AlgR2 on elastase protease synthesis is exerted at transcriptional level on the lasB gene. We also demonstrate that AlgR2 negatively modulates the expression of quorum sensing regulatory genes lasR and rhlR. Finally, results obtained from DNA retardation assays provide evidence that AlgR2 can bind specifically to the lasR and rhlR promoters. Altogether, these data provide strong support for the hypothesis that AlgR2 is a global transcriptional regulator in P. aeruginosa.
authors.affiliation: Laboratoire d'Ingiénérie des Systèmes Macromoléculaires, Centre National de la Recherche Scientifique, 31 chemin Joseph Aiguier, 13402 Marseille cedex 20, France.
authors.forename: Fouzia
authors.initials: F
authors.lastname: Ledgham
authors.forename: Chantal
authors.initials: C
authors.lastname: Soscia
authors.forename: Ananda
authors.initials: A
authors.lastname: Chakrabarty
authors.forename: Andrée
authors.initials: A
authors.lastname: Lazdunski
authors.forename: Maryline
authors.initials: M
authors.lastname: Foglino
mesh_terms: D000464:Alginates / Q000378:metabolism; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics; D024202:Electrophoretic Mobility Shift Assay; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D020723:Glucuronic Acid; D006603:Hexuronic Acids; D008666:Metalloendopeptidases / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D015534:Trans-Activators / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D014158:Transcription, Genetic; D015854:Up-Regulation
chemical_list: C079502:AlgQ protein, Pseudomonas aeruginosa; D000464:Alginates; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D006603:Hexuronic Acids; C080365:LasR protein, Pseudomonas aeruginosa; D011994:Recombinant Proteins; C086515:RhlR protein, Pseudomonas aeruginosa; D015534:Trans-Activators; D020723:Glucuronic Acid; D008666:Metalloendopeptidases; C043859:pseudolysin, Pseudomonas aeruginosa