title: RhlR expression in Pseudomonas aeruginosa is modulated by the Pseudomonas quinolone signal via PhoB-dependent and -independent pathways.
abstract: The expression of virulence determinants in Pseudomonas aeruginosa is coordinately regulated in response to both the social environment--commonly referred to as quorum sensing--and to environmental cues. In this study we have dissected the various independent regulation levels for pyocyanin production, which is influenced by the homoserine lactone- and Pseudomonas quinolone signal (PQS)-mediated quorum-sensing systems as well as by iron and phosphate availability. We demonstrate that the phosphate regulon is involved in the transcriptional activation of rhlR and the augmentation of PQS and pyocyanin production under phosphate limitation. However, we also observed an enhancement of rhlR transcription under low-iron medium conditions and after the addition of PQS that was independent of the phosphate regulon. These results highlight the complexity of secondary metabolite production in P. aeruginosa via environmental cues and the quorum-sensing system.
authors.affiliation: Chronic Pseudomonas Infection Research Group, Helmholtz Center for Infection Research, Inhoffenstrasse 7, D-38124 Braunschweig, Germany.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Jensen
authors.forename: Dagmar
authors.initials: D
authors.lastname: Löns
authors.forename: Caroline
authors.initials: C
authors.lastname: Zaoui
authors.forename: Florian
authors.initials: F
authors.lastname: Bredenbruch
authors.forename: Andree
authors.initials: A
authors.lastname: Meissner
authors.forename: Guido
authors.initials: G
authors.lastname: Dieterich
authors.forename: Richard
authors.initials: R
authors.lastname: Münch
authors.forename: Susanne
authors.initials: S
authors.lastname: Häussler
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D007501:Iron / Q000378:metabolism; D010710:Phosphates / Q000378:metabolism; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D011710:Pyocyanine / Q000096:biosynthesis; D015363:Quinolones / Q000494:pharmacology*; D053038:Quorum Sensing; D015398:Signal Transduction
chemical_list: D001426:Bacterial Proteins; D010710:Phosphates; D015363:Quinolones; C086515:RhlR protein, Pseudomonas aeruginosa; C061278:PhoB protein, Bacteria; C088386:homoserine lactone; D011710:Pyocyanine; D007501:Iron; D015107:4-Butyrolactone