title: Role of the Pseudomonas aeruginosa las and rhl quorum-sensing systems in rhlI regulation.
abstract: In Pseudomonas aeruginosa the LasR-LasI and RhlR-RhlI quorum-sensing (QS) systems control expression of numerous virulence genes in a population density-dependent fashion. In this study, we investigated regulation of the autoinducer synthase gene rhlI, which is responsible for C(4)-HSL signal production. Primer extension analysis was used to map the rhlI transcriptional start site and an upstream regulatory region was identified. Expression studies revealed that (i) this regulatory region is important for rhlI expression and (ii) although the rhl QS system will induce rhlI, las is the dominant regulator. Furthermore, we found that control of rhlI in Escherichia coli is markedly different than in P. aeruginosa.
authors.affiliation: Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2.
authors.forename: Teresa R
authors.initials: TR
authors.lastname: de Kievit
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Kakai
authors.forename: J Kristen
authors.initials: JK
authors.lastname: Register
authors.forename: Everett C
authors.initials: EC
authors.lastname: Pesci
authors.forename: Barbara H
authors.initials: BH
authors.lastname: Iglewski
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D008025:Ligases; D008969:Molecular Sequence Data; D009875:Operator Regions, Genetic; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000254:growth & development* / Q000472:pathogenicity; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C081237:LasI protein, Pseudomonas aeruginosa; C080365:LasR protein, Pseudomonas aeruginosa; C086515:RhlR protein, Pseudomonas aeruginosa; D015534:Trans-Activators; D014157:Transcription Factors; D008025:Ligases; C096955:RHLI protein, Pseudomonas aeruginosa