Promoter specificity elements in Pseudomonas aeruginosa quorum-sensing-controlled genes.
The LasR-dependent and RhlR-dependent quorum-sensing systems are global regulators of gene expression in Pseudomonas aeruginosa. Previous studies have demonstrated that promoter elements of the quorum-sensing-controlled genes lasB and hcnABC are important in density-dependent regulation. We have identified LasR- and RhlR-dependent determinants in promoters of quorum-sensing-controlled genes qsc102, qsc117 (acpP), and qsc131 (phzA to -G) by in silico, deletion, point-mutational, and primer extension analyses. Each of these genes (in addition to lasI and rsaL) is activated by LasR, and qsc117 and qsc131 also respond to RhlR. Point mutations in the promoters of the LasR-specific gene, qsc102, relax specificity so that this promoter can respond to RhlR in addition to LasR. Our findings indicate that quorum-sensing-controlled promoters in P. aeruginosa are either specific for LasR or respond to both LasR and RhlR and that critical bases in the promoter elements determine specificity.
Whiteley
M
M
Department of Microbiology, University of Iowa, Iowa City, Iowa 52242, USA.
Greenberg
E P
EP
D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D017354:Point Mutation; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D015398:Signal Transduction; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C080365:LasR protein, Pseudomonas aeruginosa; C086515:RhlR protein, Pseudomonas aeruginosa; D015534:Trans-Activators