Project description:The putative trancriptional regulator PA2449 was found to be essential for both glycine/serine metabolism and the production of phenazines in P. aeruignosa PAO1. We examined the regulon controlled by PA2449 via microarray analysis between wild-type P. aeruignosa PAO1 and the PA2449-null mutant P. aeruginosa PW5126. Both strains were obtained from the PA-two allele library (Univ. of Washington, Ref. Jacobs et al. 2003. PNAS 100, 14339).
Project description:The putative trancriptional regulator PA2449 was found to be essential for both glycine/serine metabolism and the production of phenazines in P. aeruignosa PAO1. We examined the regulon controlled by PA2449 via microarray analysis between wild-type P. aeruignosa PAO1 and the PA2449-null mutant P. aeruginosa PW5126. Both strains were obtained from the PA-two allele library (Univ. of Washington, Ref. Jacobs et al. 2003. PNAS 100, 14339). Strains were grown under conditions known to induce phenazine biosynthesis (peptone broth), and their resulting transcriptomes were compared. Total RNA was isolated and prepped for Affymetrix GeneChips.
Project description:The ParS/ParR two component regulatory system plays important roles for multidrug resistance in Pseudomonas aeruginosa. In this study we report RNA-seq analyses of the transcriptomes of P. aeruginosa PAO1 wild type and par mutants growing in a minimal medium containing 2% casamino acids. This has allowed the quantification of PAO1 transcriptome, and further defines the regulon that is dependent on the ParS/ParR system for expression. Our RNA-seq analysis produced the first estimates of absolute transcript abundance for the 5570 coding genes in P. aeruginosa PAO1. Comparative transcriptomics of P. aeruginosa PAO1 and par mutants identified a total of 464 genes regulated by ParS and ParR. Results also showed that mutations in the parS/parR system abolished the expression of the mexEF-oprN operon by down-regulating the regulatory gene mexS. In addition to affecting drug resistance genes, transcripts of quorum sensing genes (rhlIR and pqsABCDE-phnAB), were significantly up-regulated in both parS and parR mutants. Consistent with these results, a significant portion of the ParS/ParR regulated genes belonged to the MexEF-OprN and quorum sensing regulons. Deletion of par genes also lead to overproduction of phenazines and increased swarming motility, consistent with the up-regulation of quorum sensing genes. Our results established a link among ParS/ParR, MexEF-OprN and quorum sensing in Pseudomonas aeruginosa. Based on these results, we propose a model to illustrate the relationship among these regulatory systems in P. aeruginosa.
Project description:The ParS/ParR two component regulatory system plays important roles for multidrug resistance in Pseudomonas aeruginosa. In this study we report RNA-seq analyses of the transcriptomes of P. aeruginosa PAO1 wild type and par mutants growing in a minimal medium containing 2% casamino acids. This has allowed the quantification of PAO1 transcriptome, and further defines the regulon that is dependent on the ParS/ParR system for expression. Our RNA-seq analysis produced the first estimates of absolute transcript abundance for the 5570 coding genes in P. aeruginosa PAO1. Comparative transcriptomics of P. aeruginosa PAO1 and par mutants identified a total of 464 genes regulated by ParS and ParR. Results also showed that mutations in the parS/parR system abolished the expression of the mexEF-oprN operon by down-regulating the regulatory gene mexS. In addition to affecting drug resistance genes, transcripts of quorum sensing genes (rhlIR and pqsABCDE-phnAB), were significantly up-regulated in both parS and parR mutants. Consistent with these results, a significant portion of the ParS/ParR regulated genes belonged to the MexEF-OprN and quorum sensing regulons. Deletion of par genes also lead to overproduction of phenazines and increased swarming motility, consistent with the up-regulation of quorum sensing genes. Our results established a link among ParS/ParR, MexEF-OprN and quorum sensing in Pseudomonas aeruginosa. Based on these results, we propose a model to illustrate the relationship among these regulatory systems in P. aeruginosa. A total of 9 samples were analyzed in AB medium + 2% casamino acids, Pseudomonas aeruginosa PAO1 wild type strain (3 replicates); Pseudomonas aeruginosa parS mutant (3 replicates); Pseudomonas aeruginosa parR mutant (3 replicates).
Project description:The Pseudomonas aeruginosa PAO1 gene phaF (PA5060) is a transcriptional regulator in the closely related pseudomonad P. putida. phaF is expressed at higher levels in P. aeruginosa clinical isolates from the cystic fibrosis respiratory tract. To determine the role of phaF in regulating P. aeruginosa gene expression, we cloned it under control of the pBAD promoter in expression vector pJN105 and compared expression in this strain relative to an empty vector control strain. We used microarrays to study overall gene expression in a P. aeruginosa PAO1 phaF overexpression strain. A P. aeruginosa PAO1 strain over-expressing the transcriptional regulator phaF, PAO1 pJN105-phaF, and the corresponding empty control strain, P. aeruginosa PAO1 pJN105, were grown to exponential phase, RNA was isolated, and gene expression was analyzed via microarray analysis and compared.
Project description:The transcriptome of P. aeruginosa PAO1 in the presence of extracelluar 2-oxoglutarate at a concentration of 20 mM. We determined the transcriptional response of P. aeruignosa PAO1 to extracellular 2-oxoglutarate.
Project description:The Pseudomonas aeruginosa PAO1 gene phaF (PA5060) is a transcriptional regulator in the closely related pseudomonad P. putida. phaF is expressed at higher levels in P. aeruginosa clinical isolates from the cystic fibrosis respiratory tract. To determine the role of phaF in regulating P. aeruginosa gene expression, we cloned it under control of the pBAD promoter in expression vector pJN105 and compared expression in this strain relative to an empty vector control strain. We used microarrays to study overall gene expression in a P. aeruginosa PAO1 phaF overexpression strain.
Project description:Bacterial physiology in general and the bacterial response to the presence of nutrients and to external signals in particular is regulated at different levels, from mRNA synthesis to translational regulation and protein modification. However, there are not standardized parameters for defining post-transcriptional regulation. Herein, we propose a simple parameter, dubbed post-transcriptional variation (PTV), that allow extracting information on translational regulation from the combined analysis of transcriptomic and proteomic data. We have applied this parameter for precisely defining the regulon of the Pseudomonas aeruginosa post-transcriptional regulator Crc. P. aeruginosa is a free-living microorganism that, besides colonizing a diversity of environmental habitats, is able to infect a large number of patients at hospitals. Part of the ability of P. aeruginosa for colonizing such a variety of habitats relies on its capability of using a large number of carbon sources. This hierarchical assimilation is regulated by Crc, which together with Hfq, binds its target RNA impeding their translation when catabolite repression is triggered. Most studies cannot provide information on post-transcriptional regulation when analysed independently. Using the defined PTV parameter, we present a comprehensive map of the Crc post-transcriptional regulon.
Project description:The transcriptome of P. aeruginosa PAO1 in the presence of extracelluar 2-oxoglutarate at a concentration of 20 mM. We determined the transcriptional response of P. aeruignosa PAO1 to extracellular 2-oxoglutarate. P. aeruginosa PAO1 was grown in nutrient broth (Oxoid number 2) and induced with 20 mM 2-oxoglutarate. At 30 min post induction, total RNA was isolated and prepped for Affymetrix GeneChips.