Project description:To further determine the origin of the increased virulence of Pseudomonas aeruginosa PA14 compared to Pseudomonas aeruginosa PAO1, we report a transcriptomic approach through RNA sequencing. Next-generation sequencing (NGS) has revolutioned sistems-based analsis of transcriptomic pathways. The goals of this study are to compare the transcriptomic profile of all 5263 orthologous genes of these nearly two strains of Pseudomonas aeruginosa.
Project description:Recent studies have shown that the concentrations of proteins expressed from orthologous genes are often conserved across organisms, and to a greater extent than the abundances of the corresponding mRNAs. However, such studies have not distinguished between evolutionary (e.g., sequence divergence) and environmental (e.g., growth condition) effects on the regulation of steady-state protein and mRNA abundances. Here we systematically investigated the transcriptome and proteome of two closely related Pseudomonas aeruginosa strains, PAO1 and PA14, under identical experimental conditions, thus controlling for environmental effects. For 703 genes observed by both shotgun proteomics and microarray experiments, we find that the protein-to-mRNA ratios are highly correlated between orthologous genes in the two strains, to an extent comparable to protein and mRNA abundances. In spite of this high molecular similarity between PAO1 and PA14, we found that several metabolic, virulence, and antibiotic resistance genes are differentially expressed between the two strains, mostly at the protein but not at the mRNA level. Our data demonstrate that post-transcriptional regulation is important for understanding the discordance between mRNA and protein abundance.
Project description:Analysis of Pseudomonas aeruginosa PAO1 treated with 200 µM sphingomyelin. Results provide insight into the response to sphingomyelin in P. aeruginosa.
Project description:Pseudomonas aeruginosa is an opportunistic human pathogen, infecting immuno-compromised patients and causing persistent respiratory infections in people affected from cystic fibrosis. Pseudomonas strain Pseudomonas aeruginosa PA14 shows higher virulence than Pseudomonas aeruginosa PAO1 in a wide range of hosts including insects, nematodes and plants but the precise cause of this difference is not fully understood. Little is known about the host response upon infection with Pseudomonas and whether or not transcription is being affected as a host defense mechanism or altered in the benefit of the pathogen. In this context the social amoeba Dictyostelium discoideum has been described as a suitable host to study virulence of Pseudomonas and other opportunistic pathogens.
Project description:Microarray analysis for the biofilm cells of Pseudomonas aeruginosa PA14 wild-type vs the tpbA (PA14_13660) mutant in LB medium at 4 and 7 h at 37C Microarray analysis for the biofilm cells of Pseudomonas aeruginosa PA14 wild-type vs the tpbA (PA14_13660) mutant in LB medium at 4 and 7 h at 37C.
Project description:Pseudomonas aeruginosa PAO1 contacted with and without poplar roots gene expression Poplar contacted with and without PAO1 gene expression. All samples cultured in 1 x hrp + 0.25 % sucrose Keywords: Contact with different species
Project description:20 P. aeruginosa strains were genotyped using a custom spotted oligo array (Ausubel P. aruginosa genotyping 4.8K v1), which included primarily oligos for genes present in strain PA14 but absent in PAO1, and oligos for genes present in PAO1 but absent in PA14 (as well as controls).
Project description:Recent studies have shown that the concentrations of proteins expressed from orthologous genes are often conserved across organisms, and to a greater extent than the abundances of the corresponding mRNAs. However, such studies have not distinguished between evolutionary (e.g., sequence divergence) and environmental (e.g., growth condition) effects on the regulation of steady-state protein and mRNA abundances. Here we systematically investigated the transcriptome and proteome of two closely related Pseudomonas aeruginosa strains, PAO1 and PA14, under identical experimental conditions, thus controlling for environmental effects. For 703 genes observed by both shotgun proteomics and microarray experiments, we find that the protein-to-mRNA ratios are highly correlated between orthologous genes in the two strains, to an extent comparable to protein and mRNA abundances. In spite of this high molecular similarity between PAO1 and PA14, we found that several metabolic, virulence, and antibiotic resistance genes are differentially expressed between the two strains, mostly at the protein but not at the mRNA level. Our data demonstrate that post-transcriptional regulation is important for understanding the discordance between mRNA and protein abundance.
Project description:Microarray analysis for the biofilm cells of Pseudomonas aeruginosa PA14 wild-type vs the tpbA (PA14_13660) mutant in LB medium at 4 and 7 h at 37C
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).