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:D-Glutamate (D-Glu), an essential component of peptidoglycans, can be utilized as carbon and nitrogen source by Pseudomonas aeruginosa. DNA microarrays were employed to identify genes involved in D-Glu catabolism. Through gene knockout and growth phenotype analysis, the divergent dguR-dguABC (D-glutamate utilization) gene cluster was shown to participate in D-Glu catabolism and regulation. The dguA gene encodes a FAD-dependent D-amino acid dehydrogenase with D-Glu as its preferred substrate, and its promoter was specifically induced by exogenous D-Glu and D-Gln. The function of DguR as transcriptional activator of the dguABC operon was demonstrated by promoter activity measurements in vivo and by mobility shift assays with purified His-tagged DguR in vitro. Although the DNA-binding activity of DguR did not require D-Glu, the presence of D-Glu in the binding reaction was found to stabilize a preferred nucleoprotein complex. The dguB gene encodes a putative enamine/imine deaminase of the RidA family, but its role in D-Glu catabolism remained to be determined. While a lesion in dguC encoding a periplasmic solute binding protein did not affect growth on D-Glu, the AatJMQP transporter for acidic amino acid uptake was found essential for D-Glu and L-Glu utilization. Expression of this uptake system was subjected to induction by exogenous DL-Glu, most likely via the AauSR two-component system. In summary, DguA was identified in this study as a new member of the FAD-dependent amino acid dehydrogenase family for D-amino acid catabolism. DguR serves as a D-Glu sensor and transcriptional activator of the dguA promoter. Pseudomonas aeruginosa PAO1 was chosen as model to study gene response with different D-amino acids.
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: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:Arginine utilization in Pseudomonas aeruginosa with multiple catabolic pathways represents one of the best examples of metabolic versatility of this organism. To identify genes of this complex arginine network, we employed DNA microarray to analyze the transcriptional profiles of this organism in response to L-arginine. While most genes in arginine uptake, regulation and metabolism have been identified as members of the ArgR regulon in our previous study, eighteen putative transcriptional units of 38 genes including the two known genes of the arginine dehydrogenase (ADH) pathway, kauB and gbuA, were found inducible by exogenous L-arginine but independent of ArgR. We conducted three independent microarray experiments in the presence (experimental) of L-Glutamate or D-Arginine. P. aeruginosa PAO1 was grown aerobically in minimal medium P with 300 rpm shaking at 37°C, in the presence of L-Glu with or without the addition of D-Arg at 20 mM.
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: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:Pseudomonas aeruginosa PAO1 persister and normal cells were treated with and without Granulocyte Macrophage Colony-Stimulating Factor (GM-CSF) to understand the effect of GM-CSF on gene expression of PAO1. We used DNA microarrays to identify the down-regulated and up-regulated genes after GM-CSF treatment.
Project description:Protein complexome analysis of Pseudomonas aeruginosa PAO1 at OD 0.3 in LB media through 10-40% glycerol gradient fractionation in 21 samples.