Project description:Next to the two-component and quorum sensing systems, cell-surface signaling (CSS) has been recently identified as an important regulatory system in Pseudomonas aeruginosa. CSS senses signals from outside the cell and transmits them into the cytoplasm. It consists of a TonB-dependent outer membrane receptor, a cytoplasmic membrane-localized sigma factor regulator (or anti-sigma factor), and an extracytoplasmic function (ECF) sigma factor. Upon perception of the extracellular signal by the receptor the ECF sigma factor is activated and promotes the transcription of a specific set of gene(s). Although most P. aeruginosa ECF sigma factors are involved in the regulation of iron uptake, we have identified a novel ECF sigma factor (PA0675) involved in the regulation of virulence. By microarray analysis of cells overexpressing PA0675 from the pMUM3 plasmid we have identified the genes regulated by this sigma factor. Two different samples are analyzed namely P. aeruginosa (pMMB67EH) (control/reference sample) and P. aeruginosa (pMUM3) (overexpressing the PA0675 ECF sigma factor). Two different replicates per sample are included.
Project description:Next to the two-component and quorum sensing systems, cell-surface signaling (CSS) has been recently identified as an important regulatory system in Pseudomonas aeruginosa. CSS senses signals from outside the cell and transmits them into the cytoplasm. It consists of a TonB-dependent outer membrane receptor, a cytoplasmic membrane-localized sigma factor regulator (or anti-sigma factor), and an extracytoplasmic function (ECF) sigma factor. Upon perception of the extracellular signal by the receptor the ECF sigma factor is activated and promotes the transcription of a specific set of gene(s). Although most P. aeruginosa ECF sigma factors are involved in the regulation of iron uptake, we have identified a novel ECF sigma factor (PA0675) involved in the regulation of virulence. By microarray analysis of cells overexpressing PA0675 from the pMUM3 plasmid we have identified the genes regulated by this sigma factor.
Project description:Cell-surface signaling is a sophisticated regulatory mechanism used by gram-negative bacteria to sense signals from outside the cell and transmit them into the cytoplasm. This regulatory system consists of an outer membrane-localized TonB-dependent receptor (TonB-dependent transducer), a cytoplasmic membrane-localized anti-sigma factor and an extracytoplasmic function (ECF) sigma factor. By microarray analysis we have identified the regulons of four novel P. aeruginosa signaling systems. For that, the ECF sigmas PA0149, PA2050, PA2093 and PA4896 have been overexpressed in P. aeruginosa and their target gene candidates have been identified using DNA microarray. Keywords: Overexpression of ECF sigma factors
Project description:The Pseudomonas aeruginosa quorum-sensing (QS) systems contribute to bacterial homeostasis and pathogenicity. Although many regulators have been characterized to control the production of virulence factors and QS signaling molecules, its detailed regulatory mechanisms still remain elusive. Here, we performed chromatin immunoprecipitation followed by high-throughput DNA sequencing (ChIP-seq) on 10 key QS regulators. The direct regulation of these genes by corresponding regulator has been confirmed by Electrophoretic mobility shift assays (EMSAs) and quantitative real-time polymerase chain reactions (qRT-PCR). Binding motifs are found by using MEME suite and verified by footprint assays in vitro. Collectively, this work provides new cues to better understand the detailed regulatory networks of QS systems. ChIP-seq of 10 QS regulators in Pseudomonas aeruginosa
Project description:Cell-surface signaling is a sophisticated regulatory mechanism used by gram-negative bacteria to sense signals from outside the cell and transmit them into the cytoplasm. This regulatory system consists of an outer membrane-localized TonB-dependent receptor (TonB-dependent transducer), a cytoplasmic membrane-localized anti-sigma factor and an extracytoplasmic function (ECF) sigma factor. By microarray analysis we have identified the regulons of four novel P. aeruginosa signaling systems. For that, the ECF sigmas PA0149, PA2050, PA2093 and PA4896 have been overexpressed in P. aeruginosa and their target gene candidates have been identified using DNA microarray. Experiment Overall Design: Five different samples are analyzed namely P. aeruginosa (pMMB67EH) (control/reference sample), P. aeruginosa (pMMB-PA4896) (overexpressing the PA4896 ECF sigma factor), P. aeruginosa (pMMB-PA0149) (overexpressing the PA0149 ECF sigma factor), P. aeruginosa (pMMB-PA2050) (overexpressing the PA2050 ECF sigma factor), and P. aeruginosa (pMMB-PA2093) (overexpressing the PA2093 ECF sigma factor). Two different replicates are included for the three first samples and one for the two last samples.
Project description:Pseudomonas aeruginosa is a common bacteria leading to exacerbations of chronic obstructive pulmonary disease (COPD) patients while this bacteria can be easily eradicated by the immune systems of healthy individuals. Human airway organoids derived from healthy individuals and COPD patients were infected with pseudomonas aeruginosa. This project aims (1) to understand the differences in gene expressions in healthy and COPD airway organoids during stable condition, without infection and (2) to investigate differential pathogenic mechanism (i.e. antimicrobial defense) of pseudomonoas aeruginosa infection in healthy and COPD populations. Three healthy donors and three COPD patients were included in this study and samples were collected with and without pseudomonas aeruginosa infection.
Project description:Oberhardt2008 - Genome-scale metabolic
network of Pseudomonas aeruginosa (iMO1056)
This model is described in the article:
Genome-scale metabolic
network analysis of the opportunistic pathogen Pseudomonas
aeruginosa PAO1.
Oberhardt MA, Puchałka J, Fryer
KE, Martins dos Santos VA, Papin JA.
J. Bacteriol. 2008 Apr; 190(8):
2790-2803
Abstract:
Pseudomonas aeruginosa is a major life-threatening
opportunistic pathogen that commonly infects immunocompromised
patients. This bacterium owes its success as a pathogen largely
to its metabolic versatility and flexibility. A thorough
understanding of P. aeruginosa's metabolism is thus pivotal for
the design of effective intervention strategies. Here we aim to
provide, through systems analysis, a basis for the
characterization of the genome-scale properties of this
pathogen's versatile metabolic network. To this end, we
reconstructed a genome-scale metabolic network of Pseudomonas
aeruginosa PAO1. This reconstruction accounts for 1,056 genes
(19% of the genome), 1,030 proteins, and 883 reactions. Flux
balance analysis was used to identify key features of P.
aeruginosa metabolism, such as growth yield, under defined
conditions and with defined knowledge gaps within the network.
BIOLOG substrate oxidation data were used in model expansion,
and a genome-scale transposon knockout set was compared against
in silico knockout predictions to validate the model.
Ultimately, this genome-scale model provides a basic modeling
framework with which to explore the metabolism of P. aeruginosa
in the context of its environmental and genetic constraints,
thereby contributing to a more thorough understanding of the
genotype-phenotype relationships in this resourceful and
dangerous pathogen.
This model is hosted on
BioModels Database
and identified by:
MODEL1507180020.
To cite BioModels Database, please use:
BioModels Database:
An enhanced, curated and annotated resource for published
quantitative kinetic models.
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to
the public domain worldwide. Please refer to
CC0
Public Domain Dedication for more information.
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:Analysis of Pseudomonas aeruginosa PAO1 treated with 200 µM sphingomyelin. Results provide insight into the response to sphingomyelin in P. aeruginosa.
Project description:In the present study, we employed Affymetrix Pseudomonas aeruginosa GeneChip arrays to investigate global gene expression profiles during the cellular response of Pseudomonas aeruginosa to sodium hypochlorite Experiment Overall Design: We calculated fold change as the ratio between the signal averages of four untreated (control) and five sodium hypochlorite-treated (experimental) cultures for 20 min exposure.