Genome-wide Analysis of the Pho Regulon in a pstCA mutant of Citrobacter rodentium
Ontology highlight
ABSTRACT:
ORGANISM(S): Citrobacter rodentium
SUBMITTER: Matthew Wakefield
PROVIDER: E-GEOD-40906 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:An ability to sense and respond to changes in extracellular phosphate is critical to the survival of most bacteria. For Caulobacter crescentus, which typically lives in phosphate-limited environments, this process is especially crucial. Like many bacteria, Caulobacter responds to phosphate limitation through a conserved two-component signaling pathway called PhoR-PhoB, but the direct regulon of PhoB in this organism is unknown. Here, we use ChIP-Seq to map the global binding patterns of the phosphate-responsive transcriptional regulator PhoB in both phosphate-limited and -replete conditions. Combined with genome-wide expression profiling, our work demonstrates that PhoB is induced to regulate nearly 50 genes in phosphate-starved conditions. The PhoB regulon is comprised primarily of genes known or predicted to help Caulobacter scavenge for and import inorganic phosphate, including 15 different membrane transporters. We also investigated the regulatory role of PhoU, a widely conserved protein proposed to coordinate phosphate import with expression of the PhoB regulon by directly modulating the histidine kinase PhoR. However, our studies show that it likely does not play such a role in Caulobacter as depleting PhoU has no significant effect on PhoB-dependent gene expression. Instead, cells lacking PhoU exhibit a striking accumulation of large polyphosphate granules suggesting that PhoU participates in controlling intracellular phosphate metabolism. An allele of phoB bearing a C-terminal 3x-flag tag was integrated at its native locus, and ChIP followed by deep sequencing on Illumina MiSeq was performed on samples grown in rich medium, phosphate-limited medium, and in a pstS::Tn5 mutant background in rich medium.
2016-08-06 | E-GEOD-71860 | biostudies-arrayexpress
Project description:We used ChIP-seq to map the binding of of C-terminally FLAG3-tagged PhoB to the Escherichia coli K-12 genome during growth in MOPS minimal media with low phosphate or high phosphate (0.2 mM or 1.32 mM, respectively). As a control, we performed ChIP-seq in an untagged strain. We also used ChIP-seq to map Sigma 70 (associates with initiating RNA polymerase) binding across the E. coli K-12 genome in wild-type, ΔphoB, Δhns, and Δhns ΔphoB strains grown in low phosphate medium to determine whether PhoB modulates recruitment of RNA polymerase to promoters and whether this is modulated by H-NS.
2020-07-12 | E-MTAB-9293 | biostudies-arrayexpress
Project description:An ability to sense and respond to changes in extracellular phosphate is critical to the survival of most bacteria. For Caulobacter crescentus, which typically lives in phosphate-limited environments, this process is especially crucial. Like many bacteria, Caulobacter responds to phosphate limitation through a conserved two-component signaling pathway called PhoR-PhoB, but the direct regulon of PhoB in this organism is unknown. Here, we use ChIP-Seq to map the global binding patterns of the phosphate-responsive transcriptional regulator PhoB in both phosphate-limited and -replete conditions. Combined with genome-wide expression profiling, our work demonstrates that PhoB is induced to regulate nearly 50 genes in phosphate-starved conditions. The PhoB regulon is comprised primarily of genes known or predicted to help Caulobacter scavenge for and import inorganic phosphate, including 15 different membrane transporters. We also investigated the regulatory role of PhoU, a widely conserved protein proposed to coordinate phosphate import with expression of the PhoB regulon by directly modulating the histidine kinase PhoR. However, our studies show that it likely does not play such a role in Caulobacter as depleting PhoU has no significant effect on PhoB-dependent gene expression. Instead, cells lacking PhoU exhibit a striking accumulation of large polyphosphate granules suggesting that PhoU participates in controlling intracellular phosphate metabolism. RNA was collected from cultures grown to mid-exponential phase in rich medium (PYE) at 30 degrees C. The strain grown in the presence of 50 mM vanillate was compared to the same strain grown in the absence of vanillate.
2016-08-06 | E-GEOD-71857 | biostudies-arrayexpress
Project description:Chromatin immunoprecipitation was combined with high-density tiling array (ChIP-chip) and gene expression microarray to reveal the adaptive responses of Escherichia coli to phosphate starvation. The first sketch of the genome-wide distribution of PhoB binding profile was unveiled and 43 regions were identified as the PhoB binding regions. The presence of a significant common motif in these binding regions allowed us to reconstruct the PhoB binding pattern. By comparing the ChIP-chip and microarray datasets, we were also able to identify genes directly or indirectly affected through PhoB regulation. Nineteen out of the 287 differentially expressed genes in the presence and absence of PhoB activity were considered as the genes directly regulated by PhoB. The adaptive responses affected through PhoB regulation are discussed and these responses involve in several important biological functions including transcriptional regulation, transportation, membrane component arrangement, sigma factor modulation and DNA replication inhibition. Under phosphate starvation condition, the gene expression profiles from MG1655 and its PhoB knock-out isogenetic strain are compared to identify the PhoB affected genes.
2012-10-21 | E-GEOD-21820 | biostudies-arrayexpress
Project description:In E. coli the phosphate homeostasis is regulated by the Pst system and the two-component system PhoB/R. Pathogens like E. coli O157:H7 are responsible for many outbreaks and can be found and survive in poor inorganic phosphate (Pi) environments. To understand global EHEC O157:H7 EDL933 strain responses to Pi-starvation, we compared the transcriptomes of EDL933 the WT strain grown in MOPS Pi rich medium and that grown in MOPS Pi poor medium, using the Affymetrix GeneChip® E. coli Genome 2.0 Array. Also we investigated the EDL933 global response to the absence of PhoB by comparing the transcriptomes of the WT strain the ΔphoB mutant both grown in Low Pi EDL933WT strain and its isogenic mutant ΔphoB were grown in Pi- and/or in Pi+ conditions until the OD600 reached respectively 0.55 to 0.6. Samples equal to 5.108 CFU were taken from this mid log phase and processed for transcriptomes analysis. Ten µg of RNAs were extracted and retro-transcripted. One µg of the fragmented and biotinylated cDNAs, were hybridized onto Affymetrix GeneChip® E. coli. The data were processed using the FlexArray® software; RMA normalization and the levels of transcription obtained from 3 biological replicates of each experimental condition were compared using the EB (Wright & Simon) algorithm. We then conducted comparisons between EDL933WT grown in Pi- and in Pi+ conditions (comparison A) and between EDL933WT and EDL933∆phoB strains both grown in Pi- (comparison B). The differentially expression conditions corresponded to 2-fold change (FC) cut-off and p-value < 0.05.
2014-03-15 | E-GEOD-50529 | biostudies-arrayexpress
Project description:An ability to sense and respond to changes in extracellular phosphate is critical to the survival of most bacteria. For Caulobacter crescentus, which typically lives in phosphate-limited environments, this process is especially crucial. Like many bacteria, Caulobacter responds to phosphate limitation through a conserved two-component signaling pathway called PhoR-PhoB, but the direct regulon of PhoB in this organism is unknown. Here, we use ChIP-Seq to map the global binding patterns of the phosphate-responsive transcriptional regulator PhoB in both phosphate-limited and -replete conditions. Combined with genome-wide expression profiling, our work demonstrates that PhoB is induced to regulate nearly 50 genes in phosphate-starved conditions. The PhoB regulon is comprised primarily of genes known or predicted to help Caulobacter scavenge for and import inorganic phosphate, including 15 different membrane transporters. We also investigated the regulatory role of PhoU, a widely conserved protein proposed to coordinate phosphate import with expression of the PhoB regulon by directly modulating the histidine kinase PhoR. However, our studies show that it likely does not play such a role in Caulobacter as depleting PhoU has no significant effect on PhoB-dependent gene expression. Instead, cells lacking PhoU exhibit a striking accumulation of large polyphosphate granules suggesting that PhoU participates in controlling intracellular phosphate metabolism.
2016-08-06 | GSE71857 | GEO
Project description:An ability to sense and respond to changes in extracellular phosphate is critical to the survival of most bacteria. For Caulobacter crescentus, which typically lives in phosphate-limited environments, this process is especially crucial. Like many bacteria, Caulobacter responds to phosphate limitation through a conserved two-component signaling pathway called PhoR-PhoB, but the direct regulon of PhoB in this organism is unknown. Here, we use ChIP-Seq to map the global binding patterns of the phosphate-responsive transcriptional regulator PhoB in both phosphate-limited and -replete conditions. Combined with genome-wide expression profiling, our work demonstrates that PhoB is induced to regulate nearly 50 genes in phosphate-starved conditions. The PhoB regulon is comprised primarily of genes known or predicted to help Caulobacter scavenge for and import inorganic phosphate, including 15 different membrane transporters. We also investigated the regulatory role of PhoU, a widely conserved protein proposed to coordinate phosphate import with expression of the PhoB regulon by directly modulating the histidine kinase PhoR. However, our studies show that it likely does not play such a role in Caulobacter as depleting PhoU has no significant effect on PhoB-dependent gene expression. Instead, cells lacking PhoU exhibit a striking accumulation of large polyphosphate granules suggesting that PhoU participates in controlling intracellular phosphate metabolism.
2016-08-06 | GSE71860 | GEO
Project description:Chromatin immunoprecipitation was combined with high-density tiling array (ChIP-chip) and gene expression microarray to reveal the adaptive responses of Escherichia coli to phosphate starvation. The first sketch of the genome-wide distribution of PhoB binding profile was unveiled and 43 regions were identified as the PhoB binding regions. The presence of a significant common motif in these binding regions allowed us to reconstruct the PhoB binding pattern. By comparing the ChIP-chip and microarray datasets, we were also able to identify genes directly or indirectly affected through PhoB regulation. Nineteen out of the 287 differentially expressed genes in the presence and absence of PhoB activity were considered as the genes directly regulated by PhoB. The adaptive responses affected through PhoB regulation are discussed and these responses involve in several important biological functions including transcriptional regulation, transportation, membrane component arrangement, sigma factor modulation and DNA replication inhibition. Comparison of the E. coli K12 MG1655 wild type and a PhoB-FLAG fusion expressing strain (MG1655_PhoB_FLAG). The anti-FLAG antibody was used to recognize PhoB-FLAG fusion protein. Therefore, ChIPed DNA from the wild type strain was used as the control group. Three biological replicates were performed.
2012-10-21 | E-GEOD-21856 | biostudies-arrayexpress
Project description:Two-component systems (TCS) serve as basic stimulus-response coupling mechanisms to allow organisms to sense and respond to a large variety of environmental conditions. In the opportunistic pathogen Pseudomonas aeruginosa, more than 100 genes encode TCS components. To avoid unwanted cross-talk between TCSs, the signaling cascades are usually very specific, with one sensor talking to its cognate response regulator. However, cross-regulation may provide effective means to integrate different environmental stimuli into a harmonized output response and thus to coordinate gene expression in response to complex and challenging habitats. Here, we applied a protein-fragment complementation assay (PCA) and identified a direct interaction of two response regulators of the OmpR/PhoB subfamily, namely PhoB and TctD in P. aeruginosa in vivo. Transcriptional profiling and ChIP-seq analysis uncovered adjacent bipartite binding motifs of the two response regulators in 8 promoter regions, of which 6 showed a common PhoB-TctD binding motif with a fixed spacing between the two motifs. We further demonstrate that phosphate limitation exhibits a PhoB-dependent activating activity on the expression of those genes, whereas the presence of a preferred carbon source inhibits gene expression in a TctD-dependent manner. Thus, the perception and the integration of two important environmental signals are achieved by a titration of the relative amounts of two phosphorylated response regulators that inversely regulate a common subset of genes. In conclusion, our results shed light on the general principles underlying two-component signal transduction pathways and the exploitation of cross-regulation to adapt bacterial behavior to complex environments. Transcriptome profiling of the UCBP-PA14 phoB and tctD mutants complemented by phoB ChIP-seq experiments.
2015-06-08 | E-GEOD-64056 | biostudies-arrayexpress
Project description:Comparison of transcriptional profiles of the wild-type (WT) and the phoB-mutant strain in B. fragilis strain YCH46 during phosphate (Pi) starvation. A four chip study using total RNA isolated from the WT culture and the phoB mutant culture under Pi-excess (6.6 mM) or Pi-limiting (0.0066mM) condition. Each sample contains duplicated data.
2011-02-22 | E-GEOD-27439 | biostudies-arrayexpress