Regulation of Energy Metabolism by the Extracytoplasmic Function (ECF) σ factors of Arcobacter butzleri
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ABSTRACT:
ORGANISM(S): Aliarcobacter butzleri RM4018
PROVIDER: GSE34089 | GEO | 2011/12/31
SECONDARY ACCESSION(S): PRJNA149985
REPOSITORIES: GEO
Similar Datasets
Project description:The extracytoplasmic function (ECF) ? factors are fundamental for bacterial adaptation to distinct environments and for survival under different stress conditions. The emerging pathogen Arcobacter butzleri possesses seven putative pairs of ?/anti-? factors belonging to the ECF family. Here, we report the identification of the genes regulated by five out of the seven A. butzleri ECF ? factors. Three of the ECF ? factors play an apparent role in transport, energy generation and the maintainance of redox balance. Several genes like the nap, sox and tct genes are regulated by more than one ECF ? factor indicating that the A. butzleri ECF ? factors form a network of overlapping regulons. In contrast to other eubacteria, these A. butzleri ECF regulons appear to primarily regulate responses to changing environments in order to meet metabolic needs instead of an obvious role in stress adaptation. Eleven condition experiment, wild-type A. butzleri and 10 mutants. Three replicates for isolates RM4810, RM4810?A?1::Km, RM4018??1/A?1::Km, RM4810?A?2::Km, RM4018??2/A?2::Km, RM4018?A?4::Km, RM4018??4/A?4::Km, RM4018?A?5::Km, RM4018??5/A?5::Km, RM4018?A?7::Km, and RM4018??7/A?7::Km independently grown in BHI and incubated at 30°C on a shaking platform set at 150 rpm. RNA was isolated from 5 ml of mid-logarithmic phase cultures (OD550 of approximately 0.5). A type 2 gene expression experimental design was used, with fluorescently labeled genomic DNA as a reference channel in each experiment as described by Lucchini, S., et al. 2005. Infect Immun 73:88-102.
2011-12-31 | E-GEOD-34089 | biostudies-arrayexpress
Project description:The ability of bacteria to adapt to stress depends on their ability to conditionally express specific sets of genes. Bacillus subtilis encodes seven extracytoplasmic function (ECF) sigma (σ) factors that regulate functions important for survival under conditions eliciting cell envelope stress. Of these, four have been studied in detail: σM, σW, σX and σV . The regulons of these four σ factors overlap, although the sequences that determine promoter selectivity are incompletely understood. A major role in promoter selectivity has been ascribed to the core promoter -10 and -35recognition elements. Here, we demonstrate that a homopolymeric T-tract motif, proximal to the-35 recognition element, functions in combination with the core promoter sequences to2determine selectivity for ECF sigma factors. This motif is critical for promoter activation by σV, contributes to activation by σM and σX, but has relatively little effect for σW. We propose that this motif, which is a feature of the deduced promoter consensus for a subset of ECF s factors from many species, affects confirmation or curvature of the DNA to influence promoter activity. The differential effect of this region amongst ECF s factors thereby provides a mechanism to modulate the nature and extent of regulon overlap.
2017-02-28 | GSE95393 | GEO
Project description:Bacillus subtilis encodes seven extracytoplasmic function (ECF) sigma factors. Three (sigma M, sigma W and simga X) mediate responses to cell envelope active antibiotics. The functions of sigma Y, sigma Z, sigma V, and YlaC remain largely unknown, and strong inducers of these sigma factors and their regulons have yet to be defined. Here, we define transcriptomic and phenotypic differences under non-stress conditions between strains carrying deletions in all seven ECF sigma factor genes (Δ7ECF), a sigMWX triple mutant (∆MWX), and the parental 168 strain. Our results identify >80 genes as at least partially dependent on ECF sigma factors and, as expected, most of these are dependent on sigma M, sigma W or sigma X which are active at a significant basal level during growth. Several genes, including the eps operon encoding enzymes for exopolysaccharide (EPS) production, were decreased in expression in Δ7ECF but affected little if at all in ΔMWX. Consistent with this observation, Δ7ECF (but not ∆MWX) showed reduced biofilm formation. Extending previous observations, we also note that ∆MWX is sensitive to a variety of antibiotics and Δ7ECF is either as sensitive as, or slightly more sensitive than, the ΔMWX strain to these stressors. These findings emphasize the overlapping nature of the seven ECF s factor regulons in B. subtilis, confirm that three of these (sigma M, W or X) play the dominant role in conferring intrinsic resistance to antibiotics, and provide initial insights into the roles of the remaining ECF sigma factors.
2010-07-21 | GSE22930 | GEO
Project description:Sinorhizobium meliloti lives as a soil saprophyte, and engages in a nitrogen fixing symbiosis with plant roots. To succeed in such diverse environments, the bacteria must continually adjust gene expression. Transcriptional plasticity in eubacteria is often mediated by alternative sigma factors interacting with core RNA polymerase. The S. meliloti genome encodes 14 of these alternative sigmas, including 11 extracytoplasmic function (ECF) sigmas. We used custom Affymetrix Symbiosis Chips to characterize the global transcriptional response of S. meliloti overexpressing the ECF sigma factor, RpoE2. Our work identifies over 200 genes whose expression is dependent on RpoE2.
2013-07-22 | GSE40391 | GEO
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.
2009-04-21 | GSE15697 | GEO
Project description:Bacillus subtilis encodes seven extracytoplasmic function (ECF) sigma factors. Three (sigma M, sigma W and simga X) mediate responses to cell envelope active antibiotics. The functions of sigma Y, sigma Z, sigma V, and YlaC remain largely unknown, and strong inducers of these sigma factors and their regulons have yet to be defined. Here, we define transcriptomic and phenotypic differences under non-stress conditions between strains carrying deletions in all seven ECF sigma factor genes (Δ7ECF), a sigMWX triple mutant (∆MWX), and the parental 168 strain. Our results identify >80 genes as at least partially dependent on ECF sigma factors and, as expected, most of these are dependent on sigma M, sigma W or sigma X which are active at a significant basal level during growth. Several genes, including the eps operon encoding enzymes for exopolysaccharide (EPS) production, were decreased in expression in Δ7ECF but affected little if at all in ΔMWX. Consistent with this observation, Δ7ECF (but not ∆MWX) showed reduced biofilm formation. Extending previous observations, we also note that ∆MWX is sensitive to a variety of antibiotics and Δ7ECF is either as sensitive as, or slightly more sensitive than, the ΔMWX strain to these stressors. These findings emphasize the overlapping nature of the seven ECF s factor regulons in B. subtilis, confirm that three of these (sigma M, W or X) play the dominant role in conferring intrinsic resistance to antibiotics, and provide initial insights into the roles of the remaining ECF sigma factors. Strains WT vs. ΔMWX, WT vs. Δ7ECF, Δ7ECF vs. ΔMWX. Each experiment was conducted three times using three independent total RNA preparations (biological triplicates). For each paried comparison, one sample was was labeled with Alexa Fluor 555 and the other was with Alexa Fluor 647. For each comparison, one replicate was performed with dyewap with the same RNA preparation.
2010-07-21 | E-GEOD-22930 | biostudies-arrayexpress
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.
2009-04-21 | E-GEOD-15697 | biostudies-arrayexpress
Project description:Sinorhizobium meliloti lives as a soil saprophyte, and engages in a nitrogen fixing symbiosis with plant roots. To succeed in such diverse environments, the bacteria must continually adjust gene expression. Transcriptional plasticity in eubacteria is often mediated by alternative sigma factors interacting with core RNA polymerase. The S. meliloti genome encodes 14 of these alternative sigmas, including 11 extracytoplasmic function (ECF) sigmas. We used custom Affymetrix Symbiosis Chips to characterize the global transcriptional response of S. meliloti overexpressing the ECF sigma factor, RpoE2. Our work identifies over 200 genes whose expression is dependent on RpoE2. The gene expression profile of Sinorhizobium meliloti strain CL150 carrying the rpoE2 gene on a plasmid, where it was expressed from a melibiose-inducible promoter (the S. meliloti PmelA promoter), was compared to the gene expression profile of CL150 carrying the corresponding empty vector (pCAP11). CL150 is an Rm1021 strain that has been corrected for two point mutations: it is wild type for ecfR1 and pstC.
2013-07-22 | E-GEOD-40391 | biostudies-arrayexpress
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
2007-11-24 | GSE9657 | GEO
Project description:Extracytoplasmic function (ECF) sigma factors are known to play an important role in the bacterial response to various environmental stresses. Porphyromonas gingivalis, a prominent etiological agent in human periodontitis, possesses six putative ECF sigma factors. So far, information is limited on an ECF sigma factor, PGN_0319. It has been recently reported that the expression of genes encoding some of the ECF sigma factors including PGN_0319 was affected by hemin availability. The aim of this study was to evaluate the role of PGN_0319 in hemin utilization by P. gingivalis. We evaluated the gene expression profile of the PGN_0319 mutant by DNA microarray, and then real-time reverse transcription PCR analysis was performed to assess genes with altered expression levels. The expressions level of hmuY and hmuR, which encode an outer-membrane protein involved in hemin utilization, and cdhR, a transcriptional regulator of hmuYR, were significantly decreased in the PGN_0319 mutant. The transcription of these genes was restored in the PGN_0319 complemented strain. We observed that the PGN_0319 mutant showed reduced growth in log phase compared with wild type under hemin-limiting condition. By electrophoretic mobility shift assay we demonstrated the recombinant PGN_0319 protein bound to the promoter region of hmuY and cdhR. In addition, we observed that PGN_0319 gene was upregulated in response to low cell density. These results demonstrate that PGN_0319 play an important role in the early growth of P. gingivalis, and directly regulates hmuYR and cdhR, thereby plays a role in the mechanisms involved in hemin utilization by P. gingivalis.
2017-01-01 | GSE78048 | GEO