Hfq in Photorhabdus
Ontology highlight
ABSTRACT:
PROVIDER: PRJEB14802 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| ERR1544590.fastq.gz | Fastqsanger.gz | |||
| ERR1544591.fastq.gz | Fastqsanger.gz | |||
| ERR1544592.fastq.gz | Fastqsanger.gz | |||
| ERR1544593.fastq.gz | Fastqsanger.gz | |||
| ERR1544594.fastq.gz | Fastqsanger.gz |
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Project description:Photorhabdus luminescens bacteria alternate lifestyles between its pathogenic insect host and its mutualistic nematode host. We found that Photorhabdus changes radically from the insect pathogenic form (P-form) to slow growing small cells when initiating mutualism (M-form). Here we characterize the gene expression of the M-form relative to the P-form.
2011-09-15 | GSE32088 | GEO
Project description:The ability of bacteria to respond to environmental change is based on the exploration of sophisticated regulatory landscapes. While we can learn a great deal from reductive analyses of individual pathways, and global approaches to gene regulation, a deeper understanding of these complex signalling networks requires the simultaneous consideration of several regulatory layers at the genome-scale. To highlight the power of this approach we analysed the Hfq transcriptional/translational regulatory network in the plant-associated rhizobacterium Pseudomonas fluorescens. Extensive multi-omics analyses including proteomics quantification using isobaric isotope labelling (iTRAQ )were used to assess how hfq deletion affects gene transcription, translation and protein abundance. The subsequent integration of these datasets highlighted the discrete contributions by Hfq to gene regulation at different levels, confirmed previous predictions, and suggested novel regulatory principles for Hfq function. The integrative approach to regulatory analysis described here has significant potential, for both dissecting individual signalling pathways and understanding the strategies bacteria use to cope with external challenges.
2017-10-18 | PXD005621 | Pride
Project description:cDNA microarray analysis to identify genes regulated by the RNA chaperone, Hfq. Four experiments were performed: 1/ Hfq+ vs Hfq- strains. 269 significantly differentially regulated genes were identified by SAM (Statistical Analysis of Microarrays), of which 120 changed more than 1.5 fold (48 increased and 72 decreased in hfq-). Amongst other genes, these experiments identified significant regulation of the sigma E and sigma 32 regulons. However, only genes induced by sigma E were similarly induced in hfq-; 8 operons repressed by sigma E were not repressed in hfq-. 2/ wt vs delta rseA. RseA is the antisigma factor for sigmaE. This comparison results in elevated steady-state levels of sigma E, and confirmed induction and repression of target regulon members. 3/ hfq+ vs hfq+ rpoE overexpression. RpoE encoding sigma E was overexpressed in an hfq+ background, confirming normal regulation of the sigma E regulon. 4/ hfq+ vs hfq- rpoE overexpression. Sigma E was overexpressed in an hfq- background. This demonstrated that 8 operons normally repressed by sigma E require hfq for this repression. The simple conclusion is that sigma E regulates small RNAs that, together with Hfq, bind target mRNAs and results in their rapid degradation. This study is detailed in Guisbert et al 2007 (J Bacteriol, 189:1963-73) Keywords: Genetic modification
2007-01-01 | GSE6444 | GEO
Project description:Hfq proteins are RNA chaperones that play a critical role in post-transcription regulation of gene expression. Bacteria of the Burkholderia cepacia complex harbor two distinct and functional Hfq proteins, the Hfq and Hfq2. We have previously performed the functional analysis of Hfq and Hfq2 in the pathogen Burkholderia cenocepacia J2315. In order to examine the impacts of each RNA chaperone on the global transcriptome of B. cenocepacia J2315, we performed comparative transcriptome profile of mutants on the hfq and hfq2 genes, using as reference the wild-type strain.
2014-01-01 | GSE47344 | GEO
Project description:In Neisseria meningitidis iron responsive gene regulation is mediated primarily by the Ferric Uptake Regulator (Fur) protein. When complexed with iron, Fur represses gene expression by preventing transcription initiation. Fur can also indirectly activate gene expression via the repression of regulatory small RNAs (sRNA). One such Fur-and iron-regulated sRNA, NrrF, was previously identified in N. meningitidis and shown to repress expression of the sdhA and sdhC genes encoding subunits of the succinate dehydrogenase complex. In the majority of Gram-negative bacteria sRNA-mediated regulation requires a cofactor RNA-binding protein (Hfq) for proper gene regulation and stabilization. In this study we examined the role of Hfq in NrrF-mediated regulation of the succinate dehydrogenase genes in N. meningitidis and the effect of an hfq- mutation on iron-responsive gene regulation more broadly. We first demonstrated that the stability of Nrrf as well as the regulation of sdhC and sdhA in vivo was unaltered in the hfq- mutant. Secondly, we established that iron responsive gene regulation of the Fur-regulated sodB gene was dependent on Hfq. Finally, we demonstrate that in N. meningitidis Hfq functions to control expression of both ORFs and intergenic regions via iron independent mechanisms. Collectively these studies demonstrate that in N. meningitidis iron and NrrF mediated regulation of sdhC and sdhA can occur independently of Hfq, although Hfq functions more globally to control regulation of other N. meningitidis genes primarily by iron-independent mechanisms.
2010-02-11 | GSE20294 | GEO
Project description:Escherichia coli O157:H7 is a food-borne pathogen that causes bloody diarrhea and hemolytic uremic syndrome. Hfq is an sRNA chaperone protein that is involved in post-transcriptional regulation of virulence genes in pathogenic bacteria. In EHEC strain EDL933, Hfq acts a negative regulator of the locus of enterocyte effacement (LEE) that encodes most of the proteins involved in type three secretion and attaching and effacing lesions. We deleted hfq in E. coli O157:H7 strain 86-24 and compared global transcription profiles of the hfq mutant to the wild type strain in exponential growth phase. Deletion of hfq affected transcription of genes common to nonpathogenic and pathogenic strains of E. coli as well as pathogen-specific genes. Downregulated genes in the hfq mutant included ler as well as genes encoded in LEE2-5 that encode for type three secretion and AE lesion formation. Decreased expression of the LEE genes in the hfq mutant occurred at mid-, late, and stationary growth phases in both LB and DMEM media as detected by qRT-PCR. We also confirmed decreased regulation of the LEE genes by examining secreted proteins and AE lesion formation by the hfq mutant and WT strains. Deletion of hfq also caused decreased expression of the two-component system qseBC involved in inter-kingdom signaling and virulence gene regulation in EHEC as well as an increase in stx2AB expression that encodes for the deadly Shiga toxin. Altogether, these data indicate that Hfq plays a different regulatory role in EHEC 86-24 from what has been reported for EHEC strain EDL933 and that the role of Hfq in EHEC virulence regulation extends beyond the LEE.
2012-01-06 | GSE30893 | GEO
Project description:Secretion systems are used as weapons by a variety of Gram-negative bacteria. Among them the Type VI Secretion System (T6SS) gained more interest throughout the last years. The system functions as a molecular nano-weapon: it is used in inter-kingdom competition by various bacteria to deliver toxic effectors in target cells. Here we describe the role of the T6SS in Photorhabdus laumondii subsp. laumondii strain DJC, an entomopathogenic biocontrol agent able to live in different environmental niches, such as in symbiosis with nematodes and in the rhizosphere on plant roots. Using bioinformatic and protein motif analyses we identified four T6SS gene clusters (T6SS-1, T6SS-2, T6SS-3 and T6SS-4) and multiple orphan T6SS related genes in the genome of P. laumondii. Furthermore, we highlighted 11 T6SS effector-immunity pairs, including three undescribed membrane disrupting effectors, each with putatively different antibacterial activities. By label-free mass spectrometry of P. laumondii wild type cells and respective T6SS-deficient strains, we could point out a cross-link between T6SS and other Photorhabdus’ virulence related mechanisms such as PVCs, T3SS and pyocins. Furthermore, a change in motility as well as in the secondary metabolism was observed upon T6SS-deficiency. Here, we shed light on the T6SS in P. laumondii DJC and suggesting a cross-link of various virulence mechanisms, which could help to gain knowledge on T6SS and better figure out the Photorhabdus ability to live in polymicrobial environments.
2024-04-05 | PXD035720 | Pride
Project description:In Neisseria meningitidis iron responsive gene regulation is mediated primarily by the Ferric Uptake Regulator (Fur) protein. When complexed with iron, Fur represses gene expression by preventing transcription initiation. Fur can also indirectly activate gene expression via the repression of regulatory small RNAs (sRNA). One such Fur-and iron-regulated sRNA, NrrF, was previously identified in N. meningitidis and shown to repress expression of the sdhA and sdhC genes encoding subunits of the succinate dehydrogenase complex. In the majority of Gram-negative bacteria sRNA-mediated regulation requires a cofactor RNA-binding protein (Hfq) for proper gene regulation and stabilization. In this study we examined the role of Hfq in NrrF-mediated regulation of the succinate dehydrogenase genes in N. meningitidis and the effect of an hfq- mutation on iron-responsive gene regulation more broadly. We first demonstrated that the stability of Nrrf as well as the regulation of sdhC and sdhA in vivo was unaltered in the hfq- mutant. Secondly, we established that iron responsive gene regulation of the Fur-regulated sodB gene was dependent on Hfq. Finally, we demonstrate that in N. meningitidis Hfq functions to control expression of both ORFs and intergenic regions via iron independent mechanisms. Collectively these studies demonstrate that in N. meningitidis iron and NrrF mediated regulation of sdhC and sdhA can occur independently of Hfq, although Hfq functions more globally to control regulation of other N. meningitidis genes primarily by iron-independent mechanisms. RNA was isolated from wild-type MC58 Neisseria meningitidis, from an hfq- mutant, and from a complemented hfq- mutant under both iron-replete and iron-deplete conditions. Three biological replicates were analyzed for each strain and condition were analyzed.
2010-05-14 | E-GEOD-20294 | biostudies-arrayexpress
Project description:Escherichia coli O157:H7 is a food-borne pathogen that causes bloody diarrhea and hemolytic uremic syndrome. Hfq is an sRNA chaperone protein that is involved in post-transcriptional regulation of virulence genes in pathogenic bacteria. In EHEC strain EDL933, Hfq acts a negative regulator of the locus of enterocyte effacement (LEE) that encodes most of the proteins involved in type three secretion and attaching and effacing lesions. We deleted hfq in E. coli O157:H7 strain 86-24 and compared global transcription profiles of the hfq mutant to the wild type strain in exponential growth phase. Deletion of hfq affected transcription of genes common to nonpathogenic and pathogenic strains of E. coli as well as pathogen-specific genes. Downregulated genes in the hfq mutant included ler as well as genes encoded in LEE2-5 that encode for type three secretion and AE lesion formation. Decreased expression of the LEE genes in the hfq mutant occurred at mid-, late, and stationary growth phases in both LB and DMEM media as detected by qRT-PCR. We also confirmed decreased regulation of the LEE genes by examining secreted proteins and AE lesion formation by the hfq mutant and WT strains. Deletion of hfq also caused decreased expression of the two-component system qseBC involved in inter-kingdom signaling and virulence gene regulation in EHEC as well as an increase in stx2AB expression that encodes for the deadly Shiga toxin. Altogether, these data indicate that Hfq plays a different regulatory role in EHEC 86-24 from what has been reported for EHEC strain EDL933 and that the role of Hfq in EHEC virulence regulation extends beyond the LEE. Comparison of transcriptional regulation of the WT 86-24 isolate and the hfq mutant for the identification of regulated targets that were followed up by functional analysis.
2012-01-06 | E-GEOD-30893 | biostudies-arrayexpress