The impact of anaerobiosis on expression of the iron-responsive Fur and RyhB Regulons [ChIP-chip]
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ABSTRACT:
ORGANISM(S): Escherichia coli str. K-12 substr. MG1655
PROVIDER: GSE74931 | GEO | 2015/12/01
SECONDARY ACCESSION(S): PRJNA301962
REPOSITORIES: GEO
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Project description:As descirbed in the manuscript "The impact of anaerobiosis on expression of the iron-responsive Fur and RyhB Regulons" we profiled the gene expression of E. coli K12 during aerobic or anaerobic growth and in the presence or absence of the transcription factor Fur and/or the small RNA RyhB.
2015-12-01 | GSE74930 | GEO
Project description:As descirbed in the manuscript "The impact of anaerobiosis on expression of the iron-responsive Fur and RyhB Regulons" we mapped the locations of Fur DNA binding in E. coli K12 under aerobic or anaerobic growth conditions and anerobic iron deficient growth conditions.
2015-12-01 | GSE74932 | GEO
Project description:The impact of anaerobiosis on expression of the iron-responsive Fur and RyhB Regulons
| PRJNA301932 | ENA
Project description:UnlabelledIron, a major protein cofactor, is essential for most organisms. Despite the well-known effects of O2 on the oxidation state and solubility of iron, the impact of O2 on cellular iron homeostasis is not well understood. Here we report that in Escherichia coli K-12, the lack of O2 dramatically changes expression of genes controlled by the global regulators of iron homeostasis, the transcription factor Fur and the small RNA RyhB. Using chromatin immunoprecipitation sequencing (ChIP-seq), we found anaerobic conditions promote Fur binding to more locations across the genome. However, by expression profiling, we discovered that the major effect of anaerobiosis was to increase the magnitude of Fur regulation, leading to increased expression of iron storage proteins and decreased expression of most iron uptake pathways and several Mn-binding proteins. This change in the pattern of gene expression also correlated with an unanticipated decrease in Mn in anaerobic cells. Changes in the genes posttranscriptionally regulated by RyhB under aerobic and anaerobic conditions could be attributed to O2-dependent changes in transcription of the target genes: aerobic RyhB targets were enriched in iron-containing proteins associated with aerobic energy metabolism, whereas anaerobic RyhB targets were enriched in iron-containing anaerobic respiratory functions. Overall, these studies showed that anaerobiosis has a larger impact on iron homeostasis than previously anticipated, both by expanding the number of direct Fur target genes and the magnitude of their regulation and by altering the expression of genes predicted to be posttranscriptionally regulated by the small RNA RyhB under iron-limiting conditions.ImportanceMicrobes and host cells engage in an "arms race" for iron, an essential nutrient that is often scarce in the environment. Studies of iron homeostasis have been key to understanding the control of iron acquisition and the downstream pathways that enable microbes to compete for this valuable resource. Here we report that O2 availability affects the gene expression programs of two Escherichia coli master regulators that function in iron homeostasis: the transcription factor Fur and the small RNA regulator RyhB. Fur appeared to be more active under anaerobic conditions, suggesting a change in the set point for iron homeostasis. RyhB preferentially targeted iron-containing proteins of respiration-linked pathways, which are differentially expressed under aerobic and anaerobic conditions. Such findings may be relevant to the success of bacteria within their hosts since zones of reduced O2 may actually reduce bacterial iron demands, making it easier to win the arms race for iron.
| S-EPMC4676285 | biostudies-literature
Project description:RyhB is a non-coding RNA regulated by the Fur repressor. It has previously been shown to cause the rapid degradation of a number of mRNAs that encode proteins that utilize iron. Here we examine the effect of ectopic RyhB production on global gene expression by microarray analysis. Many of the previously identified targets were found, as well as other mRNAs encoding iron-binding proteins, bringing the total number of regulated operons to at least 18, encoding 56 genes. The two major operons involved in Fe-S cluster assembly showed different behavior; the isc operon appears to be a direct target of RyhB action, while the suf operon does not. This is consistent with previous findings suggesting that the suf genes but not the isc genes are important for Fe-S cluster synthesis under iron-limiting conditions, presumably for essential iron-binding proteins. In addition, we observed repression of Fur-regulated genes upon RyhB expression, interpreted as due to intracellular iron-sparing resulting from reduced synthesis of iron-binding proteins. Our results demonstrate the broad effects of a single non-coding RNA on iron homeostasis. Experiment Overall Design: Derivatives of MG1655 carrying either pBAD-ryhB or the control vector pNM12 were used in all experiments. Experiment Overall Design: The strains used contain the (delta)ara714 allele to prevent catabolism of arabinose and the (delta)ryhB::cat allele to restrict RyhB expression to the inducible pBAD-ryhB vector. Experiment Overall Design: Overnight bacterial cultures were incubated in LB media with ampicillin at a final concentration of 50 ug/mL at 37oC and diluted 1000-fold into 50 mL of fresh LB-ampicillin media at 37oC with agitation. To induce RyhB expression, cultures carrying the pBAD-ryhB construct were grown to an O.D.600 of 0.5 and arabinose was added to the culture at a final concentration of 0.1%. In some experiments, 50 uM FeSO4 was added to the new culture after dilution from overnight culture. Total RNA was extracted from cells at the indicated time using the hot phenol procedure.
2007-09-21 | E-GEOD-3105 | biostudies-arrayexpress
Project description:Study of the roles played by Fur and RyhB in Shewanella oneidensis
2018-01-01 | GSE104952 | GEO
Project description:This SuperSeries is composed of the SubSeries listed below.
2015-12-01 | GSE74933 | GEO
Project description:RyhB is a non-coding RNA regulated by the Fur repressor. It has previously been shown to cause the rapid degradation of a number of mRNAs that encode proteins that utilize iron. Here we examine the effect of ectopic RyhB production on global gene expression by microarray analysis. Many of the previously identified targets were found, as well as other mRNAs encoding iron-binding proteins, bringing the total number of regulated operons to at least 18, encoding 56 genes. The two major operons involved in Fe-S cluster assembly showed different behavior; the isc operon appears to be a direct target of RyhB action, while the suf operon does not. This is consistent with previous findings suggesting that the suf genes but not the isc genes are important for Fe-S cluster synthesis under iron-limiting conditions, presumably for essential iron-binding proteins. In addition, we observed repression of Fur-regulated genes upon RyhB expression, interpreted as due to intracellular iron-sparing resulting from reduced synthesis of iron-binding proteins. Our results demonstrate the broad effects of a single non-coding RNA on iron homeostasis. Keywords: RNA degradation, iron stavation, RyhB small RNA, iron-using proteins
2005-08-31 | GSE3105 | GEO
Project description:Purpose:To investigate the effect of small RNA RyhB-1and RyhB-2 deletion of Salmonella enteritidis on genes expression of genome under simulated intestinal conditions Methods:S. Enteritidis wild type (WT) strain 50336 and mutants △ryhB-1, △ryhB-2, and △ryhB-1/ryhB-2 were grown overnight in 50 mL of the LB medium with 160 rpm shaking at 37°C under aerobic condition, washed thrice, and re-suspended with iron-limited and nutrient-limited medium. The above prepared bacterial cells were cultured for 2 h at 37°C in the anaerobic workstation. Each sample was analysed in triplicate. Total RNA of the above stains was extracted using TRIzol reagentwith DNase digestion according to the manufacturer’s instruction. Ribosome RNA was removed using a Ribo-Zero rRNA removal kit (Illumina) that leaves the mRNA. Sequencing libraries were prepared using the NEBNext Ultra Directional RNA Library Prep Kit for Illumina (NEB), sequenced on an Illumina Hiseq 2000 platform at Beijing Novogene Bioinformatics Technology。 Results: Analysis of the RNA-Seq data identified 496, 250, and 553 DEGs in △ryhB-1, △ryhB-2, and △ryhB-1△ryhB-2, respectively, compared to the WT strain.A total of 213 genes changed in △ryhB-1, △ryhB-2, and △ryhB-1△ryhB-2 mutants. The transcriptional levels of 176 genes changed in △ryhB-1 and △ryhB-1△ryhB-2 but not in △ryhB-2. Furthermore, 14 genes were only changed in RyhB-2, 96 DEGs were only identified in △ryhB-1, and 12 DEGs were only identified in △ryhB-2 but not in △ryhB-1△ryhB-2. Moreover, 150 DEGs were only identified in △ryhB-1△ryhB-2 but neither in △ryhB-1 nor in △ryhB-2. Conclusions: A total of 213 genes could be regulated by △ryhB-1, △ryhB-2, and △ryhB-1△ryhB-2 mutants, 176 genes are regulated only by RyhB-1, 14 genes were regulated only by RyhB-2.
2022-04-23 | GSE201112 | GEO
Project description:Global tranascriptional profiling of Bacillus subtilis cells comparing fur mutant to mutants of the iron-sparing response: fur fsrA double mutant, fur fbpAB triple mutant, fur fbpC double mutant, and fur fbpABC quadruple mutant Abstract of associated manuscript: The Bacillus subtilis ferric uptake regulator (Fur) protein is the major sensor of cellular iron status. When iron is limiting for growth, derepression of the Fur regulon increases the cellular capacity for iron uptake and mobilizes an iron-sparing response mediated, in large part, by a small non-coding RNA named FsrA. FsrA functions together with three small, basic proteins (FbpABC) to repress many "low-priority" iron-containing enzymes. We have used transcriptome analyses to define the scope of the iron-sparing response and to define subsets of genes dependent on either FbpAB or FbpC for their repression. Enzymes of the tricarboxylic acid cycle, including both aconitase and succinate dehydrogenase, are major targets of FsrA-mediated repression and, as a consequence, flux through this pathway is significantly decreased under iron limitation. FsrA also mediates a physiologically significant repression of iron-sulfur containing enzymes required for ammonium assimilation (the GltAB glutamate synthase) and catabolism of lactic acid (LutABC). Repression of the lutABC operon requires both FsrA and FbpB which supports a model in which the Fbp proteins function to enable repression of subsets of the FsrA regulon.
2011-02-19 | GSE27416 | GEO