The Escherichia coli Fur pan-regulon has few conserved but many unique regulatory targets
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ABSTRACT:
ORGANISM(S): Escherichia coli
PROVIDER: GSE223483 | GEO | 2023/08/04
REPOSITORIES: GEO
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Project description:Regulons for many transcription factors have been elucidated in model strains leading to an understanding of their role in producing physiological states. Comparative analysis of a regulon and its target genes between different strains of the same species is lacking. Ferric uptake regulator (Fur), involved in iron homeostasis, is one of the most conserved TFs, and is present in a wide range of bacteria. Using ChIP-exo experiments, we performed a comprehensive study of Fur binding sites in nine Escherichia coli strains with different lifestyles. 79 of the 431 target genes (18%) found belong to Fur’s core regulon, comprising genes involved in ion transport and metabolism, energy production and conversion, and amino acid metabolism and transport. 179 of the target genes (42%) comprise the accessory regulon, most of which were related to cell wall structure and biogenesis, and virulence factor pathways. The remaining target genes (173 or 40%) were in the unique regulon, with gene functions that were largely unknown. Furthermore, deletion of the fur gene led to distinct phenotypes in growth, motility, antibiotic resistance, and siderophore production. These results provide a more complete understanding of how Fur regulates a set of target genes with surprising variation in closely related bacteria.
2023-08-04 | GSE150501 | GEO
Project description:Regulons for many transcription factors have been elucidated in model strains leading to an understanding of their role in producing physiological states. Comparative analysis of a regulon and its target genes between different strains of the same species is lacking. Ferric uptake regulator (Fur), involved in iron homeostasis, is one of the most conserved TFs, and is present in a wide range of bacteria. Using ChIP-exo experiments, we performed a comprehensive study of Fur binding sites in nine Escherichia coli strains with different lifestyles. 79 of the 431 target genes (18%) found belong to Fur’s core regulon, comprising genes involved in ion transport and metabolism, energy production and conversion, and amino acid metabolism and transport. 179 of the target genes (42%) comprise the accessory regulon, most of which were related to cell wall structure and biogenesis, and virulence factor pathways. The remaining target genes (173 or 40%) were in the unique regulon, with gene functions that were largely unknown. Furthermore, deletion of the fur gene led to distinct phenotypes in growth, motility, antibiotic resistance, and siderophore production. These results provide a more complete understanding of how Fur regulates a set of target genes with surprising variation in closely related bacteria.
2023-08-04 | GSE150240 | GEO
Project description:Here we dissected a regulatory network directed by the conserved iron homeostasis regulator, Ferric Uptake Regulator (Fur), in uropathogenic E. coli strain CFT073. Comparing anaerobic genome-scale Fur DNA binding, with Fur dependent transcript expression and protein levels of the uropathogen to that of commensal E. coli K-12 strain MG1655, showed that the Fur regulon of the core genome is conserved but also includes genes within the pathogenicity/genetic islands. Unexpectedly, regulons indicative of amino acid limitation and the general stress response were also indirectly activated in the uropathogen fur mutant, suggesting that induction of the Fur regulon increases amino acid demand. Using RpoS levels as a proxy, addition of amino acids mitigated the stress. In addition, iron chelation increased RpoS to the same levels as in the fur mutant. The increased amino acid demand of the fur mutant or iron chelated cells was exacerbated by aerobic conditions, which could be partly explained by the O 2 -dependent synthesis of the siderophore aerobactin, encoded within a pathogenicity island. Taken together, this data suggest in the iron-poor environment of the urinary tract, amino acid availability could play a role in the proliferation of this uropathogen, particularly if there is sufficient O 2 to produce aerobactin.
2020-05-27 | PXD017582 | Pride
Project description:Pathogenicity islands and plasmids encode genes for pathogenesis of various Escherichia coli pathotypes.Although there is a basic understanding of the contribution of these virulence factors to disease, less is known about variation in regulatory networks in determining disease phenotypes. Here we dissected aregulatory network directed by the conserved iron homeostasis regulator, Ferric Uptake Regulator (Fur), inuropathogenic E. coli strain CFT073. Comparing anaerobic genome-scale Fur DNA binding, with Fur dependent transcript expression and protein levels of the uropathogen to that of commensal E. coli K-12 strain MG1655, showed that the Fur regulon of the core genome is conserved but also includes genes within the pathogenicity/genetic islands. Unexpectedly, regulons indicative of amino acid limitation and the general stress response were also indirectly activated in the uropathogen fur mutant, suggesting that induction of the Fur regulon increases amino acid demand. Using RpoS levels as a proxy, addition of amino acids mitigated the stress. In addition, iron chelation increased RpoS to the same levels as in the fur mutant. The increased amino acid demand of the fur mutant or iron chelated cells was exacerbated by aerobic conditions, which could be partly explained by the O2-dependent synthesis of the siderophore aerobactin, encoded within a pathogenicity island. Taken together, this data suggest in the iron-poor environment of the urinary tract, amino acid availability could play a role in the proliferation of this uropathogen, particularly if there is sufficient O2 to produce aerobactin.
2020-03-10 | GSE145424 | GEO
Project description:As descirbed in the manuscript The impact of anaerobiosis on expression of the iron-responsive Fur and RyhB Regulons we performed a control ChIP-chip experiment in an E. coli strain lacking the transcription factor Fur to identify regions Fur-independent enrichment.
2015-12-01 | GSE74931 | GEO
Project description:Background: Based on 32 Escherichia coli and Shigella genome sequences, we have developed an E. coli pan-genome microarray. Publicly available genomes were annotated in a consistent manor to define all currently known genes potentially present in the species. The chip design was evaluated by hybridization of DNA from two sequenced E. coli strains, K-12 MG1655 (a commensal) and O157:H7 EDL933 (an enterotoxigenic E. coli). A dual channel and single channel analysis approach was compared for the comparative genomic hybridization experiments. Moreover, the microarray was used to characterize four unsequenced probiotic E. coli strains, currently marketed for beneficial effects on the human gut flora. Results: Based on the genomes included in this study, we were able to group together 2,041 genes that were present in all 32 genomes. Furthermore, we predict that the size of the E. coli core genome will approach ~1,560 essential genes, considerably less than previous estimates. Although any individual E. coli genome contains between 4,000 and 5,000 genes, we identified more than twice as many (11,872) distinct gene groups in the total gene pool (“pan-genome”) examined for microarray design. Benchmarking of the design based on sequenced control strain samples demonstrated a high sensitivity and relatively low false positive rate. Moreover, the array was highly sufficient to investigate the gene content of apathogenic isolates, despite the strong bias towards pathogenic E. coli strains that have been sequenced so far. Our analysis of four probiotic E. coli strains demonstrate that they share a gene pool very similar to the E. coli K-12 strains but also show significant similarity with enteropathogenic strains. Nonetheless, virulence genes were largely absent. Strain-specific genes found in probiotic E. coli but absent in E. coli K12 were most frequently phage-related genes, transposases and other genes related to mobile DNA, and metabolic enzymes or factors that may offer colonization fitness, which together with their asymptomatic nature may explain their nature. Conclusion: This high-density microarray provides an excellent tool for characterizing either DNA content or gene expression from unknown E. coli strains. Keywords: Comparative genomic hybridizations
2008-01-22 | GSE8595 | GEO
Project description:Porphyromonas gingivalis is a major pathogen associated with the microbial biofilm-mediated disease chronic periodontitis. P. gingivalis has an obligate requirement for iron and protoporphyrin IX which it satisfies by transporting heme and iron liberated from the human host. The level of cellular iron in P. gingivalis affects the expression of a distinct iron-associated regulon of 64 genes and low iron invokes an iron sparing response. Iron homeostasis is usually mediated in Gram-negative bacteria at the transcriptional level by the Ferric Uptake Regulator (Fur). There is a single predicted P. gingivalis Fur superfamily orthologue named Har (heme associated regulator) that lacks the conserved metal binding residues found in other Fur orthologues. We show that Har binds both heme and ferrous iron resulting in a conformational change in the protein. Har was unable to complement the Escherichia coli H1780 fur mutant and there was no change in cellular metal content in a P. gingivalis Har mutant compared with the wild-type. The Har regulon of 44 genes is not predicted to play a role in iron homeostasis. Together these data indicated that Har does not regulate iron homeostasis in P. gingivalis. However, Har was required for heme-responsive biofilm development and its regulon overlapped P. gingivalis regulons previously identified after growth in heme limitation or as a homotypic biofilm. P. gingivalis is unique as an iron-dependent Gram-negative bacterium with a single heme-binding Fur superfamily orthologue, Har, that does not regulate iron homeostasis.
2015-04-01 | GSE37099 | GEO
Project description:Archer2011 - Genome-scale metabolic model of
Escherichia coli (iCA1273)
This model is described in the article:
The genome sequence of E.
coli W (ATCC 9637): comparative genome analysis and an improved
genome-scale reconstruction of E. coli.
Archer CT, Kim JF, Jeong H, Park JH,
Vickers CE, Lee SY, Nielsen LK.
BMC Genomics 2011; 12: 9
Abstract:
BACKGROUND: Escherichia coli is a model prokaryote, an
important pathogen, and a key organism for industrial
biotechnology. E. coli W (ATCC 9637), one of four strains
designated as safe for laboratory purposes, has not been
sequenced. E. coli W is a fast-growing strain and is the only
safe strain that can utilize sucrose as a carbon source.
Lifecycle analysis has demonstrated that sucrose from sugarcane
is a preferred carbon source for industrial bioprocesses.
RESULTS: We have sequenced and annotated the genome of E. coli
W. The chromosome is 4,900,968 bp and encodes 4,764 ORFs. Two
plasmids, pRK1 (102,536 bp) and pRK2 (5,360 bp), are also
present. W has unique features relative to other sequenced
laboratory strains (K-12, B and Crooks): it has a larger genome
and belongs to phylogroup B1 rather than A. W also grows on a
much broader range of carbon sources than does K-12. A
genome-scale reconstruction was developed and validated in
order to interrogate metabolic properties. CONCLUSIONS: The
genome of W is more similar to commensal and pathogenic B1
strains than phylogroup A strains, and therefore has greater
utility for comparative analyses with these strains. W should
therefore be the strain of choice, or 'type strain' for group
B1 comparative analyses. The genome annotation and tools
created here are expected to allow further utilization and
development of E. coli W as an industrial organism for
sucrose-based bioprocesses. Refinements in our E. coli
metabolic reconstruction allow it to more accurately define E.
coli metabolism relative to previous models.
This model is hosted on
BioModels Database
and identified by:
MODEL1507180010.
To cite BioModels Database, please use:
BioModels Database:
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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.
2015-07-30 | MODEL1507180010 | BioModels
Project description:Background: Based on 32 Escherichia coli and Shigella genome sequences, we have developed an E. coli pan-genome microarray. Publicly available genomes were annotated in a consistent manor to define all currently known genes potentially present in the species. The chip design was evaluated by hybridization of DNA from two sequenced E. coli strains, K-12 MG1655 (a commensal) and O157:H7 EDL933 (an enterotoxigenic E. coli). A dual channel and single channel analysis approach was compared for the comparative genomic hybridization experiments. Moreover, the microarray was used to characterize four unsequenced probiotic E. coli strains, currently marketed for beneficial effects on the human gut flora. Results: Based on the genomes included in this study, we were able to group together 2,041 genes that were present in all 32 genomes. Furthermore, we predict that the size of the E. coli core genome will approach ~1,560 essential genes, considerably less than previous estimates. Although any individual E. coli genome contains between 4,000 and 5,000 genes, we identified more than twice as many (11,872) distinct gene groups in the total gene pool (âpan-genomeâ) examined for microarray design. Benchmarking of the design based on sequenced control strain samples demonstrated a high sensitivity and relatively low false positive rate. Moreover, the array was highly sufficient to investigate the gene content of apathogenic isolates, despite the strong bias towards pathogenic E. coli strains that have been sequenced so far. Our analysis of four probiotic E. coli strains demonstrate that they share a gene pool very similar to the E. coli K-12 strains but also show significant similarity with enteropathogenic strains. Nonetheless, virulence genes were largely absent. Strain-specific genes found in probiotic E. coli but absent in E. coli K12 were most frequently phage-related genes, transposases and other genes related to mobile DNA, and metabolic enzymes or factors that may offer colonization fitness, which together with their asymptomatic nature may explain their nature. Conclusion: This high-density microarray provides an excellent tool for characterizing either DNA content or gene expression from unknown E. coli strains. Factorial design: Each of four test samples (G 1/2, G3/10, G 4/9, G5) are co-hybridized with two control strain samples (K-12 MG1655 and O157:H7 EDL933). Additional replicate co-hybridizations are included of the two control strain samples (O157:H7 EDL933 vs. K-12 MG1655).
2010-05-26 | E-GEOD-8595 | biostudies-arrayexpress
Project description:To get a high resolution understanding of the effect of Fur on global gene expression, we compared by high-resolution RNAseq the transcriptomes of a wild-type E. coli K-12 strain and its Fur deletion derivative grown in minimal medium with or without supplementation of iron. Three independent total RNA extraction and RNAseq assays were performed for each strain in each condition.
2023-06-01 | GSE175957 | GEO