Adult bovine serum (10%) alters the expression of Pseudomonas aeruginosa genes
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ABSTRACT:
ORGANISM(S): Pseudomonas aeruginosa
PROVIDER: GSE30698 | GEO | 2012/07/09
SECONDARY ACCESSION(S): PRJNA144393
REPOSITORIES: GEO
Similar Datasets
Project description:As production of virulence factors by Pseudomonas aeruginosa is influenced by the host environment, we examined the effect of 10% adult bovine serum (ABS) on the global transcription with P. aeruginoas PAO1 at different phases of growth. At early exponential phase (4 h), serum significantly enhanced expression of 138 genes, most of which are repressed by iron and carry binding sequences for the ferric uptake regulator or the Fur-regulated extracytoplasmic function sigma factor PvdS. The expression of another 40 genes was reduced at 4h. However, the expression of only a few genes was significantly altered (reduced) at the early stationary phase of growth (8 h). Transcriptional fusion analyses confirmed serum enhances the expression of toxA, regA, and their regulatory genes regA and pvdS, yet does not interfere with the repression of these genes by iron. The P. aeruginosa strain PAO1 was grown in the iron-limited medium TSB-DC with or without 10% (v/v) ABS. The presence of 10% ABS reduced PAO1 growth, but despite this reduction, the cultures reached early exponential phase at 4 h and early stationary phase at 8 h in both media. Accordingly, we determined the PAO1 transcriptome in both media at these two specific time points. To standardize the comprison, we adjusted the cultures to the same optical density at 600 nm (biomass) by diluting with fresh TSB-DC PAO1 grown in TSB-DC to the same OD as PAO1 grown in TSB-DC/ABS. We obtained the transcriptome profile of 5,552 genes representing the complete P. aeruginosa PAO1 genome.
2012-07-08 | E-GEOD-30698 | biostudies-arrayexpress
Project description:In Neisseria gonorrhoeae, Fur (ferric uptake regulator) protein regulates iron homeostasis gene expression through binding to conserved sequences in promoters of iron-responsive genes. We have expanded the gonococcal Fur regulon using a custom microarray to monitor iron-responsive gene expression throughout the growth curve combined with a genome-wide in silico analysis to predict Fur boxes (FB), and in vivo FuRTA assays to detect genes able to bind Fur. Keywords: time course: (1hr ,2hr, 3hr, 4hr)
2010-01-01 | GSE16352 | GEO
Project description:The gene PA2384 in Pseudomonas aeruginosa PAO1, annotated originally as unknown function, has been previously shown to be dramatically responsive to iron limitation. In the present study, PA2384 is shown by bioinformatics analysis to have a weak similarity to the N-termini DNA binding domain of fur, a well-known ferric uptake regulator. To experimentally investigate the function of PA2384 P. aeruginosa PAO1 recombinant (pUCP20::PA2384) overexpressing PA2384 and PA2384 knock-out mutant PAO1-23844 are constructed and studied. Physiological characterization in a carefully controlled cultivation system shows that the knockout strain needed a longer lag phase to grow and exhibited a significantly reduced production speed of siderophore (pyoverdine and pyochelin) in the stationary phase. Genome-scale transcriptional profiles at different growth stages are compared between the wild type and ∆PA2384 mutant grown under iron-limiting conditions. The expression of more than 350 genes is affected. Among them, seventy-one genes involved in iron uptake are significantly induced by PA2384. 102 quorum sensing (QS) dependent genes exhibited differential transcription. They include genes related to the biosynthesis of some important virulence factors such as pyocyanin, rhamnolipids and hydrogen cyanide. Transcription of genes responsible for the synthesis of Pseudomonas Quinolone Signal (PQS) is greatly advanced by the knockout of PA2384. We postulate that PA2384 affects QS via PQS. Furthermore, the knockout of PA2384 also results in altered expression of genes involved in electron transfer, central metabolism, phosphorus starvation and translation. It implies that PA2384 may affect more basic physiology than only respond to iron uptake and is a versatile global regulator in P. aeruginosa under iron starvation. Keywords: iron starvation, quorum sensing, time course
2005-09-07 | GSE2885 | GEO
Project description:The gene PA2384 in Pseudomonas aeruginosa PAO1, annotated originally as unknown function, has been previously shown to be dramatically responsive to iron limitation. In the present study, PA2384 is shown by bioinformatics analysis to have a weak similarity to the N-termini DNA binding domain of fur, a well-known ferric uptake regulator. To experimentally investigate the function of PA2384 P. aeruginosa PAO1 recombinant (pUCP20::PA2384) overexpressing PA2384 and PA2384 knock-out mutant PAO1-23844 are constructed and studied. Physiological characterization in a carefully controlled cultivation system shows that the knockout strain needed a longer lag phase to grow and exhibited a significantly reduced production speed of siderophore (pyoverdine and pyochelin) in the stationary phase. Genome-scale transcriptional profiles at different growth stages are compared between the wild type and âPA2384 mutant grown under iron-limiting conditions. The expression of more than 350 genes is affected. Among them, seventy-one genes involved in iron uptake are significantly induced by PA2384. 102 quorum sensing (QS) dependent genes exhibited differential transcription. They include genes related to the biosynthesis of some important virulence factors such as pyocyanin, rhamnolipids and hydrogen cyanide. Transcription of genes responsible for the synthesis of Pseudomonas Quinolone Signal (PQS) is greatly advanced by the knockout of PA2384. We postulate that PA2384 affects QS via PQS. Furthermore, the knockout of PA2384 also results in altered expression of genes involved in electron transfer, central metabolism, phosphorus starvation and translation. It implies that PA2384 may affect more basic physiology than only respond to iron uptake and is a versatile global regulator in P. aeruginosa under iron starvation. Experiment Overall Design: mutant and wilde type biological replicates were analyzed at 3 timepoints
2007-09-21 | E-GEOD-2885 | biostudies-arrayexpress
Project description:Bacterial cells often modulate their transcriptional profiles in response to the changes in iron availability. Ferric uptake regulator (Fur), as a global iron biosensor, plays a central role in maintaining iron homeostasis in Bacillus subtilis. Here we utilized a high affinity Fe2+ efflux transporter, Listeria monocytogenes FrvA, as an inducible genetic tool to deplete intracellular iron. We then characterized the responses of the Fur, FsrA, and PerR regulons as cells transition from iron sufficiency to deficiency. Our results indicate that the Fur regulon is derepressed in three distinct waves. First, elemental iron uptake (ywbLMN), ferric citrate uptake (ymfCDEF-yhfQ), and petrobactin uptake (yclNOPQ) systems are induced to prevent iron deficiency. Second, B. subtilis synthesizes its own siderophore bacillibactin (dhbACEBF) and turns on bacillibactin uptake (feuABC-yusV) along with flavodoxin (ykuNOP) and hydroxamate siderophore uptake (fhuBCGD-yxeB) to scavenge iron from the environment. Third, as iron levels decline further, an iron sparing response (fsrA, fbpAB, and fbpC) is induced to block the translation of nonessential iron-using proteins and permit only essential iron-dependent enzymes to utilize the limited iron. ChIP experiments demonstrate that in vivo occupancy of Fur correlates with derepression of each operon, and the graded response observed here results, at least in part, from higher affinity binding of Fur to the late induced genes. These results provide insights into the distinct roles of Fur-regulated target genes as intracellular iron levels decline.
2017-06-30 | GSE100668 | GEO
Project description:Iron is required by almost all bacteria but concentrations of iron above the physiological levels are toxic. In bacteria, intracellular iron is regulated mostly by ferric uptake regulator, Fur or a similar functional protein. Iron limitation results in regulation of number of genes, including those involved in iron uptake process. A subset of the genes under the control of Fur is called Fur regulon. In this study we have identified the Fur- and iron- regulated genes in Listeria monocytogenes by DNA microarray analysis using fur mutant and its isogenic parent. In order to identify genes exclusively regulated in response to iron limitation, fur mutant and its isogenic parent grown in iron-deficient KRM media were compared. Similarly, to identify Fur regulated genes, fur mutant was compared with the parent under iron-deficient and excess-iron conditions. Listeria in low-iron resulted in up-regulation of 180 and down-regulation of 200 genes whereas in the fur mutant, 79 genes were up-regulated and 49 genes down-regulated. Our studies have identified at least 12 genes that are negatively controlled by Fur. In iron-deficient condition, these genes were up-regulated, while expression of fur was down-regulated. To further investigate the fur regulation, the fur promoter-lacZ transcriptional fusion strains were constructed in fur and perR mutant background. In the perR mutant, the regulation of fur, svpA, and feoB was inhibited in the iron-limited conditions. Our results indicate that fur is negatively regulated by Fur and PerR. Furthermore, these results demonstrate that regulation of some of the genes in iron-limited conditions require PerR.
2008-12-25 | GSE12735 | GEO
Project description:The ferric uptake regulator (Fur) plays a critical role in the transcriptional regulation of iron metabolism in many bacteria. However, the full regulatory potential of Fur beyond iron metabolism remains undefined. Here, we comprehensively reconstructed the Fur transcriptional regulatory network in Escherichia coli K-12 MG1655 in response to iron availability using genome-wide measurements (ChIP-exo and RNA-seq). Polyomic data analysis revealed that a total of 81 genes in 42 transcription units (TUs) are directly regulated by three different modes of Fur regulation, including apo- and holo-Fur activation as well as holo-Fur repression. We showed that Fur connects iron transport and utilization enzymes with negative-feedback loop pairs for iron homeostasis. In addition, direct involvement of Fur in the regulation of DNA synthesis, energy metabolism, and biofilm development was found. These results indicate that Fur exhibits a comprehensive regulatory role affecting many fundamental cellular processes linked to iron metabolism in order to coordinate E. coli responses to the availability of iron.
2014-09-09 | GSE54899 | GEO
Project description:The ferric uptake regulator (Fur) plays a critical role in the transcriptional regulation of iron metabolism in many bacteria. However, the full regulatory potential of Fur beyond iron metabolism remains undefined. Here, we comprehensively reconstructed the Fur transcriptional regulatory network in Escherichia coli K-12 MG1655 in response to iron availability using genome-wide measurements (ChIP-exo and RNA-seq). Polyomic data analysis revealed that a total of 81 genes in 42 transcription units (TUs) are directly regulated by three different modes of Fur regulation, including apo- and holo-Fur activation as well as holo-Fur repression. We showed that Fur connects iron transport and utilization enzymes with negative-feedback loop pairs for iron homeostasis. In addition, direct involvement of Fur in the regulation of DNA synthesis, energy metabolism, and biofilm development was found. These results indicate that Fur exhibits a comprehensive regulatory role affecting many fundamental cellular processes linked to iron metabolism in order to coordinate E. coli responses to the availability of iron.
2014-09-09 | GSE54900 | GEO
Project description:Transcriptome analysis of NTHi 86-028NPrpsL, NTHi 86-028NPrpsL∆fur, and NTHi 86-028NPrpsL∆fur(pT-fur) strains Nontypeable Haemophilus influenzae (NTHi) is a commensal microorganism of the normal human nasopharyngeal flora, yet also an opportunistic pathogen of the upper and lower respiratory tracts. Changes in gene expression patterns in response to host microenvironments are likely critical for survival. One such system of gene regulation is the ability to carefully regulate iron uptake. A central regulatory system that controls iron uptake, mediated by the ferric uptake regulator Fur, is present in multiple bacteria, including NTHi. To understand the regulation of iron homeostasis in NTHi, fur was deleted in the NTHi strain 86-028NPrpsL. Using RNA-Seq, we identified both protein-encoding and small RNA genes whose expression was repressed or activated by Fur. Overall design: These data comprise transcriptional anaylses of an rpsL mutant of 86-028NP, an isogenic fur mutant of 86-028NPrpsL and a complemented fur mutant strain. All strains were grown in defined medium containing 10 µg/ml human hemoglobin to mid-log phase. Cells were then harvested and RNA extracted. A total of three biological replicates were generated for these analyses.
2015-07-01 | GSE58890 | GEO
Project description:Ferric uptake regulator (Fur) is the major regulator of iron acquisition in Escherichia coli and other bacteria. In the present study, the role of Fur in anaerobic S. enterica serovar Typhimurium was determined by transcriptome analysis, reporter assays, and enzymatic assays. In anaerobic Δfur, 298 genes were differentially expressed. In general, Fur repressed genes required for iron acquisition/storage, metabolism, electron transport, oxidative/nitrosative stress, and modulators of virulence. There were 73 genes whose expression required Fur, eleven of which contain a putative Fur box 5‟ of the gene. Transcription of sodA was >9-fold higher in Δfur but there was no corresponding increase in the activity of SodA.
2011-10-14 | GSE18441 | GEO