GEO DataSets

(Submitter supplied) This study examined the genes under the control of sigma32 in E. coli by moderate induction of a plasmid-borne rpoH gene under defined steady-state growth condition. Samples were taken from culture at mid log phase (OD=0.2) before or 5 minutes, 10 minutes or 15 minutes after induction. Samples were then RNA-stabilized using Qiagen RNAProtect Bacterial Reagent (Qiagen). Total RNA was then isolated using MasterPure kits (Epicentre Technologies). more...

Organism:

Escherichia coli; Escherichia coli K-12

Type:

Expression profiling by array

Platform:

GPL199

8 Samples

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(Submitter supplied) DNA microarray analysis of genes regulated by the alternative sigma factor, sigma 32 (rpoH). Sigma 32-dependent genes were initially identified by comparing a wild type (wt) E. coli K-12 strain that has a low level of sigma 32, with a strain over-expressing sigma 32 (following induction of rpoH from an inducible promoter by IPTG). We monitored changes in gene expression in 4 separate time-courses. Because sigma 32 is negatively regulated, its activity decreases 10 min after overexpression. more...

Organism:

Escherichia coli

Type:

Expression profiling by array

Dataset:

GDS1804

Platform:

GPL3500

16 Samples

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Expression profiling of cells at various time points up to 10 minutes following induction by IPTG of alternative sigma factor, sigma32, from an inducible promoter. Sigma32 mediates the heat shock response. Results identify genes regulated by sigma32.

Organism:

Escherichia coli

Type:

Expression profiling by array, log2 ratio, 2 agent, 5 time sets

Platform:

GPL3500

Series:

GSE4321

16 Samples

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(Submitter supplied) This study examined the genes under the control of FlhDC and sigmaF in E. coli. Keywords: wild-type, deletion and overexepression strains

Organism:

Escherichia coli; Escherichia coli K-12

Type:

Expression profiling by array

Platform:

GPL199

15 Samples

Download data

(Submitter supplied) Vibrio cholerae, the cause of cholera, can grow in a variety of environments outside of human hosts. During infection, the pathogen must adapt to significant environmental alterations, including the elevated temperature of the human gastrointestinal tract. σ32, an alternative sigma factor encoded by rpoH, activates transcription of genes involved in the heat-shock response in several bacterial species. more...

Organism:

Vibrio cholerae; Vibrio cholerae O1 biovar El Tor str. N16961

Type:

Expression profiling by array

Platform:

GPL3651

6 Samples

Download data: TXT

(Submitter supplied) The bacterial heat-shock response is regulated by the alternative sigma factor sigma 32 (RpoH), which responds to misfolded protein stress and directs the RNA polymerase to the promoterss for genes required for protein refolding or degradation. In P. aeruginosa, RpoH is essential for viability under laboratory growth conditions. Here, we used a transcriptomics approach to identify the genes of the RpoH regulon, including RpoH-regulated genes that are essential for P. more...

Organism:

Pseudomonas aeruginosa

Type:

Expression profiling by array

Platform:

GPL84

6 Samples

Download data: CEL

(Submitter supplied) Sinorhizobium meliloti can live as a soil saprophyte, and can engage 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 two putative RpoH (heat shock) sigmas. more...

Organism:

Sinorhizobium meliloti; Medicago truncatula

Type:

Expression profiling by array

Platform:

GPL9757

27 Samples

Download data: CEL

(Submitter supplied) This SuperSeries is composed of the SubSeries listed below.

Organism:

Cereibacter sphaeroides 2.4.1

Type:

Genome binding/occupancy profiling by genome tiling array; Expression profiling by array

Platforms:

GPL162 GPL10463

21 Samples

Download data: CEL, PAIR

(Submitter supplied) In this study, we performed expression profiling experiments to determine the respective regulons of RpoHI and RpoHII in Rhodobacter sphaeroides. We grew R. sphaeroides in aerobic conditions and induced either proteins ectopically and compared the global gene expression profiles.

Organism:

Cereibacter sphaeroides 2.4.1

Type:

Expression profiling by array

Platform:

GPL162

15 Samples

Download data: CEL

(Submitter supplied) In this study, we performed a ChIP-chip experiment to determine the respective regulons of RpoHI and RpoHII in Rhodobacter sphaeroides. We grew R. sphaeroides in aerobic conditions and induced either proteins ectopically and immuno-precipitated the regions of the genomic DNA interacting with the sigma factors.

Organism:

Cereibacter sphaeroides 2.4.1

Type:

Genome binding/occupancy profiling by genome tiling array

Platform:

GPL10463

6 Samples

Download data: PAIR

(Submitter supplied) The alternative sigma factor sigmaB has an important role in the acquisition of stress-resistance in many gram-positive bacteria. In the foodborne pathogen Bacillus cereus sigmaB is activated strongly upon a heat shock and other stress conditions. Here we describe the identification of the set of sigmaB-regulated genes in B. cereus by DNA microarray analysis of the transcriptome upon a mild heat shock. more...

Organism:

Bacillus cereus ATCC 14579

Type:

Expression profiling by array

Platform:

GPL4406

7 Samples

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(Submitter supplied) In previously published work, we identified three Mycobacterium tuberculosis sigma (s) factor genes responding to heat shock (sigB, sigE and sigH ). Two of them (sigB and sigE ) also responded to SDS exposure. As these responses to stress suggested that the s factors encoded by these genes could be involved in pathogenicity, we are studying their role in physiology and virulence. In this work, we characterize a sigE mutant of M. more...

Organism:

Mycobacterium tuberculosis

Type:

Expression profiling by array

Platform:

GPL2787

15 Samples

Download data: TXT

(Submitter supplied) Inorganic polyphosphate (polyP) is synthesized by bacteria in response to various stresses, but the mechanism of its regulation is unknown. Mutants of Escherichia coli lacking the RNA polymerase-binding transcription factor dksA are defective in polyP synthesis after a nutrient limitation stress, and this defect is reversed in a dksA greA mutant. In this work, we used RNA sequencing to compare transcription in wild-type, dksA, and dksA greA strains of E. more...

Organism:

Escherichia coli

Type:

Expression profiling by high throughput sequencing

Platform:

GPL21222

6 Samples

Download data: TXT

(Submitter supplied) In Gram-positive organisms the general stress response is regulated by the alternative sigma factor sigma B (σB). In C. difficile this sigma factor has been implicated in protection against stressors such as reactive oxygen species and antimicrobial compounds. Here, we show that an anti-σB antibody can be used to demonstrate overexpression of σB in C. difficile and that this overexpression is tolerated for short periods of time, despite its toxicity. more...

Organism:

Clostridioides difficile 630

Type:

Expression profiling by array

Platform:

GPL25054

16 Samples

Download data: TXT, XLS

(Submitter supplied) Wild-type E. coli are prototrophic for all amino acid and nucleotides. These are synthesized by a network of interconnected metabolic pathways from a handful precursors molecules, which are regulated at the level of gene expression. It was hypothesized in this study, that since metabolic pathways are interconnected, transcriptional regulation should be shared across multiple pathways. To uncover these regulatory interactions, cells growing at steady state were perturbed by the addition of an end-metabolite (aa or nt), and were allowed to recover. more...

Organism:

Escherichia coli str. K-12 substr. MG1655; Escherichia coli

Type:

Expression profiling by array

Platform:

GPL3503

22 Samples

Download data: GPR

(Submitter supplied) DNA microarray analysis of genes regulated by the alternative sigma factor, sigma E (rpoE). Sigma E-dependent genes were initially identified by comparing a wild type (wt) E. coli K-12 strain that has a low level of sigma E, with a strain over-expressing sigma E (following induction of rpoE from an inducible promoter by IPTG). We monitored changes in gene expression in 4 separate time-courses after induction and used SAM (Statistical Analysis of Microarrays) to identify 75 significantly induced and 8 significantly repressed genes. more...

Organism:

Escherichia coli

Type:

Expression profiling by array

Platforms:

GPL2928 GPL2926 GPL2927

21 Samples

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(Submitter supplied) We probed the mechanism of cross-regulation of osmotic and heat stress responses by characterizing the effects of high osmolarity (0.3M vs. 0.0M NaCl) and temperature (43oC vs. 30oC) on the transcriptome of Escherichia coli K12 using E. coli Genome 2 Array (Affymetrix, Inc.). Independent array hybridizations were carried out for 3 biological replicates (independent cultures). Total RNA was extracted using a hot phenol-chloroform method. more...

Organism:

Escherichia coli

Type:

Expression profiling by array

Platform:

GPL3154

18 Samples

Download data: CEL, CHP

(Submitter supplied) The physiological role of the various nucleoid-associated proteins in bacteria and HU in particular has been addressed in a number of studies but remains so far not fully understood. In this work, a genome-wide microarray hybridization approach, combined with in vivo genetic experimentation, has been performed in order to compare and evaluate the effect of HUalpha, HUbeta and HUalphabeta on the transcription of the Escherichia coli K12 genes as a function of growth phase. more...

Organism:

Escherichia coli; Escherichia coli K-12

Type:

Expression profiling by array

Platform:

GPL199

26 Samples

Download data: CEL, EXP

(Submitter supplied) Genetically programmed deaths play important roles in the biology of unicellular prokaryotic cells. Some gene complexes force their maintenance on the host bacterial cells by killing cells that have lost them. This form of programmed death called post-segregational killing or genetic addiction is brought about by several Type II restriction-modification gene complexes, through restriction attack on the undermethylated chromosome, and underlie their behavior as selfish mobile elements. more...

Organism:

Escherichia coli; Escherichia coli K-12

Type:

Expression profiling by array

Platform:

GPL199

24 Samples

Download data: CEL

(Submitter supplied) We applied a ChIP-chip approach to elucidate the binding profiles of sigma factors (RpH, RpoN and RpoS) experimentally under different growth conditions. This technique localizes DNA fragments within DNA-protein complexes enriched by chromatin immunoprecipitation using high-density oligonucleotide tilling arrays.

Organism:

Geobacter sulfurreducens PCA

Type:

Expression profiling by genome tiling array

Platform:

GPL9112

10 Samples

Download data: PAIR