Characterization of transcriptional and fitness effects of a loss of function mutation in rho
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ABSTRACT:
ORGANISM(S): Escherichia coli Escherichia coli str. K-12 substr. MG1655
PROVIDER: GSE32022 | GEO | 2012/06/01
SECONDARY ACCESSION(S): PRJNA147515
REPOSITORIES: GEO
Similar Datasets
Project description:In order to study the effects of a mutation to the transcriptional termination regulator Rho (referred to as rho*), we made use of expression microarrays to observe the direct and indirect effects of rho* on gene expression. In addition, we used arrays to map the fitness of strains from transposon mutagenized libraries under four conditions, showing that in each case the majority of genes with significant fitness effects were dependent on the genotype at rho. For expression arrays, we performed two-color microarrays comparing transcript levels in rho* and wild type cells during exponential growth in glucose minimal media. For selection experiments, transposon insertions were mapped through selective amplification of genomic regions adjacent to them. We then measured the fitness effects of insertions throughout the genome using two-color microarrays, comparing amplified DNA from a population grown under a selective condition of interest to an isogenic control population grown under a reference condition (glucose minimal media). All arrays were performed in duplicate, and the source material for the duplicates came from separate biological replicates.
2012-05-31 | E-GEOD-32022 | biostudies-arrayexpress
Project description:Transcription termination factor Rho is essential in enterobacteria. We inhibited Rho activity with bicyclomycin and used microarray experiments to assess Rho function on a genome-wide scale. Rho is a global regulator of gene expression that matches E. coli transcription to translational needs. Remarkably, genes that are most repressed by Rho are prophages and other horizontally-acquired portions of the genome. Elimination of these foreign DNA elements increases resistance to bicyclomycin. Although rho remains essential, such reduced-genome bacteria no longer require Rho cofactors NusA and NusG. Thus, Rho termination, supported by NusA and NusG, is required to suppress the toxic activity of foreign DNA. Global regulation of transcription termination by Rho, NusA, and NusG. Experiment Overall Design: Two sets of experiments are presented. First, treatment of E. coli with Rho inhibitor bicyclomycin was performed in strains MG1655 and O157:H7 EDL933 for twenty minutes at concentrations of 10, 25, or 100 micrograms/milliliter. In the second set of experiments the reduced-genome strain MDS42 was treated with bicyclomycin as well as having deletions of the genes nusA and nusG. Total RNA was extracted and hybridized to the Affymetrix E. coli Genome 2.0 array, which contains complete genome coverage of four strains of E. coli.
2008-06-20 | E-GEOD-10345 | biostudies-arrayexpress
Project description:In this work we conducted Term-seq on Wild Type B. subtilis, and strains compromosing all logical mutations in all combinations of the genes that encode for NusA, NusG, and Rho, where we developed the first transcription termination atlas. We used this atlas to find that Rho can stimulate intrinsic termination in B. subtilis and we recapitulated this finding in vitro to dissect the mechanism.
2022-08-11 | GSE188366 | GEO
Project description:Despite the prevalence of antisense transcripts in bacterial transcriptomes, little is known about how their synthesis is controlled. We report that a major function of the Escherichia coli termination factor Rho and its co-factor NusG is suppression of ubiquitous antisense transcription genome-wide. Rho binds C-rich unstructured nascent RNA (high C/G ratio) prior to its ATP-dependent dissociation of transcription complexes. NusG is required for efficient termination at minority subsets (~20%) of both antisense and sense Rho-dependent terminators with lower C/G ratio sequences. In contrast, a widely studied nusA deletion proposed to compromise Rho-dependent termination had no effect on antisense or sense Rho-dependent terminators in vivo. Global co-localization of the nucleoid-associated protein H-NS with Rho-dependent terminators and genetic interactions between hns and rho suggest that H-NS aids Rho in suppression of antisense transcription. The combined actions of Rho, NusG, and H-NS appear to be analogous to the Sen1-Nrd1-Nab3 and nucleosome systems that suppress antisense transcription in eukaryotes. RNA-seq experiments were performed on ribosome-depleted RNA from cells treated with 20 ug/ml bicyclomycin or untreated cells. The series contains 4 datasets.
2012-11-01 | E-GEOD-41939 | biostudies-arrayexpress
Project description:This analysis is part of the study GSE27219, The condition-dependent transcriptome of Bacillus subtilis 168. In this study, 120 transcription units where identified for which transcription did not terminate at any specific site, leading to mRNA extension over long distances with slowly decreasing signal intensity. In most cases, lack of termination and read-through generated antisense transcripts. These findings together with the lack of intrinsic terminators suggested that transcription termination of the 120 transcription units could be mediated by the transcription termination factor Rho. In order to investigate the impact of Rho-mediated termination, tiling array hybridizations using RNA samples of a B. subtilis rho-null mutant and its parental strain were performed. B. subtilis 1012 wild-type and rho-mutant cells were grown in LB medium. Samples for tiling array analysis were taken during exponential growth phase. Hybridizations were performed in triplicate using RNA isolated from independent cultures.
2012-03-07 | E-GEOD-27303 | biostudies-arrayexpress
Project description:Despite the prevalence of antisense transcripts in bacterial transcriptomes, little is known about how their synthesis is controlled. We report that a major function of the Escherichia coli termination factor Rho and its co-factor NusG is suppression of ubiquitous antisense transcription genome-wide. Rho binds C-rich unstructured nascent RNA (high C/G ratio) prior to its ATP-dependent dissociation of transcription complexes. NusG is required for efficient termination at minority subsets (~20%) of both antisense and sense Rho-dependent terminators with lower C/G ratio sequences. In contrast, a widely studied nusA deletion proposed to compromise Rho-dependent termination had no effect on antisense or sense Rho-dependent terminators in vivo. Global co-localization of the nucleoid-associated protein H-NS with Rho-dependent terminators and genetic interactions between hns and rho suggest that H-NS aids Rho in suppression of antisense transcription. The combined actions of Rho, NusG, and H-NS appear to be analogous to the Sen1-Nrd1-Nab3 and nucleosome systems that suppress antisense transcription in eukaryotes. Tiling expression microarray experiments were performed in cells treated with 20 ug/ml bicyclomycin or cells deleted for nusG, or a partial deletion of nusA. Labeled cDNAs were hybridized to an E. coli K-12 MG1655 tiling array with overlapping probes at ~12bp spacing across the entire genome. The series contains 14 datasets.
2012-11-01 | E-GEOD-41938 | biostudies-arrayexpress
Project description:Despite the prevalence of antisense transcripts in bacterial transcriptomes, little is known about how their synthesis is controlled. We report that a major function of the Escherichia coli termination factor Rho and its co-factor NusG is suppression of ubiquitous antisense transcription genome-wide. Rho binds C-rich unstructured nascent RNA (high C/G ratio) prior to its ATP-dependent dissociation of transcription complexes. NusG is required for efficient termination at minority subsets (~20%) of both antisense and sense Rho-dependent terminators with lower C/G ratio sequences. In contrast, a widely studied nusA deletion proposed to compromise Rho-dependent termination had no effect on antisense or sense Rho-dependent terminators in vivo. Global co-localization of the nucleoid-associated protein H-NS with Rho-dependent terminators and genetic interactions between hns and rho suggest that H-NS aids Rho in suppression of antisense transcription. The combined actions of Rho, NusG, and H-NS appear to be analogous to the Sen1-Nrd1-Nab3 and nucleosome systems that suppress antisense transcription in eukaryotes.
2012-11-01 | GSE41939 | GEO
Project description:Despite the prevalence of antisense transcripts in bacterial transcriptomes, little is known about how their synthesis is controlled. We report that a major function of the Escherichia coli termination factor Rho and its co-factor NusG is suppression of ubiquitous antisense transcription genome-wide. Rho binds C-rich unstructured nascent RNA (high C/G ratio) prior to its ATP-dependent dissociation of transcription complexes. NusG is required for efficient termination at minority subsets (~20%) of both antisense and sense Rho-dependent terminators with lower C/G ratio sequences. In contrast, a widely studied nusA deletion proposed to compromise Rho-dependent termination had no effect on antisense or sense Rho-dependent terminators in vivo. Global co-localization of the nucleoid-associated protein H-NS with Rho-dependent terminators and genetic interactions between hns and rho suggest that H-NS aids Rho in suppression of antisense transcription. The combined actions of Rho, NusG, and H-NS appear to be analogous to the Sen1-Nrd1-Nab3 and nucleosome systems that suppress antisense transcription in eukaryotes.
2012-11-01 | GSE41938 | GEO
Project description:Despite the prevalence of antisense transcripts in bacterial transcriptomes, little is known about how their synthesis is controlled. We report that a major function of the Escherichia coli termination factor Rho and its co-factor NusG is suppression of ubiquitous antisense transcription genome-wide. Rho binds C-rich unstructured nascent RNA (high C/G ratio) prior to its ATP-dependent dissociation of transcription complexes. NusG is required for efficient termination at minority subsets (~20%) of both antisense and sense Rho-dependent terminators with lower C/G ratio sequences. In contrast, a widely studied nusA deletion proposed to compromise Rho-dependent termination had no effect on antisense or sense Rho-dependent terminators in vivo. Global co-localization of the nucleoid-associated protein H-NS with Rho-dependent terminators and genetic interactions between hns and rho suggest that H-NS aids Rho in suppression of antisense transcription. The combined actions of Rho, NusG, and H-NS appear to be analogous to the Sen1-Nrd1-Nab3 and nucleosome systems that suppress antisense transcription in eukaryotes.
2012-11-01 | GSE41936 | GEO
Project description:Rho dependent transcription termination is a dominant mechanism of transcription termination in Mycobacterium tuberculosis
2017-08-01 | GSE97559 | GEO