Condensin mediates the chromosomal clustering of highly transcribed genes in bacteria
Ontology highlight
ABSTRACT:
ORGANISM(S): Escherichia coli
PROVIDER: GSE69250 | GEO | 2015/05/29
SECONDARY ACCESSION(S): PRJNA285205
REPOSITORIES: GEO
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Project description:Mutations in the rifampicin (Rif)-binding site of RNA polymerase (RNAP) impart antibiotic resistance and inextricably affect transcription initiation, elongation, and termination properties as well. At each step of the transcription cycle, RNAP responds to non-essential transcription factors, signaling molecules, and substrate availability. As such, the non- essential genome and its impact on fitness cost potentially represent an untapped resource for new combination therapies. Using transposon sequencing (Tn-seq), we present a genome- wide analysis of resistance cost in a clinically common rpoB H526Y mutant. Our data show that cost-compounding genes include factors that promote high transcription elongation rate, whereas cost-mitigating genes function in cell wall synthesis and division. We demonstrate that cell wall synthesis and division defects in rpoB H526Y are a consequence of an abnormally high transcription elongation rate, which is further exacerbated by superfluous activity of the uracil salvage pathway and indifference of the mutant RNAP to alarmone ppGpp. Leveraging on this knowledge, we identified drugs that are highly potent against rpoB H526Y and other RifR alleles from the same phenotypic class. Thus, genome-wide analysis of fitness cost of antibiotic resistant mutants should expedite discovery of new combination therapies and delineate cellular pathways that underlie molecular mechanisms of cost.
2021-11-25 | PXD027810 | Pride
Project description:HupA is a nucleoid associated protein, homologic to E. coli HU protein. Its binding is affected by DNA supercoiling. ChIP-seq experiment goal was to analyze changing of HupA binding in the strain with depleted levels of TopA (high supercoling) vs strain with normal level of TopA.
2022-12-01 | E-MTAB-11369 | biostudies-arrayexpress
Project description:We studied the response to increased DNA-supercoiling in Streptococcus pneumoniae by using seconeolitsine (SCN), a DNA topoisomerase I inhibitor. A homeostatic transcriptional response allowing recovering of supercoiling density was observed in cells treated with subinhibitory SCN concentrations. Supercoiling increases up to 40.7% (6 µM SCN) and 72.9% (8 µM SCN) were reverted to 8.5% and 44.1%, respectively. Likewise, recovery of viability and DNA-supercoiling were observed when cells were treated with those SCN concentrations and the drug was removed. The main DNA topoisomerase gene affected was topA, whose transcription depended on the supercoiling level. A two stage global transcriptomic response with 8 µM seconeolitsine was detected. The early stage (5 and 15 min, 10% of the genome) represented a response induced by increased supercoiling. The second stage represented supercoiling recovery (30 min, 2.0% of the genome). Almost 25% of the early responsive genes formed clusters with coordinated transcriptional regulation. Twelve clusters were evident, with sizes of 6.7 to 31.4 Kb (9 to 22 responsive genes). Strikingly, clusters did not contradict those observed under DNA relaxation, suggesting that bacteria manage supercoiling stress using overlapping responses. This is the first study describing a global transcriptomic response triggered by an increase in DNA supercoiling in bacteria.
2016-07-07 | GSE77748 | GEO
Project description:We studied the response to increased DNA-supercoiling in Streptococcus pneumoniae by using seconeolitsine (SCN), a DNA topoisomerase I inhibitor. A homeostatic transcriptional response allowing recovering of supercoiling density was observed in cells treated with subinhibitory SCN concentrations. Supercoiling increases up to 40.7% (6 µM SCN) and 72.9% (8 µM SCN) were reverted to 8.5% and 44.1%, respectively. Likewise, recovery of viability and DNA-supercoiling were observed when cells were treated with those SCN concentrations and the drug was removed. The main DNA topoisomerase gene affected was topA, whose transcription depended on the supercoiling level. A two stage global transcriptomic response with 8 µM seconeolitsine was detected. The early stage (5 and 15 min, 10% of the genome) represented a response induced by increased supercoiling. The second stage represented supercoiling recovery (30 min, 2.0% of the genome). Almost 25% of the early responsive genes formed clusters with coordinated transcriptional regulation. Twelve clusters were evident, with sizes of 6.7 to 31.4 Kb (9 to 22 responsive genes). Strikingly, clusters did not contradict those observed under DNA relaxation, suggesting that bacteria manage supercoiling stress using overlapping responses. This is the first study describing a global transcriptomic response triggered by an increase in DNA supercoiling in bacteria.
2016-07-07 | GSE77587 | GEO
Project description:We studied the response to increased DNA-supercoiling in Streptococcus pneumoniae by using seconeolitsine (SCN), a DNA topoisomerase I inhibitor. A homeostatic transcriptional response allowing recovering of supercoiling density was observed in cells treated with subinhibitory SCN concentrations. Supercoiling increases up to 40.7% (6 µM SCN) and 72.9% (8 µM SCN) were reverted to 8.5% and 44.1%, respectively. Likewise, recovery of viability and DNA-supercoiling were observed when cells were treated with those SCN concentrations and the drug was removed. The main DNA topoisomerase gene affected was topA, whose transcription depended on the supercoiling level. A two stage global transcriptomic response with 8 µM seconeolitsine was detected. The early stage (5 and 15 min, 10% of the genome) represented a response induced by increased supercoiling. The second stage represented supercoiling recovery (30 min, 2.0% of the genome). Almost 25% of the early responsive genes formed clusters with coordinated transcriptional regulation. Twelve clusters were evident, with sizes of 6.7 to 31.4 Kb (9 to 22 responsive genes). Strikingly, clusters did not contradict those observed under DNA relaxation, suggesting that bacteria manage supercoiling stress using overlapping responses. This is the first study describing a global transcriptomic response triggered by an increase in DNA supercoiling in bacteria. Total RNA was extracted from S. pneumoniae R6 cultures during exponential growth and used for RNA-Seq. Two independent replicates per condition were performed.
2016-07-07 | E-GEOD-77748 | biostudies-arrayexpress
Project description:We studied the response to increased DNA-supercoiling in Streptococcus pneumoniae by using seconeolitsine (SCN), a DNA topoisomerase I inhibitor. A homeostatic transcriptional response allowing recovering of supercoiling density was observed in cells treated with subinhibitory SCN concentrations. Supercoiling increases up to 40.7% (6 µM SCN) and 72.9% (8 µM SCN) were reverted to 8.5% and 44.1%, respectively. Likewise, recovery of viability and DNA-supercoiling were observed when cells were treated with those SCN concentrations and the drug was removed. The main DNA topoisomerase gene affected was topA, whose transcription depended on the supercoiling level. A two stage global transcriptomic response with 8 µM seconeolitsine was detected. The early stage (5 and 15 min, 10% of the genome) represented a response induced by increased supercoiling. The second stage represented supercoiling recovery (30 min, 2.0% of the genome). Almost 25% of the early responsive genes formed clusters with coordinated transcriptional regulation. Twelve clusters were evident, with sizes of 6.7 to 31.4 Kb (9 to 22 responsive genes). Strikingly, clusters did not contradict those observed under DNA relaxation, suggesting that bacteria manage supercoiling stress using overlapping responses. This is the first study describing a global transcriptomic response triggered by an increase in DNA supercoiling in bacteria. RNA was extracted from S. pneumoniae R6 cultures during exponential growth, amplified and used for microarray hibridization. Two independent replicates were performed.
2016-07-07 | E-GEOD-77587 | biostudies-arrayexpress
Project description:The stringent response enables bacteria to respond to a variety of environmental stresses, especially various forms of nutrient limitation. During the stringent response the cell produces large quantities of the nucleotide alarmone ppGpp, which modulates many aspects of cell physiology, including reprogramming transcription, blocking protein translation, and inhibiting new rounds of DNA replication. The mechanism by which ppGpp inhibits DNA replication initiation in Escherichia coli remains unclear. Prior work suggested that ppGpp blocks new rounds of DNA replication by inhibiting transcription of the essential initiation factor dnaA, but we found that replication is still inhibited by ppGpp in cells ectopically producing DnaA. Instead, we provide evidence that a global reduction of transcription by ppGpp prevents replication initiation by modulating the supercoiling state of the origin of replication, oriC. Active transcription normally introduces negative supercoils into oriC to help promote replication initiation, so the accumulation of ppGpp reduces initiation potential at oriC. We find that maintaining transcription near oriC, either by expressing a ppGpp-blind RNA polymerase mutant or by inducing transcription from a ppGpp-insensitive promoter, can strongly bypass the inhibition of replication by ppGpp. Additionally, we show that increasing global negative supercoiling by inhibiting topoisomerase I or by deleting the nucleoid-associated protein seqA, also relieves inhibition. We propose a model, potentially conserved across proteobacteria, in which ppGpp indirectly creates an unfavorable energy landscape for initiation by preventing the introduction of negative supercoils into oriC.
2019-06-11 | GSE128606 | GEO
Project description:We report active promoters in five adult mouse tissues - brain, kidney, liver, lung and spleen using ChIP-Seq aganist RNAP-II antibody. We identified 38,639 active RNAP-II transcribed promoters, including 12,270 novel promoters. Of these, 6384 promoters are tissue specific which are CpG poor and contain multiple core promoter elements. By identifying the RNAP-II bound promoter(s) we found that 37% of the protein coding genes use alternative promoters in the five mouse tissues. Roughly 34% of the novel promoters are loacted in CpG-islands suggesting that novel promoters are mostly tissue specific.
2010-09-07 | GSE21773 | GEO
Project description:In cyanobacteria DNA supercoiling varies over the diurnal light/dark cycle and is integrated with temporal programs of transcription and replication. We manipulated DNA supercoiling in Synechocystis sp. PCC 6803 by CRISPRi-based knockdown of gyrase subunits gyrA, gyrB and overexpression of topoisomerase I (TopoI) topA and analyzed the transcriptional response to gyrase knock-downs (endpoint in triplicate) and topoisomerase I overexpression (endpoint in triplicate, and 19 time points time series before and after induction) in Synechocystis sp. PCC 6803 via RNA-seq of coding RNA. In detail, Illumina Ribo-Zero Plus rRNA Depletion Kit was used to remove the ribosomal RNA molecules from the isolated total RNA. Removal of rRNA was evaluated with the RNA Pico 6000 kit on the Agilent 2100 Bioanalyzer. RNA was free of detectable rRNA. Preparation of cDNA libraries was performed according to the manufacturer’s instructions for the TruSeq stranded mRNA kit (Illumina, San Diego, CA, United States). Subsequently, each cDNA library was sequenced on an Illumina NextSeq 500 system (2 x 75 nt PE high output v2.5).
2021-12-06 | E-MTAB-10949 | biostudies-arrayexpress
Project description:DNA supercoiling is essential for life because it controls critical processes, including transcription, replication and recombination. Current methods to measure DNA supercoiling in vivo are laborious and unable to examine single cells. Here we report a method for high-throughput measurement of bacterial DNA supercoiling in vivo. Fluorescent Evaluation of DNA Supercoiling (FEDS) utilizes a plasmid harboring the gene for a green fluorescent protein transcribed by a discovered promoter that responds exclusively to DNA supercoiling, and the gene for a red fluorescent protein transcribed by a constitutive promoter as internal standard. Using FEDS, we uncovered single cell heterogeneity in DNA supercoiling and established that, surprisingly, population-level decreases in DNA supercoiling result from a low mean/high variance DNA supercoiling subpopulation, rather than a homogeneous shift in supercoiling of the whole population. In addition, we identified a regulatory loop in which a gene that decreases DNA supercoiling is transcriptionally repressed when DNA supercoiling increases.
2020-07-02 | GSE137586 | GEO