Expression profile for BW25113 M-NM-^TmqsRA with deoxycholate stress
Ontology highlight
ABSTRACT:
ORGANISM(S): Escherichia coli BW25113
SUBMITTER: Thomas Wood
PROVIDER: E-GEOD-59441 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Publications
The MqsR/MqsA toxin/antitoxin system protects Escherichia coli during bile acid stress.
Kwan Brian W BW Lord Dana M DM Peti Wolfgang W Page Rebecca R Benedik Michael J MJ Wood Thomas K TK
Environmental microbiology 20150214 9
Toxin/antitoxin (TA) systems are ubiquitous within bacterial genomes, and the mechanisms of many TA systems are well characterized. As such, several roles for TA systems have been proposed, such as phage inhibition, gene regulation and persister cell formation. However, the significance of these roles is nebulous due to the subtle influence from individual TA systems. For example, a single TA system has only a minor contribution to persister cell formation. Hence, there is a lack of defining phy ...[more]
Similar Datasets
Project description:Persisters are a subpopulation of metabolically-dormant cells in biofilms that are resistant to antibiotics; hence, understanding persister cell formation is important for controlling bacterial infections. Previously we discerned that MqsR and MqsA of Escherichia coli are a toxin/antitoxin pair that influence persister cell production via their regulation of Hha, CspD, and HokA. Here, to gain more insights into the origin of persisters, we used protein engineering to increase the toxicity of toxin MqsR by reasoning it would be easier to understand the effect of this toxin if it were more toxic. We found that two mutations (K3N and N31Y) increase the toxicity four fold and increase persistence 73 fold compared to native MqsR by making the protein less labile. A whole transcriptome study revealed that the MqsR variant represses acid resistance genes (gadABCEWX and hdeABD), multidrug resistance genes (mdtEF), and osmotic resistance genes (osmEY). Corroborating these microarray results, deletion of rpoS as well as the genes that the master stress response regulator RpoS controls, gadB, gadX, mdtF, and osmY, increased persister formation dramatically to the extent that nearly the whole population became persistent. Therefore, the more toxic MqsR increases persistence by decreasing the ability of the cell to respond to antibiotic stress through its RpoS-based regulation of acid resistance, multidrug resistance, and osmotic resistance systems. For the whole-transcriptome study of BW25113 mqsR/pBS(Kan)-mqsR 2-1 versus BW25113 mqsR/pBS(Kan)-mqsR, planktonic cells were grown to a turbidity of 0.5 at 600 nm in LB medium with 1 mM IPTG at 37 M-BM-0C, adjusted the turbidity to 1, and exposed to 20 M-NM-<g/mL ampicillin with 1 mM IPTG for 1 h. Cells were isolated by centrifuging at 0M-BM-0C, and RNALaterM-BM-. buffer (Ambion, Cat# AM7021) was added to stabilize RNA during the RNA preparation steps. Total RNA was isolated from cell pellets with Qiagen RNeasy mini Kit (Cat# 74104) using a bead beater. cDNA was synthesized and fragmented to obtain 50-200 base cDNA fragments. The fragmented cDNA was labelled with Biotin-ddUTP, and hybridization was performed at 45M-BM-0C with 60 rpm for 16 hours. The probe array was washed, stained using Affymetrix Genechip Fluidics Station 450 and the software GenomeChipOperating Software (GCOS)M-bM-^@M-^], and scanned using Affymetrix Genechip scanner GCS3000 7G system and the software GenomeChipOperating Software (GCOS). Data were processed with MAS 5.0 Expression Analysis Default Setting. Genes were identified as differentially expressed if the expression ratio was higher than the standard deviation: 4.0 fold (enriched and differentially degraded) cutoff for the DNA microarrays (standard deviation 1.3 fold), and if the p-value for comparing two chips was less than 0.05.
2012-04-02 | E-GEOD-31054 | biostudies-arrayexpress
Project description:Persisters are cells which evade stresses like antibiotics and which are characterized by reduced metabolism and a lack of genetic alterations required to achieve this state. We showed previously that MqsR and MqsA of Escherichia coli are a toxin-antitoxin pair that influence cell physiology (e.g., biofilm formation and motility) via RNase activity as well as through regulation of toxin CspD. Here, we show that deletion of the mqsRA locus decreases persister cell formation and, consistent with this result, overexpression of MqsR increases persister cell formation. Furthermore, toxins Hha, CspD, and HokA increase persister cell formation. In addition, by overproducing MqsR in a series of isogenic mutants, we show that Hha and CspD are necessary for persister cell formation via MqsR overexpression. Surprisingly, Hfq, a small RNA chaperone, decreases persistence. A whole-transcriptome study shows that Hfq induces transport-related genes (oppA, oppB, oppC, oppD, oppF, and dppA), outer membrane protein-related genes (ybfM and ybfN), toxins (hha), and proteases (clpX, clpP, and lon). Taken together, these results indicate that toxins CspD and Hha influence persister cell formation via MqsR and that Hfq plays an important role in the regulation of persister cell formation via regulation of transport or outer membrane proteins. Strains: E. coli BW25113 K-12 hfq deleted mutant vs. wild-type Medium: LB Culture: Planktonic cell grown OD=0.5, adjusted OD=1.0, and then exposed to 100 ug/mL ampicillin for 2 h.
2009-11-07 | E-GEOD-18852 | biostudies-arrayexpress
Project description:Toxin-antitoxin (TA) systems are ubiquitous throughout bacterial and archaeal genomes. TA systems consist of a stable toxin that inhibits growth and a labile antitoxin that prevents toxicity of the toxin. Here we made an artificial TA system (arT/arA) and performed a DNA microarray study for overproduction of the toxin. arT was overexpressed in Escherichia coli BW25113 and compared to the empty vector.
2014-05-13 | E-GEOD-54271 | biostudies-arrayexpress
Project description:MqsR/MqsA is a well-characterized toxin/antitoxin system with several regulatory roles. Deletion of mqsRA reduced growth with deoxycholate stress. Here we performed a microarray to determine the expression profile with and without mqsRA under deoxycholate stress to determine transcriptional regulation.
2015-01-09 | GSE59441 | GEO
Project description:Quorum sensing controls the expression of multiple virulence factors. PA14 genes lasR and rhlR are necessary for quorum sensing via homoserine lactones. A PA14 lasR rhlR deficient mutant exhibits a reduced oxidative stress response. Here we conducted a microarray to determine oxidative stress response gene regulation mediated by the homoserine lactone quorum sensing circuits. A PA14 lasR rhlR deficient mutant was compared to the wild-type with and without H2O2 stress.
2015-01-09 | E-GEOD-54245 | biostudies-arrayexpress
Project description:E. coli K-12 BW25113 mutant strain yncC expression in biofilm cells relative to E. coli wild-type strain expression in biofilm cells. All samples were cultured in LB with glasswool at 37C for 15 hours and E. coli K-12 MG1655 mutant yncC colony cells vs wild type colony cells in LB plates 15h 37C. Quorum-sensing signal autoinducer 2 (AI-2) stimulates Escherichia coli biofilm formation through the motility regulator MqsR that induces expression of the putative transcription factor encoded by yncC. Here we show YncC increases biofilm formation by decreasing mucoidy (corroborated by decreased exopolysaccharide production and increased sensitivity to bacteriophage P1 infection). Differential gene expression and gel shift assays demonstrated that YncC is a repressor of the predicted periplasmic protein-encoding gene ybiM which was corroborated by the isogenic yncC ybiM double mutation which repressed the yncC phenotypes (biofilm formation, mucoidy, and bacteriophage resistance). Through nickel-enrichment microarrays and additional gel shift assays, we found that the putative transcription factor B3023 (directly upstream of mqsR) binds the yncC promoter. Overexpressing MqsR, AI-2 import regulators LsrR/LsrK, and AI-2 exporter TqsA induced yncC transcription whereas the AI-2 synthase LuxS and B3023 repressed yncC. MqsR has a toxic effect on E. coli bacterial growth which is partially reduced by the b3023 mutation. Therefore, AI-2 quorum-sensing control of biofilm formation is mediated through regulator MqsR that induces expression of the transcription factor YncC which serves to inhibit the expression of periplasmic YbiM; this inhibition of YbiM prevents it from overexpressing exopolysaccharide (causing mucoidy) and prevents YbiM from inhibiting biofilm formation. Experiment Overall Design: Strains: E. coli K-12 BW25113 wild-type, mutant yncC Experiment Overall Design: and E. coli K-12 MG1655 wild-type, mutant yncC Experiment Overall Design: Medium: LB Experiment Overall Design: Biofilm grown on glasswool or colony cells growth in LB plates Experiment Overall Design: Time: 15 hours Experiment Overall Design: Temperature: 37C Experiment Overall Design: Cell type: biofilm or colony Experiment Overall Design: For the biofilm arrays in BW25113 background: Experiment Overall Design: Overnight cultures (16 h, 2.5 mL) of wild type E. coli BW25113 and BW25113 yncC in LB and LB with kanamycin (50 μg/mL), respectively, were used to inoculate 250 mL LB with 10 g of glass wool (Corning Glass Works, Corning, NY) for forming biofilm. After incubating at 37°C for 15 h with shaking (250 rpm), biofilm cells were prepared by rinsing and sonicating the glass wool in sterile 0.85% NaCl solution at 0°C as described before. The total RNA was isolated from biofilm cells as described previously. Experiment Overall Design: The E. coli Genechip antisense genome array (P/N 900381, Affymetrix, Santa Clara, CA) containing probes for more than 4200 open reading frames (ORFs) was used to analyze the complete E. coli transcriptome as described previously. Hybridizations were performed for 16 h and the total cell intensity was scaled automatically in the software to an average value of 630. The Gene Expression Technical Manual (Affymetrix) was followed for the procedures of DNA microarrays, and the GeneChip operating software (Affymetrix) was applied to analyze data of DNA microarrays. The data quality was assessed following the manufacturer's guidelines (GeneChip Expression Analysis: Data Analysis Fundamentals; Affymetrix) and also was based on the expected signals of E. coli BW25113 and the yncC mutant genotypes (e.g., signals of the deleted genes, araA and rhaA, were low for both BW25113 and BW25113 yncC, while the signal of yncC was low for the yncC mutant). A gene was identified as differentially-expressed when the P value based on the False Discovery Rate Method was less than 0.05 and the expression ratio was greater than threefold since the standard deviation for the expression ratio for all of genes was 2. Experiment Overall Design: for the colony arrays in MG1655 background: Experiment Overall Design: For the agar biofilm, fresh single colonies of wild-type E. coli MG1655 and MG1655 yncC were re-streaked on LB agar plates, incubated, and about 0.05 g of the colony cultures on LB plate were quickly transferred to 2-mL collection tubes. The total RNA was isolated from these colony cells as described previously. The E. coli GeneChip Genome 2.0 Array (Affymetrix, P/N 900551, Santa Clara, CA) containing 10,208 probe sets for open reading frames, rRNA, tRNA, and intergenic regions for four E. coli strains: MG1655, CFT073, O157:H7-Sakai, and O157:H7-EDL933, was used to analyze the complete E. coli transcriptome. A gene was identified as differentially-expressed when the P value based on the False Discovery Rate Method (Benjamini & Hochberg, 1995) was less than 0.05 and the expression ratio was greater than threefold since the standard deviation for the expression ratio for all of MG1655 genes (except the deleted yncC gene) was 2.
2008-04-07 | E-GEOD-8706 | biostudies-arrayexpress
Project description:Persister cells are a sub-population of all bacterial cultures which exhibit a non-inheritable, multi-drug tolerance when subjected to lethal antibiotic challenge. These persisters arise as a result of metabolic dormancy, and can resume growth subsequent to antibiotic challenge, leading to recalcitrance of bacterial infections. Overproduction of DosP, an oxygen sensing protein with phosphodiesterase activity, increases bacterial persistence. Here we performed a microarray to determine the expression profile induced by DosP as a means to elucidate mechanisms of persister cell formation. dosP was overexpressed in Escherichia coli K-12 BW25113 and compared to the empty vector.
2014-09-15 | E-GEOD-47427 | biostudies-arrayexpress
Project description:To provide more evidence of the specificity of the RNase activity of GhoS, we performed a whole-transcriptome study for the production of GhoS vs. an empty plasmid so that we could investigate all of the cellM-bM-^@M-^Ys transcripts for cleavage with GhoS, in vivo (i.e., BW25113/pCA24N-ghoS vs. BW25113/pCA24N with 1 mM IPTG induction of ghoS for 90 min). Under these conditions, only 20 genes were found to be repressed by more than 4-fold; there were no induced genes. These GhoS-repressed genes were all involved in the biosynthesis/transport of purines and pyrimidines; among them, pyrI was most highly repressed (-20 fold). These results suggest that GhoS selectively cleaves only a few cellular targets. Overnight cultures of E. coli strains BW25113-pCA24N-ghoS and BW25113-pCA24N (emtpy plasmid) were inoculated into fresh LB medium to a turbidity of 0.05 at 600 nm and grown at 37M-BM-0C. IPTG (1 mM) induction was performed when turbidity reached 0.2 and continued for 90 min. Total RNAs were isolated from the cultures and converted to cDNA for the application on E. coli genome 2.0 array.
2012-08-30 | E-GEOD-36779 | biostudies-arrayexpress
Project description:Here evidence is presented that MqsR and B3021 are a novel toxin-antitoxin (TA) system related to biofilm development and quorum sensing. Using whole-transcriptome studies and nickel enrichment DNA binding microarrays coupled with cell survival studies in which MqsR was overexpressed in isogenic mutants, we identified seven genes involved in MqsR toxicity (clpX, clpP, yfjZ, cspD, relB, relE, and hokA). Quantitative real-time polymerase chain reaction (qRT-PCR) confirmed consistent induction of the seven genes by the overexpression of MqsR as well as induction of nutrient starvation related genes (cstA, rpoS, and dps). Taken together, our results indicate that MqsR toxicity is caused via CspD (a DNA replication inhibitor), other TA systems (RelE/RelB and YfjZ), HokA (a small membrane toxin peptide), and nutrient-starvation conditions induced via CstA, RpoS, and Dps. Additionally, in vivo binding results show antitoxin B3021 binds to the promoter regions of genes encoding essential proteins for stress, growth and normal physiology. Experiment Overall Design: Strain: E. coli K-12 BW25113 wt and mqsR deleted mutant Experiment Overall Design: Medium: LB medium Experiment Overall Design: Temperature: 37 oC Experiment Overall Design: Time: 24 h Experiment Overall Design: Cell type: Biofilm grown on glass wool and planktonic culture
2009-12-05 | E-GEOD-14203 | biostudies-arrayexpress
Project description:Here evidence is presented that MqsR and B3021 are a novel toxin-antitoxin (TA) system related to biofilm development and quorum sensing. Using whole-transcriptome studies and nickel enrichment DNA binding microarrays coupled with cell survival studies in which MqsR was overexpressed in isogenic mutants, we identified seven genes involved in MqsR toxicity (clpX, clpP, yfjZ, cspD, relB, relE, and hokA). Quantitative real-time polymerase chain reaction (qRT-PCR) confirmed consistent induction of the seven genes by the overexpression of MqsR as well as induction of nutrient starvation related genes (cstA, rpoS, and dps). Taken together, our results indicate that MqsR toxicity is caused via CspD (a DNA replication inhibitor), other TA systems (RelE/RelB and YfjZ), HokA (a small membrane toxin peptide), and nutrient-starvation conditions induced via CstA, RpoS, and Dps. Additionally, in vivo binding results show antitoxin B3021 binds to the promoter regions of genes encoding essential proteins for stress, growth and normal physiology.
2009-11-27 | GSE14203 | GEO