High resolution definition of the Staphylococcus aureus WalKR regulon [ChIP-seq]
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ABSTRACT:
ORGANISM(S): Staphylococcus aureus
PROVIDER: GSE212318 | GEO | 2022/09/01
REPOSITORIES: GEO
Similar Datasets
Project description:Here, we use a panel of defined walKR mutants and functional genomics including ChIP-seq to confirm a high-resolution consensus WalR DNA-binding motif and characterise a 61-gene direct regulon
2022-09-01 | GSE212319 | GEO
Project description:The WalKR regulon was studied by comparing genes expression in a strain producing a constitutively active WalR regulator (WalRc) versus the wild type strain carrying the empty expression vector. Hybridizations were performed with three independent biological replicates. Our data allowed to identify 165 genes differentially expressed in the walRc expressing strain with a P-value ≤ 0.05 using Z-test and a threshold value of two-fold change in transcriptional levels. Among them, 108 genes are activated, and 57 genes are repressed. About 10% of these results were confirmed by quantitative real time PCR, revealing the high reliability of this overall study. Beyond the major effect of the WalKR system on genes expressing cell wall hydrolases, we have shown that it activates a large number of genes involved in virulence, and probably through its positive impact on the SaeRS two-component system, is a major activator of S. aureus virulence.
2012-09-13 | GSE29337 | GEO
Project description:The WalKR regulon was studied by comparing genes expression in a strain producing a constitutively active WalR regulator (WalRc) versus the wild type strain carrying the empty expression vector. Hybridizations were performed with three independent biological replicates. Our data allowed to identify 165 genes differentially expressed in the walRc expressing strain with a P-value M-bM-^IM-$ 0.05 using Z-test and a threshold value of two-fold change in transcriptional levels. Among them, 108 genes are activated, and 57 genes are repressed. About 10% of these results were confirmed by quantitative real time PCR, revealing the high reliability of this overall study. Beyond the major effect of the WalKR system on genes expressing cell wall hydrolases, we have shown that it activates a large number of genes involved in virulence, and probably through its positive impact on the SaeRS two-component system, is a major activator of S. aureus virulence. Cells were grown in TSB rich medium added with 0.25 M-BM-5M CdCl2 to allow walRc expression until OD600nm of 1. Gene expression was compared between the HG001 wild type reference strain carrying the pCN51 empty vector (HG001/pCN51) and the HG001 strain carrying a pCN51 derivative with the walRc allele under the control of the Pcad inducible promoter (HG001/pSD3-12). Each condition was done in triplicate and the data were analyzed using the Arraystat software. Genes were considered as differentially expressed if their transcriptional level differed by at least two-fold with a Z-test P-value M-bM-^IM-$ 0.05 in at least two of the replicates.
2012-09-13 | E-GEOD-29337 | biostudies-arrayexpress
Project description:WalKR is an essential two component regulatory system in S. aureus, thought to control cell wall metabolism. Using genome sequencing of 5 paired clinical isolates of vancomycin-susceptible and vancomycin-intermediate S. aureus we found frequent, but unique, mutations in this locus. To investigate the contribution of these mutations to vancomycin resistance allelic replacement WalK (G223D) and WalR (K208R) mutants were generated and compared to the parent strains. Mutations in walk and walR led to increased vancomycin resistance, reduced biofilms formation and attenuation of virulence, demonstrating that minor genetic changes in this locus can lead to significant changes in bacterial resistance and virulence. Microarray transcriptional comparisons were performed to investigate the regulatory effects of the WalK (G223D) and WalR (K208R) mutations, and demonstrated that while changes in genes affecting cell wall metabolism were detected, more dramatic changes were found in regulation of cellular metabolism. Transcriptional profiling of laboratory derived S. aureus walKR mutants compared to the parent isolates. TPS3130 has a single point mutation in walK, and TPS3190 has a single point mutation in walR. Two condition experiment TPS3130 vs JKD6009 and TPS3190 vs JKD6004. 3 biological replicates per isolate pair, one replicate per slide.
2012-05-31 | E-GEOD-29157 | biostudies-arrayexpress
Project description:WalKR is an essential two component regulatory system in S. aureus, thought to control cell wall metabolism. Using genome sequencing of 5 paired clinical isolates of vancomycin-susceptible and vancomycin-intermediate S. aureus we found frequent, but unique, mutations in this locus. To investigate the contribution of these mutations to vancomycin resistance allelic replacement WalK (G223D) and WalR (K208R) mutants were generated and compared to the parent strains. Mutations in walk and walR led to increased vancomycin resistance, reduced biofilms formation and attenuation of virulence, demonstrating that minor genetic changes in this locus can lead to significant changes in bacterial resistance and virulence. Microarray transcriptional comparisons were performed to investigate the regulatory effects of the WalK (G223D) and WalR (K208R) mutations, and demonstrated that while changes in genes affecting cell wall metabolism were detected, more dramatic changes were found in regulation of cellular metabolism.
2012-06-01 | GSE29157 | GEO
Project description:This SuperSeries is composed of the SubSeries listed below.
2022-09-01 | GSE212321 | GEO
Project description:Transcriptome analysis of the WalKR regulon in Staphylococcus aureus
| PRJNA140141 | ENA
Project description:WalKR is a two-component system that is essential for viability in Gram-positive bacteria that regulates the all-important autolysins. Here we show a T101M mutation in walR confers a defect in autolysis, a thickened cell wall and decreased sensitivity to antibiotics that target the lipid II cycle, a phenotype that is reminiscent of the clinical resistance form known as vancomycin intermediate-resistant Staphylococcus aureus. Importantly, this is accompanied by dramatic sensitization to tunicamycin. We demonstrate that this phenotype is due to partial collapse of a pathway consisting of autolysins, AtlA and Sle1, a transmembrane sugar permease, MurP, and GlcNAc recycling enzymes, MupG and MurQ. We suggest that this causes a shortage of substrate for MraY causing it to be hypersensitive to competitive inhibition by tunicamycin. This constitutes a new molecular model for antibiotic sensitivity in S. aureus and a promising new route for antibiotic discovery.
2022-08-25 | GSE211745 | GEO
Project description:Background The catabolite control protein A (CcpA) is a member of the LacI/GalR family of transcriptional regulators controlling carbon-metabolism pathways in low-GC Gram positive bacteria. It functions as a catabolite repressor or activator, allowing the bacteria to utilize the preferred carbon source over secondary carbon sources. This study is the first CcpA-dependent transcriptome and proteome analysis in S. aureus wild type and ccpA-deleted mutant, focussing on short-time effects of glucose under stable pH conditions. Results The addition of glucose to exponentially growing S. aureus increased enzymes of glycolytic pathway, indicating a higher glycolytic activity, while proteins required for the complete oxidation in the TCA cycle were repressed via CcpA. Phosphotransacetylase and acetate kinase, converting acetylCoA to acetate with a concomitant substrate-level phosphorylation were neither regulated by glucose nor by CcpA. Most CcpA directly repressed genes were involved in utilization of amino acids as secondary carbon sources. More genes were found to be differentially expressed by CcpA in a glucose-independent manner than in the classical, glucose dependent way, suggesting that glucose-independent regulation by CcpA may be of particular importance in S. aureus. In the presence of glucose, CcpA was found to regulate expression of genes involved in metabolism, but that of genes coding for virulence determinants. Conclusions This study identified the CcpA regulon of exponentially growing S. aureus, for the first time. As in other bacteria, the CcpA-regulon of S. aureus comprised a large amount of metabolic genes but also some 50 genes associated with virulence. CcpA seemed to work in a glucose- as well as glucose-independent way.
2008-12-20 | GSE12614 | GEO
Project description:CodY is a conserved broad acting transcriptional factor that regulates the expression of genes related to amino acid metabolism and virulence in Staphylococcus aureus. CodY target genes have been studied by using in vitro DNA affinity purification and deep sequencing (IDAP-Seq). In this study we performed the first in vivo determination of CodY target genes using a novel CodY monoclonal antibody in established ChIP-exo protocols. Our results showed, 1) The same 165 CodY target genes in both strains; 2) That the differential binding intensity for the same target genes under the same conditions were due to sequence differences in the same CodY binding site in the two strains; 3) Based on transcriptomic data, a CodY regulon comprising 72 target genes that revealed that CodY is mainly involved in amino acid transport and metabolism, inorganic ion transport and metabolism, and cellular transcription and translation; and 4) CodY systematically regulated central metabolic flux to generate branched-chain amino acids (BCAAs) by mapping the CodY regulon onto a genome-scale metabolic model of S. aureus. Our study performed the first system-level analysis of CodY in two closely related dominant USA300 TCH1516 and LAC strains, thus expanding the size of the known CodY regulon, and giving new insights into the similarities and differences of CodY regulatory roles between closely related strains.
2022-08-29 | GSE163312 | GEO