GAS M49: wild type vs Δralp3 mutant
Ontology highlight
ABSTRACT:
ORGANISM(S): Streptococcus pyogenes M49 591
SUBMITTER: Nikolai Siemens
PROVIDER: E-GEOD-30397 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:In this study, we introduce for the first time a growth chamber system suitable for physical plasma treatment of bacteria in liquid medium. Bacillus subtilis 168 cells were treated with argon plasma in order to investigate their specific stress response usong a proteomic and transcriptomic approach. The treatment with three different discharge voltages revealed not only growth differences, but also clear cellular stress responses. B. subtilis faces severe cell wall stress, which was made visible alsoelectron microscopy, DNA damages and oxidative stress. The biological findings could be supported by the reactive plasma species, found by plasma diagnostics, i.e. optical emission spectroscopy (OES) and Fourier transformed infrared spectroscopy (FTIR). Cells were grown in LB medium. At OD540 of 0.5, argon plasma treatment was set for 15 min with a discharge power of 5 W. Samples for mircroarray analysis were taken 5 min after the 15 min plasma treatment. Microarray hybridizations were performed with RNA from three biological replicates. The individual samples were labeled with Cy5; a reference pool containing equal amounts of RNA from all samples was labeled with Cy3.
2011-06-01 | E-GEOD-27113 | biostudies-arrayexpress
Project description:Spx is a global regulator of genes that are induced by disulfide stress in Bacillus subtilis. Most of the Spx-regulated genes (SRGs) are of unknown function, but many encode products conserved in low %GC Gram positive bacteria. Using a gene-disruption library of B. subtilis genomic mutations, the SRGs were screened for phenotypes related to Spx-controlled activities, such as growth in minimal medium and sensitivity to methylglyoxal, but nearly all of the SRG mutations showed little if any phenotype. To uncover SRG function, the mutations were rescreened in an spx mutant background to determine which mutant SRG allele would enhance the spx mutant phenotype. One of the SRGs, ytpQ, was the site of a mutation that, when combined with an spx null mutation, elevated the severity of the Spx mutant phenotype, as shown by reduced growth in a minimal medium and by hypersensitivity to methylglyoxal. Proteomic and transcriptomic data indicated that the ytpQ mutation caused the derepression of the Fur and PerR regulons, as well as heightened LexA-controlled gene expression. Our study suggests that the ytpQ gene, encoding a conserved DUF1444 protein, functions directly or indirectly in repairing or stabilizing Fe-bearing proteins, which are sensitive to thiol reactive agents and, therefore, likely influenced by Spx-controlled genes. The wild type parent, ytpQ and spx mutants were grown in a glucose minimal medium, with and without 2.8 mM methylglyoxal, to mid-log phase. Cells were harvested and RNA was extracted for microarray hybridization analysis to determine if any changes in the transcriptome could be detected that were attributable to the ytpQ mutation. Microarray hybridizations were performed with RNA from three biological replicates.
2011-10-24 | E-GEOD-28872 | biostudies-arrayexpress
Project description:Protein S-thiolation is a post-translational thiol-modification that controls redox-sensing transcription factors and protects active site cysteine residues against irreversible oxidation. In B. subtilis, the MarR-type repressor OhrR was shown to sense organic hydroperoxides via formation of mixed disulfides with the redox buffer bacillithiol (Cys-GlcN-Malate) termed as S-bacillithiolation. We have studied changes in the transcriptome and redox proteome caused by the strong oxidant hypochloric acid (NaOCl), the active component of house-hold bleach. The OhrR-controlled peroxiredoxin OhrA was most strongly up-regulated by NaOCl stress and conferred specific protection against NaOCl. Inactivation of the OhrR repressor was caused by S-bacillithiolation of the redox-sensing Cys15 residue in response to NaOCl. Two cobalamin-independent methionine synthases MetE and YxjG were identified as S-bacillithiolated at their essential active site cysteines resulting in hypochlorite-induced methionine limitation. In summary, our studies show that S-bacillithiolation of OhrR and the methionine synthases is the major mechanism in protection against hypochlorite stress in B. subtilis. The B. subtilis 168 wild type strain was grown in minimal medium to OD500 of 0.4 and harvested before and 10 minutes after exposure to 50 µM NaOCl. Microarray hybridizations were performed in triplicate using RNA isolated from independent cultures.
2011-07-04 | E-GEOD-27637 | biostudies-arrayexpress
Project description:RNA processing and degradation is initiated by endonucleolytic cleavage of the target RNAs. In many bacteria, this activity is performed by RNase E which is not present in Bacillus subtilis and other Gram-positive bacteria. Recently, the essential endoribonuclease RNase Y has been discovered in B. subtilis. This RNase is involved in the degradation of bulk mRNA suggesting a major role in mRNA metabolism. However, only a few targets of RNase Y have been identified so far. In order to assess the global impact of RNase Y, we compared the transcriptomes of strains expressing RNase Y or depleted for RNase Y. Our results indicate that processing by RNase Y results in accumulation of about 80 mRNAs. Some of these targets were substantially stabilized by RNase Y depletion, resulting in half-lives in the range of an hour. Moreover, about 40 mRNAs were less abundant when RNase Y was depleted among them the mRNAs of the operons required for biofilm formation. Interestingly, overexpression of RNase Y was sufficient to induce biofilm formation. The results emphasize the importance of RNase Y for B. subtilis and are in support of the idea that RNase Y is the functional equivalent of RNase E. To study the global function of RNase Y, a microarray analysis was performed with a B. subtilis strain allowing controlled depletion of RNase Y. Strain GP193 (Commichau et al., 2009, Mol. Cell. Proteomics 8: 1350-1360) expressing the rny gene under the control of a xylose-inducible promoter was cultivated in CSE minimal medium in the presence or absence of the inducer xylose. The transcriptomes of the two cultures (i.e. expressing RNase Y and depleted for RNase Y) were compared at a timepoint at which the reduced RNase Y amounts already affected the mRNA turnover whereas the growth rates of the two cultures were still almost identical.
2011-08-31 | E-GEOD-30430 | biostudies-arrayexpress
Project description:In this study, we present a follow up investigation on the effects of argon plasma on vegetative growing Bacillus subtilis 168 (see GSE27113). A growth chamber system suitable for low temperature gas plasma treatment of bacteria in liquid medium enabled a first glimpse on the complex cellular response. In order to gain further knowledge, a second kind of plasma treatment was applied and combined proteomic and transcriptomic analyses were used to investigate the specific stress response of B. subtilis cells to treatment with not only argon but also air plasma. Besides similar cellular responses, due to both argon and air plasma treatment, a variety of different responses such as growth retardation and morphological changes were observed. Furthermore, we analyzed the specific response to DNA damages and oxidative stress. The biological findings such as oxidative stress responses were supported by the detection of reactive plasma species by OES and FTIR measurements. Cells were grown in LB medium. At OD540 of 0.5, air plasma treatment was set for 15 min with a discharge power of 7.4 W. Samples for mircroarray analysis were taken 5 min after the 15 min plasma treatment. Microarray hybridizations were performed with RNA from three biological replicates. The individual samples were labeled with Cy5; a reference pool containing equal amounts of RNA from all samples was labeled with Cy3.
2013-08-22 | E-GEOD-32865 | biostudies-arrayexpress
Project description:In this study, temporal changes in the proteome, transcriptome and extracellular metabolome of B. subtilis caused by glucose starvation were monitored. For proteomic profiling, a combination of in vivo metabolic labeling and shot gun mass spectrometric analysis was carried out for five different proteomic subfractions (i. cytosolic, ii. extracellular, iii. membrane, iv. integral membrane, and v. surface proteome fraction) leading to the identification of about 52% of the predicted proteome of B. subtilis. Acquired proteomic and transcriptomic data were analyzed using Voronoi treemaps which link functional classifications and relative expression changes of gene products according to their fate in the stationary phase. The data obtained enables for in-depth analysis of major physiological processes including protein degradation and is the first comprehensive profiling of changes in the membrane subfraction. Cells were grown in a minimal medium with glucose and L-malate (0.05 % each) to induce glucose starvation after growth to an OD500 of 1.0. Samples were taken at different time points along the growth curve (exponential growth, transition phase, transition phase +30, +60 and +120 minutes). Microarray hybridizations were performed with RNA from two biological replicates. The individual samples were labeled with Cy5; a reference pool containing equal amounts of RNA from all 10 samples was labeled with Cy3.
2010-12-01 | E-GEOD-24058 | biostudies-arrayexpress
Project description:Reversible protein phosphorylation is an important and ubiquitous protein modification in all living cells. We report that protein arginine phosphorylation plays a physiological significant role for the regulation of protein activity. We detected 121 arginine phospho-sites for 87 proteins in the Gram-positive model organism Bacillus subtilis in vivo. Moreover, we provide evidences that arginine phosphorylations are involved in the fine-tuned signal transduction of many critical cellular processes, such as protein degradation, motility, competence, stringent and stress response. Our results suggest that in B. subtilis the activity of a protein arginine phosphatase allows a fast regulation of protein activity by protein arginine kinases and that protein arginine phosphorylations play an important role as a reversible post-translational modification in bacteria. Cells were grown under vigorous agitation at 37 M-BM-0C in a defined medium (StM-CM-<lke et al., 1993, J Gen Microbiol 139, 2041-2045). Samples were taken at OD500 0.4 and 1h upon entry into stationary phase. Microarray hybridizations were performed with RNA from three biological replicates. The individual samples were labeled with Cy5; a reference pool containing equal amounts of RNA from all 10 samples was labeled with Cy3.
2012-03-31 | E-GEOD-31249 | biostudies-arrayexpress
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2014-03-31 | E-GEOD-53333 | biostudies-arrayexpress
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2016-02-22 | E-GEOD-65209 | biostudies-arrayexpress
Project description:Escherichia coli strain MG1655 was grown in a New Brunswick Scientific Bioflow III Biofermentor under continuous culture (chemostat) conditions. Cells were grown in Evans media containing 2 mM glucose as the sole and limiting source of energy and carbon. The working volume was 200 ml, and the dilution rate 0.2 h-1. For aerobic growth, the air-flow rate was 0.1 l/min, and the dissolved oxygen tension was maintained at ~7% air saturation by measuring oxygen dissolved in the culture using a Broadley James D140 OxyProbe® electrode. For anaerobic growth, cells are grown on 100 % nitrogen gas bubbled at 0.1 l/min Cells were grown as above to steady-state, At steady-state, CO gas was bubbled through the culture at 0.1L/min. Samples were taken immediately prior to the addition of CO gas and over a time course of 2.5, 5, 10, 20, 40 and 80 min exposure to CO gas for subsequent analysis using microarrays. Cells were harvested directly into phenol:ethanol to stabilize RNA, and total RNA was purified using Qiagenâ??s RNeasy Mini kit as recommended by the suppliers. Time course experiment with samples taken immediately prior to or 2.5, 5, 10, 20, 40 or 80 minutes after addition of CO gas under either 0 or 100 % perceived aerobiosis. 2 biological repeats were performed for the aerobic condition with 2 technical (dye swap) repeats per biological repeat, and three biological repeats were perfomed for the anaerobic condition with 2 technical (dye swap) repeats per biological repeat.
2016-09-01 | E-GEOD-50713 | biostudies-arrayexpress