Similar effects of an NO challenge and an lpdA knockout on transcription of Salmonella enterica sv Typhimurium 14028
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ABSTRACT:
ORGANISM(S): Salmonella enterica subsp. enterica serovar Typhimurium
SUBMITTER: Michael McClelland
PROVIDER: E-GEOD-29735 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:Transcriptional profiling of Salmonella enterica sv Typhimurium under NO stress and comparison of profiles between wild type and lpdA mutant cultures. We investigated the bacteriostatic nature of NO·. S. Typhmurium 14028s is prototrophic for all amino acids but cannot synthesize Methionine or Lysine during nitrosative stress. This MK auxotrophy results from reduced availability of succinyl-CoA, a consequence of NO· targeting lipoamide-dependent LpdA activity. LpdA is an essential component of the pyruvate and α-ketoglutarate dehydrogenase complexes. Additional effects of NO· on gene regulation prevent compensatory pathways of succinyl-CoA production. By microarray analysis, more than 50% of the transcriptional response of S. Typhimurium to nitrosative stress is attributable to LpdA inhibition.
2011-06-04 | GSE29735 | GEO
Project description:Typically, the expression of sRNAs is activated in response to environmental stimuli in order to regulate gene expression through post-transcriptional mechanisms. In the present work we show that the Salmonella Typhimurium paralog sRNAs RyhB-1 and RyhB-2 are induced in response to the nitrosating agent S-nitrosoglutathione (GSNO). Inactivation of these sRNAs decreased S. Typhimurium resistance to GSNO and increased the levels of nitrosylated proteins. These results prompted us to evaluate a possible role of these sRNAs in nitrosative stress resistance. RNA profiling was used as a screening to identify novel RyhB-1 and RyhB-2 regulated targets, and a subset of genes was filtered based on their potential role in the response to nitrosative stress. To confirm our observation, expression of the candidate targets was analyzed by quantitative RT-PCR in a wild type, single and double mutant strains (M-NM-^TryhB1, M-NM-^TryhB2 and M-NM-^TryhB1 M-NM-^TryhB2) treated with GSNO. In response to GSNO RyhB-1 and RyhB-2 negatively regulate the expression of the genes cyoABC (cytochrome o oxidase complex), cydB (cytochrome d oxidase complex), cybC (cytochrome b-562), and positively regulate the nirBCD operon (nitrite reductase system). Together, these results suggest that RyhB-1 and RyhB-2 finely tune the expression of genes coding for cytochrome and the nitrate reductase system, allowing the cell to cope with GSNO-induced stress. Total RNA was harvested from two biological replicates of wt S. Typhimurium overexpressing the sRNA RyhB-2 grown in LB medium, in order to identify RhyB-2 targets that might be implicated in reactive nitrogen stress resistance.
2014-06-10 | E-GEOD-58110 | biostudies-arrayexpress
Project description:Abstract of associated manuscript: The Bacillus subtilis extracytoplasmic function (ECF) sigma(M) factor is activated by cell envelope stress elicited by antibiotics, and by acid, heat, ethanol and superoxide stresses. Here, we have used several complementary approaches to identify genes controlled by sigma(M). In many cases, expression is only partially dependent on sigma(M) because of both overlapping promoter recognition with other ECF sigma factors and the presence of additional promoter elements. Genes regulated by sigma(M) have a characteristic pattern of induction in response to cell envelope-acting antibiotics as evidenced by hierarchical clustering analysis. sigma(M) also contributes to the expression of the Spx transcription factor and thereby indirectly regulates genes of the Spx regulon. Cell envelope stress responses also include regulons controlled by sigma(W), sigma(B) and several two-component regulatory systems (e.g. LiaRS, YycFG, BceRS). Activation of the sigma(M) regulon increases expression of proteins functioning in transcriptional control, cell wall synthesis and shape determination, cell division, DNA damage monitoring, recombinational repair and detoxification. WT (-van) vs. WT (+van), sigM (-van) vs. sigM (+van), WT (-van) vs. sigM (-van), WT (+van) vs. sigM (+van), WT (-van) vs. spx (-van), WT (+van) vs. spx (+van). Each experiment was conducted at least twice using two independent total RNA preparations. For vancomycin untreated and treated experiments, untreated samples were labeled with Alexa Fluor 555 and treated samples with Alexa Fluor 647. For WT vs. mutant experiments, wild type was labeled with Alexa Fluor 555 and mutants with Alexa Fluor 647. For dye swap experiment, wild-type was labeled with Alexa Fluor 647 and mutant with Alexa Fluor 555. Bacillus subtilis CU1065, WT (-van) vs. WT (+van), sigM (-van) vs. sigM (+van), WT (-van) vs. sigM (-van), WT (+van) vs. sigM (+van), WT (-van) vs. spx (-van), WT (+van) vs. spx (+van)
2010-05-15 | E-GEOD-13820 | biostudies-arrayexpress
Project description:“Stress, survival and virulence: the multi-faceted host/microbial interactions.” Bacteria employ epinephrine and norepinephrine, which converge to distinct bacterial crucial processes, like survival and pathogenicity. A novel stress periplasmic membrane protein belonging to previously described BOF family, protein renamed here SrpP, and together with membrane sensor kinase QseC has an essential role in stress response and virulence of S. Typhimurium. SrpP employs its predicted binding pocket, specifically the SrpPE110 residue, and interacts with lipid A modification enzyme, LpxO dioxygenase. Upon this interaction SrpP in S. Typhimurium finely manages multiple membrane functions to culminate in survival upon stress and pathogenesis in vivo, connecting host-stress chemical signaling to cell stress in bacteria. Comparison of sensor histidine kinase qseC mutant expression levels versus wild type strain.
2012-05-31 | E-GEOD-38353 | biostudies-arrayexpress
Project description:The capacity to sense and transduce temperature signals pervades all aspects of biology, and temperature exerts powerful control over the development and virulence of diverse pathogens. In the leading fungal pathogen of humans, Candida albicans, temperature has a profound impact on morphogenesis, a key virulence trait. Many cues that induce the transition from yeast to filamentous growth are contingent on a minimum temperature of 37ºC, while further elevatation to 39ºC serves as an independent inducing cue. The molecular chaperone Hsp90 is a key regulator of C. albicans temperature-dependent morphogenesis, as induction of filamentous growth requires relief from Hsp90-mediated repression of the morphogenetic program. Compromise of Hsp90 function genetically, pharmacologically, or by elevated temperature induces filamentation in a manner that depends on protein kinase A (PKA) signaling, but is independent of the terminal transcription factor, Efg1. Here, we determine that despite morphological and regulatory differences, inhibition of Hsp90 induces a transcriptional profile similar to that induced by other filamentation cues, and does so in a manner that is independent of Efg1. Further, we identify Hms1 as a transcriptional regulator required for morphogenesis induced by elevated temperature or compromise of Hsp90 function. Hms1 functions downstream of the cyclin Pcl, and the cyclin-dependent kinase Pho85, both of which are required for temperature-dependent filamentation. Upon Hsp90 inhibition, Hms1 binds to DNA elements involved in filamentous growth, including UME6 and RBT5, and regulates their expression, providing a mechanism through which Pho85, Pcl1, and Hms1 govern morphogenesis. Consistent with the importance of morphogenetic flexibility with virulence, deletion of C. albicans HMS1 attenuates virulence in a metazoan model of infection. Thus, we establish a new mechanism through which Hsp90 orchestrates C. albicans morphogenesis, and define novel regulatory circuitry governing a temperature-dependent developmental program, with broad implications for temperature sensing and virulence of microbial pathogens. Two-color experimental design testing the effect of geldanamycin on wild type of delta-efg1 cells. RNA from each replicate came from independent cultures.
2012-03-20 | E-GEOD-34255 | biostudies-arrayexpress
Project description:Salmonella enterica serotype Typhimurium produces a variety of fimbrial appendages, among which the type 1 fimbriae is the most common type. In vitro static broth culture favors S. Typhimurium to produce type 1 fimbriae, while solid agar inhibits its expression. A transposon inserted in the stbC gene, which would encode an usher protein for Stb fimbriae of a non-flagellar S. Typhimurium LB5010 strain, conferred it to agglutinate yeast cells on both cultures, and was mannose-sensitive. Reverse transcription polymerase chain reaction (RT-PCR) revealed that the expression of the fimbrial major subunit gene fimA, and fimZ, a positive regulator gene of fimA, were both increased in the stbC mutant strain when grown on LB agar; fimW, a repressor gene of fimA, exhibited lower expression. Flagella were observed in the stbC mutant and this phenotype was correlated with the motile phenotype detected by MSRV agar medium and reaction with flagella antiserum. Microarray data and RT-PCR also indicated that the expression of three genes, motA, motB, and cheM, was enhanced in the stbC mutant. The S. Typhimurium stbC mutant was resistant to a variety of antibiotics, consistent with the finding that expression of yhcQ and ramA, two genes involved in multidrug resistance, was enhanced. A complementation test revealed that transforming a recombinant plasmid possessing the coding sequence of the stbC gene restored the mannose-sensitive agglutination phenotype to the stbC mutant much as that in the parental S. Typhimurium LB5010 strain, indicating the possibility of an interplay of different fimbrial systems in coordinating their expression. Key Words: Salmonella enterica serotype Typhimurium, fimbriae, type 1 fimbriae, stbC, transposon, multidrug resistant, flagella RNA transcript of Salmonella Typhimurium LB5010 strain comparing wild-type with stbC mutant. Two-cindition experiment, wild-type vs. stbC mutant strain.
2011-12-25 | E-GEOD-34685 | biostudies-arrayexpress
Project description:Zinc (Zn2+) is an important trace metal ion that has been shown to regulate the expression of several (virulence) genes in streptococci. Previously, we analyzed the genome-wide response of S. pneumoniae to Zn2+-stress. In this work, we have performed a transcriptomic analysis to identify genes that are differentially expressed under intracellular Zn2+-limitation. This revealed a number of genes that are highly upregulated in the absence of extracellular Zn2+, amongst which the genes belonging to the regulon of the Zn2+-responsive repressor AdcR, like adcBCA, encoding a Zn2+-dependent ABC-uptake system, adcAII, encoding a Zn2+-binding lipoprotein, and also virulence genes belonging to the Pht family (phtA, phtB, phtD and phtE). Using transcriptome analysis, lacZ-reporter studies, in vitro DNA binding experiments, and in silico operator predictions, we show that AdcR directly represses the promoters of adcRCBA, adcAII-phtD, phtA, phtB and phtE in the presence of Zn2+. AdcR can also function as an activator, since in the presence of Zn2+ it directly induces expression of adh that encodes a Zn2+-containing alcohol dehydrogenase. In conclusion, the genome-wide transcriptional response of S. pneumoniae to Zn2+-limitation was established, which is mainly mediated via direct regulation by the Zn2+-dependent regulator AdcR. Two condition design comparison of Wild-type strain including a dye swap Refer to individual Series. This SuperSeries is composed of the following subset Series: GSE29234: adcR mutant vs wild type D39 GSE29235: Low Zn vs high Zn in CDM
2011-05-13 | E-GEOD-29236 | biostudies-arrayexpress
Project description:1. Comparison of transcripts during growth in pure culture of a wild-type strain compared to a mutant deficient in the transcriptional activator encoded by the gene prhG.<br><br>2. Transcriptome analysis for identification of the prhG regulon by comparison of a prhG overexpressing mutant to the wild type strain.
2010-01-01 | E-MEXP-2456 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the following subset Series: GSE34255: Pho85, Pcl1, and Hms1 Signaling Governs Candida albicans Morphogenesis Induced by Elevated Temperature or Hsp90 Compromise [mRNA] GSE34938: Pho85, Pcl1, and Hms1 Signaling Governs Candida albicans Morphogenesis Induced by Elevated Temperature or Hsp90 Compromise [ChIP-chip] Refer to individual Series
2012-03-20 | E-GEOD-34939 | biostudies-arrayexpress
Project description:Erwinia carotovora subsp. atroseptica (Eca) is an enterobacterial phytopathogen causing economically-significant soft rot disease. Pathogenesis is mediated by multiple secreted virulence factors, many of which are secreted by the Type II (Out) secretion system. DsbA catalyses the introduction of disulphide bonds into periplasmic and secreted proteins. In this study, the extracellular proteome (secretome) of wild type Eca SCRI1043 and dsbA and out mutants was analysed by spectral counting mass spectrometry. This revealed that dsbA inactivation had a huge impact on the secretome and identified diverse DsbA- and Out-dependent secreted proteins, representing known, predicted and novel candidate virulence factors. Further characterisation of the dsbA mutant showed that secreted enzyme activities, motility, production of the quorum sensing signal and virulence were absent or greatly reduced. The impact of DsbA on secreted virulence factor production was mediated at multiple levels, including impacting on the Out secretion system and the virulence gene regulatory network. Transcriptome analyses revealed that the abundance of a broad, but defined, set of transcripts, including many virulence factors, was altered in the dsbA mutant, identifying a new virulence regulon responsive to extracytoplasmic conditions. In conclusion, DsbA plays a crucial, multi-faceted role in the pathogenesis of Eca. Keywords: Mutant comparison RNA samples used for genome-wide transcriptional profiling using microarrays: RNA was hybridised to four Eca genomic arrays, with each array hybridising one wild type and one dsbA mutant sample (from four independent cultures of each strain) and incorporating a dye-swap (i.e. wild type labelled with Cy3 in 2/4 and with Cy5 in 2/4).
2010-06-20 | E-GEOD-10647 | biostudies-arrayexpress