Project description:To compare the transcriptional profiling of a FimZ-expressing strain or non-expressing strain in E. coli under stationary phase. For overexpression of fimZ gene was cloned into pBAD33 plasmid under control of the arabinose-inducible PBAD promoter, which was induced by addition of 0.2% arabinose. Goal was to determine the FimZ regulon in E. coli. Biological replicates: 2 replicates.
Project description:The cold shock proteins belong to a family of RNA binding proteins presenting a highly conserved domain, called cold shock domain (CSD). They are involved in various cellular processes, including adaptation to low temperature, nutritional stress, cell growth and stationary phase. Here we investigate the role of CspC in C. crescentus stationary phase and the molecular mechanisms underlying gene regulation by this protein. A global transcriptional profiling experiment comparing cspC and the wild type strain both at exponential and stationary phases was carried out. The results showed that the absence of cspC affected the transcription of 20 genes at exponential phase and 65 genes at stationary phase. Genes encoding enzymes of the glyoxylate cycle were severely downregulated in the mutant at stationary phase. The stationary phase-induced RNA binding protein CspC has an important role in gene expression at this phase. It is required for the expression of the essential gene sciP, the ECF sigma factor sigU, as well as of the genes for the glyoxylate cycle enzymes and for oxidative stress response. Two and three replicates were performed to determine the stationary phase stimulon and CspC regulon, respectively. Each replicate was conducted with an independent biological sample.
Project description:The cold shock proteins belong to a family of RNA binding proteins presenting a highly conserved domain, called cold shock domain (CSD). They are involved in various cellular processes, including adaptation to low temperature, nutritional stress, cell growth and stationary phase. Here we investigate the role of CspC in C. crescentus stationary phase and the molecular mechanisms underlying gene regulation by this protein. A global transcriptional profiling experiment comparing cspC and the wild type strain both at exponential and stationary phases was carried out. The results showed that the absence of cspC affected the transcription of 20 genes at exponential phase and 65 genes at stationary phase. Genes encoding enzymes of the glyoxylate cycle were severely downregulated in the mutant at stationary phase. The stationary phase-induced RNA binding protein CspC has an important role in gene expression at this phase. It is required for the expression of the essential gene sciP, the ECF sigma factor sigU, as well as of the genes for the glyoxylate cycle enzymes and for oxidative stress response.
Project description:As the foodborne pathogen Listeria monocytogenes has the ability to grow at refrigeration temperatures, whole-genome microarray experiments were performed using L. monocytogenes strain 10403S to define the cold stress regulon and to identify genes differentially expressed during growth at 4°C and 37°C. Microarray analysis using a stringent cutoff (adjusted p<0.001; fold-change >2.0) revealed 105 and 170 genes that showed higher transcript levels in logarithmic- and stationary-phase cells, respectively, at 4°C (compared to cells at 37°C). A total of 74 and 102 genes showed lower transcript levels in logarithmic- and stationary-phase cells grown at 4°C, respectively. Genes upregulated at 4°C during both stationary- and log-phase included those encoding a two-component response regulator (lmo0287), a cold shock protein (cspL), and two RNA helicases (lmo0866 and lmo1722), whereas genes encoding selected virulence factors and heat shock proteins were downregulated at 4°C. Selected genes that were upregulated at 4°C during both stationary- and log-phase were confirmed by quantitative reverse transcriptase PCR. Our data show (i) a large number of L. monocytogenes genes are differentially expressed at 4 and 37°C with a larger number of genes showing higher transcript level at 4°C than genes showing lower transcript levels at 4°C; (ii) L. monocytogenes genes upregulated at 4°C include a number of genes and operons with previously reported or plausible roles in cold adaptation; and (iii) L. monocytogenes genes downregulated at 4°C include a number of virulence and virulence-associated genes as well as some heat shock genes. Keywords: Listeria monocytogenes, cold regulon, temperature
Project description:We studied the proteomic dynamics of Escherichia coli cells exiting stationary phase and identified unique dynamics for the proteins.
Project description:To determine sites where RpoS binds (and hence likely plays a direct role in transcription), we used ChIP-seq to map the association of RpoS across the Escherichia coli chromosome during stationary phase growth in minimal medium. To facilitate ChIP, RpoS was C-terminally SPA-tagged at its native locus.
Project description:E. coli RNA was hybridized to tiling arrays to study the pattern of gene expression across the chromosome. 1 sample for stationary phase and 1 for mid-exponential phase
Project description:We have deep sequenced the small transcriptome of Escherichia coli growing in LB and in MOPS, in exponential and stationary phase, and analyzed the resulting reads by a novel pipeline STARPA (Stable RNA Processing Product Analyzer). Our analysis reveals over 14,000 small transcripts enriched during both growth stages. RNA samples were collected from total RNA pools or from crude ribosome pools and then size selected by electrophoresis to limit the products to 20-300nt.