Project description:FabR ChIP-chip on Salmonella enterica subsp. enterica serovar Typhimurium SL1344 using anti-Myc antibody against strain with chromosomally 9Myc-tagged FabR (IP samples) and wildtype strain (mock IP samples)
Project description:Summary: Salmonella enterica serovar Typhimurium strain 14028s transcriptome response to lettuce medium (LM) and lettuce root exudates (LX) to minimal medium (MM). Purpose: Salmonella mRNA profile, when grown in different media was compared to minimal medium to reveal environment specific transcriptional changes. Methods: mRNA profiles were generated using Illumina HiSeq in triplicates. The sequences were analysed using Bowtie2 followed by Cufflinks.
Project description:Summary: Salmonella enterica serovar Typhimurium strain 14028s transcriptome response to tomato medium (TM) and tomato root exudates (TX) compared to minimal medium (MM). Purpose: Salmonella mRNA profile, when grown in different media was compared to minimal medium to reveal environment specific transcriptional changes. Methods: mRNA profiles were generated using Illumina HiSeq in triplicates. The sequences were analysed using Bowtie2 followed by Cufflinks.
Project description:Summary: Salmonella enterica serovar Typhimurium strain 14028s transcriptome response to DS soil suspension (DS) and suspension of autoclaved DS soil (DA) compared to minimal medium (MM). Purpose: Salmonella mRNA profile, when grown in different media was compared to minimal medium to reveal environment specific transcriptional changes. Methods: mRNA profiles were generated using Illumina HiSeq in triplicates. The sequences were analysed using Bowtie2 followed by Cufflinks.
Project description:InvF ChIP-chip on Salmonella enterica serovar Typhimurium SL1344 using anti-Myc antibody against strain with chromosomally 9Myc-tagged InvF (IP samples) and wildtype strain (mock IP samples) Salmonella enterica serovar Typhimurium causes a range of diseases from self-limiting gastroenteritis to life-threatening systemic infections. Its complex infection process is initiated by the invasion of the intestinal epithelial monolayer by means of a type three secretion system. InvF is one of the key regulators governing the invasion of epithelial cells. By mapping the InvF regulon, i.e. locating its direct target genes, the gene network underlying invasion can be further examined, including identifying possible new effector-encoding genes. In order to map the InvF regulon, we performed chromatin immunoprecipitation combined with tiling microarray analysis (ChIP-chip) and compared expression of the identified target genes in an invF mutant and a wildtype strain. In addition, the promoter regions of these target genes were searched for the presence of an InvF recognition site. Finally, a query-driven biclustering method, combined with a microarray compendium containing publically available S. Typhimurium gene expression data, was applied as an in silico validation technique for functional relatedness between newly identified target genes and known invasion genes. As expected, under invasion inducing conditions, InvF activates the expression of invasion chaperone encoding sicA and the effector-encoding genes sopB, sopE, sopE2 and sopA by binding their promoter region. Newly identified InvF targets are steB, encoding a secreted effector, and STM1239. The presence of an InvF recognition site in the promoter regions of these target genes further supports this observation. In addition, the query-driven biclustering method revealed similarities in expression profiles between STM1239 and known InvF regulated invasion genes over a range of experimental conditions. In conclusion, we here deliver the first evidence for direct binding of InvF to the promoter regions of sopA and sopE2, and associate genes encoding a secreted effector (steB) and a putative novel effector (STM1239) with the Salmonella invasion regulator InvF.
Project description:InvF ChIP-chip on Salmonella enterica serovar Typhimurium SL1344 using anti-Myc antibody against strain with chromosomally 9Myc-tagged InvF (IP samples) and wildtype strain (mock IP samples) Salmonella enterica serovar Typhimurium causes a range of diseases from self-limiting gastroenteritis to life-threatening systemic infections. Its complex infection process is initiated by the invasion of the intestinal epithelial monolayer by means of a type three secretion system. InvF is one of the key regulators governing the invasion of epithelial cells. By mapping the InvF regulon, i.e. locating its direct target genes, the gene network underlying invasion can be further examined, including identifying possible new effector-encoding genes. In order to map the InvF regulon, we performed chromatin immunoprecipitation combined with tiling microarray analysis (ChIP-chip) and compared expression of the identified target genes in an invF mutant and a wildtype strain. In addition, the promoter regions of these target genes were searched for the presence of an InvF recognition site. Finally, a query-driven biclustering method, combined with a microarray compendium containing publically available S. Typhimurium gene expression data, was applied as an in silico validation technique for functional relatedness between newly identified target genes and known invasion genes. As expected, under invasion inducing conditions, InvF activates the expression of invasion chaperone encoding sicA and the effector-encoding genes sopB, sopE, sopE2 and sopA by binding their promoter region. Newly identified InvF targets are steB, encoding a secreted effector, and STM1239. The presence of an InvF recognition site in the promoter regions of these target genes further supports this observation. In addition, the query-driven biclustering method revealed similarities in expression profiles between STM1239 and known InvF regulated invasion genes over a range of experimental conditions. In conclusion, we here deliver the first evidence for direct binding of InvF to the promoter regions of sopA and sopE2, and associate genes encoding a secreted effector (steB) and a putative novel effector (STM1239) with the Salmonella invasion regulator InvF. Three IP samples (from three biological replicates using anti-Myc antibody against Salmonella Typhimurium SL1344 strain encoding chromosomally 9Myc-tagged InvF) and three control mock IP samples (from three biological replicates using anti-Myc antibody against Salmonella Typhimurium SL1344 wildtype strain) were labeled with Cy5 and hybridized against a common genomic DNA reference, labeled with Cy3, on 6 S. Typhimurium LT2 whole genome tiling arrays
Project description:Two well-characterized enzymes in Salmonella enterica serovar Typhimurium and Escherichia coli are able to hydrolyze N-terminal aspartyl (Asp) dipeptides: peptidase B, a broad-specificity aminopeptidase, and peptidase E, an Asp-specific dipeptidase. A serovar Typhimurium strain lacking both of these enzymes, however, can still utilize most N-terminal Asp dipeptides as sources of amino acids, and extracts of such a strain contain additional enzymatic activities able to hydrolyze Asp dipeptides. Here we report two such activities from extracts of pepB pepE mutant strains of serovar Typhimurium identified by their ability to hydrolyze Asp-Leu. Although each of these activities hydrolyzes Asp-Leu at a measurable rate, the preferred substrates for both are N-terminal isoAsp peptides. One of the activities is a previously characterized isoAsp dipeptidase from E. coli, the product of the iadA gene. The other is the product of the serovar Typhimurium homolog of E. coli ybiK, a gene of previously unknown function. This gene product is a member of the N-terminal nucleophile structural family of amidohydrolases. Like most other members of this family, the mature enzyme is generated from a precursor protein by proteolytic cleavage and the active enzyme is a heterotetramer. Based on its ability to hydrolyze an N-terminal isoAsp tripeptide as well as isoAsp dipeptides, the enzyme appears to be an isoAsp aminopeptidase, and we propose that the gene encoding it be designated iaaA (isoAsp aminopeptidase). A strain lacking both IadA and IaaA in addition to peptidase B and peptidase E has been constructed. This strain utilizes Asp-Leu as a leucine source, and extracts of this strain contain at least one additional, as-yet-uncharacterized, peptidase able to cleave Asp dipeptides.