Transcription profiling of Pseudomonas putida mt-2 with TOL plasmid in response to pWW0 m-xylene, o-xylene, 3MBA and heat shock
ABSTRACT: A sub-genomic array of structural and regulatory genes of the TOL plasmid pWW0 of Pseudomonas putida mt-2 has been taiolored for inferring the genetic network of m-xylene metabolism through expression profiling of xyl genes. To this end we visualized the response to m-xylene, o-xylene, 3MBA and to a heat shock.
Project description:P388D1 murine macrophages were cultured in 85 mm tissue culture plates to about semi confluency. L. monocytogenes serotypes (1/2a EGD-e, 4a L99, 4b CLIP80459 and 4b F2365) were infected to the P388D1 cell monolayer at a MOI of 100 per eukaryotic cell. Infection was carried for 45 min and followed by addition of fresh medium containing 20 µg/ml gentamicin. The medium of the plates (containing 20 µg/ml gentamicin) infected with L. monocytogenes serotypes were replaced after 2 h post infection with fresh medium containing 50 µg/ml gentamicin. At each step the plates were washed extensively with 1x PBS. Incubation of the bacterial tissue culture plates was carried out in a humidified incubator for up to 4 h post infection.
Project description:Exponentially growing Sulfolobus acidocaldarius were treated with NaAc to generate replication runout and arrest in G2 phase. The cells were then resuspended in fresh acetate-free media which generates a synchronous population. Samples for investigation of gene expression change were taken during the synchronised populations progress through the cell cycle.
Project description:Genome-wide chromatin-immunoprecipitation (ChIP-chip) detects binding of transcriptional regulators to DNA in vivo at low resolution. Motif discovery algorithms can be used to discover sequence patterns in the bound regions that may be recognized by the immunoprecipitated protein. However, the discovered motifs often do not agree with the binding specificity of the protein, when it is known. RESULTS: We present a powerful approach to analyzing ChIP-chip data, called THEME, that tests hypotheses concerning the sequence specificity of a protein. Hypotheses are refined using constrained local optimization. Cross-validation provides a principled standard for selecting the optimal weighting of the hypothesis and the ChIP-chip data and for choosing the best refined hypothesis. We demonstrate how to derive hypotheses for proteins from 36 domain families. Using THEME together with these hypotheses, we analyze ChIP-chip datasets for 14 human and mouse proteins. In all the cases the identified motifs are consistent with the published data with regard to the binding specificity of the proteins.
Project description:The NF-KappaB family of transcription factors plays a critical role in numerous cellular processes, particularly the immune response. Our understanding of how the different NF-kappaB subunits act coordinately to regulate gene expression is based on a limited set of genes. We used genome-scale location analysis to identify targets of all five NF-kappaB proteins before and after stimulation of monocytic cells with bacterial lipopolysaccharide (LPS). In unstimulated cells, p50 and p52 bound to a significant number of gene promoters. p50 occupied genes together with RNA polymerase II and defined a set of genes to which other NF-kappaB proteins bound after LPS induction. In stimulated cells, genes bound by multiple NF-kappaB subunits exhibited the greatest increases in RNA polymerase II occupancy and gene expression. This study identifies novel NF-kappaB target genes, reveals how the different NF-kappaB proteins coordinate their activity and maps transcriptional regulatory networks that underlie the host response to infection.
Project description:An experiment was performed to understand its role in cell type specification, we have determined the human genomic binding sites of MLL1. MLL1 localizes with Pol II to the 5' end of actively transcribed genes, where histone H3 lysine 4 (H3-K4) trimethylation occurs. The ability of MLL1 to serve as a start site-specific global transcriptional regulator and to participate in larger chromatin domains at the Hox genes reveals the dual roles MLL1 plays in maintenance of cellular identity.
Project description:Hormones and nutrients often induce genetic programs via signaling pathways that interface with gene-specific activators. Activation of the cAMP pathway, for example, stimulates cellular gene expression by means of the PKA-mediated phosphorylation of cAMP-response element binding protein (CREB) at Ser-133. Here, we use genome-wide approaches to characterize target genes that are regulated by CREB in different cellular contexts. CREB was found to occupy approximately 4,000 promoter sites in vivo, depending on the presence and methylation state of consensus cAMP response elements near the promoter. The profiles for CREB occupancy were very similar in different human tissues, and exposure to a cAMP agonist stimulated CREB phosphorylation over a majority of these sites. Only a small proportion of CREB target genes was induced by cAMP in any cell type, however, due in part to the preferential recruitment of the coactivator CREB-binding protein to those promoters. These results indicate that CREB phosphorylation alone is not a reliable predictor of target gene activation and that additional CREB regulatory partners are required for recruitment of the transcriptional apparatus to the promoter.