Project description:Transcription has the capacity to modify mechanically DNA topology, DNA structure, and nucleosome arrangement. Resulting from ongoing transcription, these modifications in turn, may provide instant feedback to the transcription machinery. To substantiate the connection between transcription and DNA dynamics, we charted an ENCODE map of transcription-dependent dynamic supercoiling in human Burkitt lymphoma cells using psoralen photobinding to probe DNA topology in vivo. Dynamic supercoils spread ~1.5 kb upstream of the start sites of active genes. Low and high output promoters handle this torsional stress differently as shown using inhibitors of transcription and topoisomerases, and by chromatin immunoprecipation of RNA polymerase and topoisomerases I and II. Whereas lower outputs are managed adequately by topoisomerase I, high output promoters additionally require topoisomerase II. The genome-wide coupling between transcription and DNA topology emphasizes the importance of dynamic supercoiling for gene regulation. Raji cells: untreated and treated with DRB, CPT and BLAP. Three biological replicates per treatment, each hybridized to new array. Total: 12 samples (4 treatments x 3 replicates).
Project description:Maps of open chromatin in a megakaryocytic (CHRF-288-11) and an erythroblastoid (K562) cell line using the formaldehyde-assisted isolation of regulatory elements (FAIRE) method. We profiled chromatin structure at 62 non-redundant genetic loci representing all known associations (as of November 2009, CEU population) with 11 cardiovascular traits: coronary artery disease (CAD), (early-onset) myocardial infarction (MI), mean platelet volume (MPV), platelet counts (PLT), platelet signaling (PLS), white blood cell counts (WBC), red blood cell counts (RBC), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), systolic blood pressure (SBP), diastolic blood pressure (DBP), hypertension (HYP). A total of 4 experiments: FAIRE using two different cross-linking times (8 and 12 min) in two cell types (CHRF-288-11 and K562 cells).
Project description:Using DNaseI hypersensitivity (HS) assays (Dnase-seq), high resolution DNaseI digestion profiles were generated genome-wide in diverse human cell types. We showed that within general regions of DNaseI HS that are known to identify locations of gene regulatory elements, DNaseI digestion patterns allowed us to identify locations of individual transcription factor binding sites that protected against the bound DNA against digestion. To measure the accuracy of these footprints, we also generated ChIP-seq data for the CTCF DNA binding factor in the same cell growths. We found that DNaseI footprints containing the CTCF canonical binding motif show significant ChIP-seq signal while CTCF binding motifs not in footprints show almost no signal providing one measure of valdation of the DNaseI footprints. For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf Five cell lines representing cervica carcinoma, chronic myeloid leukemia, embryonic stem cells, epidermal keratinocytes, and umbilical vein endothelial cells were analyzed using ChIP-seq.
Project description:This SuperSeries is composed of the following subset Series: GSE19622: Individual-specific and allele-specific chromatin signatures in diverse human populations GSE25416: High-resolution genome-wide in vivo footprinting of diverse transcription factors in human cells (ChIP-seq) GSE30226: Open chromatin defined by DNaseI and FAIRE identifies regulatory elements that shape cell-type identity [ChIP_seq]. GSE32692: Cell-type specific and combinatorial usage of diverse transcription factors revealed by genome-wide binding studies in multiple human cells [new ChIP-Seq samples] For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf Refer to individual Series
Project description:This SuperSeries is composed of the following subset Series: GSE25344: High-resolution genome-wide in vivo footprinting of diverse transcription factors in human cells (Dnase-seq) GSE25416: High-resolution genome-wide in vivo footprinting of diverse transcription factors in human cells (ChIP-seq) For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf Refer to individual Series
Project description:Nuclear RNA from Raji human B cells was hybridized to NimbleGen arrays to quantify gene expression levels. Three biological replicates, each hybridized to new array.
Project description:This SuperSeries is composed of the following subset Series: GSE16183: Genome-Wide Promoter Analysis of Epigenetic Regulation by Cocaine (MM5 data) GSE16184: Genome-Wide Promoter Analysis of Epigenetic Regulation by Cocaine (MM8 data) Refer to individual Series
Project description:We applied a ChIP-chip approach to elucidate the binding profiles of RNAP and RpoD experimentally under different growth conditions. This technique localizes DNA fragments within DNA-protein complexes enriched by chromatin immunoprecipitation using high-density oligonucleotide tilling arrays. A 21 ChIP-chip study using immunoprecipitated DNA (IP-DNA) from three culture conditions for RNAP and four culture conditions for RpoD. The high-density oligonucleotide tiling arrays used consisted of 381,174 oligonucleotide probes spaced 20 bp apart (30-bp overlap between two probes) across the G. sulfurreducens genome (NimbleGen). Experiments were conducted as three bioliogical replicates (different cultures).
Project description:DRM is a conserved transcription factor complex that includes E2F/DP and pRB family proteins and plays important roles in development and cancer. Here we analyze genome-wide binding and function of the C. elegans DRM subunit LIN-54. We demonstrate that LIN-54 DNA-binding activity is required for the DRM complex to efficiently bind and regulate target genes containing adjacent putative E2F/DP and LIN-54 binding sites. We show that LIN-54 binds to the promoters of genes involved in cell division, development, and reproduction, and acts differently in the germline versus the soma. The E2F/DP-LIN-54 binding motif, individual target genes, and overall DRM function are conserved among worms, flies, and humans. Despite this conservation, we discovered one striking feature of C. elegans DRM not shared in flies or humans: it is depleted from X chromosomes. We show that DRM binding, the E2F-LIN-54 hybrid motif, and LIN-54-regulated genes are all autosome-enriched. Chromatin-immunoprecipitation of mixed staged wild-type C.elegans (N2, Bristol strain) was performed using non-commercial anti-LIN-54 antibody raised in guinea pig (Harrison et at. 2006).
Project description:Changes in gene expression contribute to the long-lasting regulation of the brain's reward circuitry seen in drug addiction, however, the specific genes regulated and the transcriptional mechanisms underlying such regulation remain poorly understood. Here, we used chromatin immunoprecipitation coupled with promoter microarray analysis to characterize genome-wide epigenetic changes in the mouse nucleus accumbens, a crucial brain reward region, after repeated cocaine administration. Our findings reveal several interesting principles of gene regulation by cocaine and of the role of Î?FosB and CREB, two prominent cocaine-induced transcription factors, in this brain region. Mice were treated with cocaine or saline. Chromatin immunoprecipitation was performed for acetylated histone H3 and H4 as described previously (Kumar et al., 2005) with minor modifications. Immunoprecipitated DNA was amplified via ligation-mediated PCR and hybridized to Nimblgen mouse MM5 promoter arrays. 2 biological replicates per condition.