Drosophila melanogaster
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA213006 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Nucleosomes are barriers to transcription in vitro, however, their effects on RNA polymerase in vivo are unknown. Here we describe a simple and general strategy to comprehensively map the positions of elongating and arrested RNA Polymerase II (RNAPII) at nucleotide resolution. Our results suggest that nucleosomes present significant, context-specific barriers to RNAPII in vivo that can be tuned by the incorporation of H2A.Z. 8 sets of two replicates each of paired-end and 3 sets of two replicates each of single-end samples were sequenced and analyzed.
2014-03-06 | E-GEOD-49106 | biostudies-arrayexpress
Project description:Nucleosomes are barriers to transcription in vitro, however, their effects on RNA polymerase in vivo are unknown. Here we describe a simple and general strategy to comprehensively map the positions of elongating and arrested RNA Polymerase II (RNAPII) at nucleotide resolution. Our results suggest that nucleosomes present significant, context-specific barriers to RNAPII in vivo that can be tuned by the incorporation of H2A.Z.
2014-03-06 | GSE49106 | GEO
Project description:RNA Polymerase-II-generated DNA supercoils destabilize nucleosomes
| PRJNA208068 | ENA
Project description:Nucleosomes that contain the histone variant H2A.Z are enriched around transcriptional start sites in many organisms. A single octameric nucleosome can contain two H2A.Z histones (homotypic) or one H2A.Z and one canonical H2A (heterotype). We generated high-resolution maps of homotypic and heterotypic Drosophila H2A.Z (H2Av) nucleosomes. Although homotypic and heterotypic H2Av nucleosomes map throughout most of the genome, homotypic nucleosomes are enriched and heterotypic nucleosomes are depleted downstream of active promoters and intron/exon boundaries. The distribution of homotypic H2A.Z nucleosomes resembles that of salt-soluble nucleosomes and shows evidence of displacement during transcriptional elongation. Homotypic nucleosomes are also depleted downstream of paused polymerases, where salt-soluble nucleosomes are conspicuously depleted. Our results suggest a model whereby H2A.Z enrichment patterns result from different structural interactions within the core of heterotypic and homotypic nucleosomes following disruption during transcriptional elongation. We analyzed two replicates for input, heterotypic and homotypic purifications. We sequenced one library for each of the single H2Av pulldown and 80mM salt soluble samples.
2010-11-01 | E-GEOD-21615 | biostudies-arrayexpress
Project description:Nucleosomes that contain the histone variant H2A.Z are enriched around transcriptional start sites in many organisms. A single octameric nucleosome can contain two H2A.Z histones (homotypic) or one H2A.Z and one canonical H2A (heterotype). We generated high-resolution maps of homotypic and heterotypic Drosophila H2A.Z (H2Av) nucleosomes. Although homotypic and heterotypic H2Av nucleosomes map throughout most of the genome, homotypic nucleosomes are enriched and heterotypic nucleosomes are depleted downstream of active promoters and intron/exon boundaries. The distribution of homotypic H2A.Z nucleosomes resembles that of salt-soluble nucleosomes and shows evidence of displacement during transcriptional elongation. Homotypic nucleosomes are also depleted downstream of paused polymerases, where salt-soluble nucleosomes are conspicuously depleted. Our results suggest a model whereby H2A.Z enrichment patterns result from different structural interactions within the core of heterotypic and homotypic nucleosomes following disruption during transcriptional elongation.
2010-11-01 | GSE21615 | GEO
Project description:Sequence-specific targeting of dosage compensation in Drosophila favors an active chromatin context (mRNA)
| PRJNA156275 | ENA
Project description:Histone variant H2A.Z-containing nucleosomes are incorporated at most eukaryotic promoters. This incorporation is mediated by the conserved SWR1 complex, which replaces histone H2A in canonical nucleosomes with H2A.Z in an ATP-dependent manner. Here, we show that promoter-proximal nucleosomes are highly heterogeneous for H2A.Z in Saccharomyces cerevisiae, with substantial representation of nucleosomes containing one, two, or no H2A.Z molecules. SWR1-catalyzed H2A.Z replacement in vitro occurs in a stepwise and unidirectional fashion, one H2A.Z-H2B dimer at a time, producing heterotypic nucleosomes as intermediates and homotypic H2A.Z nucleosomes as end products. The ATPase activity of SWR1 is specifically stimulated by H2A-containing nucleosomes without ensuing histone H2A eviction. Remarkably, further addition of free H2A.Z-H2B dimer leads to hyperstimulation of ATPase activity, eviction of nucleosomal H2A-H2B and deposition of H2A.Z-H2B. These results suggest that the combination of H2A-containing nucleosome and free H2A.Z-H2B dimer acting as both effector and substrate for SWR1 governs the specificity and outcome of the replacement reaction. Total nucleosomes from MNase-treated nuclear extracts were fractionated by sequential immunoprecipitation into homotypic H2A/H2A (AA), heterotypic H2A/H2A.Z (AZ), and homotypic H2A.Z/H2A.Z (ZZ) nucleosomes.
2010-10-12 | E-GEOD-24618 | biostudies-arrayexpress
Project description:Sequence-specific targeting of dosage compensation in Drosophila favors an active chromatin context (ChIP-chip)
| PRJNA156273 | ENA
Project description:The histone variant H2A.Z is a hallmark of nucleosomes flanking the promoters of protein coding genes, and is often found in nucleosomes that also carry lysine 56- acetylated histone H3 (H3-K56Ac), a mark which promotes rapid replication- independent turnover of nucleosomes. Although H2A.Z and H3-K56Ac have been generally implicated in transcriptional activation, their exact contributions have remained elusive. Here we find that H3-K56Ac promotes RNA polymerase II occupancy at a large number of protein coding and noncoding loci, yet neither H3- K56Ac nor H2A.Z has a significant impact on steady state mRNA levels in yeast. Instead, broad effects of H3-K56Ac or H2A.Z on levels of both coding and noncoding RNAs (ncRNAs) are only revealed in the absence of the nuclear RNA exosome. H2A.Z is also necessary for expression of divergent, promoter-proximal ncRNAs in mouse embryonic stem cells, suggesting a conserved role for H2A.Z across eukaryotes. Finally, we show that H2A.Z functions with H3-K56Ac in chromosome folding, facilitating formation of chromosome interaction domains (CIDs). Our study suggests that H2A.Z and H3-K56Ac work in concert with the RNA exosome to control mRNA and ncRNA expression, perhaps in part by regulating higher order chromatin structures. 2 replicates of WT (CY1089), rtt109â (CY2210), rrp6â (CY2071) and one replicate of the W303 input (Sample 7). TableS5.xlsx contains the processed IP/input values for each ORF transcript.
2015-11-12 | E-GEOD-72692 | biostudies-arrayexpress
Project description:Transcriptional regulators compete with nucleosomes post-replication
| PRJNA306358 | ENA