Effect of DNA binding small molecules on the genomic distribution of nucleosomes with H3K27Ac
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE117409 | GEO | 2018/07/20
REPOSITORIES: GEO
Similar Datasets
Project description:CBL0137 id non-genotoxic DNA binding compounds which directly destabilizes nucleosomes in cells. Effect of different doses of CBL0137 on the abundance of mRNA was studied in two cell types, multiple myeloma MM1.S and cervical carcinoma HeLa cell.
2018-07-25 | GSE117611 | GEO
Project description:H3K27ac modified nucleosomes are a major epigenetic mark of active chromatin that can be used to identify cell type specific chromatin regulatory regions which serve as binding sites for transcription factors. Here we show that H3K27ac modified nucleosomes recruit the ubiquitous nucleosome binding proteins HMGN1 and HMGN2 to cell-type specific chromatin regulatory regions. We find that HMGNs bind directly to the acetylated nucleosome and that the H3K27ac residue and linker DNA are necessary and sufficient for the preferential binding of HMGNs to the modified nucleosomes. Loss of HMGNs increases the levels of H3K27me3 and the histone H1 occupancy at enhancers and promoters and alters the interaction of several transcription factors with chromatin. These experiments identify an additional mechanism whereby the H3K27ac epigenetic mark promotes chromatin decompaction and provide insights into the molecular mechanism whereby HMGN proteins, which bind to chromatin without DNA sequence specificity, modulate cell type specific gene expression.
2020-09-20 | GSE156697 | GEO
Project description:Effect of DNA binding small molecules on the genomic distribution of nucleosomes with H3K27Ac
| PRJNA481998 | ENA
Project description:Nuc-MS characterizes histone modifications and variants directly from intact
endogenous mono-nucleosomes. Preserving whole nucleosome particles enables
precise interrogation of their protein content, as for H3.3-containing nucleosomes which
had 6-fold co-enrichment of variant H2A.Z over bulk chromatin. Moreover, Nuc-MS
showed co-occurrence of oncogenic H3.3K27M with euchromatic marks (e.g., H4K16ac
and >40-fold enrichment of H3K79me2). By capturing the entire epigenetic landscape,
Nuc-MS provides a new, quantitative readout of nucleosome-level biology.
2020-04-06 | MSV000085238 | MassIVE
Project description:The structural complexity of nucleosomes underlies their functional versatility. Here we report a new type of complexity – nucleosome fragility, manifested as high sensitivity to micrococcal nuclease, in contrast to the common presumption that nucleosomes are similar in resistance to MNase digestion. Using differential MNase digestion of chromatin and high-throughput sequencing, we have identified a special group of nucleosomes termed fragile nucleosomes throughout the yeast genome, nearly one thousand of which are at previously determined “nucleosome free” loci. Nucleosome fragility is broadly implicated in multiple chromatin processes, including transcription, translocation and replication, in correspondence to specific physiological states of cells. In the environmental-stress-response genes, the presence of fragile nucleosomes prior to the occurrence of environmental changes suggests that nucleosome fragility poises genes for swift up-regulation in response to the environmental changes. We propose that nucleosome fragility underscores distinct functional statuses of the chromatin and provides a new dimension for portraying the landscape of genome organization. Comparing nucleosome occupancy under different MNase digestion levels and growth conditions.
2011-01-24 | E-GEOD-26412 | biostudies-arrayexpress
Project description:Characteristic features of chromatin states are not limited to particular epigenetic modifications but include other regulatory cues, such as linker DNA length, typically ranging from around 35-55 bp in most eu- and heterochromatin domains (Valouev et al, 2011; Voong et al., 2016, Cell) to over 200 bp in nucleosome-depleted regions (NDRs) found at active enhancers and promoters (Schones et al, 2008; Hansen He et al, 2010). To investigate whether and how nucleosome linker DNA affects chromatin recognition by nuclear proteins we performed an additional set of affinity purifications using di-nucleosomes incorporating different DNA linkers. Here, we investigated the effect of a 200 bp di-nucleosome linker DNA represented by scrambled DNA or SV40 enhancer DNA sequence on the nuclear protein binding to di-nucleosome decorated with enhancer-associated modifications, including H3K4me1 and H3K27ac.
2023-12-12 | PXD041443 | Pride
Project description:Every nucleosome across the genome must be disrupted and reformed when the replication fork passes, but how chromatin organization is re-established following replication is unknown. To address this problem, we have developed Mapping In vivo Nascent Chromatin with EdU and sequencing (MINCE-seq) to characterize the genome-wide location of nucleosomes and other chromatin proteins behind replication forks at high temporal and spatial resolution. We find that the characteristic chromatin landscape at Drosophila promoters and enhancers is lost upon replication. The most conspicuous changes are at promoters that have high levels of RNA polymerase II (RNAPII) stalling and DNA accessibility and show specific enrichment for the BRM remodeler. Enhancer chromatin is also disrupted during replication, suggesting a role for transcription factor (TF) competition in nucleosome re-establishment. Thus, the characteristic nucleosome landscape emerges from a uniformly packaged genome by the action of TFs, RNAPII and remodelers minutes after replication fork passage.
2016-04-07 | GSE76120 | GEO
Project description:The structural complexity of nucleosomes underlies their functional versatility. Here we report a new type of complexity – nucleosome fragility, manifested as high sensitivity to micrococcal nuclease, in contrast to the common presumption that nucleosomes are similar in resistance to MNase digestion. Using differential MNase digestion of chromatin and high-throughput sequencing, we have identified a special group of nucleosomes termed fragile nucleosomes throughout the yeast genome, nearly one thousand of which are at previously determined “nucleosome free” loci. Nucleosome fragility is broadly implicated in multiple chromatin processes, including transcription, translocation and replication, in correspondence to specific physiological states of cells. In the environmental-stress-response genes, the presence of fragile nucleosomes prior to the occurrence of environmental changes suggests that nucleosome fragility poises genes for swift up-regulation in response to the environmental changes. We propose that nucleosome fragility underscores distinct functional statuses of the chromatin and provides a new dimension for portraying the landscape of genome organization.
2011-01-24 | GSE26412 | GEO
Project description:Characteristic features of chromatin states are not limited to particular epigenetic modifications but include other regulatory cues, such as linker DNA length, typically ranging from around 35-55 bp in most eu- and heterochromatin domains (Valouev et al, 2011; Voong et al., 2016, Cell) to over 200 bp in nucleosome-depleted regions (NDRs) found at active enhancers and promoters (Schones et al, 2008; Hansen He et al, 2010). To investigate whether and how the nucleosome linker DNA affects chromatin recognition by nuclear proteins we performed a set of affinity purifications using di-nucleosomes incorporating different DNA linkers. Here, we investigated the effect of a 200 bp di-nucleosome linker DNA represented by scrambled DNA or SV40 promoter DNA sequence on the nuclear protein binding to di-nucleosome decorated with promoter-associated modifications, including H3K4me3K9acK14acK18acK23acK27ac, H4K5acK8acK12acK16acK20me2 and histone variant H2A.Z Below is a description (modifications and linker) of di-nucleosomes used in pull-downs with HeLa nuclear extracts followed by label-free MS: 1. H3K4me3-5ac,H4K20me2-4ac, H2AZ, 50bp linker 2. H3K4me3-5ac,H4K20me2-4ac, H2AZ, 200bp scrambled DNA linker 3. H3K4me3-5ac,H4K20me2-4ac, H2AZ, 200bp SV40 promoter DNA linker 4. Unmod. H3&H4, 50bp linker 5. Unmod. H3&H4, 200bp scrambled DNA linker 6. Unmod. H3&H4, 200bp SV40 promoter DNA linker
2023-12-10 | PXD041835 | Pride
Project description:Nucleosomes in active chromatin are dynamic, but whether they have distinct structural conformations is unknown. To identify nucleosomes with alternative structures genome-wide, we used H4S47C-anchored cleavage mapping, which revealed that nucleosomes at 5% of budding yeast nucleosome positions have asymmetric histone-DNA interactions. These asymmetric interactions are enriched at nucleosome positions that flank promoters. Micrococcal nuclease (MNase) sequence-based profiles of asymmetric nucleosome positions revealed a corresponding asymmetry in MNase protection near the dyad axis, suggesting that the loss of DNA contacts around H4S47 is accompanied by protection of the DNA from MNase. Chromatin immunoprecipitation mapping of selected nucleosome remodelers indicated that asymmetric nucleosomes are bound by the RSC chromatin remodeling complex, which is required for maintaining nucleosomes at asymmetric positions. These results imply that the asymmetric nucleosome-RSC complex is a metastable intermediate representing partial unwrapping and protection of nucleosomal DNA on one side of the dyad axis during chromatin remodeling. We have analyzed the chromatin landscape of the yeast genome using paired-end MNase-seq and the chromatin binding of yeast remodelers Swr1, Ino80 and RSC at base-pair resolution using native chromatin immunoprecipitation followed by sequencing (N-ChIP-seq).
2014-12-04 | E-GEOD-59523 | biostudies-arrayexpress