Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

MEDIATOR subunit med8 binding in Saccharomyces cerevisiae

ABSTRACT: The Mediator complex transmits activation signals from DNA bound transcription factors to the core transcription machinery. Genome wide localization studies have demonstrated that Mediator occupancy not only correlates with high levels of transcription, but that the complex also is present at transcriptionally silenced locations. We provide evidence that Mediator localization is guided by an interaction with histone tails, and that this interaction is regulated by their post-translational modifications. A quantitative, high-density genetic interaction map revealed links between Mediator components and factors affecting chromatin structure, especially histone deacetylases. Peptide binding assays demonstrated that pure wild type Mediator forms stable complexes with the tails of Histone H3 and H4. These binding assays also showed Mediator – histone H4 peptide interactions are specifically inhibited by acetylation of the histone H4 lysine 16, a residue critical in transcriptional silencing. Finally, these findings were validated by tiling array analysis, that revealed a broad correlation between Mediator and nucleosome occupancy in vivo, but a negative correlation between Mediator and nucleosomes acetylated at histone H4 lysine 16. Our studies show that chromatin structure and the acetylation state of histones are intimately connected to Mediator localization.

ORGANISM(S): Saccharomyces cerevisiae

PROVIDER: GSE28613 | GEO | 2011/11/22

SECONDARY ACCESSION(S): PRJNA138751

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

MEDIATOR subunit med8 binding in Saccharomyces cerevisiae

Project description:The Mediator complex transmits activation signals from DNA bound transcription factors to the core transcription machinery. Genome wide localization studies have demonstrated that Mediator occupancy not only correlates with high levels of transcription, but that the complex also is present at transcriptionally silenced locations. We provide evidence that Mediator localization is guided by an interaction with histone tails, and that this interaction is regulated by their post-translational modifications. A quantitative, high-density genetic interaction map revealed links between Mediator components and factors affecting chromatin structure, especially histone deacetylases. Peptide binding assays demonstrated that pure wild type Mediator forms stable complexes with the tails of Histone H3 and H4. These binding assays also showed Mediator – histone H4 peptide interactions are specifically inhibited by acetylation of the histone H4 lysine 16, a residue critical in transcriptional silencing. Finally, these findings were validated by tiling array analysis, that revealed a broad correlation between Mediator and nucleosome occupancy in vivo, but a negative correlation between Mediator and nucleosomes acetylated at histone H4 lysine 16. Our studies show that chromatin structure and the acetylation state of histones are intimately connected to Mediator localization. Med8-TAP strain ChIPed with IgG beads vs. Input in Saccharomyces cerevisiae

2011-11-22 | E-GEOD-28613 | biostudies-arrayexpress

Acetyl-CoA production by Mediator-bound 2-ketoacid dehydrogenases boosts de novo histone acetylation and is regulated by nitric oxide

Project description:Histone modifying enzymes depend on the availability of cofactors, with acetyl-CoA being required for lysine acetyltransferase (KAT) activity. The discovery that mitochondrial acyl-CoA producing enzymes are also delivered to the nucleus, suggests that high concentrations of metabolites generated locally may impact acetylation of histones and other nuclear substrates and eventually control gene regulation. Here we show that 2-ketoacid dehydrogenase complexes were stably associated with the Mediator complex in macrophages, thus providing a local supply of acetyl-CoA and increasing the generation of hyper-acetylated histone tails. Nitric oxide (NO), which is produced in large amounts in LPS-stimulated macrophages, inhibited both the activity of 2-ketoacid dehydrogenases and their association with Mediator. Consequently, NO reduced de novo histone acetylation at genomic regions with high acetyl-CoA deposition rates. Our findings indicate that a local supply of acetyl-CoA generated by Mediator-bound 2-ketoacid dehydrogenases is required to maximize acetylation of histone tails at sites of elevated HAT activity.

2024-02-14 | PXD040937 | Pride

Genetic dissection of NuA4-directed chromatin transactions throughout the S. cerevisiae genome

Project description:Acetylation of histone tails has long been associated with gene activation. Exactly how acetylation regulates gene expression is not fully known. Acetylation events at specific sites or collections of sites on histones elicit distinct outcomes. Here we examine the downstream consequences of histone acetylation by the histone H4 acetyltransferase NuA4 on a genomic scale. Evidence is presented that Bdf1, which is known to bind to acetylated lysine H4 tails in vitro, binds to nucleosomes in vivo and that this binding is dependent upon Esa1, the catalytic subunit of NuA4. Loss of NuA4 results in a coordinate depletion of Bdf1, the transcription complex assembly factor TFIID, and the H2A.Z assembly complex SWR-C at highly acetylated promoter regions. This finding is consistent with known interactions between Bdf1 and TFIID and SWR-C. Loss of Bdf1 results in little or no depletion of TFIID or SWR-C at these promoter regions, possibly due to substitution by the Bdf1 paralog Bdf2. Consistent with this possibility, loss of Bdf1 results in accumulation of Bdf2 at sites normally bound by Bdf1. Together, the findings presented here strengthen the proposed cascade of events whereby nucleosome H4 acetylation by NuA4 at promoters target Bdf1, which then recruits TFIID and SWR-C to assemble the transcription machinery. Keywords: chIP-chip, histone acetylation, transcription factor recruitment

2007-06-06 | GSE6707 | GEO

Dynamic competing histone H4 K5K8 acetylation and butyrylation are hallmarks of highly active gene promoters

Project description:Newly discovered histone lysine acylations increase the functional diversity of nucleosomes well beyond acetylation. Here, we focus on histone butyrylation in the context of sperm cell differentiation. Specifically, we investigate the butyrylation of histone H4 lysine 5 and 8 at gene promoters, where acetylation guides the binding of Brdt, a bromodomain-and-extra-terminal protein, thereby mediating stage-specific gene expression programs. Genome-wide mapping data show that highly active Brdt-bound gene promoters systematically harbour competing histone acetylation and butyrylation marks at H4 K5 and K8. Histone butyrylation, despite acting as a direct stimulator of transcription, competes with acetylation, especially at H4 K5, to prevent Brdt binding. The observed in vivo H4 K5K8 acetylation butyrylation state at active promoters is reproduced in vitro where p300 indistinctly acetylates and butyrylates H4 K5 and K8. Altogether, highly active gene promoter regions are characterized by alternating H4 acetylation and butyrylation sustaining direct gene activation and a dynamic bromodomain binding.

2016-07-13 | GSE77277 | GEO

ChIP-Seq of H4K5acK8ac and BRD2 in H23 NSCLC cell line treated with 500 nM JQ1 for 24h

Project description:Changes in acetylation of histone H4 are a common hallmark of cancer cells. In leukemia cells, histone H4 is characterized by loss of K16 mono-acetylation. Bromodomain proteins specifically recognize acetylated lysines and have been used as a target for anti cancer drug, JQ1 and iBET. Although acetylation and de-acetylation of histone H4 have been shown to have big impact in cancer cells, little attention has been focused on histone H4-acetylation at a genome level. To uncover potential epigenetic role of hyper-acetylated histone H4 at a genome-wide level in cancer cell, we generated a novel monoclonal antibody specifically recognizing histone H4 with at least two acetylated lysine residues (H4K5ac+K8ac). At the genome-wide level, hyper-acetylated histone H4 is associated with promoter and regulatory element (active enhancer, eRNA and super enhancer). We show that diacetylation at K5 and K8 of histone H4 co-localizes H3K27ac and BRD2 in the majority of active enhancer and promoters. However BRD2 has a stronger association with H4K5acK8ac. Furthermore we identified two specific chromatin states, which separately contain either H3K27ac or acetylated histone H4. Although JQ1 led to global reduction of BRD2 binding on the chromatin, only local changes of histone H4 multi-acetylation were observed upon BET inhibition by JQ1

2018-06-04 | GSE113714 | GEO

Multi-omic analysis of gametogenesis reveals a novel signature at the promoters and distal enhancers of active genes

Project description:Epigenetic regulation of gene expression is tightly controlled by the dynamic modification of histones by chemical groups, the diversity of which has largely expanded over the past decade with the discovery of lysine acylations, catalyzed from acyl-coenzymes A. Here, we investigated the dynamics of lysine acetylation and crotonylation on histones H3 and H4 during mouse spermatogenesis. Lysine crotonylation appeared to be of significant abundance compared to acetylation, particularly on Lys27 of histone H3 (H3K27cr) that accumulates in sperm in a cleaved form of H3. We identified the genomic localization of H3K27cr and studied its effects on transcription compared to the classical active mark H3K27ac at promoters and distal enhancers. The presence of both marks was strongly associated with highest gene expression. Assessment of their co-localization with transcription regulators (SLY, SOX30) and chromatin-binding proteins (BRD4, BORIS and CTCF) indicated systematic highest binding when both active marks were present and different selective binding when present alone at chromatin. H3K27cr and H3K27ac finally mark the building of some sperm super-enhancers. This integrated analysis of omics data provides an unprecedented level of understanding of gene expression regulation by H3K27cr in comparison to H3K27ac, and reveals both synergistic and specific actions of each histone modification.

2020-03-11 | E-MTAB-8328 | biostudies-arrayexpress

ING4 ChIP-chip in HT1080 cells

Project description:Aberrations in chromatin dynamics play a fundamental role in tumorigenesis, yet relatively little is known of the molecular mechanisms linking histone lysine methylation to neoplastic disease. ING4 (Inhibitor of Growth 4) is a native subunit of an HBO1 histone acetyltransferase (HAT) complex and a tumor suppressor protein. Here we show a critical role for the specific read-out of histone H3 trimethylated at lysine 4 (H3K4me3) by the ING4 PHD finger in mediating ING4 gene expression and tumor suppressor functions. The interaction between ING4 and H3K4me3 augments the acetylation activity of HBO1 on H3 tails, and drives H3 acetylation at ING4 target promoters to effect a DNA damage-dependent gene expression program. Further, ING4 facilitates apoptosis in response to genotoxic stress and inhibits anchorage-independent cell growth, and these functions are dependent on ING4 interactions with H3K4me3. Together, our results demonstrate a mechanism for brokering crosstalk between H3K4 methylation and histone H3 acetylation, and reveal a new molecular link between chromatin modulation and tumor suppressor mechanisms. ING4 ChIP-chip +/- Doxorubicin treatment in HT1080 cells on Nimblegen whole genome promoter array 4 samples: HT1080 cell lines stably expressing Flag-ING4 or Flag-ING4-D213A, +/- doxorubicin

2010-05-17 | E-GEOD-13412 | biostudies-arrayexpress

Acetyl-CoA production by Mediator-bound 2-ketoacid dehydrogenases boosts de novo histone acetylation and is regulated by nitric oxide [Chipseq_MED1_RAW2647]

Project description:Histone modifying enzymes depend on the availability of cofactors, with acetyl-CoA being required for histone acetyltransferase (HAT) activity. The discovery that mitochondrial acyl-CoA producing enzymes are also delivered to the nucleus suggests that high concentrations of metabolites generated locally may impact acetylation of histones and other nuclear substrates and eventually control gene regulation. Here we show that 2-ketoacid dehydrogenases were stably associated with the Mediator complex in macrophages, thus providing a local supply of acetyl-CoA and increasing the generation of hyper-acetylated histone tails. Nitric oxide (NO), which is produced in large amounts in LPS-stimulated macrophages, inhibited both the activity of 2-ketoacid dehydrogenases and their association with Mediator. Consequently, NO reduced de novo histone acetylation at genomic regions with high acetyl-CoA deposition rates. Our findings indicate that a local supply of acetyl-CoA generated by Mediator-bound 2-ketoacid dehydrogenases is required to maximize acetylation of histone tails at sites of elevated HAT activity.

2024-11-19 | GSE245579 | GEO

Acetyl-CoA production by Mediator-bound 2-ketoacid dehydrogenases boosts de novo histone acetylation and is regulated by nitric oxide [Chrom_RNAseq_iNOS1400W]

2024-11-19 | GSE245445 | GEO

Acetyl-CoA production by Mediator-bound 2-ketoacid dehydrogenases boosts de novo histone acetylation and is regulated by nitric oxide [Chipseq_panAc_spikein]

2024-11-19 | GSE245444 | GEO