Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA142179 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Coordinated Chromatin Remodeling induced by Demethylation requires SRCAP mediated H2A.Z exchange
| PRJNA136591 | ENA
Project description:Coordinated Chromatin Remodeling induced by Demethylation requires SRCAP mediated H2A.Z exchange [Methylation]
| PRJNA142265 | ENA
Project description:The site-specific chromatin incorporation of eukaryotic histone variant H2A.Z is driven by the multi-component chromatin remodeling complex SWR1/SRCAP/ p400. The budding yeast SWR1 complex replaces the H2A-H2B dimer in the canonical nucleosome with the H2A.Z-H2B dimer, but the mechanism governing the directionality of H2A-to-H2A.Z exchange remains elusive. Here, we use single-molecule force spectroscopy to dissect the disassembly/ reassembly of H2A-nucleosome and H2A.Z-nucleosome. We find that the N-terminal 1-135 residues of yeast SWR1-complex-protein-2 (previously termed Swc2-Z) facilitate the disassembly of nucleosomes containing H2A but not H2A.Z. The Swc2-mediated nucleosome disassembly/reassembly requires the inherently unstable H2A-nucleosome, whose instability is conferred by three H2A α2-helix residues Gly47, Pro49 and Ile63 as they selectively weaken the structural rigidity of H2A-H2B dimer. It also requires Swc2-ZN (residues 1-37) that directly anchors to H2A-nucleosome and functions in the SWR1-catalyzed H2A.Z replacement in vitro and yeast H2A.Z deposition in vivo. Our findings providecrucial insights into how SWR1 complex discriminates between the H2A-nucleosome and H2A.Z-nucleosome, establishing a simple paradigm for the governace of unidirectional H2A.Z exchange.
2021-04-12 | GSE171844 | GEO
Project description:The histone variant H2A.Z plays key roles in gene expression, DNA repair, and centromere function. H2A.Z deposition is controlled by SWR-C chromatin remodeling enzymes that catalyze the nucleosomal exchange of canonical H2A with H2A.Z. Here we report that acetylation of histone H3 lysine 56 (H3-K56Ac) alters the substrate specificity of SWR-C, leading to promiscuous dimer exchange where either H2A.Z or H2A can be exchanged from nucleosomes. This result is confirmed in vivo, where genome-wide analysis demonstrates widespread decreases in H2A.Z levels in yeast mutants with hyperacetylated H3K56. Our work also suggests that a conserved SWR-C subunit may function as a M-bM-^@M-^\lockM-bM-^@M-^] that prevents removal of H2A.Z from nucleosomes. Our study identifies a histone modification that regulates a chromatin remodeling reaction and provides insights into how histone variants and nucleosome turnover can be controlled by chromatin regulators. H2A.Z ChIP seq experiments in mutants with constitutive H3K56ac
2013-04-15 | E-GEOD-43935 | biostudies-arrayexpress
Project description:The histone variant H2A.Z plays key roles in gene expression, DNA repair, and centromere function. H2A.Z deposition is controlled by SWR-C chromatin remodeling enzymes that catalyze the nucleosomal exchange of canonical H2A with H2A.Z. Here we report that acetylation of histone H3 lysine 56 (H3-K56Ac) alters the substrate specificity of SWR-C, leading to promiscuous dimer exchange where either H2A.Z or H2A can be exchanged from nucleosomes. This result is confirmed in vivo, where genome-wide analysis demonstrates widespread decreases in H2A.Z levels in yeast mutants with hyperacetylated H3K56. Our work also suggests that a conserved SWR-C subunit may function as a “lock” that prevents removal of H2A.Z from nucleosomes. Our study identifies a histone modification that regulates a chromatin remodeling reaction and provides insights into how histone variants and nucleosome turnover can be controlled by chromatin regulators.
2013-04-15 | GSE43935 | GEO
Project description:Eukaryotic genomes are repetitively packaged into chromatin by nucleosomes, however they are regulated by the differences between nucleosomes, which establish various chromatin states. Replication-independent histone exchange could potentially perturb chromatin status if histone exchange chaperones, such as Swr1C, loaded histone variants into wrong sites. Here we use ChIP-chip analysis of H2A.Z-myc to show that in S.pombe, like S.cerevisiae, Swr1C is required for loading H2A.Z into specific sites, including the promoters of lowly expressed genes. However S.pombe Swr1C has an extra subunit, Msc1, which is a JumonjiC-domain protein of the Lid/Jarid1 family. The absence of Msc1 does not disrupt the S.pombe Swr1C or H2A.Z distribution in euchromatin. However in the absence of either Msc1 or Swr1 H2A.Z is ectopically found in the inner centromere and in subtelomeric chromatin. Normally this subtelomeric region, which appears to be a novel chromatin domain that we term ST-chromatin, not only lacks H2A.Z but also shows uniformly lower levels of H3K4me2, H4K5 and K12K5 acetylation than euchromatin. It also disproportionately contains the most lowly expressed genes during vegetative growth, including many meiotic-specific genes. These data describe H2A.Z distribution in S.pombe and identify a new mode of chromatin surveillance and maintenance based on negative regulation of histone variant misincorporation.
2009-11-09 | E-MEXP-1986 | biostudies-arrayexpress
Project description:ANP32e, a chaperone of H2A.Z, is receiving increasing attention because of its link to cancer growth and progression. An unanswered question is whether ANP32e regulates H2A.Z dynamics during the cell cycle; if so, this could have clear implications for the proliferation of cancer cells. Using the human U2OS cancer cell line model system, we have confirmed that ANP32e regulates the growth of these cells. ANP32e preferentially interacts with H2A.Z during G1 phase of the cell cycle. Unexpectedly, however, ANP32e does not mediate the removal of H2A.Z from chromatin, is not a stable component of the p400 remodeling complex, and is not strongly associated with chromatin. Instead, most ANP32e is in the cytoplasm. Here, ANP32e preferentially interacts with H2A.Z in G1 phase in response to an increase in H2A.Z protein abundance and regulates its protein stability. This G1-specific interaction between ANP32e and H2A.Z is also observed in the nucleoplasm but is unrelated to any change in H2A.Z abundance. Collectively, these results challenge the idea that ANP32e is involved in regulating the abundance of H2A.Z in chromatin as part of a chromatin remodeling complex. Rather, we propose that ANP32e acts as a molecular chaperone that maintains the soluble pool of H2A.Z by regulating its protein stability and acting as a buffer in response to cell cycle-dependent changes in H2A.Z abundance.
2024-05-23 | PXD033229 | Pride
Project description:The histone variant H2A.Z has been implicated in nucleosome exchange, transcriptional activation and Polycomb repression. However, the relationships among these seemingly disparate functions remain obscure. We mapped H2A.Z genome-wide in mammalian ES cells and neural progenitors. H2A.Z is deposited promiscuously at promoters and enhancers, and correlates strongly with H3K4 methylation. Accordingly, H2A.Z is present at poised promoters with bivalent chromatin and at active promoters with H3K4 methylation, but is absent from stably repressed promoters that are specifically enriched for H3K27 trimethylation. We also characterized post-translational modification states of H2A.Z, including a novel species dually-modified by ubiquitination and acetylation that is enriched at bivalent chromatin. Our findings associate H2A.Z with functionally distinct genomic elements, and suggest that post-translational modifications may reconcile its contrasting locations and roles. Examination of histone variant, histone modifications and transcription machinery in 3 cell types
2012-07-19 | E-GEOD-39237 | biostudies-arrayexpress
Project description:Background: Repair of DNA damage requires chromatin remodeling to permit removal of the lesions. How nucleosomes are remodelled to initiate repair of DNA damage remains largely unknown. Here, we describe how chromatin is altered during repair of UV-induced DNA damage at the level of the linear organisation of nucleosomes. Results: Using MNase-seq, we identified a subset of nucleosomes in the genome that are remodelled in UV-damaged wild-type yeast cells. We mapped the genomic location of these nucleosomes, showing that they contain the histone variant H2A.Z. The remodelling observed is consistent with histone exchange or eviction at these positions. This depends on the yeast SWI/SNF global genome nucleotide excision repair (GG-NER) chromatin-remodelling complex. Remarkably, we found that in the absence of DNA damage, the GG-NER complex occupies chromatin at nucleosome free regions separating adjacent nucleosomes. This establishes the nucleosome structure at these genomic locations, which we refer to as GG-NER complex binding sites (GCBS’s). We observed that these sites are frequently located precisely at certain boundary regions that delineate chromasomally interacting domains (CIDs). These boundaries define chromosomal domains of higher-order nucleosome-nucleosome interaction. We demonstrate that the GG-NER complex redistributes following remodelling of these nucleosomes after DNA damage taking up genomic positions located within the CIDs. This permits the efficient removal of DNA damage at these sites. Conclusions: We argue that organising DNA repair in the genome as described may define origins of DNA repair that greatly reduces the genomic search space for DNA damage recognition, thus ensuring the efficient repair of damage in chromatin.
2018-12-06 | E-MTAB-6569 | biostudies-arrayexpress
Project description:Glucocorticoid hormone plays a major role in metabolism and many related diseases. The hormone-bound glucocorticoid receptor (GR) binds to a specific set of enhancers in different cell types, resulting in unique patterns of gene expression. GR-responsive enhancers have an accessible chromatin structure prior to hormone treatment (“pre-programmed”), whereas unresponsive enhancers specific to other cell types are inaccessible and inactive. Here we have addressed the role of chromatin structure in cell-specific GR-enhancer programming by precise mapping of nucleosome positions in mouse adenocarcinoma cells. We show that, before hormone treatment, some pre-programmed GR-enhancers are nucleosome-depleted, associated with the Brg1 chromatin remodeler and flanked by nucleosomes exchanging histones H2A.Z and H2A. However, most pre-programmed GR-enhancers are assembled into a nucleosome that exchanges H2A.Z and H2A, with little or no Brg1. After hormone treatment, nucleosomes at both types of pre-programmed GR-enhancer shift apart, coinciding with increased levels of Brg1, and continue to exchange H2A.Z and H2A. Hormone removal rapidly reverses these nucleosome shifts. In contrast, inactive GR-enhancers are nucleosomal, lack Brg1, do not exchange H2A.Z or H2A and do not respond to hormone. Thus, pre-programmed GR-enhancers are marked by a dynamic, mutable chromatin structure characterized by high levels of H2A.Z exchange. We propose that nucleosome-depleted GR-enhancers result from the binding of other transcription factors together with Brg1 to assist loading of GR after hormone treatment. At nucleosomal enhancers, GR binding may be directly facilitated by increased transient exposure of enhancer DNA associated with H2A.Z exchange.
2017-11-06 | GSE92505 | GEO