Browse
Submit Data
Databases
API
Help

Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Chromatin immunoprecipitation of wild type msc1D and swr1D fission yeast to determine genome-wide distribution of H2A.Z

ABSTRACT: 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.

ORGANISM(S): Schizosaccharomyces pombe

SUBMITTER: Luke Buchanan

PROVIDER: E-MEXP-1986 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Json Xml

Similar Datasets

A histone acetylation switch regulates H2A.Z deposition by the SWR-C remodeling enzyme

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

A histone acetylation switch regulates H2A.Z deposition by the SWR-C remodeling enzyme

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:In eukaryotes, DNA wraps around histones to form nucleosomes, which are compacted into chromatin. DNA-templated processes, including transcription, require chromatin disassembly and reassembly mediated by histone chaperones. Additionally, distinct histone variants can replace core histones to regulate chromatin structure and function. Although replacement of H2A with the evolutionarily conserved H2A.Z via the SWR1 histone chaperone complex has been extensively studied, in plants little is known about how a reduction of H2A.Z levels can be achieved. Here, we show that NRP proteins cause a decrease of H2A.Z-containing nucleosomes in Arabidopsis under standard growing conditions. nrp1-1 nrp2-2 double mutants show an over-accumulation of H2A.Z genome-wide, especially at heterochromatic regions normally H2A.Z-depleted in wild-type plants. Our work suggests that NRP proteins regulate gene expression by counteracting SWR1, thereby preventing excessive accumulation of H2A.Z.

2020-05-18 | PXD019248 | Pride

Identification of PWWP2A interactors using label-free quantitative affinity enrichment mass spectrometry

Project description:Chromatin structure and function is regulated by reader proteins recognizing histone modifications and/or histone variants. We recently identified PWWP2A, which tightly binds to H2A.Z-containing nucleosomes and is involved in mitotic progression and cranial-facial development. Here, using in vitro assays we show that distinct domains of PWWP2A moreover mediate binding to free linker DNA as well as H3K36me3 nucleosomes. In vivo, PWWP2A strongly recognizes H2A.Z-containing regulatory regions and weakly H3K36me3-containing gene bodies. Additionally, PWWP2A bind to an MTA1-specific core NuRD (M1HR) complex solely consisting of MTA1, HDAC1 and RBBP4/7, excluding CHD and MBD proteins. Depletion of PWWP2A leads to an increase of acetylation levels on H3K27 as well as H2A.Z, presumably by impaired chromatin recruitment of M1HR. Thus, this study identifies PWWP2A as an ever more complex chromatin binding protein serving as adapter for M1HR to H2A.Z-containing chromatin, thereby promoting changes in histone acetylation levels and likely fine-tuning the transcriptional balance.

2018-08-27 | PXD010424 | Pride

Epigenetically induced paucity of histone H2A.Z stabilizes fission yeast ectopic centromeres

Project description:In most eukaryotes, the centromere is epigenetically defined by nucleosomes that contain the histone H3 variant centromere protein A (CENP-A). Specific targeting of the CENP-A-loading chaperone to the centromere is vital for stable centromere propagation; however, the existence of ectopic centromeres (neocentromeres) indicates that this chaperone can function in different chromatin environments. The mechanism responsible for accommodating the CENP-A chaperone at novel chromatin regions is poorly understood. Here, we report the identification of transient, immature neocentromeres in Schizosaccharomyces pombe, which show reduced association with the CENP-A chaperone Scm3 attributable to persistence of the histone H2A variant H2A.Z. Following acquisition of adjacent heterochromatin or relocation of the immature neocentromeres to subtelomeric regions, H2A.Z was depleted and Scm3 was replenished, leading to subsequent stabilization of the neocentromeres. These findings provide novel insights into histone variant-mediated epigenetic control of neocentromere establishment. Comparison of chromosomal distributions of centromeric proteins and heterochromatin proteins between the NC survivors and their derivatives.

2013-11-03 | E-GEOD-37094 | biostudies-arrayexpress

H2A.Z marks the 5' end of genes

Project description:In S. cerevisiae, histone variant H2A.Z is deposited in euchromatin at the flanks of silent heterochromatin to prevent its ectopic spread. The degree to which H2A.Z is found and functions elsewhere is unknown. Here we show that H2A.Z nucleosomes are found at promoter regions of nearly all genes in euchromatin. They generally occur as two positioned nucleosomes that flank a nucleosome-free region (NFR) that contains the transcription start site. Astonishingly, enrichment at 5’ ends is independent of transcriptional state as it is observed not only at actively transcribed genes, but also at inactive loci. Mutagenesis of a typical promoter revealed a 22 bp segment of DNA sufficient to program formation of a NFR flanked by two H2A.Z nucleosomes. This segment contains a binding site of the Myb-related protein Reb1 and an adjacent dT:dA tract. Efficient deposition of H2A.Z is further promoted by a specific pattern of histone H3 and H4 tail acetylation and the bromodomain protein Bdf1, a component of the Swr1 complex that deposits H2A.Z. These data define DNA- and histone-based mechanisms by which dividing cells define the 5’ ends of genes and preserve their euchromatic state in the absence of transcription. Keywords: ChIP-chip

2005-10-07 | GSE3411 | GEO

Chromatin immunoprecipitation DNA-sequencing (ChIP-seq) for histone H2A variants and histone modifications in WT Col-0 seedlings.

Project description:How histone intrinsic sequence variation or regulatory modifications regulate nucleosome interactions with transcription remain unclear. To clarify this question, we examined how histone variants and histone modifications assemble in the Arabidopsis thaliana genome, identifying a limited number of chromatin states that divide euchromatin and heterochromatin in biologically significant subdomains. We showed that histone variants were as significant as histone modifications to determine the composition of chromatin states. The loss of function of the chromatin remodeler DECREASED IN DNA METHYLATION (DDM1) prevented the exchange between the histone variants H2A.Z and H2A.W over transposons resulting in their enrichment in chromatin states found only on proteins coding genes in the wild type. Hence, the dynamics of histone H2A variants exchange impacted the definition and distribution of chromatin states. We propose that dynamics of histone variants control the organization of histone modifications into chromatin states to achieve landmarks that signify the ability for transcription. Chromatin immunoprecipitation DNA-sequencing (ChIP-seq) for histone H2A variants and histone modifications in seedlings .

2023-05-09 | GSE226469 | GEO

ChIP-seq for Histone variants and Histone modifictaions in WT and ddm1(-/-) in 1st generation Leaves.

Project description:How histone intrinsic sequence variation or regulatory modifications regulate nucleosome interactions with transcription remain unclear. To clarify this question, we examined how histone variants and histone modifications assemble in the Arabidopsis thaliana genome, identifying a limited number of chromatin states that divide euchromatin and heterochromatin in biologically significant subdomains. We showed that histone variants were as significant as histone modifications to determine the composition of chromatin states. The loss of function of the chromatin remodeler DECREASED IN DNA METHYLATION (DDM1) prevented the exchange between the histone variants H2A.Z and H2A.W over transposons resulting in their enrichment in chromatin states found only on proteins coding genes in the wild type. Hence, the dynamics of histone H2A variants exchange impacted the definition and distribution of chromatin states. We propose that dynamics of histone variants control the organization of histone modifications into chromatin states to achieve landmarks that signify the ability for transcription. Chromatin immunoprecipitation sequencing (ChIP-seq) for histone H2A variants and histone modifications in Col0 and ddm1(-/-) .

2023-05-09 | GSE231398 | GEO

A systematic analysis of Trypanosoma brucei chromatin factors identifies novel protein interaction networks associated with sites of transcription initiation and termination

Project description:Nucleosomes composed of histones are the fundamental units around which DNA is wrapped to form chromatin. Transcriptionally active euchromatin or repressive heterochromatin is regulated in part by the addition or removal of histone post-translational modifications (PTMs) by ‘writer’ and ‘eraser’ enzymes, respectively. Nucleosomal PTMs are recognised by a variety of ‘reader’ proteins which alter gene expression accordingly. The histone tails of the evolutionarily divergent eukaryotic parasite Trypanosoma brucei have atypical sequences and PTMs distinct from those often considered universally conserved. Here we identify 65 predicted readers, writers and erasers of histone acetylation and methylation encoded in the T. brucei genome and, by epitope tagging, systemically localize 60 of them in the parasite’s bloodstream form. ChIP-seq demonstrated that fifteen candidate proteins associate with regions of RNAPII transcription initiation. Eight other proteins exhibit a distinct distribution with specific peaks at a subset of RNAPII transcription termination regions marked by RNAPIII-transcribed tRNA and snRNA genes. Proteomic analyses identified distinct protein interaction networks comprising known chromatin regulators and novel trypanosome-specific components. Notably, several SET-domain and Bromo-domain protein networks suggest parallels to RNAPII promoter-associated complexes in conventional eukaryotes. Further, we identify likely components of TbSWR1 and TbNuA4 complexes whose enrichment coincides with the SWR1-C exchange substrate H2A.Z at RNAPII transcriptional start regions. The systematic approach employed provides detail of the composition and organization of the chromatin regulatory machinery in Trypanosoma brucei and establishes a route to explore divergence from eukaryotic norms in an evolutionarily ancient but experimentally accessible eukaryote.

2021-08-05 | PXD026743 | Pride

Stepwise histone replacement by SWR1 requires dual activation with histone H2A.Z and canonical nucleosome

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

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data