Distinct factors control histone variant H3.3 localization at specific genomic regions
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE16893 | GEO | 2010/03/04
SECONDARY ACCESSION(S): PRJNA117667
REPOSITORIES: GEO
Similar Datasets
Project description:The incorporation of histone H3 variants has been implicated in the epigenetic memory of cellular state. Using genome editing with zinc finger nucleases to tag endogenous H3.3, we report genome-wide profiles of H3 variants in mammalian embryonic stem (ES) cells and neuronal precursor cells. Genome-wide patterns of H3.3 are dependent on amino acid sequence, and change with cellular differentiation at developmentally regulated loci. The H3.3 chaperone Hira is required for H3.3 enrichment at active and repressed genes. Strikingly, Hira is not essential for localization of H3.3 at telomeres and many transcription factor binding sites. Immunoaffinity purification and mass spectrometry reveal that the proteins Atrx and Daxx associate with H3.3 in a Hira-independent manner. Atrx is required for Hira-independent localization of H3.3 at telomeres, and for the repression of telomeric RNA. Our data demonstrate that multiple and distinct factors are responsible for H3.3 localization at specific genomic locations in mammalian cells. Crosslinking ChIP-seq: Examination of 1 histone variant (H3.3), 2 histone modifications, and Serine-5 phosphorylated RNA polymerase in 2 different cell types (H3.3-HA ES samples 1-4, and H3.3-HA NPC samples 7-10). Examination of 1 histone variant (H3.2), and one histone modification (H3K36me3) in 2 different cell types (H3.2-HA ES samples 5-6, and H3.2-HA NPC samples 11-12). Examination of 1 histone variant (H3.3), input control, and one histone modification (H3K36me3) in one cell type (H3.3-HA hybrid ES, samples 13-15). Examination of 1 histone variant (H3.1S31), input control, and one histone modification (H3K36me3) in one cell type (H3.1S31-HA hybrid ES, samples 16-18). Native ChIP-seq: Examination of 1 histone variant (H3.3), input control, and one histone modification (H3K4me3) in one cell type (H3.3-HA ES, samples 19-21). Examination of 1 histone variant (H3.2), input control, and two histone modifications (H3K4me3 and H3K27me3) in one cell type (H3.2-HA ES, samples 22-25). Examination of 1 histone variant (H3.3), input control, and two histone modifications (H3K4me1 and H3K36me3) in one cell type (H3.3-EYFP ES, samples 26-29). Examination of 1 histone variant (H3.3), input control, and two histone modifications (H3K4me1 and H3K36me3) in one cell type (Hira -/- H3.3-EYFP ES, samples 30-33). Examination of 1 histone variant (H3.3) and input control in one cell type (Atrxflox H3.3-EYFP ES, samples 34-37). Examination of HA antibody background in one cell type (wild-type ES, sample 38).
2010-03-04 | E-GEOD-16893 | biostudies-arrayexpress
Project description:Establishment of a proper chromatin landscape is central to genome function. Here, we explain H3 variant distribution by specific targeting and dynamics of deposition involving the CAF-1 and HIRA histone chaperones. Impairing replicative H3.1 incorporation via CAF-1 enables an alternative H3.3 deposition at replication sites via HIRA. Conversely, the H3.3 incorporation throughout the cell cycle via HIRA cannot be replaced by H3.1. ChIP-seq analyses reveal correlation between HIRA-dependent H3.3 accumulation and RNA pol II at transcription sites and specific regulatory elements, further supported by their biochemical association. Remarkably, the HIRA complex shows unique DNA binding properties and depleting HIRA increases DNA sensitivity to nucleases. We propose that protective gap-filling of naked DNA by HIRA leads to a broad distribution of H3.3, and HIRA association with Pol II ensures local H3.3 enrichment at specific sites. Examination of genome-wide localization of two histone H3 variants.
2011-12-16 | E-GEOD-31794 | biostudies-arrayexpress
Project description:Alterations to chromatin modifiers, such as the inactivating mutations in the ATRX-DAXX chromatin remodeling/histone H3.3 deposition complex, are implicated as drivers of the cancer-specific Alternative Lengthening of Telomeres (ALT) pathway. Prior studies revealed that HIRA adapts to compensate for ATRX-DAXX loss to sustain ALT cancer cell survival. However, the specific mechanisms underlying HIRA’s ability to rescue telomeres from the consequences of ATRX-DAXX loss remain unclear. Here, using ATAC-seq and CUT&RUN, we demonstrate that HIRA-mediated deposition of new H3.3 is essential to maintain chromatin accessibility and to prevent the detrimental accumulation of nucleosome-free single-stranded DNA (ssDNA) at telomeres in ATRX-deficient ALT cancer cells. We provide evidence that the timely deposition of new H3.3 by HIRA and interacting partners UBN1 and UBN2 is crucial to prevent unwarranted TERRA R-loop formation and transcription-replication conflicts (TRCs) at telomeres. Furthermore, we determined that the delivery of H3.3 to telomeric chromatin by HIRA may link the phosphorylation of an H3.3-specific amino acid, serine 31, by Chk1 with mechanisms that promote productive ALT. Therefore, these studies identify a role for HIRA-mediated histone H3.3 deposition in TERRA R-loop homeostasis that we propose is essential for ensuring the survival of ALT cancer cells where the ATRX-DAXX complex is activated.
2024-10-21 | GSE269268 | GEO
Project description:Alterations to chromatin modifiers, such as the inactivating mutations in the ATRX-DAXX chromatin remodeling/histone H3.3 deposition complex, are implicated as drivers of the cancer-specific Alternative Lengthening of Telomeres (ALT) pathway. Prior studies revealed that HIRA adapts to compensate for ATRX-DAXX loss to sustain ALT cancer cell survival. However, the specific mechanisms underlying HIRA’s ability to rescue telomeres from the consequences of ATRX-DAXX loss remain unclear. Here, using ATAC-seq and CUT&RUN, we demonstrate that HIRA-mediated deposition of new H3.3 is essential to maintain chromatin accessibility and to prevent the detrimental accumulation of nucleosome-free single-stranded DNA (ssDNA) at telomeres in ATRX-deficient ALT cancer cells. We provide evidence that the timely deposition of new H3.3 by HIRA and interacting partners UBN1 and UBN2 is crucial to prevent unwarranted TERRA R-loop formation and transcription-replication conflicts (TRCs) at telomeres. Furthermore, we determined that the delivery of H3.3 to telomeric chromatin by HIRA may link the phosphorylation of an H3.3-specific amino acid, serine 31, by Chk1 with mechanisms that promote productive ALT. Therefore, these studies identify a role for HIRA-mediated histone H3.3 deposition in TERRA R-loop homeostasis that we propose is essential for ensuring the survival of ALT cancer cells where the ATRX-DAXX complex is activated.
2024-10-21 | GSE269261 | GEO
Project description:Maintenance of chromatin homeostasis involves proper delivery of histone variants to the genome. The interplay between different chaperones regulating the supply of histone variants to distinct chromatin domains remains largely undeciphered. We report a role of promyelocytic leukemia (PML) protein in the routing of histone variant H3.3 to chromatin and in the organization of megabase-size heterochromatic PML-associated domains that we call PADs. Loss of PML alters the heterochromatic state of PADs by shifting the histone H3 methylation balance from K9me3 to K27me3. Loss of PML impairs deposition of H3.3 by ATRX and DAXX in PADs but preserves the H3.3 loading function of HIRA in these regions. Our results unveil an unappreciated role of PML in the large-scale organization of chromatin and demonstrate a PML-dependent role of ATRX/DAXX in the deposition of H3.3 in PADs. Our data suggest that H3.3 loading by HIRA and ATRX-dependent H3K27 trimethylation constitute mechanisms ensuring maintenance of heterochromatin when the integrity of these domains is compromised.
2017-03-06 | GSE66364 | GEO
Project description:Histone chaperones prevent promiscuous histone interactions before chromatin assembly. They guarantee faithful deposition of canonical histones and functionally specialized histone variants into chromatin in a spatial- and temporally-restricted manner. Here, we identify the binding partners of the primate-specific and H3.3-related histone variant H3.Y using several quantitative mass spectrometry approaches, and biochemical and cell biological assays. We find the HIRA, but not the DAXX/ATRX, complex to specifically recognize H3.Y, explaining its presence in transcriptionally active euchromatic regions. Accordingly, H3.Y nucleosomes are enriched in the transcription-promoting FACT complex and depleted of repressive posttranslational histone modifications. H3.Y mutational gain-of-function analyses screens reveal an unexpected combinatorial amino acid sequence requirement for histone H3.3 interaction with DAXX but not HIRA, and for H3.3 recruitment to PML nuclear bodies. We demonstrate the importance and necessity of specific H3.3 core region and C-terminal amino acids in discriminating between distinct chaperone complexes. Further, ChIP-seq experiments reveal that in contrast to euchromatic HIRA-dependent deposition sites, human DAXX/ATRX-dependent regions of histone H3 variant incorporation are enriched in heterochromatic H3K9me3 and simple repeat sequences. These data demonstrate that H3.Y's unique amino acids allow a functional distinction between HIRA and DAXX binding and its consequent deposition into open chromatin.
2017-03-13 | GSE94034 | GEO
Project description:The synthesis of poly(ADP-ribose) (PAR) reconfigures the local environment and recruits repair complexes to damaged chromatin. The degradation of PAR by PARG is essential for progression and completion of DNA repair. Here, we show that inhibition of PARG disrupts homology-directed repair (HDR) mechanisms that underpin alternative telomere lengthening (ALT). By proteomics, we uncovered a novel role for PARylation in regulating the chromatin assembly factor, HIRA in ALT cancer cells. We show that HIRA is enriched at telomeres during G2 phase and is indispensable for histone H3.3 deposition and telomere DNA synthesis. Depletion of HIRA elicits systemic death of ALT cancer cells was mitigated by re-expression of ATRX protein that is frequently inactivated in ALT tumors. We propose that PARylation enables HIRA to fulfill its essential role in the adaptive response due to ATRX deficiency that pervades ALT cancers.
2020-10-12 | PXD020243 | Pride
Project description:<p>Many tumors maintain chromosome ends through a telomerase-independent, homologous recombination based mechanism called alternative lengthening of telomeres (ALT). While ALT occurs in only a subset of tumors, it is strongly associated with mutations in the genes encoding components of the histone H3.3 chaperone complex, ATRX and DAXX. To date the mechanistic role of ATRX and particularly DAXX mutations in potentiating ALT remains poorly understood. We identify an osteosarcoma cell line, G292, with a unique chromosomal translocation resulting in loss of DAXX function, while retaining functional ATRX. Using this distinctive resource, we demonstrate that introduction of wild type DAXX suppresses the ALT phenotype and restores localization of the ATRX/DAXX complex to PML bodies. This provides the first direct molecular evidence that ongoing DAXX deficiency is essential for maintenance of the ALT phenotype and highlights the potential for therapeutic targeting of this oncogenic pathway.</p>
| phs001495 | dbGaP
Project description:We developed a new sequencing assay to track the de novo deposition of the histone H3 variants H3.1 and H3.3 during S phase. We use cells stably expressing H3.1-SNAP or H3.3-SNAP, and synchronize them in G1/S by double-thymidine block. The SNAP-tag enables to discriminate newly synthesized histones from preexisting ones, via a quench-chase-capture strategy. We applied this strategy to isolate new H3.1 and H3.3 after releasing cells into S phase, and probed their distribution by MNase digestion and sequencing. We could thus characterize H3.1 and H3.3 dynamics from early to mid S phase at genome-wide resolution. We further applied our method to investigate the consequences of perturbations upon deletion of the H3.3 chaperone HIRA. We used HIRA knockout and control cells, and compared H3.1 and H3.3 distribution to early replication patterns by EdU labeling and sequencing of nascent DNA.
2022-03-31 | E-MTAB-10619 | biostudies-arrayexpress
Project description:ATRX is a chromatin remodelling protein of the SWI/SNF family, mutations in which cause alpha thalassemia X-linked (ATRX) intellectual disability syndrome and are highly associated with a number of cancers characterized by alternative lengthening of telomeres. ATRX functions with the histone chaperone DAXX to facilitate deposition of the histone variant H3.3 at heterochromatic regions such as telomere and pericentric repeats, resulting in a unique form of heterochromatin characterized by both trimethylation of histone H3 at lysine 9 (H3K9me3) and H3.3. How ATRX is recruited to these regions remain unclear.To better understand it, we therefore used immunoprecipitation-coupled to mass spectrometry (IP-MS) to identify potential factors that interact with ATRX and may promote its localization and function. Based on our proteomics results, we identified known ATRX-interacting proteins, DAXX and MRE11. We also identified a number of proteins that have been genetically linked to G-quadruplex structures. Interestingly, we identified members of DNA replcation machinery MCM complex (e.g. MCM2, MCM4, MCM6, and MCM7) and the faciliates chromatin transcription (FACT) comeplex as novel ATRX-interacting proteins. We then verified the interaction of ATRX to MCM proteins and FACT subunits by co-immunoprecipition/immunoblot and proximity ligation assay.
2020-06-03 | MSV000085543 | MassIVE