Study of mitotic chromatin shows involvement of histone modifications in bookmarking and reveals nucleosome deposition patterns
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE108173 | GEO | 2018/08/26
REPOSITORIES: GEO
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Project description:Javasky E, Shamir I, Gandhi S, Egri S, Sandler O, Rothbart SB, Kaplan N, Jaffe JD, Goren A, and Simon I. Genome Research 2018. Mitosis encompasses key molecular changes including chromatin condensation, nuclear envelope breakdown and reduced transcription levels. Immediately after mitosis, the interphase chromatin structure is reestablished and transcription resumes. The reestablishment of the interphase chromatin requires bookmarking, i.e., the retention of at least partial information during mitosis. Yet, while recent studies demonstrate that chromatin accessibility is generally preserved during mitosis and is only locally modulated, the exact details of the bookmarking process and its components are still unclear. To gain a deeper understanding of the mitotic bookmarking process, we merged proteomics, immunofluorescence, and ChIP-seq approaches to study the mitotic and interphase organization in human cells. We focused on key histone modifications, and employed the HeLa-S3 cells as a model system. Generally, we observed a global concordance between the genomic organization of histone modifications in interphase and mitosis, yet the abundance of the two types of modifications we investigated was different. Whereas histone methylation patterns remain highly similar, histone acetylation patterns show a general reduction while maintaining their genomic organization. In line with a recent study demonstrating that minimal transcription is retained during mitosis, we show that RNA polymerase II does not fully disassociate from the genome, but rather maintains its genomic localization at reduced levels. Next, we followed up on previous studies demonstrating that nucleosome depleted regions (NDRs) become occupied by a nucleosome during mitosis. Surprisingly, we observed that the nucleosome introduced into the NDR during mitosis encompasses a distinctive set of histone modifications, differentiating it from the surrounding nucleosomes. We show that the nucleosomes in the vicinity of the NDR appear to both shift into the NDR during mitosis and undergo deacetylation. HDAC inhibition by the small molecule TSA reverts the deacetylation pattern of the shifted nucleosome. Taken together, our results demonstrate that the epigenomic landscape can serve as a major component of the mitotic bookmarking process, and provide evidence for a mitotic deposition and deacetylation of the nucleosomes surrounding the NDR.
2018-08-14 | MSV000082818 | MassIVE
Project description:Study of mitotic chromatin shows involvement of histone modifications in bookmarking and reveals nucleosome deposition patterns
| PRJNA422751 | ENA
Project description:To maintain cellular identities during development, gene expression profiles must be faithfully propagated through cell generations. The reestablishment of gene expression patterns upon mitotic exit is thought to be mediated, in part, by mitotic bookmarking by transcription factors (TF). However, the mechanisms and functions of TF mitotic bookmarking during early embryogenesis remain poorly understood. In this study, taking advantage of the naturally synchronized mitoses of Drosophila early embryos, we provide evidence that the pioneer-like transcription factor GAF acts as stable mitotic bookmarker during zygotic genome activation. We report that GAF remains associated to a large fraction of its interphase targets (37%). Mitotically-bound loci include cis-regulatory sequences of key developmental genes, with both active and repressive chromatin signatures. GAF mitotic targets are globally accessible during mitosis and a subset is also mitotically bookmarked via histone acetylation (H4K8ac). By monitoring the kinetics of transcriptional activation in living embryos, we provide evidence that GAF binding establishes competence for rapid activation upon mitotic exit.
2022-02-25 | GSE180812 | GEO
Project description:Mitotic bookmarking transcription factors (TFs) are thought to mediate rapid and accurate post-mitotic gene reactivation. However, the loss of individual bookmarking TFs often leads to the deregulation of only a small proportion of their mitotic targets, raising doubts on the significance and importance of their bookmarking function. Here, we used targeted proteomics of the mitotic bookmarking TF ESRRB, an orphan nuclear receptor, to discover an unexpected redundancy among members of the protein superfamily of nuclear receptors. Focusing on the nuclear receptor NR5A2, which together with ESRRB is essential in maintaining pluripotency in mouse embryonic stem cells, we demonstrate conjoint bookmarking activity of both factors on promoters and enhancers of a large fraction of active genes, particularly the most rapidly and strongly reactivated ones. Upon fast and simultaneous degradation of both factors during mitotic exit, hundreds of mitotic targets of ESRRB/NR5A2, including key players of the pluripotency network, display attenuated transcriptional reactivation. We propose that redundancy in mitotic bookmarking TFs, especially nuclear receptors, confers robustness to the reestablishment of gene regulatory networks after mitosis.
2022-12-06 | GSE220253 | GEO
Project description:In mitosis, most transcription factors detach from chromatin, but some are retained and bookmark genomic sites. Mitotic bookmarking has been implicated in lineage inheritance, pluripotency and reprogramming. However, the biological significance of this mechanism in vivo remains unclear. Here, we address mitotic retention of the hemogenic factors GATA2, GFI1B and FOS during haematopoietic specification. We show that GATA2 remains bound to chromatin throughout mitosis, in contrast to GFI1B and FOS, via C-terminal zinc finger-mediated DNA binding. GATA2 bookmarks a subset of its interphase targets that are co-enriched for RUNX1 and other regulators of definitive haematopoiesis. Remarkably, homozygous mice harbouring the cyclin B1 mitosis degradation domain upstream Gata2 partially phenocopy knockout mice. Degradation of GATA2 at mitotic exit abolishes definitive haematopoiesis at aorta-gonad-mesonephros, placenta and foetal liver, but does not impair yolk sac haematopoiesis. Our findings implicate GATA2-mediated mitotic bookmarking as critical for definitive haematopoiesis and highlight a dependency on bookmarkers for lineage commitment.
2023-06-27 | GSE221691 | GEO
Project description:In mitosis, most transcription factors detach from chromatin, but some are retained and bookmark genomic sites. Mitotic bookmarking has been implicated in lineage inheritance, pluripotency and reprogramming. However, the biological significance of this mechanism in vivo remains unclear. Here, we address mitotic retention of the hemogenic factors GATA2, GFI1B and FOS during haematopoietic specification. We show that GATA2 remains bound to chromatin throughout mitosis, in contrast to GFI1B and FOS, via C-terminal zinc finger-mediated DNA binding. GATA2 bookmarks a subset of its interphase targets that are co-enriched for RUNX1 and other regulators of definitive haematopoiesis. Remarkably, homozygous mice harbouring the cyclin B1 mitosis degradation domain upstream Gata2 partially phenocopy knockout mice. Degradation of GATA2 at mitotic exit abolishes definitive haematopoiesis at aorta-gonad-mesonephros, placenta and foetal liver, but does not impair yolk sac haematopoiesis. Our findings implicate GATA2-mediated mitotic bookmarking as critical for definitive haematopoiesis and highlight a dependency on bookmarkers for lineage commitment.
2023-06-27 | GSE207551 | GEO
Project description:Mitotic bookmarking transcription factors (TFs) are thought to mediate rapid and accurate post-mitotic gene reactivation. However, the loss of individual bookmarking TFs often leads to the deregulation of only a small proportion of their mitotic targets, raising doubts on the significance and importance of their bookmarking function. Here, we used targeted proteomics of the mitotic bookmarking TF ESRRB, an orphan nuclear receptor, to discover an unexpected redundancy among members of the protein superfamily of nuclear receptors. Focusing on the nuclear receptor NR5A2, which together with ESRRB is essential in maintaining pluripotency in mouse embryonic stem cells, we demonstrate conjoint bookmarking activity of both factors on promoters and enhancers of a large fraction of active genes, particularly the most rapidly and strongly reactivated ones. Upon fast and simultaneous degradation of both factors during mitotic exit, hundreds of mitotic targets of ESRRB/NR5A2, including key players of the pluripotency network, display attenuated transcriptional reactivation. We propose that redundancy in mitotic bookmarking TFs, especially nuclear receptors, confers robustness to the reestablishment of gene regulatory networks after mitosis.
2023-11-20 | PXD038950 | Pride
Project description:The experiment was performed to assess the importance of nucleosome eviction for the binding of condensin to chromatin during mitosis. The condensin complex associates with chromatin during mitosis to ensure chromosome condensation and accurate segregation, but how this binding is achieved remains poorly understood. Our study indicates that transcription co-activators Gcn5 and Mst2 assist condensin binding during mitosis by evicting nucleosomes. To reach this conclusion, we mapped nucleosomes, during mitosis, in wild-type and gcn5mst2 mutant strains. This experiment allowed us (1) to identify nucleosome-depleted regions (ndrs) during mitosis and to show that condensin tends to colocalize with ndr at the 3ends of genes, and (2) to confirm the importance of nucleosome eviction from ndrs by gcn5 and mst2, during mitosis, for the binding of condensin to chromatin.this experiment determines the patterns of nucleosomes in wild type and mutant fission yeast cells arrested in early mitosis. We analysed wild-type cells, cells lacking Gcn5 histone acetylatransferase (gcn5D) and cells lacking both Gcn5 and Mst2 histone acetyltransferases (Gcn5Dmst2D). All cells used in this study expressed a GFP-tagged version of condensin (Cnd2-GFP) and were blocked in early mitosis at 19C by the nda3-KM311 mutation. Mitotic indexes were determined by scoring the accumulation of Cnd2-GFP in the nucleus. Mitotic cells were collected and chromatin was digested by increasing amount of MNase to produce mononucleosomes. Mononucleosomal DNA was purified on an agarose gel and sequence on an Illumina Nextseq 500 apparatus. Three replicates of wild type, gcn5D and gcn5Dmst2D were analysed. Nucleosome patterns were determined in wild-type cells, cells lacking Gcn5 and cells lacking both Gcn5 and Mst2.
2016-04-18 | E-MTAB-4620 | biostudies-arrayexpress
Project description:For cells to initiate and sustain a differentiated state, it is necessary that a “memory” of this state is transmitted through mitosis to the daughter cells. Mammalian SWItch/ Sucrose Non- Fermentable (SWI/SNF) complexes, also called Brg1/ Brg- associated factors (BAF), control cell identity by modulating chromatin architecture to regulate gene expression, but whether they participate in cell fate memory is unclear. Here, we provide evidence that subunits of SWI/SNF act as mitotic bookmarks to safeguard cell identity during cell division. The SWI/SNF core subunits SMARCE1 and SMARCB1 are displaced from enhancers but bound on promoters during mitosis and we show that this binding is required for appropriate reactivation of bound genes after mitotic exit. Ablation of SMARCE1 during a single mitosis in mouse embryonic stem cells is sufficient to disrupt gene expression, impair the occupancy of several established bookmarks at a subset of their targets, and cause aberrant neural differentiation. Thus, SWI/SNF subunit SMARCE1 plays a mitotic bookmarking role and is essential for heritable epigenetic fidelity during transcriptional reprogramming.
2023-03-18 | GSE189563 | GEO
Project description:Genetic and epigenetic changes in mammary epithelial cells facilitate epithelial-to-mesenchymal transition (EMT) which leads to invasion and metastasis. RUNX1 is a phenotypic transcription factor pivotal for maintenance of mammary epithelial phenotype, whose loss leads to EMT. However, the mechanisms by which RUNX1 maintains mammary epithelial phenotype are not known. Here, we report RUNX1-mediated mitotic gene bookmarking as a key epigenetic mechanism through which RUNX1 stabilizes mammary epithelial phenotype by conveying regulatory information for cell proliferation, growth, and identity through successive cell divisions. Immunofluorescence microscopy and chromatin immunoprecipitation with high throughput sequencing of asynchronous, mitotic, and G1 MCF10A breast epithelial cells revealed RUNX1 association with target genes through interphase and mitosis. RUNX1 mitotically bookmarked both RNA Pol and II transcribed genes involved in proliferation, growth, and mammary epithelial phenotype maintenance. Inhibition of RUNX1 DNA binding by a specific small molecule inhibitor led to phenotypic changes, apoptosis, and differential expression of ribosomal RNA as well as protein coding genes (e.g. HES1 and H2AFX) and long non-coding RNA (e.g. NEAT1 and MALAT1) genes involved in cellular phenotype. Together these findings reveal a novel epigenetic regulatory role of RUNX1 in normal-like breast epithelial cells and demonstrate mitotic bookmarking target genes by RUNX1 is necessary to maintain breast epithelial phenotype. Disruption of RUNX1 bookmarking by a pharmacological inhibitor results in initiation of epithelial to mesenchymal transition, an essential first step in the onset of breast cancer.
2020-07-14 | GSE121370 | GEO