Similar Datasets
Project description:Heterochromatin stability is crucial for progenitor proliferation during development. It relays on the maintenance of local hubs of H3K9me. However, the mechanisms underlying the establishment of competent local levels of H3K9me remain poorly understood. To address this intriguing question, we used a neural stem cell (NSC) model to analyze the significance of the H3K9me2 demethylase PHF2, which is crucial for progenitor proliferation. Through mass spectroscopy and genome-wide assays, we uncovered that PHF2 interacts with heterochromatin components and it is enriched at pericentromeric heterochromatin (PcH) boundaries. This binding is essential for maintaining silenced the satellite repeats and to prevent DNA damage and genome instability. To do that, PHF2 balances H3K9me3 levels at these boundaries to ensure high H3K9me3 levels at satellite repeats. Mechanistically, we discover that while its catalytic and PHD domains are indispensable, the intrinsically disordered region within PHF2 is dispensable for stabilizing PcH. Altogether, our study sheds light on the intricate relationship between heterochromatin stability and progenitor proliferation during mammalian neurogenesis.
2024-06-17 | GSE242383 | GEO
Project description:Heterochromatin stability is crucial for progenitor proliferation during development. It relays on the maintenance of local hubs of H3K9me. However, the mechanisms underlying the establishment of competent local levels of H3K9me remain poorly understood. To address this intriguing question, we used a neural stem cell (NSC) model to analyze the significance of the H3K9me2 demethylase PHF2, which is crucial for progenitor proliferation. Through mass spectroscopy and genome-wide assays, we uncovered that PHF2 interacts with heterochromatin components and it is enriched at pericentromeric heterochromatin (PcH) boundaries. This binding is essential for maintaining silenced the satellite repeats and to prevent DNA damage and genome instability. To do that, PHF2 balances H3K9me3 levels at these boundaries to ensure high H3K9me3 levels at satellite repeats. Mechanistically, we discover that while its catalytic and PHD domains are indispensable, the intrinsically disordered region within PHF2 is dispensable for stabilizing PcH. Altogether, our study sheds light on the intricate relationship between heterochromatin stability and progenitor proliferation during mammalian neurogenesis.
2024-09-12 | GSE242384 | GEO
Project description:PHF2 maintains neural progenitor genome stability by preserving pericentric heterochromatin integrity
| PRJNA1013331 | ENA
Project description:PHF2 maintains neural progenitor genome stability by preserving pericentric heterochromatin integrity (ATAC-Seq)
| PRJNA1111462 | ENA
Project description:PHF2 maintains neural progenitor genome stability by preserving pericentric heterochromatin integrity (ChIP-Seq)
| PRJNA1014578 | ENA
Project description:Heterochromatin stability is crucial for progenitor proliferation during early neurogenesis. It relays on the maintenance of local hubs of H3K9me. However, the current understanding of the processes involved in the formation of efficient localized levels of H3K9me remains limited. To address this intriguing question, we used a neural stem cell (NSC) to analyze the function of the H3K9me2 demethylase PHF2, which is crucial for progenitor proliferation. Through mass spectroscopy and genome-wide assays, we uncovered that PHF2 interacts with heterochromatin components and it is enriched at pericentromeric heterochromatin (PcH) boundaries. This binding is essential for maintaining silenced the satellite repeats thereby preventing DNA damage and genome instability. Depletion of PHF2 led to increased transcription of heterochromatic repeats, accompanied by a decrease in H3K9me3 levels and alterations in PcH organization. Further analysis revealed that PHF2's PHD and catalytic domains are crucial for maintaining PcH stability and preventing unscheduled repeat transcription, thereby safeguarding genome integrity. These results highlight the multifaceted nature of PHF2's functions in maintaining heterochromatin stability and regulating gene expression during neural development. Altogether, our study unravels the intricate relationship between heterochromatin stability and progenitor proliferation during mammalian neurogenesis, shedding light on its potential as a therapeutic target for neurodevelopmental disorders
2024-06-11 | PXD051336 | Pride
Project description:Methyl-CpG binding protein 2 (MeCP2) is a multi-function factor involved in locus-specific transcriptional modulation and the regulation of genome architecture, e.g., pericentric heterochromatin (PCH) organization. MECP2 mutations are responsible for Rett syndrome (RTT), a devastating postnatal neurodevelopmental disorder, the pathogenetic mechanisms of which are still unknown. MeCP2, together with Alpha-thalassemia/mental retardation syndrome X-linked protein (ATRX), accumulates at chromocenters, which are repressive PCH domains. As with MECP2, mutations in ATRX cause ATR-X syndrome which is associated with severe intellectual disability. We exploited two murine embryonic stem cell lines, in which the expression of MeCP2 or ATRX is abolished. Through immunostaining, chromatin immunoprecipitation and western blot, we show that MeCP2 and ATRX are reciprocally dependent both for their expression and targeting to chromocenters. Moreover, ATRX plays a role in the accumulation of members of the heterochromatin protein 1 (HP1) family at PCH and, as MeCP2, modulates their expression. Furthermore, ATRX and HP1 targeting to chromocenters depends on an RNA component. 3D-DNA fluorescence in situ hybridization (FISH) highlighted, for the first time, a contribution of ATRX in MeCP2-mediated chromocenter clustering during neural differentiation. Overall, we provide a detailed dissection of the functional interplay between MeCP2 and ATRX in higher-order PCH organization in neurons. Our findings suggest molecular defects common to RTT and ATR-X syndrome, including an alteration in PCH.
| S-EPMC6862095 | biostudies-literature
Project description:Maintenance of proper chromatin states and genomic stability is vital for normal development and health across a range of organisms. Here, we report on the role of KLLN in maintenance of pericentric H3K9 trimethylation (H3K9me3) and genomic stability. Germline hypermethylation of KLLN, a gene uncovered well after the human genome project, has been linked to Cowden cancer-predisposition syndrome (CS) in PTEN wild-type cases. KLLN first identified as a p53-dependent tumor suppressor gene, was believed to bind randomly to DNA and cause S-phase arrest. Using chromatin immunoprecipitation-based sequencing (ChIP-seq), we demonstrated that KLLN binds to DNA regions enriched with H3K9me3. KLLN overexpression correlated with increased H3K9 methyltransferase activity and increased global H3K9me3, while knockdown of KLLN had an opposite effect. We also found KLLN to localize to pericentric regions, with loss of KLLN resulting in dysregulation of pericentric heterochromatin, with consequent chromosomal instability manifested by increased micronuclei formation and numerical chromosomal aberrations. Interestingly, we show that KLLN interacts with DBC1, with consequent abrogation of DBC1 inhibition of SUV39H1, a H3K9 methyltransferase, suggesting the mode of KLLN regulating H3K9me3. These results suggest a critical role for KLLN as a potential regulator of pericentric heterochromatin formation, genomic stability and gene expression.
| S-EPMC4856962 | biostudies-literature
Project description:The cell establishes heritable patterns of active and silenced chromatin via interacting factors that set, remove, and read epigenetic marks. To understand how the underlying networks operate, we have dissected transcriptional silencing in pericentric heterochromatin (PCH) of mouse fibroblasts. We assembled a quantitative map for the abundance and interactions of 16 factors related to PCH in living cells and found that stably bound complexes of the histone methyltransferase SUV39H1/2 demarcate the PCH state. From the experimental data, we developed a predictive mathematical model that explains how chromatin-bound SUV39H1/2 complexes act as nucleation sites and propagate a spatially confined PCH domain with elevated histone H3 lysine 9 trimethylation levels via chromatin dynamics. This "nucleation and looping" mechanism is particularly robust toward transient perturbations and stably maintains the PCH state. These features make it an attractive model for establishing functional epigenetic domains throughout the genome based on the localized immobilization of chromatin-modifying enzymes.
| S-EPMC4299515 | biostudies-literature
Project description:Lrwd1, a protein containing a leucine-rich repeat and a WD40 repeat domain, interacts with the origin replication complex (ORC), a protein complex involved in both initiation of DNA replication and heterochromatin silencing. Lrwd1 and ORC are known to co-purify with repressive histone marks (trimethylated lysine 9 of histone H3 (H3K9me3) and trimethylated lysine 20 of histone H4 (H4K20me3)) and localize to pericentric heterochromatin. However, how the Lrwd1 is recruited to heterochromatin and the functional significance of the localization of Lrwd1 to the heterochromatin are not known. Here, we show that Lrwd1 preferentially binds to trimethylated repressive histone marks in vitro, which is dependent on an intact WD40 domain but independent of ORC proteins. The localization of Lrwd1 and Orc2 at pericentric heterochromatin in mouse cells is lost in cells lacking H3K9me3 but not in cells lacking H4K20me3. In addition, depletion of HP1? has little impact on the localization of Lrwd1 on pericentric heterochromatin. Finally, depletion of Lrwd1 and Orc2 in mouse cells leads to increased transcription of major satellite repeats. These results indicate that the Lrwd1 is recruited to pericentric heterochromatin through binding to H3K9me3 and that the association of Lrwd1 with pericentric heterochromatin is required for heterochromatin silencing and maintenance.
| S-EPMC3340258 | biostudies-literature