Chromatin spreading in 3D through Insulator looping regulates genes through to H3K27me3 micro-domains
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ABSTRACT:
PROVIDER: PRJNA534289 | ENA |
REPOSITORIES: ENA
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Project description:We used the technology of ChIP-sequencing to analyze changes in H3K27me3 levels in Drosophila Schneider S2 depleted of endogenous Beaf32 and expressing insulator mutants ('mut-Beaf32' or 'muBeaf') as compared to control cells expressing wild-type Beaf32 (Control; 'CTL')
2020-04-28 | GSE130211 | GEO
Project description:Chromatin insulators are DNA-protein complexes that can prevent the spread of repressive chromatin and block communication between enhancers and promoters to regulate gene expression. In Drosophila, the gypsy chromatin insulator complex consists of three core proteins: CP190, Su(Hw), and Mod(mdg4)67.2. These factors concentrate at nuclear foci termed insulator bodies, and their normal localization is correlated with proper insulator function. Here, we identified NURF301/E(bx), a nucleosome remodeling factor, as a novel regulator of gypsy insulator body localization through a high-throughput RNAi imaging screen. NURF301 promotes gypsy-dependent insulator barrier activity and physically interacts with gypsy insulator proteins. Using ChIP-seq, we found that NURF301 co-localizes with insulator proteins genome-wide, and NURF301 promotes chromatin association of Su(Hw) and CP190 at gypsy insulator binding sites. These effects correlate with NURF301-dependent nucleosome repositioning. At the same time, CP190 and Su(Hw) are also required for recruitment of NURF301 to chromatin. Finally, Oligopaint FISH combined with immunofluorescence revealed that NURF301 promotes 3D contact between insulator bodies and gypsy binding site DNA, and NURF301 is required for proper nuclear positioning of gypsy binding sites. Our data provide new insights into how a nucleosome remodeling factor and insulator proteins cooperatively contribute to nuclear organization.
2022-10-14 | PXD032165 | Pride
Project description:Nucleation and spreading rejuvenate polycomb domains every cell cycle
2023-12-01 | GSE209818 | GEO
Project description:Chromatin insulators are DNA-protein complexes that can prevent the spread of repressive chromatin and block communication between enhancers and promoters to regulate gene expression. In Drosophila, the gypsy chromatin insulator complex consists of three core proteins: CP190, Su(Hw), and Mod(mdg4)67.2. These factors concentrate at nuclear foci termed insulator bodies, and their normal localization is correlated with proper insulator function. Here, we identified NURF301/E(bx), a nucleosome remodeling factor, as a novel regulator of gypsy insulator body localization through a high-throughput RNAi imaging screen. NURF301 promotes gypsy-dependent insulator barrier activity and physically interacts with gypsy insulator proteins. Using ChIP-seq, we found that NURF301 co-localizes with insulator proteins genome-wide, and NURF301 promotes chromatin association of Su(Hw) and CP190 at gypsy insulator binding sites. These effects correlate with NURF301-dependent nucleosome repositioning. At the same time, CP190 and Su(Hw) are also required for recruitment of NURF301 to chromatin. Finally, Oligopaint FISH combined with immunofluorescence revealed that NURF301 promotes 3D contact between insulator bodies and gypsy binding site DNA, and NURF301 is required for proper nuclear positioning of gypsy binding sites. Our data provide new insights into how a nucleosome remodeling factor and insulator proteins cooperatively contribute to nuclear organization.
2022-06-28 | GSE198361 | GEO
Project description:Estrogen-mediated Epigenetic Repression of Large Chromosomal Regions through DNA Looping
| PRJNA126731 | ENA
Project description:Insulators are multiprotein–DNA complexes that regulate nuclear architecture. The Drosophila CP190 protein is a common cofactor of two main insulator complexes formed by the DNA-binding proteins Su(Hw) and dCTCF. Here, we have identified two new DNA-binding proteins, Pita and ZIPIC, that interact with CP190. In vitro, CP190 interacts with Pita through the BTB domain and with ZIPIC through the centrosomal targeting domain. The artificial binding sites for Pita or ZIPIC partially block enhancers and protect gene expression from PRE-mediated silencing in transgenic lines. Pita binds adjacent to dCTCF in the well-studied Mcp insulator and is required for its activity, which indicates that two insulator proteins can cooperate in organizing a functional insulator. Pita and ZIPIC preferentially bind to the promoter regions and extensively colocalize with dCTCF and BEAF. These results suggest that insulator proteins can fulfill multiple functions in chromosome architecture and gene expression.
2014-10-01 | GSE54337 | GEO
Project description:The Drosophila insulator-binding proteins (IBPs) dCTCF/Beaf32 mark the physical borders of chromosomal domains involving co-factors that participate in long-range interactions. Chromosomal borders are further enriched in specific histone modifications yet the implication of histone modifiers and nucleosome dynamics remains largely unknown in such context. Here, we show that IBP depletion impairs nucleosome dynamics over genes flanked by their binding sites. Biochemical purification identifies a key histone methyltransferase of H3K36, NSD/dMes-4, as a novel co-factor of IBPs involved in chromatin accessibility, which specifically co-regulates hundreds of genes flanked by Beaf32/dCTCF. dMes-4 presets chromatin before the recruitment of transcriptional activators including DREF that triggers Set2/Hypb-mediated H3K36me3, RNA splicing and nucleosome positioning. Our results unveil a model for how IBPs regulate gene expression and nucleosome dynamics through NSD/dMes-4, which may contribute to regulate H3K27me3 spreading. Together, our data suggest a division of labor for how IBPs may dynamically regulate chromatin organization depending on distinct co-factors. Nucleosome profiles of Beaf32-depleted or Wild-Type control Drosophila S2 cells by MNase-Seq (Illumina/TruSeq) for total/bulk nucleosomes or following immunoprecipitation with anti-H3K27me3 antibodies
2014-04-30 | E-GEOD-57166 | biostudies-arrayexpress
Project description:Chromatin insulators organize the genome into distinct transcriptional domains and contribute to cell type-specific chromatin organization. However, factors regulating tissue-specific insulator function have not yet been discovered. Here we identify the RNA recognition motif-containing protein, Shep, as a direct interactor of two individual components of the gypsy insulator complex in Drosophila. Mutation of shep improves gypsy-dependent enhancer blocking, indicating a role as a negative regulator of insulator activity. Unlike ubiquitously expressed core gypsy insulator proteins, Shep is highly expressed in the central nervous system (CNS) with lower expression in other tissues. We developed a novel, quantitative tissue-specific barrier assay to demonstrate that Shep functions as a negative regulator of insulator activity in the CNS but not in muscle tissue. Additionally, mutation of shep alters insulator complex nuclear localization in the CNS but not other tissues. Consistent with negative regulatory activity, ChIP-seq analysis of Shep in a CNS-derived cell line indicates substantial genome-wide colocalization with a single gypsy insulator component but limited overlap with intact insulator complexes. Taken together, these data reveal a novel, tissue-specific mode of regulation of a chromatin insulator.
2012-11-30 | GSE40797 | GEO
Project description:The Drosophila insulator-binding proteins (IBPs) dCTCF/Beaf32 mark the physical borders of chromosomal domains involving co-factors that participate in long-range interactions. Chromosomal borders are further enriched in specific histone modifications yet the implication of histone modifiers and nucleosome dynamics remains largely unknown in such context. Here, we show that IBP depletion impairs nucleosome dynamics over genes flanked by their binding sites. Biochemical purification identifies a key histone methyltransferase of H3K36, NSD/dMes-4, as a novel co-factor of IBPs involved in chromatin accessibility, which specifically co-regulates hundreds of genes flanked by Beaf32/dCTCF. dMes-4 presets chromatin before the recruitment of transcriptional activators including DREF that triggers Set2/Hypb-mediated H3K36me3, RNA splicing and nucleosome positioning. Our results unveil a model for how IBPs regulate gene expression and nucleosome dynamics through NSD/dMes-4, which may contribute to regulate H3K27me3 spreading. Together, our data suggest a division of labor for how IBPs may dynamically regulate chromatin organization depending on distinct co-factors. ChIP-Seq profiles of H3K36 methylation and RNA Pol II in Drosophila S2 cell line (wild-type) cells
2014-04-30 | E-GEOD-57165 | biostudies-arrayexpress
Project description:The Drosophila insulator-binding proteins (IBPs) dCTCF/Beaf32 mark the physical borders of chromosomal domains involving co-factors that participate in long-range interactions. Chromosomal borders are further enriched in specific histone modifications yet the implication of histone modifiers and nucleosome dynamics remains largely unknown in such context. Here, we show that IBP depletion impairs nucleosome dynamics over genes flanked by their binding sites. Biochemical purification identifies a key histone methyltransferase of H3K36, NSD/dMes-4, as a novel co-factor of IBPs involved in chromatin accessibility, which specifically co-regulates hundreds of genes flanked by Beaf32/dCTCF. dMes-4 presets chromatin before the recruitment of transcriptional activators including DREF that triggers Set2/Hypb-mediated H3K36me3, RNA splicing and nucleosome positioning. Our results unveil a model for how IBPs regulate gene expression and nucleosome dynamics through NSD/dMes-4, which may contribute to regulate H3K27me3 spreading. Together, our data suggest a division of labor for how IBPs may dynamically regulate chromatin organization depending on distinct co-factors.
2014-04-30 | GSE57166 | GEO