Similar Datasets
Project description:Chromatin insulators are DNA-protein complexes that establish distinct higher order transcriptional domains. In Drosophila, CP190 is the only common factor for all the DNA-binding insulator protein complex. Insulators harbour two properties: they can block communication between an enhancer and a promoter, and also act as a barrier between heterochromatin and euchromatin. In Drosophila, the gypsy insulator complex contains three core components; Su(Hw), CP190 and Mod(mdg4)67.2. In our studies, using mass-spec analysis and of immunopurified complexes from Drosophila embryonic nuclear extracts, we identified the transcription factor Motif 1 Binding Protein (M1BP) associated with CP190 and verified this interaction by coimmunoprecipitation. Furthermore, depletion of M1BP results in loss of both enhancer-blocking and barrier activities, also disrupts the nuclear localization of CP190-marked insulator bodies within the developing fly. ChIP-seq analysis of both factors in Kc167 cultured hemocytes revealed extensive overlap of the two factors, particularly at Motif 1 containing promoters. Depletion of M1BP results in extensive loss of CP190 chromatin association, and depletion of CP190 also greatly affects M1BP chromatin association. Moreover, EU-seq analysis after depletion of either CP190 or M1BP suggests they regulate gene expression in similar fashion. Further analysis using reporter assays verifies that CP190-dependent gene expression changes are dependent on the presence of Motif 1. Our results suggest a novel mechanistic relationship between CP190 and M1BP function with respect to transcriptional regulation and higher order chromatin organization.
2020-10-27 | GSE142532 | GEO
Project description:Chromatin insulators are DNA-protein complexes that establish distinct higher order transcriptional domains. In Drosophila, CP190 is the only common factor for all the DNA-binding insulator protein complex. Insulators harbour two properties: they can block communication between an enhancer and a promoter, and also act as a barrier between heterochromatin and euchromatin. In Drosophila, the gypsy insulator complex contains three core components; Su(Hw), CP190 and Mod(mdg4)67.2. In our studies, using mass-spec analysis and of immunopurified complexes from Drosophila embryonic nuclear extracts, we identified the transcription factor Motif 1 Binding Protein (M1BP) associated with CP190 and verified this interaction by coimmunoprecipitation. Furthermore, depletion of M1BP results in loss of both enhancer-blocking and barrier activities, also disrupts the nuclear localization of CP190-marked insulator bodies within the developing fly. ChIP-seq analysis of both factors in Kc167 cultured hemocytes revealed extensive overlap of the two factors, particularly at Motif 1 containing promoters. Depletion of M1BP results in extensive loss of CP190 chromatin association, and depletion of CP190 also greatly affects M1BP chromatin association. Moreover, EU-seq analysis after depletion of either CP190 or M1BP suggests they regulate gene expression in similar fashion. Further analysis using reporter assays verifies that CP190-dependent gene expression changes are dependent on the presence of Motif 1. Our results suggest a novel mechanistic relationship between CP190 and M1BP function with respect to transcriptional regulation and higher order chromatin organization.
2020-10-27 | GSE142531 | GEO
Project description:Genome organization is driven by forces affecting transcriptional state, but the relationship between transcription and genome architecture remains unclear. Here, we identified the Drosophila transcription factor Motif 1 Binding Protein (M1BP) in physical association with the gypsy chromatin insulator core complex, including the universal insulator protein CP190. M1BP is required for enhancer-blocking and barrier activities of the gypsy insulator as well as its proper nuclear localization. Genome-wide, M1BP specifically colocalizes with CP190 at Motif 1-containing promoters, which are enriched at topologically associating domain (TAD) borders. M1BP facilitates CP190 chromatin binding at many shared sites and vice versa. Both factors promote Motif 1-dependent gene expression and transcription near TAD borders genome-wide. Finally, loss of M1BP reduces chromatin accessibility and increases both inter- and intra-TAD local genome compaction. Our results reveal physical and functional interaction between CP190 and M1BP to activate transcription at TAD borders and mediate chromatin insulator-dependent genome organization.
| S-EPMC8263732 | biostudies-literature
Project description:The transcription factor M1BP targets CP190 to chromatin to regulate transcription and chromatin insulator activity
| PRJNA597330 | ENA
Project description:The transcription factor M1BP targets CP190 to chromatin to regulate transcription and chromatin insulator activity (RNA-Seq)
| PRJNA597333 | ENA
Project description:The transcription factor M1BP targets CP190 to chromatin to regulate transcription and chromatin insulator activity (ChIP-Seq)
| PRJNA597334 | ENA
Project description:Genome organization is driven by forces affecting transcriptional state, but the relationship between transcription and genome architecture remains unclear. Here, we identified the Drosophila transcription factor Motif 1 Binding Protein (M1BP) in physical association with the gypsy chromatin insulator core complex, including the universal insulator protein CP190. M1BP is required for enhancer-blocking and barrier activities of the gypsy insulator as well as its proper nuclear localization. Genome-wide, M1BP specifically colocalizes with CP190 at Motif 1-containing promoters, which are enriched at topologically associating domain (TAD) borders. M1BP facilitates CP190 chromatin binding at many shared sites and vice versa. Both factors promote Motif 1-dependent gene expression and transcription near TAD borders genome-wide. Finally, loss of M1BP reduces chromatin accessibility and increases both inter- and intra-TAD local genome compaction. Our results reveal physical and functional interaction between CP190 and M1BP to activate transcription at TAD borders and mediate chromatin insulator-dependent genome organization.
2021-06-07 | PXD026497 | Pride
Project description:In order to identify more gypsy insulator interactors, we performed immunoaffinity purification of Drosophila embryonic nuclear extracts using antibodies specific for CP190 and analyzed the eluates using quantitative mass spectrometry.
2021-06-07 | PXD026493 | Pride
Project description:Genome organization is driven by forces affecting transcriptional state, but the relationship between transcription and genome architecture remains unclear. Here, we identified the Drosophila transcription factor Motif 1 Binding Protein (M1BP) in physical association with the gypsy chromatin insulator core complex, including the universal insulator protein CP190. M1BP is required for enhancer-blocking and barrier activities of the gypsy insulator as well as its proper nuclear localization. Genome-wide, M1BP specifically colocalizes with CP190 at Motif 1-containing promoters, which are enriched at topologically associating domain (TAD) borders. M1BP is required for CP190 chromatin binding at many shared sites, and CP190 also affects M1BP chromatin association. Both factors are required for Motif 1-dependent gene expression and transcription near TAD borders genome-wide. Finally, loss of M1BP alters local genome compaction. Our results reveal physical and functional interaction between CP190 and M1BP to activate transcription at TAD borders and mediate chromatin insulator-dependent genome organization.
2021-04-14 | GSE169105 | GEO
Project description:A major role of the RNAi pathway in Schizosaccharomyces pombe is to nucleate heterochromatin, but it remains unclear whether this mechanism is conserved. To address this question in Drosophila, we performed genome-wide localization of Argonaute2 (AGO2) by chromatin immunoprecipitation (ChIP)-seq in two different embryonic cell lines and found that AGO2 localizes to euchromatin but not heterochromatin. This localization pattern is further supported by immunofluorescence staining of polytene chromosomes and cell lines, and these studies also indicate that a substantial fraction of AGO2 resides in the nucleus. Intriguingly, AGO2 colocalizes extensively with CTCF/CP190 chromatin insulators but not with genomic regions corresponding to endogenous siRNA production. Moreover, AGO2, but not its catalytic activity or Dicer-2, is required for CTCF/CP190-dependent Fab-8 insulator function. AGO2 interacts physically with CTCF and CP190, and depletion of either CTCF or CP190 results in genome-wide loss of AGO2 chromatin association. Finally, mutation of CTCF, CP190, or AGO2 leads to reduction of chromosomal looping interactions, thereby altering gene expression. We propose that RNAi-independent recruitment of AGO2 to chromatin by insulator proteins promotes the definition of transcriptional domains throughout the genome.
| S-EPMC3165934 | biostudies-literature