Project description:Trithorax group (TrxG) proteins counteract Polycomb silencing by an as yet uncharacterized mechanism. A well-known member of the TrxG is the histone methyltransferase Absent, Small, or Homeotic discs 1 (ASH1). In Drosophila ASH1 is needed for the maintenance of Hox gene expression throughout development, which is tightly coupled to preservation of cell identity. In order to understand the molecular function of ASH1 in this process, we performed affinity purification of tandem-tagged ASH1 followed by mass spectrometry (AP-MS) and identified FSH, another member of the TrxG as interaction partner. Here we provide genome-wide chromatin maps of both proteins based on ChIP-seq.
Project description:Trithorax group (TrxG) proteins counteract Polycomb silencing by an as yet uncharacterized mechanism. A well-known member of the TrxG is the histone methyltransferase Absent, Small, or Homeotic discs 1 (ASH1). In Drosophila ASH1 is needed for the maintenance of Hox gene expression throughout development, which is tightly coupled to preservation of cell identity. In order to understand the molecular function of ASH1 in this process, we performed affinity purification of tandem-tagged ASH1 followed by mass spectrometry (AP-MS) and identified FSH, another member of the TrxG as interaction partner. Here we provide genome-wide chromatin maps of both proteins based on ChIP-seq. Our Dataset comprises of 4 ChIP-seq samples using chromatin from S2 cells which was immunoprecipitated, using antibodies against Ash1, FSH-L and FSH-SL.
Project description:The Polycomb group (PcG) and Trithorax group (TrxG) of proteins are required for stable and heritable maintenance of repressed and active gene expression states. Their antagonistic function on gene control, repression for PcG and activity for TrxG, is mediated by binding to chromatin and subsequent epigenetic modification of target loci. Despite our broad knowledge about composition and enzymatic activities of the protein complexes involved, our understanding still lacks important mechanistic detail and a comprehensive view on target genes. In this study, we use an extensive data set of ChIP-seq, RNA-seq, and genome-wide detection of transcription start sites (TSSs) to identify and analyze thousands of binding sites for the PcG proteins and Trithorax from a Drosophila S2 cell line. In addition to finding a preference for stalled promoter regions of annotated genes, we uncover many intergenic PcG-binding sites coinciding with non-annotated transcription start sites. Interestingly, this set includes previously unknown promoters for primary transcripts of microRNA genes, thereby expanding the scope of Polycomb control to non-coding RNAs essential for development, apoptosis and growth.
Project description:Cohesin and Polycomb proteins functionally interact to control transcription at silenced, restrained, and active genes [expression array data]
Project description:Cohesin and Polycomb proteins functionally interact to control transcription at silenced, restrained, and active genes [tiling array data]
Project description:The Polycomb group (PcG) and Trithorax group (TrxG) proteins are key epigenetic regulators controlling silenced and active states of genes in multicellular organisms, respectively. In Drosophila PcG/TrxG proteins are recruited to chromatin via binding to specialized DNA-elements termed Polycomb Response Elements (PREs). While precise mechanisms of PcG/TrxG proteins recruitment remains unknown, the important role is suggested to belong to sequence specific DNA-binding factors. Here, using affinity purification coupled with high throughput mass spectrometry (IP/MS), we isolated factors associated with Combgap, Psq, Zeste and Adf1 PRE DNA-binding Drosophila proteins. As a control we used unspecific IgG. For affinity purification the nuclear extract from Drosophila S2 cells and polyclonal antibodies against Combgap, Psq, Zeste and Adf1 were used.