Polycomb repressive complex 2 (PRC2) is composed of EED, SUZ12, and EZH1/2, and mediates mono-, di- and tri-methylation of Histone H3 at Lysine 27.
More...Polycomb repressive complex 2 (PRC2) is composed of EED, SUZ12, and EZH1/2, and mediates mono-, di- and tri-methylation of Histone H3 at Lysine 27. While, two subcomplexes defined by their specific accessory proteins, termed PRC2.1 (Polycomb-like proteins 1-3, EPOP and PALI1/2) and PRC2.2 (AEBP2 and JARID2) exist, little is known about their differential functions. Here, we show that PRC2.1 and PRC2.2 share the majority of their target genes in mouse embryonic stem cells (ESCs). While loss of all three Polycomb-like proteins (PHF1, MTF2, PHF19) leads to eviction of EPOP and PALI1 from chromatin, PRC2.2 specific components are maintained together with SUZ12 and H3K27me3 at broad Polycomb domains. We show that PRC2.2 localises to PRC1 mediated H2AK119ub1 at these broad Polycomb domains to maintain H3K27me3, even in the absence of PRC2.1. Taken together, these data establish that PRC2.1 and PRC2.2 co-operate to direct H3K27me3, but have independent recruitment mechanisms.
Overall design: Quantitative ChIP-Rx analysis of Pcl1-3 WT and Pcl1-3 TKO mouse embryonic stem cells. ChIPs for certain histone modification include a 1.67% spike in of Drosophila chromatin (S2 cell line). ChIPs for PRC2 components and H2AK119ub1 include a 10% spike in of human chromatin (NT2 cell line). 19 samples are included
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