First Author | Tardat M | Year | 2015 |
Journal | Mol Cell | Volume | 58 |
Issue | 1 | Pages | 157-71 |
PubMed ID | 25801166 | Mgi Jnum | J:220831 |
Mgi Id | MGI:5636539 | Doi | 10.1016/j.molcel.2015.02.013 |
Citation | Tardat M, et al. (2015) Cbx2 Targets PRC1 to Constitutive Heterochromatin in Mouse Zygotes in a Parent-of-Origin-Dependent Manner. Mol Cell 58(1):157-71 |
abstractText | Polycomb repressive complexes PRC1 and PRC2 regulate expression of genes involved in proliferation and development. In mouse early embryos, however, canonical PRC1 localizes to paternal pericentric heterochromatin (pat-PCH), where it represses transcription of major satellite repeats. In contrast, maternal PCH (mat-PCH) is enriched for H3 lysine 9 tri-methylation (H3K9me3) and Hp1beta. How PRC1 is targeted to pat-PCH, yet excluded from mat-PCH, has remained elusive. Here, we identify a PRC1 targeting mechanism that relies on Cbx2 and Hp1beta. Cbx2 directs catalytically active PRC1 to PCH via its chromodomain (CD(Cbx2)) and neighboring AT-hook (AT(Cbx2)) binding to H3K27me3 and AT-rich major satellites, respectively. CD(Cbx2) prevents AT(Cbx2) from interacting with DNA at PCH marked by H3K9me3 and Hp1beta. Loss-of-function studies show that Hp1beta and not H3K9me3 prevents PRC1 targeting to mat-PCH. Our findings indicate that CD(Cbx2) and AT(Cbx2) separated by a short linker function together to integrate H3K9me3/HP1 and H3K27me3 states. |