A conserved switch to less catalytically active Polycomb repressive complexes in non-dividing cells.

Polycomb repressive complex 2 (PRC2), composed of the core subunits EED, SUZ12, and either EZH1 or EZH2, is critical for maintaining cellular identity in multicellular organisms. PRC2 deposits H3K27me3, which is thought to recruit the canonical form of PRC1 (cPRC1) to promote gene repression. Here, we show that EZH1-PRC2 and cPRC1 are the primary Polycomb complexes on target genes in non-dividing, quiescent cells.