Polycomb group protein displacement and gene activation through MSK-dependent H3K27me3S28 phosphorylation.

Epigenetic regulation of chromatin structure is essential for the expression of genes determining cellular specification and function. The Polycomb repressive complex 2 (PRC2) di- and trimethylates histone H3 on lysine 27 (H3K27me2/me3) to establish repression of specific genes in embryonic stem cells and during differentiation. How the Polycomb group (PcG) target genes are regulated by environmental cues and signaling pathways is quite unexplored.

A model for transmission of the H3K27me3 epigenetic mark.

Organization of chromatin by epigenetic mechanisms is essential for establishing and maintaining cellular identity in developing and adult organisms. A key question that remains unresolved about this process is how epigenetic marks are transmitted to the next cell generation during cell division. Here we provide a model to explain how trimethylated Lys 27 of histone 3 (H3K27me3), which is catalysed by the EZH2-containing Polycomb Repressive Complex 2 (PRC2), is maintained in proliferating cells.