Structural insights into the interactions of Polycomb Repressive Complex 2 with chromatin

Polycomb repressive complexes are a family of chromatin modifier enzymes which are critical for regulating gene expression and maintaining cell-type identity. The reversible chemical modifications of histone H3 and H2A by the Polycomb proteins are central to its ability to function as a gene silencer. PRC2 is both a reader and writer of the trimethylation of histone H3 lysine 27 (H3K27me3) which serves as a marker for transcription repression, and heterochromatin boundaries. Over the last few years, several studies have provided key insights into the mechanisms regulating the recruitment and activation of PRC2 at Polycomb target genes. In this review, we highlight the recent structural studies which have elucidated the roles played by Polycomb cofactor proteins in mediating crosstalk between histone post-translational modifications and the recruitment of PRC2 and the stimulation of PRC2 methyltransferase activity.

Automated summary

Polycomb repressive complexes are a family of chromatin modifier enzymes critical for regulating gene expression and maintaining cell-type identity. PRC2 acts as both a reader and writer of histone H3 lysine 27 trimethylation, serving as a marker for transcription repression and heterochromatin boundaries. Recent structural studies have provided insights into the roles of Polycomb cofactor proteins in mediating crosstalk between histone modifications and the recruitment of PRC2 for methyltransferase activity.