Accessory subunits of PRC2 mimic H3K27me3 to restrict the spread of Polycomb domains
Some proteins mimic the repressive mark H3K27me3, but the physiological relevance of this phenomenon was unclear. Agius et al. show that the PRC2 subunits JARID2 and PALI1 mimic H3K27me3 to antagonize PRC2-mediated H3K27me3 deposition, limit Polycomb domain spreading, and enable timely activation of developmental genes in vivo.
