Acts as an accessory subunit for the core Polycomb repressive complex 2 (PRC2), which mediates histone H3K27 (H3K27me3) trimethylation on chromatin leading to transcriptional repression of the affected target gene (PubMed:15225548, PubMed:29499137, PubMed:31959557). Plays a role in nucleosome localization of the PRC2 complex (PubMed:29499137).
