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 ( ). Plays a role in nucleosome localization of the PRC2 complex .
Subcellular locations: Nucleus
Localizes to chromatin as part of the PRC2 complex.