PIAS2-2 (PIASxbeta) SUMOylates SUZ12, a subunit of the Polycomb Repressive Complex 2 (PRC2), at lysine-75 with SUMO1 (Riising et al. 2008). SUMOyation does not affect the repression of transcription by PRC2. The effect of SUMOylation on PRC2 function is unknown. The EZH2 subunit of PRC2 can also be SUMOylated at multiple positions.