RANBP2 of the nuclear pore complex SUMOylates PML with SUMO1 at lysine-65, lysine-160, and lysine-490 (Sternsdorf et al. 1997, Kamitani et al. 1998, Duprez et al. 1999). SUMOylated PML is observed during interphase but not during mitosis (Everett et al. 1999). RANBP2 contains both a binding site for SUMO1 and a binding site for UBE2I (Tatham et al. 2005). The binding site for SUMO1 may play a role in SUMOylation of PML with SUMO1. Knockdown of RANBP2 reduces the number of PML bodies (Saitoh et al. 2006).