(F) Ni-pulldown of 6xHisSUMO1/2/3-conjugated proteins from HEK293 extracts expressing 6xHis-tagged SUMO1, SUMO2 or SUMO3 in combination with CBX2-EGFP. CBX2 and SUMO-conjugated CBX2 were detected with an anti-GFP antibody. 