Contributes to the neddylation of all cullins by transferring NEDD8 from N-terminally acetylated NEDD8-conjugating E2s enzyme to different cullin C-terminal domain-RBX complexes. At the cell membrane, can promote and as well inhibit cullins neddylation. May interact (via the DCUN1 domain) with unneddylated cullins. The DCUN1 domain, also known as PONY domain, mediates the interaction with different cullins.