NEDD8 family contains ubiquitin-like protein which plays an important role in cell cycle control and embryogenesis. Attachment of NEDD8 to cullins activates their associated E3 ubiquitin ligase activity, and thus promotes polyubiquitination and proteasomal degradation of cyclins and other regulatory proteins. NEDD8 pathway is essential for SCF(beta -TrCP)-mediated ubiquitination (1).

1. Amir RE, Iwai K, Ciechanover A(2002) The NEDD8 pathway is essential for SCF(beta -TrCP)-mediated ubiquitination and processing of the NF-kappa B precursor p105. J Biol Chem., 277(26):23253-9. PMID:11953428