Q13618

CUL3 is a member of the family of human cullin genes (CUL 1, 2, 3, 4a, 4b, and 5) homologous to the S. cerevisiae cdc 53 gene. CUL 1 forms a complex with human p19 skp1 and F box protein p45 skp2. Together with cdc 53 (Known as Cul A), as three subunits, they form a ubiquitin ligase-controlling proteolysis of G1 cell cycle regulatory proteins. In contrast to CUL 1, CUL 2 does not associate with p19 skp1 and p45 skp2. Instead, CUL 2 forms a complex with an inactive transcriptional elongation complex, SIII, formed by three subunits: Elongain C, Elongin B and VHL. The function of this association remains unknown.