Cullin 3 (CUL3)

CUL3 is a component of a ubiquitin E3 ligase that is essential for mitotic division. The CUL3/KLHL9/KLHL13 complex was the minimum unit required for correct chromosome alignment in metaphase, proper midzone and midbody formation, and completion of cytokinesis. CUL3/KLHL9/KLHL13 acted as an E3 ligase and regulated dynamic localization of the chromosomal passenger protein Aurora B (AURKB) on mitotic chromosomes and accumulation of Aurora B on the central spindle after anaphase onset. Aurora B directly bound the substrate-recognition domains of KLHL9 and KLHL13 in vitro and coimmunoprecipitated with the CUL3/KLHL9/KLHL13 complex during mitosis. Moreover, Aurora B was ubiquitylated in a CUL3-dependent manner in vivo and by reconstituted CUL3/KLHL9/KLHL13 in vitro.