Cdc20 associates with the kinase aurora2/Aik

Cdc20/fizzy family proteins are involved in activation of the anaphase-prom oting complex/cyclosome, which catalyzes the ubiquitin-dependent proteolysi s of cell cycle regulatory proteins such as anaphase inhibitors and mitotic cyclins, leading to chromosome segregation and exit from mitosis, Previous work has shown that human Cdc20 (hCdc20/p55CDC) associates with one or mor e kinases, We report here that Cdc20-associated myelin basic protein kinase activity peaks sharply in early III phase (embryonic cells) or in G(2) pha se (somatic cells). In HeLa cells, Cdc20 is associated with the kinase auro ra2/Aik. Aurora2/Aik is a member of the aurora/Ipl1 family of kinases that, like Cdc20, previously has been shown to be localized at mitotic spindle p oles and is involved in regulating chromosome segregation and maintaining g enomic stability. The demonstration that Cdc20 is associated with aurora2/A ik suggests that some function of Cdc20 is carried out or regulated through its association with aurora2/Aik.