Cell Division Cycle Associated Protein 3 (CDCA3)

In Xenopus, Ayad et al. (2003) identified a G1 substrate of the anaphase-promoting complex (APC) that they termed Tome1 and isolated the corresponding cDNA. Xenopus Tome1 contains 2 N-terminal destruction boxes, an F box, and a C-terminal KEN domain. It is 30% identical to the 268-amino acid human TOME1 protein.

Tome1 associated with Skp1and was required for degradation of the Cdk1 inhibitory tyrosine kinase Wee1 . Tome1, therefore, appeared to be acting as part of an SCF-type E3 for Wee1. Degradation of Tome1 during G1 allowed for Wee1 accumulation during interphase, thereby providing a critical link between the APC and SCF pathways in regulation of Cdk1/cyclin B activity and thus mitotic entry and exit.