The anaphase-promoting complex (APC) or cyclosome is a macromolecular complex that contains cullin-ring E3 ubiquitin ligase activity and is conserved across all eukaryotes (for a review, see [15] ). It has at least eleven subunits and two co-activator proteins (CDC20 (cell-division cycle protein 20) and Cdh1 (CDC20 homologue 1)), which are separated into three subcomplexes. These include the cullin-ring ligase domain (composed of APC2, 10, and 11), the specificity arm (composed of APC3, 6, 7, and 8), and the bridge (composed of APC1, 4, and 5). Cdh1 and CDC20 activate APC activity to prevent premature entry into S phase and to promote progression through mitosis, respectively. The APC complex ubiquitinates more than 40 proteins, including A-and B-type cyclins, to regulate their stability. It also regulates degradation of its own coactivator proteins, Cdh1 and CDC20, as a form of feedback regulation. Due to its central role in cell cycle progression, the APC is also a promising target for anti-cancer therapeutics [16] .