Function
Probably catalytic subunit of the anaphase promoting complex/cyclosome (APC/C), a cell cycle-regulated E3 ubiquitin-protein ligase complex that controls progression through mitosis and the G1 phase of the cell cycle. The APC/C is thought to confer substrate specificity and, in the presence of ubiquitin-conjugating E2 enzymes, it catalyzes the formation of protein-ubiquitin conjugates that are subsequently degraded by the 26S proteasome. In early mitosis, the APC/C is activated by CDC20 and targets securin PDS1, the B-type cyclin CLB5, and other anaphase inhibitory proteins for proteolysis, thereby triggering the separation of sister chromatids at the metaphase-to-anaphase transition. In late mitosis and in G1, degradation of CLB5 allows activation of the APC/C by CDH1, which is needed to destroy CDC20 and the B-type cyclin CLB2 to allow exit from mitosis and creating the low CDK state necessary for cytokinesis and for reforming prereplicative complexes in G1 prior to another round of replication. APC11 is required to recruit the ubiquitin-conjugating enzyme E2 to the APC/C.