Component of the anaphase promoting complex/cyclosome (APC/C), a cell cycle-regulated E3 ubiquitin ligase that controls progression through mitosis and the G1 phase of the cell cycle. In the complex, plays a role in the release of the mitotic checkpoint complex (MCC) from the APC/C: not required for APC/C activity itself, but promotes the turnover of CDC20 and MCC on the APC/C, thereby participating in the responsiveness of the spindle assembly checkpoint. Also required for degradation of CDC20 (By similarity). The mammalian APC/C is composed at least of 14 distinct subunits ANAPC1, ANAPC2, CDC27/APC3, ANAPC4, ANAPC5, CDC16/APC6, ANAPC7, CDC23/APC8, ANAPC10, ANAPC11, CDC26/APC12, ANAPC13, ANAPC15 and ANAPC16 that assemble into a complex of at least 19 chains with a combined molecular mass of around 1.2 MDa; APC/C interacts with FZR1 and FBXO5. Belongs to the APC15 family.