Anaphase-promoting complex

This article refers to the cell-cycle regulatory complex, APC/C. For the tumor suppressor APC, in which mutations lead to colon cancer, see Adenomatous polyposis coli.

Anaphase-Promoting Complex (also called the cyclosome or APC/C) is an E3 ubiquitin ligase that marks target cell cycle proteins for degradation by the 26S proteasome. The APC/C is a large complex of 11–13 subunit proteins, including a cullin (Apc2) and RING (Apc11) subunit much like SCF. Other parts of the APC/C still have unknown functions, but are highly conserved.

It was the discovery of the APC/C (and SCF) and their key role in eukaryotic cell reproduction that established once and for all the importance of ubiquitin-mediated proteolysis in eukaryotic cell biology. Once perceived as a system exclusively involved in removing damaged protein from the cell, ubiquitination and subsequent protein degradation by the proteasome is now perceived as a universal regulatory mechanism for signal transduction whose importance approaches that of protein phosphorylation.