Anaphase Promoting Complex

The successful completion of anaphase also depends on the activity of a ubiquitin ligase called anaphase-promoting complex or cyclosome APC/C.

During the transition to anaphase, the protein Cdc20 binds to and activates APC/C. The activated APC/C ubiquitinates the regulatory proteins, S-cyclins and M-cyclins, thereby targeting them for proteasomal degradation.

Cyclin degradation inhibits the activity of most Cdks. The absence of cyclin-dependent kinase activity enables phosphatases to dephosphorylate most of the Cdk-substrates within the cell, which is required for the completion of anaphase.