Completion of Mitosis: Chromosome Segregation and Exit from Mitosis
Cleavage of cohesin by separase induces chromosome segregation during anaphase.
At the onset of anaphase, APC/C is directed by Cdc20 to ubiquitinylate securin, which is subsequently degraded by proteasomes. The degradation of securin activates separase.
Exit from mitosis is triggered by mitotic CDK inactivation mainly brought about by mitotic cyclin degradation.
Exit from mitosis requires the activity of protein phosphatases such as Cdc14 to remove mitotic phosphates from many different proteins, permitting mitotic spindle disassembly, the decondensation of chromosomes, and the reassembly of the nuclear envelope.
Cytokinesis finalizes cell fission and must be coordinated with the site of nuclear division. This coordination is especially important in cells undergoing an asymmetric division.