Separase

The second step involves cleavage of the cohesin subunit SCC1 (RAD21) by separase, which initiates the final separation of sister chromatids.

Esp1 is a separase protein that cleaves the cohesin subunit Scc1 (RAD21), allowing sister chromatids to separate at the onset of anaphase during mitosis.

Separase initiates the activation of Cdc14 in early anaphase[13] and Cdc14 has been found to dephosphorylate securin, thereby increasing its efficiency as a substrate for degradation.

The presence of this positive feedback loop offers a potential mechanism for giving anaphase a more switch-like behavior.

[12] This article incorporates text from the United States National Library of Medicine, which is in the public domain.

Yeast cohesin complex
The yeast cohesin complex consists of specialized proteins, including Scc1. [ 10 ]
Network diagram with feedback loops to generate switch-like activation of anaphase. [ 12 ]
network diagram
Figure 4: Potential network diagram involving securin and separase to generate switch-like activation of anaphase