Separase is a marker for prognosis and mitotic activity in breast cancer

Separase (extra spindle poles-like 1), a cysteine protease and endopeptidase, has a central role in cell cycle progression in ensuring immaculate genetic inheritance. In the normal cell, activation of separase initiates anaphase at two diligently controlled consecutive events (Mora-Santos et al, 2011; Hellmuth et al, 2015; Meadows and Millar, 2015; Zhang and Pati, 2017). In the first event, separase triggers the cleavage of the Scc1/Rad21 subunit of cohesin, thus inactivating the complex. In the next event, separase participates in the final unleashing of the sister-chromatids at anaphase onset (Sun et al, 2009; Schockel et al, 2011). Abnormally increased proteolytic activity of separase has been described to predispose the cell to uncontrolled centriole duplication, chromosomal missegregation and aneuploidy (Pati, 2008; Haas et al, 2012). Owing to its central role in metaphase–anaphase transition, both premature and delayed activation of separase will result in chromosomal instability (Zhang and Pati, 2017).