Cleavable component of the cohesin complex; involved in chromosome cohesion during cell cycle; in DNA repair; and in apoptosis. The cohesin complex is required for the cohesion of sister chromatids after DNA replication. The cohesin complex apparently forms a large proteinaceous ring within which sister chromatids can be trapped. At metaphase-anaphase transition; this protein is cleaved by separase/ESPL1 and dissociates from chromatin; allowing sister chromatids to segregate. The cohesin complex may also play a role in spindle pole assembly during mitosis. Also plays a role in apoptosis; via its cleavage by caspase-3/CASP3 or caspase-7/CASP7 during early steps of apoptosis: the C-terminal 64 kDa cleavage product may act as a nuclear signal to initiate cytoplasmic events involved in the apoptotic pathway. {ECO:0000269|PubMed:11875078; ECO:0000269|PubMed:12417729}.