Involved in chromosome cohesion during mitosis and meiosis by preventing premature dissociation of cohesin complex from centromeres after prophase; when most of cohesin complex dissociates from chromosomes arms. Required for faithful mitotic chromosome segregation and proper kinetochore orientation during meiosis I. In contrast to sgo1; it is dispensable for centromeric protection of rec8 during meiosis I as well as protection of rad21 during mitosis. Required to sense the lack of tension at centromeres during mitosis. {ECO:0000269|PubMed:14730319; ECO:0000269|PubMed:14972679; ECO:0000269|PubMed:16229998}.