Plays a central role in chromosome cohesion during mitosis by preventing premature dissociation of cohesin complex from centromeres after prophase, when most of cohesin complex dissociates from chromosomes arms. May act by preventing phosphorylation of the stag2 subunit of cohesin complex at the centromere, ensuring cohesin persistence at centromere until cohesin cleavage by espl1/separase at anaphase. May regulate kinetochore microtubule stability in mitosis, possibly to sense tension on mitotic chromosomes. Binds microtubules. Localizes to the centromere. At anaphase, it dissociates from centromeres when chromatids separate. Localizes to kinetochores. High level during prophase and prometaphase and weaker after the chromosomes attach to the spindle and align at the metaphase plate. During anaphase, it is degraded, allowing the separation of sister centromeres (at protein level). Ubiquitinated by the anaphase promoting complex (APC) at the onset of anaphase, conducting to its degradation. Belongs to the shugoshin family.