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. {ECO:0000269|PubMed:15339662}.