Centromere proteins

Human anti-centromere sera from scleroderma patients were used to detect centromere antigens of mouse fibroblast cells. An M_r=59000 centromere protein was localized exclusively on mitotic chromosomes. The association of this protein with the mitotic chromosomes proved to be DNase I sensitive. In interphase nuclei, this centromere antigen was not detectable by immunoblot techniques. The results suggest that the M_r=59000 mitosis specific protein may be necessary for the structural stability of kinetochores during mitosis.