Centromere proteins. I. Mitosis specific centromere antigen recognized by anti-centromere autoantibodies.

Human anti-centromere sera from scleroderma patients were used to detect centromere antigens of mouse fibroblast cells. An Mr = 59,000 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 Mr = 59,000 mitosis specific protein may be necessary for the structural stability of kinetochores during mitosis.