Component of the CENPA-CAD (nucleosome distal) complex, a complex recruited to centromeres which is involved in assembly of kinetochore proteins, mitotic progression and chromosome segregation. May be involved in incorporation of newly synthesized CENPA into centromeres via its interaction with the CENPA-NAC complex. Modulates the kinetochore-bound levels of NDC80 complex (By similarity). Component of the CENPA-CAD complex, composed of CENPI, CENPK, CENPL, CENPO, CENPP, CENPQ, CENPR and CENPS. The CENPA-CAD complex interacts with the CENPA-NAC complex, at least composed of CENPA, CENPC, CENPH, CENPM, CENPN, CENPT and CENPU (By similarity). Localizes exclusively in the centromeres. The CENPA-CAD complex is probably recruited on centromeres by the CENPA-NAC complex (By similarity). Belongs to the CENP-O/MCM21 family.