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. {ECO:0000269|PubMed:16622420, ECO:0000269|PubMed:16716197, ECO:0000269|PubMed:16932742, ECO:0000269|PubMed:18007590}. This is the function of CENPO (centromere protein O, ENSG00000138092).