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. Required for the localization of CENPF, MAD1L1 and MAD2 (MAD2L1 or MAD2L2) to kinetochores. Involved in the response of gonadal tissues to follicle-stimulating hormone (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. Interacts with SENP6 (By similarity). Localizes exclusively in the centromeres. The CENPA-CAD complex is probably recruited on centromeres by the CENPA-NAC complex (By similarity). Highly expressed in testis, ovary and spleen. A much lower mRNA level is found in brain and lung, and no expression is detected in liver, kidney, heart, muscle, pituitary gland, prostate, epididymis and seminal vesicle. By follicle-stimulating hormone (FSH). Sumoylated. Sumoylated form can be polyubiquitinated by RNF4, leading to its degradation. Desumoylation by SENP6 prevents its degradation (By similarity). Belongs to the CENP-I/CTF3 family.