CENPI is a component of the CENPA-CAD (nucleosome distal) complex, which is recruited to centromeres and is involved in the assembly of kinetochore proteins, mitotic progression and chromosome segregation. It is also described as part of the CENPA-NAC (nucleosome-associated) complex, which is critical for accurate chromosome alignment and segregation. CENPI may contribute to the incorporation of newly synthesised CENPA into centromeres through its interaction with the CENPA-NAC complex.

The CENPI protein regulates the recruitment of kinetochore-associated proteins needed to generate the spindle checkpoint signal. It is required for the localisation of CENPF, MAD1L1 and MAD2 (MAD2L1 or MAD2L2) to kinetochores. The protein localises to the nucleus and to the centromere of chromosomes, and belongs to the CENP-I/CTF3 family. The CENPI gene lies on the X chromosome, a pseudogene is found on chromosome 13, and alternate splicing gives rise to multiple transcript variants. Mouse and rat both carry a Cenpi ortholog.

Beyond its mitotic role, CENPI is involved in the response of gonadal tissues to follicle-stimulating hormone, and mutations in the gene may be involved in human X-linked disorders of gonadal development and gametogenesis. This is reflected in its earlier names, FSH primary response (LRPR1 homolog, rat) 1, and in the aliases LRPR1 and FSHPRH1. The alias Mis6 refers to the related centromere factor name used in other systems. HGNC places CENPI in the constitutive centromere associated network gene group.