| In mammalian cells, 2 broad groups of centromere-interacting proteins have been described: constitutively binding centromere proteins and 'passenger,' or transiently interacting, proteins. The constitutive proteins include CENPA (centromere protein A), CENPB, CENPC1, and CENPD. The term 'passenger proteins' encompasses a broad collection of proteins that localize to the centromere during specific stages of the cell cycle. These include CENPE; MCAK; KID; cytoplasmic dynein; CliPs and CENPF/mitosin. The inner centromere proteins (INCENPs), the initial members of the passenger protein group, display a broad localization along chromosomes in the early stages of mitosis but gradually become concentrated at centromeres as the cell cycle progresses into mid-metaphase. During telophase, the proteins are located within the midbody in the intercellular bridge, where they are discarded after cytokinesis. |
