INCENP

In mammalian cells, 2 broad groups of centromere-interacting proteins have been described: constitutively binding centromere proteins and 'passenger,' or transiently interacting, proteins (reviewed by Choo, 1997). The constitutive proteins include CENPA (centromere protein A; MIM 117139), CENPB (MIM 117140), CENPC1 (MIM 117141), and CENPD (MIM 117142). The term 'passenger proteins' encompasses a broad collection of proteins that localize to the centromere during specific stages of the cell cycle (Earnshaw and Mackay, 1994 [PubMed 8088460]). These include CENPE (MIM 117143); MCAK (MIM 604538); KID (MIM 603213); cytoplasmic dynein (e.g., MIM 600112); CliPs (e.g., MIM 179838); and CENPF/mitosin (MIM 600236). The inner centromere proteins (INCENPs) (Earnshaw and Cooke, 1991 [PubMed 1860899]), 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 (Cutts et al., 1999 [PubMed 10369859]).

Inner Centromere Protein

Component of the chromosomal passenger complex (CPC), a complex that acts as a key regulator of mitosis. The CPC complex has essential functions at the centromere in ensuring correct chromosome alignment and segregation and is required for chromatin-induced microtubule stabilization and spindle assembly. Acts as a scaffold regulating CPC localization and activity. The C-terminus associates with AURKB or AURKC, the N-terminus associated with BIRC5/survivin and CDCA8/borealin tethers the CPC to the inner centromere, and the microtubule binding activity within the central SAH domain directs AURKB/C toward substrates near microtubules (PubMed:15316025, PubMed:12925766, PubMed:27332895).
The flexibility of the SAH domain is proposed to allow AURKB/C to follow substrates on dynamic microtubules while ensuring CPC docking to static chromatin (By similarity).
Activates AURKB and AURKC (PubMed:27332895).
Required for localization of CBX5 to mitotic centromeres (PubMed:21346195).
Controls the kinetochore localization of BUB1 (PubMed:16760428).

Chromosome segregationManual Assertion Based On ExperimentIMP:UniProtKB
Histone phosphorylationManual Assertion Based On ExperimentIBA:GO_Central
Meiotic spindle midzone assemblyManual Assertion Based On ExperimentIBA:GO_Central
Metaphase plate congressionManual Assertion Based On ExperimentIBA:GO_Central
Mitotic cytokinesisManual Assertion Based On ExperimentIMP:UniProtKB
Mitotic sister chromatid segregationIEA:InterPro
Positive regulation of protein serine/threonine kinase activityManual Assertion Based On ExperimentIBA:GO_Central
Regulation of mitotic cytokinesisIEA:InterPro

Nucleus; Cytoplasm, cytoskeleton, spindle; Midbody; Chromosome, centromere, kinetochore. Colocalized at synaptonemal complex central element from zygotene up to late pachytene when it begins to relocalize to heterochromatic chromocenters. Colocalizes with AURKB at a connecting strand traversing the centromere region and joining sister kinetochores, in metaphase II centromeres. This strand disappears at the metaphase II/anaphase II transition and relocalizes to the spindle midzone (By similarity).
Colocalizes with AURKB at mitotic chromosomes (PubMed:11453556).
Localizes to inner kinetochore (PubMed:16760428).
Localizes on chromosome arms and inner centromeres from prophase through metaphase and then transferring to the spindle midzone and midbody from anaphase through cytokinesis (PubMed:15316025).
Cocalizes to the equatorial cell cortex at anaphase (PubMed:11453556).

Phosphorylation by AURKB or AURKC at its C-terminal part is important for AURKB or AURKC activation by INCENP.