Component of the CENPA-NAC (nucleosome-associated) complex, a complex that plays a central role in assembly of kinetochore proteins, mitotic progression and chromosome segregation. The CENPA-NAC complex recruits the CENPA-CAD (nucleosome distal) complex and may be involved in incorporation of newly synthesized CENPA into centromeres. Plays an important role in the correct PLK1 localization to the mitotic kinetochores. A scaffold protein responsible for the initial recruitment and maintenance of the kinetochore PLK1 population until its degradation. Involved in transcriptional repression (By similarity). Component of the CENPA-NAC complex, at least composed of CENPA, CENPC, CENPH, CENPM, CENPN, CENPT and CENPU. The CENPA-NAC complex interacts with the CENPA-CAD complex, composed of CENPI, CENPK, CENPL, CENPO, CENPP, CENPQ, CENPR and CENPS. Interacts with MLF1 (By similarity). Localizes in the kinetochore domain of centromeres. Colocalizes with PLK1 at the interzone between the inner and the outer kinetochore plates (By similarity). Expressed at high levels in glioblastoma cell lines. Up-regulated in GBM (glioblastoma multiforme) tumors. Significantly increased in both the tumor core as well as the contralateral striatum and cortex in gliomas. Phosphorylated by PLK1 at Thr-73, creating a self-tethering site that specifically interacts with the polo-box domain of PLK1. Belongs to the CENP-U/AME1 family.