CENP-A Is Required for Accurate Chromosome Segregation and Sustained Kinetochore Association of BubR1

• DOI: 10.1128/mcb.25.10.3967-3981.2005
• Publication Date: 2005-05-03T17:48:40Z
• Authors: Vinciane Régnier; Paola Vagnarelli; Tatsuo Fukagawa; Tatiana Zerjal; Elizabeth Burns; Didier Trouche; William Earnshaw; William Brown
• Keywords: 0301 basic medicine; Prometaphase; Chromosomal Proteins, Non-Histone; G1 Phase; Mitosis; Nuclear Proteins; Apoptosis; Cell Cycle Proteins; Protein Serine-Threonine Kinases; Autoantigens; 03 medical and health sciences; Cell Line, Tumor; Chromosome Segregation; Multiprotein Complexes; Animals; RNA, Messenger; Carrier Proteins; Kinetochores; Chickens; Protein Kinases; Centromere Protein A; Protein Binding

CENP-A is an evolutionarily conserved, centromere-specific variant of histone H3 that is thought to play a central role in directing kinetochore assembly and in centromere function. Here, we have analyzed the consequences of disrupting the CENP-A gene in the chicken DT40 cell line. In CENP-A-depleted cells, kinetochore protein assembly is impaired, as indicated by mislocalization of the inner kinetochore proteins CENP-I, CENP-H, and CENP-C as well as the outer components Nuf2/Hec1, Mad2, and CENP-E. However, BubR1 and the inner centromere protein INCENP are efficiently recruited to kinetochores. Following CENP-A depletion, chromosomes are deficient in proper congression on the mitotic spindle and there is a transient delay in prometaphase. CENP-A-depleted cells further proceed through anaphase and cytokinesis with unequal chromosome segregation, suggesting that some kinetochore function remains following substantial depletion of CENP-A. We furthermore demonstrate that CENP-A-depleted cells exhibit a specific defect in maintaining kinetochore localization of the checkpoint protein BubR1 under conditions of checkpoint activation. Our data thus point to a specific role for CENP-A in assembly of kinetochores competent in the maintenance of mitotic checkpoint signaling.