The CENP-H-I complex is required for the efficient incorporation of newly synthesized CENP-A into centromeres.
In vertebrates, centromeres lack defined sequences and are thought to be propagated by epigenetic mechanisms involving the incorporation of specialized nucleosomes containing the histone H3 variant centromere protein (CENP)-A. However, the precise mechanisms that target CENP-A to centromeres remain poorly understood. Here, we isolated a multi-subunit complex, which includes the established inner kinetochore components CENP-H and CENP-I, and nine other proteins, from both human and chicken cells. Our analysis of these proteins demonstrates that the CENP-H-I complex can be divided into three functional sub-complexes, each of which is required for faithful chromosome segregation. Interestingly, newly expressed CENP-A is not efficiently incorporated into centromeres in knockout mutants of a subclass of CENP-H-I complex proteins, indicating that the CENP-H-I complex may function, in part, as a marker directing CENP-A deposition to centromeres.
Okada
Masahiro
M
Department of Molecular Genetics, National Institute of Genetics and The Graduate University for Advanced Studies, Mishima, Shizuoka 411-8540, Japan.
Cheeseman
Iain M
IM
Hori
Tetsuya
T
Okawa
Katsuya
K
McLeod
Ian X
IX
Yates
John R
JR
Desai
Arshad
A
Fukagawa
Tatsuo
T
D000818:Animals; D001324:Autoantigens / Q000096:biosynthesis* / Q000378:metabolism*; D002453:Cell Cycle; D002478:Cells, Cultured; D002503:Centromere / Q000737:chemistry / Q000378:metabolism*; D000076247:Centromere Protein A; D002645:Chickens; D002868:Chromosomal Proteins, Non-Histone / Q000096:biosynthesis* / Q000378:metabolism*; D020090:Chromosome Segregation / Q000235:genetics; D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008954:Models, Biological; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D009687:Nuclear Proteins / Q000378:metabolism; D011485:Protein Binding; D021381:Protein Transport
D001324:Autoantigens; C000619700:CENPA protein, human; C121933:CENPH protein, human; C484297:CENPI protein, human; D000076247:Centromere Protein A; D002868:Chromosomal Proteins, Non-Histone; D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins; C120529:NDC80 protein, human; D009687:Nuclear Proteins