title: Proteome analysis of human metaphase chromosomes.
abstract: DNA is packaged as chromatin in the interphase nucleus. During mitosis, chromatin fibers are highly condensed to form metaphase chromosomes, which ensure equal segregation of replicated chromosomal DNA into the daughter cells. Despite >1 century of research on metaphase chromosomes, information regarding the higher order structure of metaphase chromosomes is limited, and it is still not clear which proteins are involved in further folding of the chromatin fiber into metaphase chromosomes. To obtain a global view of the chromosomal proteins, we performed proteome analyses on three types of isolated human metaphase chromosomes. We first show the results from comparative proteome analyses of two types of isolated human metaphase chromosomes that have been frequently used in biochemical and morphological analyses. 209 proteins were quantitatively identified and classified into six groups on the basis of their known interphase localization. Furthermore, a list of 107 proteins was obtained from the proteome analyses of highly purified metaphase chromosomes, the majority of which are essential for chromosome structure and function. Based on the information obtained on these proteins and on their localizations during mitosis as assessed by immunostaining, we present a four-layer model of metaphase chromosomes. According to this model, the chromosomal proteins have been newly classified into each of four groups: chromosome coating proteins, chromosome peripheral proteins, chromosome structural proteins, and chromosome fibrous proteins. This analysis represents the first compositional view of human metaphase chromosomes and provides a protein framework for future research on this topic.
authors.affiliation: Department of Biotechnology, Graduate School of Engineering, Osaka University, Suita, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Uchiyama
authors.forename: Shouhei
authors.initials: S
authors.lastname: Kobayashi
authors.forename: Hideaki
authors.initials: H
authors.lastname: Takata
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ishihara
authors.forename: Naoto
authors.initials: N
authors.lastname: Hori
authors.forename: Tsunehito
authors.initials: T
authors.lastname: Higashi
authors.forename: Kayoko
authors.initials: K
authors.lastname: Hayashihara
authors.forename: Takefumi
authors.initials: T
authors.lastname: Sone
authors.forename: Daisuke
authors.initials: D
authors.lastname: Higo
authors.forename: Takashi
authors.initials: T
authors.lastname: Nirasawa
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Takao
authors.forename: Sachihiro
authors.initials: S
authors.lastname: Matsunaga
authors.forename: Kiichi
authors.initials: K
authors.lastname: Fukui
mesh_terms: D002843:Chromatin / Q000378:metabolism; D002874:Chromosome Mapping; D002875:Chromosomes / Q000648:ultrastructure*; D019295:Computational Biology / Q000379:methods; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D006367:HeLa Cells; D006801:Humans; D013058:Mass Spectrometry; D008677:Metaphase; D008856:Microscopy, Fluorescence; D020543:Proteome; D040901:Proteomics / Q000379:methods*
chemical_list: D002843:Chromatin; D020543:Proteome