2026-09-29 東京大学
ヒト細胞から精製されたCENP-Aヌクレオソーム構造を解明
＜関連情報＞
- https://www.iqb.u-tokyo.ac.jp/pressrelease/260929/
- https://www.nature.com/articles/s42003-026-10946-x
ヒト細胞から単離されたCENP-Aヌクレオソームのクライオ電子顕微鏡構造 Cryo-EM structures of CENP-A nucleosomes isolated from human cells
Eisho Tanida, Suguru Hatazawa, Takumi Oishi, Yuki Kobayashi, Mitsuo Ogasawara, Marta A. Jaskiewicz, Akihito Harada, Takeru Fujii, Yasuyuki Ohkawa, Yoshimasa Takizawa & Hitoshi Kurumizaka
Communications Biology Published:29 September 2026
DOI:https://doi.org/10.1038/s42003-026-10946-x
Abstract
Centromeres ensure accurate chromosome segregation, and their identity is specified epigenetically by the histone H3 variant CENP-A. Although the structures of reconstituted CENP-A nucleosomes have provided important insights, how this epigenetic mark is structurally organized within native chromatin remains incompletely understood. Here, we combine cryogenic electron microscopy with chromatin immunoprecipitation (ChIP-CryoEM) to determine the structures of human CENP-A nucleosomes isolated directly from cells without crosslinking or stabilizing agents. We resolved two distinct cellular CENP-A nucleosome structures: a homotypic CENP-A nucleosome and a heterotypic CENP-A/H3 nucleosome, which have been proposed to represent centromeric and ectopic nucleosomes, respectively. Both cellular CENP-A nucleosomes assemble as histone octamers and wrap DNA in a left-handed superhelix, supporting an octameric model proposed for native CENP-A chromatin. In addition, the hallmark CENP-A-specific structural features previously characterized in vitro, including the shortened CENP-A N-terminal α-helix and the distinctive RG loop, are preserved in cellular CENP-A nucleosomes. These findings define the structural organization of CENP-A nucleosomes in cellular chromatin.
