title: Nucleosome compaction facilitates HP1γ binding to methylated H3K9.
abstract: The α, β and γ isoforms of mammalian heterochromatin protein 1 (HP1) selectively bind to methylated lysine 9 of histone H3 via their chromodomains. Although the phenotypes of HP1-knockout mice are distinct for each isoform, the molecular mechanisms underlying HP1 isoform-specific function remain elusive. In the present study, we found that in contrast to HP1α, HP1γ could not bind tri-methylated H3 lysine 9 in a reconstituted tetra-nucleosomes when the nucleosomes were in an uncompacted state. The hinge region connecting HP1's chromodomain and chromoshadow domain contributed to the distinct recognition of the nucleosomes by HP1α and HP1γ. HP1γ, but not HP1α, was strongly enhanced in selective binding to tri-methylated lysine 9 in histone H3 by the addition of Mg(2+) or linker histone H1, which are known to induce compaction of nucleosomes. We propose that this novel property of HP1γ recognition of lysine 9 in the histone H3 tail in different nucleosome structures plays a role in reading the histone code.
authors: Laboratory of Epigenetics, Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan.
authors: Yuichi
authors: Y
authors: Mishima
authors: Laboratory of Epigenetics, Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan.
authors: Chanika D
authors: CD
authors: Jayasinghe
authors: Institute for Integrated Cell-Material Sciences, Kyoto University, Kyoto 606-8501, Japan.
authors: Kai
authors: K
authors: Lu
authors: Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan.
authors: Junji
authors: J
authors: Otani
authors: Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan CREST, Japan Science and Technology Agency, Saitama 332-0012, Japan.
authors: Masahiro
authors: M
authors: Shirakawa
authors: Laboratory of Organic Chemistry, Institute for Protein Research, Osaka University, Osaka 565-0871, Japan.
authors: Toru
authors: T
authors: Kawakami
authors: Laboratory of Epigenetics, Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan.
authors: Hironobu
authors: H
authors: Kimura
authors: Laboratory of Organic Chemistry, Institute for Protein Research, Osaka University, Osaka 565-0871, Japan.
authors: Hironobu
authors: H
authors: Hojo
authors: Institute for Integrated Cell-Material Sciences, Kyoto University, Kyoto 606-8501, Japan.
authors: Peter
authors: P
authors: Carlton
authors: Laboratory of Epigenetics, Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan.
authors: Shoji
authors: S
authors: Tajima
authors: Laboratory of Epigenetics, Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan CREST, Japan Science and Technology Agency, Saitama 332-0012, Japan suetake@protein.osaka-u.ac.jp.
authors: Isao
authors: I
authors: Suetake
mesh_terms: D000090266:Chromobox Protein Homolog 5; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D006657:Histones / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D008239:Lysine / Q000378:metabolism; D008274:Magnesium / Q000737:chemistry; D008745:Methylation; D009707:Nucleosomes / Q000378:metabolism*; D011485:Protein Binding; D020033:Protein Isoforms / Q000378:metabolism; D055503:Protein Multimerization
chemical_list: C518294:CBX3 protein, human; C000715594:CBX5 protein, human; D002868:Chromosomal Proteins, Non-Histone; D006657:Histones; D009707:Nucleosomes; D020033:Protein Isoforms; D000090266:Chromobox Protein Homolog 5; D008274:Magnesium; D008239:Lysine