title: Self-interaction of heterochromatin protein 1 is required for direct binding to histone methyltransferase, SUV39H1.
abstract: Heterochromatin protein 1 (HP1) binds to the nucleosome via a methylated lysine residue 9 of histone H3 which is catalyzed by a histone methyltransferase such as SUV39H1. Although co-localization of HP1 and SUV39H1 has been evident in immunostaining and immunoprecipitation experiments, direct protein-protein interactions have remained to be characterized. We examined interactions between mouse HP1 alpha (mHP1 alpha) and SUV39H1 in yeast and in vitro. A yeast two-hybrid and a glutathione S-transferase pull-down study indicated that the chromo shadow domain of mHP1 alpha directly interacts with the N-terminal 39 amino acid stretch of SUV39H1. The IY165/168EE mutation in the chromo shadow domain of mHP1 alpha abrogated a self-interaction and this mutant did not interact with SUV39H1. The 13-mer peptide containing a consensus sequence for binding to the dimer surface formed by the chromo shadow domains inhibited interaction between mHP1 alpha and SUV39H1. It seems that self-interaction through the chromo shadow domain of HP1 is crucial for recruitment of SUV39H1 onto nucleosomes.
authors.affiliation: Division of Molecular Population Genetics, Department of Molecular Genetics, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka-shi, Fukuoka-ken 812-8582, Japan. kyama@bioreg.kyushu-u.ac.jp
authors.forename: Ken
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Miki
authors.initials: M
authors.lastname: Sonoda
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D000090266:Chromobox Protein Homolog 5; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism*; D019281:Dimerization; D011495:Histone-Lysine N-Methyltransferase / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008780:Methyltransferases / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D010455:Peptides / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D020798:Two-Hybrid System Techniques
chemical_list: D002868:Chromosomal Proteins, Non-Histone; D010455:Peptides; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D000090266:Chromobox Protein Homolog 5; C407843:SUV39H1 protein, human; C498700:Suv39h1 protein, mouse; D008780:Methyltransferases; D011495:Histone-Lysine N-Methyltransferase