title: Remodeling of nucleosome-dimer particles with yIsw2 promotes their association with ALL-1 SET domain in vitro.
abstract: Functioning of histone lysine methyltransferases (HKMTs) involves interactions of their catalytic domain "SET" with the N-termini of histone H3. However, these interactions are restricted in canonical nucleosomes due to the limited accessibility of H3 termini. Here we investigated whether nucleosome remodeling with the yeast Isw2 affects nucleosome affinity to the SET domain of ALL-1 HKMT. Reconstitution of mononucleosomes by salt dilutions also produces some nucleosome-dimer particles (self-associated mononucleosomes, described by: Tatchell and van Holde (1977) Biochemistry, 16, 5295-5303). The GST-tagged SET-domain polypeptide of ALL-1 was assayed for binding to assembled mononucleosomes and nucleosome-dimer particles, either intact or remodeled with purified yeast Isw2. Remodeling of mononucleosomes does not noticeably affect their affinity to SET domain; however, yIsw2 remodeling of nucleosome-dimer particles facilitated their association with GST-SET polypeptide. Therefore, it is conceivable that nucleosome interactions in trans could be implicated in the maintenance of chromatin methylation patterns in vivo.
authors.affiliation: Institute of Developmental Biology of Russian Academy of Sciences, Moscow, 119334 Russia. wkrajewski@hotmail.com
authors.forename: Wladyslaw A
authors.initials: WA
authors.lastname: Krajewski
authors.forename: Oleg L
authors.initials: OL
authors.lastname: Vassiliev
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D042002:Chromatin Assembly and Disassembly; D019281:Dimerization; D006367:HeLa Cells; D011495:Histone-Lysine N-Methyltransferase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D051788:Myeloid-Lymphoid Leukemia Protein / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D009707:Nucleosomes / Q000378:metabolism*; D054730:Protein Interaction Domains and Motifs; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: C086468:ISWI protein; C497422:KMT2A protein, human; D009707:Nucleosomes; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D051788:Myeloid-Lymphoid Leukemia Protein; D011495:Histone-Lysine N-Methyltransferase; D000251:Adenosine Triphosphatases