title: Influence of DNA methylation on positioning and DNA flexibility of nucleosomes with pericentric satellite DNA.
abstract: DNA methylation occurs on CpG sites and is important to form pericentric heterochromatin domains. The satellite 2 sequence, containing seven CpG sites, is located in the pericentric region of human chromosome 1 and is highly methylated in normal cells. In contrast, the satellite 2 region is reportedly hypomethylated in cancer cells, suggesting that the methylation status may affect the chromatin structure around the pericentric regions in tumours. In this study, we mapped the nucleosome positioning on the satellite 2 sequence in vitro and found that DNA methylation modestly affects the distribution of the nucleosome positioning. The micrococcal nuclease assay revealed that the DNA end flexibility of the nucleosomes changes, depending on the DNA methylation status. However, the structures and thermal stabilities of the nucleosomes are unaffected by DNA methylation. These findings provide new information to understand how DNA methylation functions in regulating pericentric heterochromatin formation and maintenance in normal and malignant cells.
authors.affiliation: Laboratory of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan.
authors.forename: Akihisa
authors.initials: A
authors.lastname: Osakabe
authors.affiliation: Laboratory of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan.
authors.forename: Fumiya
authors.initials: F
authors.lastname: Adachi
authors.affiliation: Laboratory of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Arimura
authors.affiliation: Department of Advanced Medical Initiatives, Faculty of Medicine, Kyushu University, Fukuoka 812-8582, Japan.
authors.forename: Kazumitsu
authors.initials: K
authors.lastname: Maehara
authors.affiliation: Department of Advanced Medical Initiatives, Faculty of Medicine, Kyushu University, Fukuoka 812-8582, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Ohkawa
authors.affiliation: Laboratory of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan kurumizaka@waseda.jp.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Kurumizaka
mesh_terms: D001483:Base Sequence; D042002:Chromatin Assembly and Disassembly; D018360:Crystallography, X-Ray; D019175:DNA Methylation / Q000235:genetics; D004276:DNA, Satellite / Q000737:chemistry* / Q000235:genetics; D006657:Histones / Q000235:genetics; D006801:Humans; D009707:Nucleosomes / Q000235:genetics / Q000648:ultrastructure*
chemical_list: D004276:DNA, Satellite; D006657:Histones; D009707:Nucleosomes
keywords: DNA methylation; chromatin; nucleosome; pericentric heterochromatin