title: Partitioning of histone H3-H4 tetramers during DNA replication-dependent chromatin assembly.
abstract: Semiconservative DNA replication ensures the faithful duplication of genetic information during cell divisions. However, how epigenetic information carried by histone modifications propagates through mitotic divisions remains elusive. To address this question, the DNA replication-dependent nucleosome partition pattern must be clarified. Here, we report significant amounts of H3.3-H4 tetramers split in vivo, whereas most H3.1-H4 tetramers remained intact. Inhibiting DNA replication-dependent deposition greatly reduced the level of splitting events, which suggests that (i) the replication-independent H3.3 deposition pathway proceeds largely by cooperatively incorporating two new H3.3-H4 dimers and (ii) the majority of splitting events occurred during replication-dependent deposition. Our results support the idea that "silent" histone modifications within large heterochromatic regions are maintained by copying modifications from neighboring preexisting histones without the need for H3-H4 splitting events.
authors.affiliation: Graduate Program, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100730, People's Republic of China.
authors.forename: Mo
authors.initials: M
authors.lastname: Xu
authors.forename: Chengzu
authors.initials: C
authors.lastname: Long
authors.forename: Xiuzhen
authors.initials: X
authors.lastname: Chen
authors.forename: Chang
authors.initials: C
authors.lastname: Huang
authors.forename: She
authors.initials: S
authors.lastname: Chen
authors.forename: Bing
authors.initials: B
authors.lastname: Zhu
mesh_terms: D000595:Amino Acid Sequence; D016590:Aphidicolin / Q000494:pharmacology; D002453:Cell Cycle; D002843:Chromatin / Q000378:metabolism; D042002:Chromatin Assembly and Disassembly; D004261:DNA Replication; D044127:Epigenesis, Genetic; D006367:HeLa Cells; D006570:Heterochromatin / Q000378:metabolism; D006657:Histones / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D006918:Hydroxyurea / Q000494:pharmacology; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D009707:Nucleosomes / Q000378:metabolism*; D055503:Protein Multimerization; D016196:S Phase; D014162:Transfection
chemical_list: D002843:Chromatin; D006570:Heterochromatin; D006657:Histones; D009707:Nucleosomes; D016590:Aphidicolin; D006918:Hydroxyurea