Helbling Chadwick Lisa, Chadwick Brian P, Jaye David L, Wade Paul A
Laboratory of Molecular Carcinogenesis, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA.
Chromosoma. 2009 Aug;118(4):445-57. doi: 10.1007/s00412-009-0207-7. Epub 2009 Mar 19.
Chromosomal replication results in the duplication not only of DNA sequence but also of the patterns of histone modification, DNA methylation, and nucleoprotein structure that constitute epigenetic information. Pericentromeric heterochromatin in human cells is characterized by unique patterns of histone and DNA modification. Here, we describe association of the Mi-2/NuRD complex with specific segments of pericentromeric heterochromatin consisting of Satellite II/III DNA located on human chromosomes 1, 9, and 16 in some but not all cell types. This association is linked in part to DNA replication and chromatin assembly and may suggest a role in these processes. Mi-2/NuRD accumulation is independent of Polycomb association and is characterized by a unique pattern of histone modification. We propose that Mi-2/NuRD constitutes an enzymatic component of a pathway for assembly and maturation of chromatin utilized by rapidly proliferating lymphoid cells for replication of constitutive heterochromatin.
染色体复制不仅导致DNA序列的复制，还导致构成表观遗传信息的组蛋白修饰、DNA甲基化和核蛋白结构模式的复制。人类细胞中的着丝粒周围异染色质具有独特的组蛋白和DNA修饰模式。在这里，我们描述了Mi-2/NuRD复合物与着丝粒周围异染色质的特定片段的关联，这些片段由位于人类1号、9号和16号染色体上的卫星II/III DNA组成，存在于部分而非所有细胞类型中。这种关联部分与DNA复制和染色质组装相关，可能暗示其在这些过程中发挥作用。Mi-2/NuRD的积累独立于多梳蛋白关联，并且具有独特的组蛋白修饰模式。我们提出，Mi-2/NuRD构成了快速增殖的淋巴细胞用于组成型异染色质复制的染色质组装和成熟途径的酶成分。
