Distinct DNA methylation activity of Dnmt3a and Dnmt3b towards naked and nucleosomal DNA
Distinct DNA methylation activity of Dnmt3a and Dnmt3b towards naked and nucleosomal DNA
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DOI：
10.1093/jb/mvj044
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发表时间：
2006-03-01
影响因子：
2.7
通讯作者：
Tajima, S
中科院分区：
文献类型：
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作者：
Takeshima, H;Suetake, I;Tajima, S
在哺乳动物中，早期胚胎和生殖细胞中DNA甲基化模式的重置对发育至关重要。从头型DNA甲基转移酶Dnmt3a和Dnmt3b负责在胚胎发生和生殖细胞中产生DNA甲基化模式。虽然它们在体外DNA甲基化特性相似，但Dnmt3a和Dnmt3b在体内甲基化不同的基因组DNA区域。在本研究中，我们检测了Dnmt 3a和Dnmt 3b对重组组蛋白和DNA重建的核小体的DNA甲基化活性，并将其与相应的裸DNA进行了比较。Dnmt 3a对裸DNA和核小体裸部分的甲基化活性高于Dnmt 3b。DNA.另一方面，Dnmt3a几乎不甲基化核小体核心区域内的DNA，而Dnmt3b显着，虽然活性低。我们认为Dnmt3a对核小体裸露部分的优先甲基化活性和Dnmt3b对核小体核心区域的显著甲基化活性有助于它们在体内对基因组DNA的独特甲基化。
In mammals, the resetting of DNA methylation patterns in early embryos and germ cells is crucial for development. De novo type DNA methyltransferases Dnmt3a and Dnmt3b are responsible for creating DNA methylation patterns during embryogenesis and in germ cells. Although their in vitro DNA methylation properties are similar, Dnmt3a and Dnmt3b methylate different genomic DNA regions in vivo. In the present study, we have examined the DNA methylation activity of Dnmt3a and Dnmt3b towards nucleo-somes reconstituted from recombinant histones and DNAs, and compared it to that of the corresponding naked DNAs. Dnmt3a showed higher DNA methylation activity than Dnmt3b towards naked DNA and the naked part of nucleosomal. DNA. On the other hand, Dnmt3a scarcely methylated the DNA within the nucleosome core region, while Dnmt3b significantly did, although the activity was low. We propose that the preferential DNA methylation activity of Dnmt3a towards the naked part of nucleosomal DNA and the significant methylation activity of Dnmt3b towards the nucleosome core region contribute to their distinct methylation of genomic DNA in vivo.