DNMT3L stimulates the DNA methylation activity of Dnmt3a and Dnmt3b through a direct interaction
DNMT3L stimulates the DNA methylation activity of Dnmt3a and Dnmt3b through a direct interaction
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DOI：
10.1074/jbc.m400181200
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发表时间：
2004-06-25
影响因子：
4.8
通讯作者：
Tajima, S
中科院分区：
文献类型：
--
作者：
Suetake, I;Shinozaki, F;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。两种DNA甲基转移酶，DNMT3a和Dnmt3b，负责DNA甲基化模式的创建。Dnmt3L是Dnmt3家族的成员之一，据报道，它可能通过与DNMT3A和/或Dnmt3b(Hata，K.，Okano，M.，Lei，H.和Li，E.(2002)Development 129,1983-1993)相互作用，在母体甲基化印记中是必需的。本研究检测了人DNMT3L的同源物DNMT3L对小鼠DNMT3a和Dnmt3b细胞DNA甲基化活性的影响。DNMT3L使DNMT3A和Dnmt3b的DNA甲基化活性增加约1.5-3倍，并呈剂量依赖关系，但不增强Dnmt1的DNA甲基化活性。尽管刺激的程度不同，但对所有底物的DNA甲基化活性都有刺激作用，如母系甲基化的Snrpn和Lit-1印记基因、父系甲基化的H19印记基因、myoD基因的CpG岛、5 S核糖体RNA基因、人工28bpDNA、聚(DG-DC)-聚(DG-DC)和聚(Di-DC)-聚(Di-DC)。DNMT3L不能与DNA结合，但能与DNMT3a和Dnmt3b结合，提示DNMT3L对DNA甲基化活性的刺激作用可能不是由于DNMT3a和Dnmt3b对靶DNA序列的引导，而是对其催化活性的直接影响。DNMT3L的羧基末端是酶活性增强的原因。
In mammals, the resetting of DNA methylation patterns in early embryos and germ cells is crucial for development. Two DNA methyltransferases, Dnmt3a and Dnmt3b, are responsible for the creation of DNA methylation patterns. Dnmt3L, a member of the Dnmt3 family, has been reported to be necessary for maternal methylation imprinting, possibly by interacting with Dnmt3a and/or Dnmt3b (Hata, K., Okano, M., Lei, H., and Li, E. ( 2002) Development 129, 1983 - 1993). In the present study, the effect of DNMT3L, a human homologue of Dnmt3L, on the DNA methylation activity of mouse Dnmt3a and Dnmt3b was examined in vitro. DNMT3L enhanced the DNA methylation activity of Dnmt3a and Dnmt3b about 1.5-3-fold in a dose-dependent manner but did not enhance the DNA methylation activity of Dnmt1. Although the extents of stimulation were different, a stimulatory effect on the DNA methylation activity was observed for all of the substrate DNA sequences examined, such as those of the maternally methylated SNRPN and Lit-1 imprinting genes, the paternally methylated H19 imprinting gene, the CpG island of the myoD gene, the 5 S ribosomal RNA gene, an artificial 28-bp DNA, poly(dG-dC)- poly(dG-dC), and poly(dI-dC)- poly(dI-dC). DNMT3L could not bind to DNA but could bind to Dnmt3a and Dnmt3b, indicating that the stimulatory effect of DNMT3L on the DNA methylation activity may not be due to the guiding of Dnmt3a and Dnmt3b to the targeting DNA sequence but may comprise a direct effect on their catalytic activity. The carboxyl-terminal half of DNMT3L was found to be responsible for the enhancement of the enzyme activity.