MIWI2 as an Effector of DNA Methylation and Gene Silencing in Embryonic Male Germ Cells
MIWI2 as an Effector of DNA Methylation and Gene Silencing in Embryonic Male Germ Cells
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DOI：
10.1016/j.celrep.2016.08.027
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发表时间：
2016-09-13
期刊：
影响因子：
8.8
通讯作者：
Nakano, Toru
中科院分区：
文献类型：
--
作者：
Kojima-Kita, Kanako;Kuramochi-Miyagawa, Satomi;Nakano, Toru
在哺乳动物胚胎生殖细胞的发育过程中，会发生全局去甲基化和从头DNA甲基化。在小鼠胚胎生殖细胞中，两个PIWI家族蛋白，MILI和MIWI2，对于逆转录转座子的DNA从头甲基化至关重要，可能是通过PIWI相互作用的rna （piRNAs）进行的。尽管pirna相关的MIWI2已被报道在这一过程中发挥关键作用，但其分子机制仍不清楚。为了确定其作用机制，我们制备了转基因小鼠；它们含有MIWI2和锌指（ZF）的融合蛋白，锌指（ZF）识别a型LINE-1基因的启动子区域。ZF-MIWI2融合蛋白带来DNA甲基化，抑制A型LINE-1基因，部分恢复mili缺失小鼠的精子发生受损。此外，ZF-MIWI2与参与DNA甲基化的蛋白相关。这些数据表明，MIWI2作为反转录转座子从头DNA甲基化的效应物起作用。
During the development of mammalian embryonic germ cells, global demethylation and de novo DNA methylation take place. In mouse embryonic germ cells, two PIWI family proteins, MILI and MIWI2, are essential for the de novo DNA methylation of retrotransposons, presumably through PIWI-interacting RNAs (piRNAs). Although piRNA-associated MIWI2 has been reported to play critical roles in the process, its molecular mechanisms have remained unclear. To identify the mechanism, transgenic mice were produced; they contained a fusion protein of MIWI2 and a zinc finger (ZF) that recognized the promoter region of a type A LINE-1 gene. The ZF-MIWI2 fusion protein brought about DNA methylation, suppression of the type A LINE-1 gene, and a partial rescue of the impaired spermatogenesis of MILI-null mice. In addition, ZF-MIWI2 was associated with the proteins involved in DNA methylation. These data indicate that MIWI2 functions as an effector of de novo DNA methylation of the retrotransposon.