Usp7-dependent histone H3 deubiquitylation regulates maintenance of DNA methylation.
Usp7-dependent histone H3 deubiquitylation regulates maintenance of DNA methylation.
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DOI：
10.1038/s41598-017-00136-5
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发表时间：
2017-03-03
影响因子：
4.6
通讯作者：
Nakanishi M
中科院分区：
文献类型：
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作者：
Yamaguchi L;Nishiyama A;Misaki T;Johmura Y;Ueda J;Arita K;Nagao K;Obuse C;Nakanishi M
Uhrf1依赖的组蛋白H3泛素化通过将DNA甲基转移酶Dnmt 1募集到DNA甲基化位点，在DNA甲基化的维持中起着至关重要的作用。然而，靶向泛素化组蛋白H3的去泛素化酶（DUBs）参与DNA甲基化的维持在很大程度上是未知的。使用非洲爪蟾卵提取物，我们在这里证明，Usp7，泛素羧基末端水解酶，形成一个稳定的复合物与Dnmt 1和招募DNA甲基化位点在DNA复制。Usp7在体外使泛素化组蛋白H3去泛素化。在鸡蛋提取物中抑制Usp7活性或耗尽其导致Dnmt 1与染色质的结合增强和延长，抑制DNA甲基化。HeLa细胞中Usp7的缺失导致DNA复制过程中组蛋白H3泛素化增强和Dnmt 1核灶扩大。因此，我们的研究结果表明，Usp7是调节DNA甲基化维持的关键因素。
Uhrf1-dependent histone H3 ubiquitylation plays a crucial role in the maintenance of DNA methylation via the recruitment of the DNA methyltransferase Dnmt1 to DNA methylation sites. However, the involvement of deubiquitylating enzymes (DUBs) targeting ubiquitylated histone H3 in the maintenance of DNA methylation is largely unknown. With the use of Xenopus egg extracts, we demonstrate here that Usp7, a ubiquitin carboxyl-terminal hydrolase, forms a stable complex with Dnmt1 and is recruited to DNA methylation sites during DNA replication. Usp7 deubiquitylates ubiquitylated histone H3 in vitro. Inhibition of Usp7 activity or its depletion in egg extracts results in enhanced and extended binding of Dnmt1 to chromatin, suppressing DNA methylation. Depletion of Usp7 in HeLa cells causes enhanced histone H3 ubiquitylation and enlargement of Dnmt1 nuclear foci during DNA replication. Our results thus suggest that Usp7 is a key factor that regulates maintenance of DNA methylation.