DNA methylation requires a DNMT1 ubiquitin interacting motif (UIM) and histone ubiquitination.
DNA methylation requires a DNMT1 ubiquitin interacting motif (UIM) and histone ubiquitination.
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DOI：
10.1038/cr.2015.72
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发表时间：
2015-08
期刊：
影响因子：
44.1
通讯作者：
Leonhardt H
中科院分区：
文献类型：
--
作者：
Qin W;Wolf P;Liu N;Link S;Smets M;La Mastra F;Forné I;Pichler G;Hörl D;Fellinger K;Spada F;Bonapace IM;Imhof A;Harz H;Leonhardt H
DNMT1被PCNA和UHRF1募集来维持DNA复制后的甲基化。UHRF1通过SRA结构域识别半甲基化的DNA底物，但也通过其TTD抑制H3K9me3组蛋白标记。通过系统诱变和功能分析，我们可以证明染色质结合进一步涉及UHRF1 PHD与未修饰的H3R2的结合。这些互补分析清楚地表明，UHRF1环结构域的泛素连接酶活性是维持DNA甲基化所必需的。UHRF1缺陷细胞的质谱分析显示，H3K18是哺乳动物细胞中UHRF1泛素化的新靶点。通过生物信息学和突变分析，我们在DNMT1的n端调控域中发现了一个泛素相互作用基序（UIM），该基序与泛素化的H3尾部结合，对体内DNA甲基化至关重要。H3泛素化和随后的DNA甲基化需要UHRF1 PHD与H3R2结合。这些结果表明，控制DNMT1活性的多种调控机制需要UHRF1读取和写入表观遗传标记，并说明了DNA和组蛋白修饰之间的多方面相互作用。DNMT1 UIM的鉴定和功能表征提示了一种新的调控原理，我们推测组蛋白H2AK119泛素化也可能导致DNMT1的UIM依赖性募集和DNA甲基化，而不是传统的维持。
DNMT1 is recruited by PCNA and UHRF1 to maintain DNA methylation after replication. UHRF1 recognizes hemimethylated DNA substrates via the SRA domain, but also repressive H3K9me3 histone marks with its TTD. With systematic mutagenesis and functional assays, we could show that chromatin binding further involved UHRF1 PHD binding to unmodified H3R2. These complementation assays clearly demonstrated that the ubiquitin ligase activity of the UHRF1 RING domain is required for maintenance DNA methylation. Mass spectrometry of UHRF1-deficient cells revealed H3K18 as a novel ubiquitination target of UHRF1 in mammalian cells. With bioinformatics and mutational analyses, we identified a ubiquitin interacting motif (UIM) in the N-terminal regulatory domain of DNMT1 that binds to ubiquitinated H3 tails and is essential for DNA methylation in vivo. H3 ubiquitination and subsequent DNA methylation required UHRF1 PHD binding to H3R2. These results show the manifold regulatory mechanisms controlling DNMT1 activity that require the reading and writing of epigenetic marks by UHRF1 and illustrate the multifaceted interplay between DNA and histone modifications. The identification and functional characterization of the DNMT1 UIM suggests a novel regulatory principle and we speculate that histone H2AK119 ubiquitination might also lead to UIM-dependent recruitment of DNMT1 and DNA methylation beyond classic maintenance.