Faculty of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn Str. 4a, 44227, Dortmund, Germany.
Department of Epigenetics and Tumor Biology, Medical Faculty, University of Cologne, Kerpener Str. 62, 50937, Köln, Germany.
Angew Chem Int Ed Engl. 2021 Jun 7;60(24):13507-13512. doi: 10.1002/anie.202103945. Epub 2021 May 5.
5-Methylcytosine (5mC), the central epigenetic mark of mammalian DNA, plays fundamental roles in chromatin regulation. 5mC is written onto genomes by DNA methyltransferases (DNMT), and perturbation of this process is an early event in carcinogenesis. However, studying 5mC functions is limited by the inability to control individual DNMTs with spatiotemporal resolution in vivo. We report light-control of DNMT catalysis by genetically encoding a photocaged cysteine as a catalytic residue. This enables translation of inactive DNMTs, their rapid activation by light-decaging, and subsequent monitoring of de novo DNA methylation. We provide insights into how cancer-related DNMT mutations alter de novo methylation in vivo, and demonstrate local and tuneable cytosine methylation by light-controlled DNMTs fused to a programmable transcription activator-like effector domain targeting pericentromeric satellite-3 DNA. We further study early events of transcriptome alterations upon DNMT-catalyzed cytosine methylation. Our study sets a basis to dissect the order and kinetics of diverse chromatin-associated events triggered by normal and aberrant DNA methylation.
5- 甲基胞嘧啶（5mC）是哺乳动物 DNA 中的核心表观遗传标记，在染色质调控中发挥着基础性作用。5mC 由 DNA 甲基转移酶（DNMT）写入基因组，该过程的扰动是致癌作用的早期事件。然而，由于无法在体内具有时空分辨率地控制单个 DNMT，因此对 5mC 功能的研究受到限制。我们通过将光笼巯基氨酸遗传编码为催化残基来报告对 DNMT 催化作用的光控制。这使得失活的 DNMT 能够被翻译，通过光去笼化快速激活，随后监测新的 DNA 甲基化。我们深入了解了与癌症相关的 DNMT 突变如何在体内改变新的甲基化，并通过与靶向着丝粒卫星-3 DNA 的可编程转录激活子样效应物结构域融合的光控 DNMT 来展示局部和可调的胞嘧啶甲基化。我们进一步研究了 DNMT 催化的胞嘧啶甲基化后转录组改变的早期事件。我们的研究为剖析正常和异常 DNA 甲基化引发的各种染色质相关事件的顺序和动力学奠定了基础。
