IDH1/2 Mutants Inhibit TET-Promoted Oxidation of RNA 5mC to 5hmC.
IDH1/2 Mutants Inhibit TET-Promoted Oxidation of RNA 5mC to 5hmC.
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IDH1/2 突变体抑制 TET 促进的 RNA 5mC 氧化为 5hmC
DOI：
10.1371/journal.pone.0161261
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发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Yang Q
中科院分区：
文献类型：
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作者：
Xu Q;Wang K;Wang L;Zhu Y;Zhou G;Xie D;Yang Q
TET（TET 1/2/3）通过将DNA 5 mdC氧化为5 hmdC而驱动DNA去甲基化，在多细胞过程中发挥关键作用。有趣的是，最近的研究表明，TdR还将RNA 5 mC氧化为5 hmC。然而，关于RNA 5 hmC在人体中的分布及其调控机制的研究还很少。在这里，我们表明，5 hmC是丰富的mRNA，IDH 1/2突变体抑制TET促进的RNA 5 mC氧化为5 hmC。由于IDH 1/2突变已被描述为阻断TdR的DNA氧化活性，我们假设IDH 1/2突变也可能抑制TdR的RNA氧化活性。为了评估IDH 1/2突变在RNA 5 hmC中的作用，在人HEK 293细胞中过表达具有/不具有IDH 1/2突变体的TcR。将所得DNA和RNA消化并通过三重四极杆LC质谱仪分析。用适当标准品的外部校准曲线定量DNA 5 hmdC和RNA 5 hmC修饰。结果发现，与总RNA（5 hmC/C：小于2 × 10−7）相比，mRNA显示出更高的5 hmC水平（5 hmC/C：约7 × 10−6）。进一步的研究表明IDH 1/2突变体对TET启动的RNA 5 hmC有明显的抑制作用。与该结果一致，IDH 1/2突变体的过表达也抑制了泰特催化结构域促进的RNA氧化。在这项研究中，我们不仅显示了5 hmC在mRNA中的富集，而且还显示了RNA 5 hmC-IDH 1/2突变抑制TET促进的RNA 5 hmC的调节机制，这表明IDH 1/2突变通过RNA生物学的失调参与肿瘤发生。
TETs (TET1/2/3) play critical roles in multi cellular processes through DNA demethylation driven by oxidation of DNA 5mdC to 5hmdC. Interestingly, recent studies indicated that TETs also oxidate RNA 5mC to 5hmC. However, little is known about the distribution of RNA 5hmC and the regulatory mechanism of RNA 5hmC in human. Here, we show that 5hmC is enriched in mRNA, and IDH1/2 mutants inhibit TET-promoted oxidation of RNA 5mC to 5hmC. Since IDH1/2 mutations have been described to block the DNA oxidative activity of TETs, we hypothesized that IDH1/2 mutations might also inhibit the RNA oxidative activity of TETs. To evaluate the role of IDH1/2 mutations in RNA 5hmC, TETs with/without IDH1/2 mutants were overexpressed in human HEK293 cells. Resultant DNA and RNA were digested and analyzed by triple-quadrupole LC mass spectrometer. DNA 5hmdC and RNA 5hmC modifications were quantified with external calibration curves of appropriate standards. It was found that compared with total RNA (5hmC/C: less than 2 X 10−7), mRNA showed much higher 5hmC level (5hmC/C: ∼7 X 10−6). Further study indicated that IDH1/2 mutants showed significant ability to inhibit TET-promoted RNA5hmC. Consistent with this result, overexpression of IDH1/2 mutants also inhibited TET catalytic domain-promoted oxidation of RNA. In this study, we show not only the enrichment of 5hmC in mRNA, but also a regulatory mechanism of RNA 5hmC—IDH1/2 mutations inhibit TET-promoted RNA 5hmC, which suggests an involvement of IDH1/2 mutations in tumorigenesis through the deregulation of RNA biology.