RNA methylation by Dnmt2 protects transfer RNAs against stress-induced cleavage
RNA methylation by Dnmt2 protects transfer RNAs against stress-induced cleavage
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DOI：
10.1101/gad.586710
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发表时间：
2010-08-01
影响因子：
10.5
通讯作者：
Lyko, Frank
中科院分区：
文献类型：
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作者：
Schaefer, Matthias;Pollex, Tim;Lyko, Frank
DNMT2蛋白是DNA甲基转移酶家族中最保守的成员，但其底物特异性和生物学功能一直是争议的主题。我们在这里表明，除了tRNA（Asp-GTC），tRNA（Val-AAC）和tRNA（Gly-GCC）也被Dnmt 2甲基化。果蝇Dnmt2突变体在应激条件下表现出降低的生存能力，并且Dnmt2在热休克后重新定位于应激颗粒。引人注目的是，应激诱导的tRNA切割是Dnmt 2依赖性的，并且Dnmt 2介导的甲基化保护tRNA免受核糖核酸酶切割。这些结果揭示了Dnmt 2介导的tRNA甲基化的一种新的生物学功能，并表明Dnmt 2酶在tRNA衍生的小RNA的生物合成过程中的作用。
Dnmt2 proteins are the most conserved members of the DNA methyltransferase enzyme family, but their substrate specificity and biological functions have been a subject of controversy. We show here that, in addition to tRNA(Asp-GTC), tRNA(Val-AAC) and tRNA(Gly-GCC) are also methylated by Dnmt2. Drosophila Dnmt2 mutants showed reduced viability under stress conditions, and Dnmt2 relocalized to stress granules following heat shock. Strikingly, stress-induced cleavage of tRNAs was Dnmt2-dependent, and Dnmt2-mediated methylation protected tRNAs against ribonuclease cleavage. These results uncover a novel biological function of Dnmt2-mediated tRNA methylation, and suggest a role for Dnmt2 enzymes during the biogenesis of tRNA-derived small RNAs.