BCDIN3D regulates tRNAHis 3′ fragment processing
BCDIN3D regulates tRNAHis 3′ fragment processing
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DOI：
10.1371/journal.pgen.1008273
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发表时间：
2019-07-01
期刊：
影响因子：
4.5
通讯作者：
Xhemalce, Blerta
中科院分区：
文献类型：
--
作者：
Reinsborough, Calder W.;Ipas, Helene;Xhemalce, Blerta
5' 末端对于决定 RNA 分子的命运非常重要。 BCDIN3D 是一种 RNA 磷酸甲基转移酶，可甲基化特定 RNA 的 5' 单磷酸。为了获得对 BCDIN3D 分子功能的新见解，我们通过热稳定 II 族内含子逆转录酶与下一代测序 (TGIRT-seq) 结合对其相互作用的 RNA 进行了公正的分析。我们的分析表明 BCDIN3D 与全长磷酸甲基化 tRNA (His) 和 miR-4454 相互作用。有趣的是，我们发现 miR-4454 并不是从其注释的基因组位点（内源性逆转录病毒的引物结合位点）合成的，而是通过成熟 tRNA（His）的 Dicer 切割合成的。序列分析显示miR-4454与tRNA(His)的3'端相同。此外，我们能够通过成熟的 tRNA(His) 与 Dicer 一起孵育在体外生成这种“miRNA”。正如之前对几种 pre-miRNA 的发现，5'P-tRNA(His) 似乎是比磷酸甲基化 tRNA(His) 更好的 Dicer 裂解底物。此外，在 BCDIN3D 耗尽的细胞中，tRNA(His) 3'-片段/"miR-4454' 水平增加。总而言之，我们的结果表明，除了 microRNA 之外，BCDIN3D 还调节 tRNA(His) 3' 片段加工，而不会对 tRNA(His) 的典型氨酰化功能产生负面影响。
5' ends are important for determining the fate of RNA molecules. BCDIN3D is an RNA phospho-methyltransferase that methylates the 5' monophosphate of specific RNAs. In order to gain new insights into the molecular function of BCDIN3D, we performed an unbiased analysis of its interacting RNAs by Thermostable Group II Intron Reverse Transcriptase coupled to next generation sequencing (TGIRT-seq). Our analyses showed that BCDIN3D interacts with full-length phospho-methylated tRNA(His) and miR-4454. Interestingly, we found that miR-4454 is not synthesized from its annotated genomic locus, which is a primer-binding site for an endogenous retrovirus, but rather by Dicer cleavage of mature tRNA(His). Sequence analysis revealed that miR-4454 is identical to the 3' end of tRNA(His). Moreover, we were able to generate this "miRNA' in vitro through incubation of mature tRNA(His) with Dicer. As found previously for several pre-miRNAs, a 5'P-tRNA(His) appears to be a better substrate for Dicer cleavage than a phospho-methylated tRNA(His). Moreover, tRNA(His) 3'-fragment/"miR-4454' levels increase in cells depleted for BCDIN3D. Altogether, our results show that in addition to microRNAs, BCDIN3D regulates tRNA(His) 3'-fragment processing without negatively affecting tRNA(His)'s canonical function of aminoacylation.