Targeted sequencing reveals expanded genetic diversity of human transfer RNAs
Targeted sequencing reveals expanded genetic diversity of human transfer RNAs
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DOI：
10.1080/15476286.2019.1646079
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发表时间：
2019-08-10
期刊：
影响因子：
4.1
通讯作者：
Brandl, Christopher J.
中科院分区：
文献类型：
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作者：
Berg, Matthew D.;Giguere, Daniel J.;Brandl, Christopher J.
转运RNA是将遗传信息翻译成蛋白质以及调节其他细胞过程所必需的。tRNA中的核苷酸变化可导致影响蛋白质组的组成和保真度的功能的丧失或获得。尽管tRNA变异与疾病之间存在联系，但细胞质tRNA变异的重要性一直被忽视。使用自定义捕获面板，我们对来自84个个体的605个人类tRNA编码基因进行了测序。我们开发了一种生物信息学管道，可以更准确地进行tRNA读取映射，并识别同一变体中发生的多种多态性。我们的分析确定了522个独特的tRNA编码序列，这些序列与来自84个个体的参考基因组不同。每个人都有66个类似的tRNA变异体，其中包括在我们样本组中不到5%的样本中发现的9个变异体。在整个tRNA结构中鉴定出变异体，其中17%预测增强功能。鉴定了18种反密码子突变体，包括潜在的错误翻译的tRNA;例如，一种能解码苯丙氨酸密码子的tRNA（Ser）。类似的工程改造的tRNA变体先前显示出在哺乳动物细胞培养物和鸡胚中抑制细胞生长、增加细胞凋亡并诱导未折叠的蛋白质反应。我们的分析表明，人类tRNA变异被低估了。我们的结论是，大量的tRNA基因提供了一个缓冲区，使变异的出现，其中一些可能有助于疾病。
Transfer RNAs are required to translate genetic information into proteins as well as regulate other cellular processes. Nucleotide changes in tRNAs can result in loss or gain of function that impact the composition and fidelity of the proteome. Despite links between tRNA variation and disease, the importance of cytoplasmic tRNA variation has been overlooked. Using a custom capture panel, we sequenced 605 human tRNA-encoding genes from 84 individuals. We developed a bioinformatic pipeline that allows more accurate tRNA read mapping and identifies multiple polymorphisms occurring within the same variant. Our analysis identified 522 unique tRNA-encoding sequences that differed from the reference genome from 84 individuals. Each individual had similar to 66 tRNA variants including nine variants found in less than 5% of our sample group. Variants were identified throughout the tRNA structure with 17% predicted to enhance function. Eighteen anticodon mutants were identified including potentially mistranslating tRNAs; e.g., a tRNA(Ser) that decodes Phe codons. Similar engineered tRNA variants were previously shown to inhibit cell growth, increase apoptosis and induce the unfolded protein response in mammalian cell cultures and chick embryos. Our analysis shows that human tRNA variation has been underestimated. We conclude that the large number of tRNA genes provides a buffer enabling the emergence of variants, some of which could contribute to disease.