Hopper Anita K, Huang Hsiao-Yun
Department of Molecular Genetics and Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA
Department of Molecular Genetics and Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA.
Mol Cell Biol. 2015 Jun;35(12):2052-8. doi: 10.1128/MCB.00131-15. Epub 2015 Apr 6.
tRNAs perform an essential role in translating the genetic code. They are long-lived RNAs that are generated via numerous posttranscriptional steps. Eukaryotic cells have evolved numerous layers of quality control mechanisms to ensure that the tRNAs are appropriately structured, processed, and modified. We describe the known tRNA quality control processes that check tRNAs and correct or destroy aberrant tRNAs. These mechanisms employ two types of exonucleases, CCA end addition, tRNA nuclear aminoacylation, and tRNA subcellular traffic. We arrange these processes in order of the steps that occur from generation of precursor tRNAs by RNA polymerase (Pol) III transcription to end maturation and modification in the nucleus to splicing and additional modifications in the cytoplasm. Finally, we discuss the tRNA retrograde pathway, which allows tRNA reimport into the nucleus for degradation or repair.
转运RNA（tRNA）在遗传密码翻译过程中发挥着至关重要的作用。它们是通过众多转录后步骤产生的长寿RNA。真核细胞已经进化出多层质量控制机制，以确保tRNA具有适当的结构、加工和修饰。我们描述了已知的tRNA质量控制过程，这些过程会检查tRNA并纠正或破坏异常的tRNA。这些机制采用了两种类型的核酸外切酶、CCA末端添加、tRNA核氨基酰化和tRNA亚细胞运输。我们按照从RNA聚合酶（Pol）III转录产生前体tRNA，到在细胞核中进行末端成熟和修饰，再到在细胞质中进行剪接和其他修饰的步骤顺序来排列这些过程。最后，我们讨论了tRNA逆向途径，该途径允许tRNA重新导入细胞核进行降解或修复。
