Department of Microbiology and Center for RNA Biology, The Ohio State University, 318 West 12th Avenue, Columbus, Ohio 43210, USA.
Nat Microbiol. 2017 Aug 24;2:17117. doi: 10.1038/nmicrobiol.2017.117.
Faithful translation of mRNA into the corresponding polypeptide is a complex multistep process, requiring accurate amino acid selection, transfer RNA (tRNA) charging and mRNA decoding on the ribosome. Key players in this process are aminoacyl-tRNA synthetases (aaRSs), which not only catalyse the attachment of cognate amino acids to their respective tRNAs, but also selectively hydrolyse incorrectly activated non-cognate amino acids and/or misaminoacylated tRNAs. This aaRS proofreading provides quality control checkpoints that exclude non-cognate amino acids during translation, and in so doing helps to prevent the formation of an aberrant proteome. However, despite the intrinsic need for high accuracy during translation, and the widespread evolutionary conservation of aaRS proofreading pathways, requirements for translation quality control vary depending on cellular physiology and changes in growth conditions, and translation errors are not always detrimental. Recent work has demonstrated that mistranslation can also be beneficial to cells, and some organisms have selected for a higher degree of mistranslation than others. The aims of this Review Article are to summarize the known mechanisms of protein translational fidelity and explore the diversity and impact of mistranslation events as a potentially beneficial response to environmental and cellular stress.
将 mRNA 准确翻译成相应的多肽是一个复杂的多步骤过程，需要在核糖体上准确选择氨基酸、tRNA（转移 RNA）加载和 mRNA 解码。该过程的关键参与者是氨酰-tRNA 合成酶（aaRS），它不仅催化相应氨基酸与各自 tRNA 的连接，还选择性地水解不正确激活的非对应氨基酸和/或错误氨酰化的 tRNA。这种 aaRS 校对提供了质量控制检查点，可在翻译过程中排除非对应氨基酸，从而有助于防止异常蛋白质组的形成。然而，尽管翻译过程中需要高度的准确性，并且 aaRS 校对途径广泛存在进化上的保守性，但翻译质量控制的要求取决于细胞生理学和生长条件的变化，而且翻译错误并不总是有害的。最近的工作表明，错译也可能对细胞有益，并且一些生物体比其他生物体选择了更高程度的错译。本文综述的目的是总结蛋白质翻译保真度的已知机制，并探讨错译事件的多样性和影响，将其作为对环境和细胞应激的一种潜在有益反应。
