Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Postdoctoral Research Associate Training Program, National Institute of General Medical Sciences, National Institutes of Health, Bethesda, MD 20892, USA.
Nucleic Acids Res. 2021 Jun 21;49(11):6007-6026. doi: 10.1093/nar/gkab036.
Ribonuclease L (RNase L) is activated as part of the innate immune response and plays an important role in the clearance of viral infections. When activated, it endonucleolytically cleaves both viral and host RNAs, leading to a global reduction in protein synthesis. However, it remains unknown how widespread RNA decay, and consequent changes in the translatome, promote the elimination of viruses. To study how this altered transcriptome is translated, we assayed the global distribution of ribosomes in RNase L activated human cells with ribosome profiling. We found that RNase L activation leads to a substantial increase in the fraction of translating ribosomes in ORFs internal to coding sequences (iORFs) and ORFs within 5' and 3' UTRs (uORFs and dORFs). Translation of these alternative ORFs was dependent on RNase L's cleavage activity, suggesting that mRNA decay fragments are translated to produce short peptides that may be important for antiviral activity.
核糖核酸酶 L（RNase L）作为先天免疫反应的一部分被激活，在清除病毒感染方面发挥着重要作用。当被激活时，它对内切核酸酶切割病毒和宿主的 RNA，导致蛋白质合成的全面减少。然而，目前尚不清楚广泛的 RNA 降解以及随之而来的转译组变化如何促进病毒的清除。为了研究这种改变的转录组是如何被翻译的，我们用核糖体谱法检测了 RNase L 激活的人细胞中核糖体的全球分布。我们发现，RNase L 的激活导致编码序列（iORFs）内部和 5' 和 3' UTR（uORFs 和 dORFs）内的翻译核糖体的比例显著增加。这些替代 ORF 的翻译依赖于 RNase L 的切割活性，这表明 mRNA 降解片段被翻译产生短肽，这些短肽可能对抗病毒活性很重要。
