Medical Research Council Human Immunology Unit, Medical Research Council Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DS, UK.
Curr Opin Microbiol. 2013 Aug;16(4):485-92. doi: 10.1016/j.mib.2013.04.009. Epub 2013 May 23.
Some RNA virus genomes bear 5'-triphosphates, which can be recognized in the cytoplasm of infected cells by host proteins that mediate anti-viral immunity. Both the innate sensor RIG-I and the interferon-induced IFIT proteins bind to 5'-triphosphate viral RNAs. RIG-I signals for induction of interferons during RNA virus infection while IFITs sequester viral RNAs to exert an anti-viral effect. Notably, the structures of these proteins reveal both similarities and differences, which are suggestive of independent evolution towards ligand binding. 5'-triphosphates, which are absent from most RNAs in the cytosol of uninfected cells, are thus a marker of virus infection that is targeted by the innate immune system for both induction and execution of the anti-viral response.
一些 RNA 病毒基因组带有 5'-三磷酸基团，这些基团可以被宿主蛋白识别，这些宿主蛋白介导抗病毒免疫。先天传感器 RIG-I 和干扰素诱导的 IFIT 蛋白都与 5'-三磷酸病毒 RNA 结合。在 RNA 病毒感染过程中，RIG-I 信号诱导干扰素的产生，而 IFITs 将病毒 RNA 隔离以发挥抗病毒作用。值得注意的是，这些蛋白的结构既存在相似之处，也存在差异，这表明它们是朝着配体结合的方向独立进化的。因此，5'-三磷酸基团是病毒感染的一个标志物，未感染细胞的细胞质中大多数 RNA 都不含有 5'-三磷酸基团，先天免疫系统将其作为靶标，启动和执行抗病毒反应。
