de Duve Institute, Université Catholique de Louvain, VIRO B1.74.07, 74, Avenue Hippocrate, 1200 Brussels, Belgium.
Viruses. 2021 Jun 23;13(7):1210. doi: 10.3390/v13071210.
Picornaviruses are positive-stranded RNA viruses. Even though replication and translation of their genome take place in the cytoplasm, these viruses evolved different strategies to disturb nucleocytoplasmic trafficking of host proteins and RNA. The major targets of picornavirus are the phenylalanine-glycine (FG)-nucleoporins, which form a mesh in the central channel of the nuclear pore complex through which protein cargos and karyopherins are actively transported in both directions. Interestingly, while enteroviruses use the proteolytic activity of their 2A protein to degrade FG-nucleoporins, cardioviruses act by triggering phosphorylation of these proteins by cellular kinases. By targeting the nuclear pore complex, picornaviruses recruit nuclear proteins to the cytoplasm, where they increase viral genome translation and replication; they affect nuclear translocation of cytoplasmic proteins such as transcription factors that induce innate immune responses and retain host mRNA in the nucleus thereby preventing cell emergency responses and likely making the ribosomal machinery available for translation of viral RNAs.
小核糖核酸病毒是正链 RNA 病毒。尽管它们的基因组的复制和翻译发生在细胞质中，但这些病毒进化出了不同的策略来干扰宿主蛋白和 RNA 的核质运输。小核糖核酸病毒的主要靶标是苯丙氨酸-甘氨酸（FG）核孔蛋白，它在核孔复合物的中央通道中形成一个网格，通过这个网格，蛋白货物和核转运蛋白被主动地双向运输。有趣的是，虽然肠道病毒利用其 2A 蛋白的蛋白水解活性来降解 FG 核孔蛋白，但心脏病毒通过细胞激酶触发这些蛋白的磷酸化来发挥作用。通过靶向核孔复合物，小核糖核酸病毒将核蛋白募集到细胞质中，在那里它们增加病毒基因组的翻译和复制；它们还影响细胞质蛋白的核转位，如转录因子，这些转录因子诱导先天免疫反应，并将宿主 mRNA 保留在核内，从而阻止细胞应急反应，并可能使核糖体机制可用于翻译病毒 RNA。
