Coordinated assembly of viral and host factors is essential for the successful propagation of viruses as well as the generation of host antiviral response. Previous studies from our group, as well as from other groups, have identified host proteins interacting with various components of the hepatitis E virus (HEV). However, the functional relevance of host protein interactions in HEV replication context has been notably overlooked. The present study reports that heterogeneous nuclear ribonucleoproteins (hnRNPs), namely hnRNPK, hnRNPA2B1, hnRNPH, PCBP1 and PCBP2, interact with HEV RNA promoter and RNA-dependent RNA polymerase to regulate HEV replication. We found that hnRNPK and hnRNPA2B1 are the virus-supportive factors interacting with HEV RNA at promoter regions along with HEV polymerase protein, which are essential for HEV replication in the cells. Contrarily, hnRNPH, PCBP1 and PCBP2 are the antiviral factors that interact exclusively with HEV genomic promoter and inhibit HEV replication in Huh7 S10-3 cells. In vitro RNA-binding assays revealed that the antiviral hnRNP proteins hamper the binding of virus-supportive hnRNP proteins at HEV genomic promoter. In the binding reaction, the binding of HEV polymerase protein to the genomic promoter is slightly affected by the presence of antiviral hnRNPH. In an effort of visualizing the subcellular localization of hnRNP proteins in the HEV replication scenario in the Huh7 cells, we showed that hnRNPK, hnRNPA2B1, hnRNPH, PCBP1 and PCBP2 redistribute from nucleus to cytoplasm. In conclusion, our study highlights the importance of hnRNP proteins in HEV replication regulation.

中文翻译：

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异核核糖核蛋白参与戊型肝炎病毒复制。

病毒和宿主因子的协调装配对于病毒的成功繁殖以及宿主抗病毒反应的产生至关重要。我们小组以及其他小组的先前研究已经确定了与戊型肝炎病毒（HEV）各种成分相互作用的宿主蛋白。但是，宿主蛋白相互作用在HEV复制环境中的功能相关性已被明显忽略。本研究报告异质核核糖核蛋白（hnRNPs），即hnRNPK，hnRNPA2B1，hnRNPH，PCBP1和PCBP2与HEV RNA启动子和RNA依赖性RNA聚合酶相互作用，以调节HEV复制。我们发现hnRNPK和hnRNPA2B1是与HEV聚合酶蛋白一起在启动子区域与HEV RNA相互作用的病毒支持因子，这对于HEV在细胞中复制至关重要。相反，hnRNPH，PCBP1和PCBP2是抗病毒因子，它们仅与HEV基因组启动子相互作用，并抑制Huh7 S10-3细胞中的HEV复制。体外RNA结合测定显示抗病毒hnRNP蛋白阻碍了HEV基因组启动子上病毒支持的hnRNP蛋白的结合。在结合反应中，抗病毒hnRNPH的存在会稍微影响HEV聚合酶蛋白与基因组启动子的结合。在可视化Huh7细胞中HEV复制场景中hnRNP蛋白的亚细胞定位中，我们显示hnRNPK，hnRNPA2B1，hnRNPH，PCBP1和PCBP2从细胞核重新分布到细胞质。总之，我们的研究突出了hnRNP蛋白在HEV复制调控中的重要性。PCBP1和PCBP2是仅与HEV基因组启动子相互作用并抑制Huh7 S10-3细胞中HEV复制的抗病毒因子。体外RNA结合测定显示抗病毒hnRNP蛋白阻碍了HEV基因组启动子上病毒支持的hnRNP蛋白的结合。在结合反应中，抗病毒hnRNPH的存在会稍微影响HEV聚合酶蛋白与基因组启动子的结合。在可视化Huh7细胞中HEV复制场景中hnRNP蛋白的亚细胞定位中，我们显示hnRNPK，hnRNPA2B1，hnRNPH，PCBP1和PCBP2从细胞核重新分布到细胞质。总之，我们的研究突出了hnRNP蛋白在HEV复制调控中的重要性。PCBP1和PCBP2是仅与HEV基因组启动子相互作用并抑制Huh7 S10-3细胞中HEV复制的抗病毒因子。体外RNA结合测定显示抗病毒hnRNP蛋白阻碍了HEV基因组启动子上病毒支持的hnRNP蛋白的结合。在结合反应中，抗病毒hnRNPH的存在会稍微影响HEV聚合酶蛋白与基因组启动子的结合。在可视化Huh7细胞中HEV复制场景中hnRNP蛋白的亚细胞定位中，我们显示了hnRNPK，hnRNPA2B1，hnRNPH，PCBP1和PCBP2从细胞核重新分布到细胞质。总之，我们的研究突出了hnRNP蛋白在HEV复制调控中的重要性。