VPg of murine norovirus binds translation initiation factors in infected cells.
VPg of murine norovirus binds translation initiation factors in infected cells.
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DOI：
10.1186/1743-422x-3-33
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发表时间：
2006-05-23
期刊：
影响因子：
4.8
通讯作者：
Hardy ME
中科院分区：
文献类型：
--
作者：
Daughenbaugh KF;Wobus CE;Hardy ME
诺如病毒基因组和亚基因组RNA在5'核苷酸处共价连接至称为VPg的15 kD蛋白。两株人诺如病毒的VPg在体外结合翻译起始因子eIF 3和其他eIFs，表明VPg在启动病毒RNA上的蛋白质合成中起作用。人诺如病毒株是不可培养的，因此缺乏感染细胞中VPg和eIF之间相互作用的实验证据。我们使用可培养的鼠诺如病毒MNV-1作为模型来研究感染细胞中VPg和eIFs之间的相互作用。如先前对于人诺如病毒VPg所示，通过GST下拉测定，MNV-1 VPg结合细胞提取物中的eIF 3、eIF 4GI、eIF 4 E和S6核糖体蛋白。重要的是，MNV-1 VPg从感染的巨噬细胞中共沉淀eIF 4GI和eIF 4 E，这提供了VPg与诺如病毒感染的细胞中的翻译机制的组分相互作用的证据。MNV-1 VPg和eIF之间的相互作用完全模拟了人类诺如病毒VPg的报道，说明MNV-1作为研究人类诺如病毒复制机制的相关分子模型的实用性。
Norovirus genomic and subgenomic RNAs are covalently linked at the 5' nucleotide to a 15 kD protein called VPg. VPg of two human norovirus strains binds translation initiation factor eIF3 and other eIFs in vitro, suggesting VPg functions in initiation of protein synthesis on viral RNA. Human norovirus strains are not cultivable, and thus experimental evidence of interactions between VPg and eIFs in infected cells has been lacking. We used the cultivable murine norovirus MNV-1 as a model to study interactions between VPg and eIFs in infected cells. As shown previously for human norovirus VPg, MNV-1 VPg bound eIF3, eIF4GI, eIF4E, and S6 ribosomal protein in cell extracts by GST pull-down assay. Importantly, MNV-1 VPg co-precipitated eIF4GI and eIF4E from infected macrophages, providing evidence that VPg interacts with components of the translation machinery in norovirus infected cells. The interactions between MNV-1 VPg and eIFs completely mimic those reported for the human norovirus VPg, illustrating the utility of MNV-1 as a relevant molecular model to study mechanisms of human norovirus replication.