The Spike Protein VP4 Defines the Endocytic Pathway Used by Rotavirus To Enter MA104 Cells
The Spike Protein VP4 Defines the Endocytic Pathway Used by Rotavirus To Enter MA104 Cells
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DOI：
10.1128/jvi.02086-12
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发表时间：
2013-02-01
影响因子：
5.4
通讯作者：
Arias, Carlos F.
中科院分区：
文献类型：
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作者：
Diaz-Salinas, Marco A.;Romero, Pedro;Arias, Carlos F.
轮状病毒通过内吞作用内化到MA104细胞中，不同的病毒株使用不同的内吞途径。牛轮状病毒UK株通过笼蛋白介导的内吞过程进入细胞，而猴轮状病毒(RRV)株使用的内吞途径定义不明确，不依赖于笼蛋白和小窝蛋白。病毒表面蛋白VP7和刺突蛋白VP4在细胞结合和穿透过程中与细胞受体相互作用。为了确定定义内化机制的病毒蛋白，我们使用了一组UK x RRV重组病毒，它们具有不同的病毒结构蛋白组合。这些重组体在MA104细胞中的感染性鉴定表明，VP4决定了病毒进入的途径。这些重组体在MA104细胞中的感染力要么是针对分子筛蛋白重链的小干扰RNA(SiRNA)，要么是与破坏分子筛蛋白外壳稳定的高渗介质孵育。有趣的是，RRV的一个唾液酸不依赖的变体Nar3的特征表明，VP4中的单个氨基酸变化就会将进入途径从依赖于网状蛋白转变为不依赖于网状蛋白。此外，对另外几个轮状病毒株在细胞受体使用上的不同进行了鉴定，结果表明它们都是通过网状蛋白介导的内吞作用进入细胞的，这表明不同的VP4与细胞表面的相互作用可以导致轮状病毒通过这种内吞途径进入细胞。
Rotaviruses are internalized into MA104 cells by endocytosis, with different endocytic pathways used depending on the virus strain. The bovine rotavirus UK strain enters cells through a clathrin-mediated endocytic process, while the simian rhesus rotavirus (RRV) strain uses a poorly defined endocytic pathway that is clathrin and caveolin independent. The viral surface protein VP7 and the spike protein VP4 interact with cellular receptors during cell binding and penetration. To determine the viral protein that defines the mechanism of internalization, we used a panel of UK x RRV reassortant viruses having different combinations of the viral structural proteins. Characterization of the infectivities of these reassortants in MA104 cells either transfected with a small interfering RNA (siRNA) against the heavy chain of clathrin or incubated with hypertonic medium that destabilizes the clathrin coat clearly showed that VP4 determines the pathway of virus entry. Of interest, the characterization of Nar3, a sialic acid-independent variant of RRV, showed that a single amino acid change in VP4 shifts the route of entry from being clathrin dependent to clathrin independent. Furthermore, characterizations of several additional rotavirus strains that differ in their use of cellular receptors showed that all entered cells by clathrin-mediated endocytosis, suggesting that diverse VP4-cell surface interactions can lead to rotavirus cell entry through this endocytic pathway.