Expression of measles virus V protein is associated with pathogenicity and control of viral RNA synthesis
Expression of measles virus V protein is associated with pathogenicity and control of viral RNA synthesis
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DOI：
10.1128/jvi.72.10.8124-8132.1998
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发表时间：
1998-10-01
影响因子：
5.4
通讯作者：
Schneider-Schaulies, S
中科院分区：
文献类型：
--
作者：
Tober, C;Seufert, M;Schneider-Schaulies, S
由麻疹病毒（MV）编码的非结构蛋白包括从编辑的P mRNA翻译的V蛋白。V蛋白不与细胞内或释放的病毒颗粒相关，并且最近发现其在细胞培养物中对MV增殖起抑制作用（H.施耐德K. Kaelin和M. A. Billeter，Virology 227：314-322，1997）。使用重组MV（菌株Edmonston [艾德]）进行遗传工程改造以过表达V蛋白（ED-V+）或缺乏V蛋白（ED-V-），我们发现在不存在V的情况下，MV特异性蛋白和RNA积累到高于亲本MV分子克隆（ED-标签）中的水平，而在用ED-V+感染后，MV特异性基因表达在人U-87胶质母细胞瘤细胞中强烈减弱。用任一V突变病毒感染后48小时从这些细胞释放的病毒滴度低于用ED标签感染的细胞。类似地，与从ED标签感染的动物分离的滴度相比，在用两种编辑突变体鼻内感染后，从棉鼠（Sigmodon hispidus）的肺组织中重新分离出显著降低滴度的感染性病毒。在细胞培养中，V蛋白的表达导致MV N蛋白在双重转染的Cos-7细胞中的重新分布，表明这些蛋白形成异源复合物。这种相互作用通过使用双杂交方法与表达为Gal 4或VP 16融合产物的两种蛋白质进一步证实。此外，V蛋白有效地竞争MV N和P蛋白之间形成的复合物。这些结果表明，V蛋白的作用，以平衡积累的病毒基因产物在细胞培养中，这可能是依赖于它与MV N蛋白的相互作用。此外，V蛋白的表达可能有助于病毒在体内的致病性。
Nonstructural proteins encoded by measles virus (MV) include the V protein which is translated from an edited P mRNA. V protein is not associated with intracellular or released viral particles and has recently been found to be dispensable for MV propagation in cell culture (H. Schneider, K. Kaelin, and M. A. Billeter, Virology 227:314-322, 1997). Using recombinant MVs (strain Edmonston [ED]) genetically engineered to overexpress V protein (ED-V+) or to be deficient for V protein (ED-V-), we found that in the absence of V both MV-specific proteins and RNAs accumulated to levels higher than those in the parental MV molecular clone (ED-tag), whereas MV-specific gene expression was strongly attenuated in human U-87 glioblastomas cells after infection with ED-V+. The titers of virus released from these cells 48 h after infection with either V mutant virus were lower than those from cells infected with ED-tag. Similarly, significantly reduced titers of infectious virus were reisolated from lung tissue of cotton rats (Sigmodon hispidus) after intranasal infection with both editing mutants compared to titers isolated from ED-tag-infected animals. In cell culture, expression of V protein led to a redistribution of MV N protein in doubly transfected Cos-7 cells, indicating that these proteins form heterologous complexes. This interaction was further confirmed by using a two-hybrid approach with both proteins expressed as Gal4 or VP16 fusion products. Moreover, V protein efficiently competed complexes formed between MV N and P proteins. These findings indicate that V protein acts to balance accumulation of viral gene products in cell culture, and this may be dependent on its interaction with MV N protein. Furthermore, expression of V protein may contribute to viral pathogenicity in vivo.