Egger D, Teterina N, Ehrenfeld E, Bienz K
Institute for Medical Microbiology, University of Basel, Basel, Switzerland.
J Virol. 2000 Jul;74(14):6570-80. doi: 10.1128/jvi.74.14.6570-6580.2000.
Poliovirus (PV) infection induces the rearrangement of intracellular membranes into characteristic vesicles which assemble into an RNA replication complex. To investigate this transformation, endoplasmic reticulum (ER) membranes in HeLa cells were modified by the expression of different cellular or viral membrane-binding proteins. The membrane-binding proteins induced two types of membrane alterations, i.e., extended membrane sheets and vesicles similar to those found during a PV infection. Cells expressing membrane-binding proteins were superinfected with PV and then analyzed for virus replication, location of membranes, viral protein, and RNA by immunofluorescence and fluorescent in situ hybridization. Cultures expressing cellular or viral membrane-binding proteins, but not those expressing soluble proteins, showed a markedly reduced ability to support PV replication as a consequence of the modification of ER membranes. The altered membranes, regardless of their morphology, were not used for the formation of viral replication complexes during a subsequent PV infection. Specifically, membrane sheets were not substrates for PV-induced vesicle formation, and, surprisingly, vesicles induced by and carrying one or all of the PV replication proteins did not contribute to replication complexes formed by the superinfecting PV. The formation of replication complexes required active viral RNA replication. The extensive alterations induced by membrane-binding proteins in the ER resulted in reduced viral protein synthesis, thus affecting the number of cells supporting PV multiplication. Our data suggest that a functional replication complex is formed in cis, in a coupled process involving viral translation, membrane modification and vesicle budding, and viral RNA synthesis.
脊髓灰质炎病毒（PV）感染会诱导细胞内膜重排形成特征性囊泡，这些囊泡组装成RNA复制复合体。为了研究这种转变，通过表达不同的细胞或病毒膜结合蛋白对HeLa细胞中的内质网（ER）膜进行修饰。膜结合蛋白诱导了两种类型的膜改变，即延伸的膜片层和类似于PV感染期间发现的囊泡。用PV对表达膜结合蛋白的细胞进行超感染，然后通过免疫荧光和荧光原位杂交分析病毒复制、膜的位置、病毒蛋白和RNA。表达细胞或病毒膜结合蛋白的培养物，而不是表达可溶性蛋白的培养物，由于ER膜的修饰，支持PV复制的能力明显降低。无论其形态如何，改变后的膜在随后的PV感染期间都不用于形成病毒复制复合体。具体而言，膜片层不是PV诱导的囊泡形成的底物，而且令人惊讶的是，由一种或所有PV复制蛋白诱导并携带这些蛋白的囊泡对超感染PV形成的复制复合体没有贡献。复制复合体的形成需要活跃的病毒RNA复制。ER中膜结合蛋白诱导的广泛改变导致病毒蛋白合成减少，从而影响支持PV增殖的细胞数量。我们的数据表明，功能性复制复合体在顺式中形成，这是一个涉及病毒翻译、膜修饰和囊泡出芽以及病毒RNA合成的耦合过程。
