College of Bioscience and Biotechnology, Yangzhou University, Yangzhou 225009, China.
Virol Sin. 2012 Apr;27(2):100-8. doi: 10.1007/s12250-012-3237-x. Epub 2012 Apr 11.
Rice stripe virus (RSV) infects rice and is transmitted in a propagative manner by the small brown planthopper. How RSV enters an insect cell to initiate the infection cycle is poorly understood. Sequence analysis revealed that the RSV NSvc2 protein was similar to the membrane glycoproteins of several members in the family Bunyaviridae and might induce cell membrane fusion. To conveniently study the membrane fusion activity of NSvc2, we constructed cell surface display vectors for expressing Nsvc2 on the insect cell surface as the membrane glycoproteins of the enveloped viruses. Our results showed that NSvc2 was successfully expressed and displayed on the surface of insect Sf9 cells. When induced by low pH, the membrane fusion was not observed in the cells that expressed NSvc2. Additionally, the membrane fusion was also not detected when co-expressing Nsvc2 and the viral capsid protein on insect cell surface. Thus, RSV NSvc2 is probably different from the phlebovirus counterparts, which could suggest different functions. RSV might enter insect cells other than by fusion with plasma or endosome membrane.
水稻条纹病毒（RSV）感染水稻，并通过褐飞虱以增殖的方式传播。RSV 如何进入昆虫细胞启动感染周期，目前还知之甚少。序列分析表明，RSV NSvc2 蛋白与 Bunyaviridae 家族的几种膜糖蛋白相似，可能诱导细胞膜融合。为了方便研究 NSvc2 的膜融合活性，我们构建了细胞表面展示载体，用于将 NSvc2 作为包膜病毒的膜糖蛋白表达在昆虫细胞表面。我们的结果表明，NSvc2 成功地在昆虫 Sf9 细胞表面表达和展示。当用低 pH 值诱导时，表达 NSvc2 的细胞中没有观察到膜融合。此外，当在昆虫细胞表面共表达 NSvc2 和病毒衣壳蛋白时，也没有检测到膜融合。因此，RSV NSvc2 可能与黄病毒不同，这可能表明其具有不同的功能。RSV 可能通过与质膜或内体膜融合以外的其他方式进入昆虫细胞。
