Ryabov E V, Oparka K J, Santa Cruz S, Robinson D J, Taliansky M E
Virology Department, Scottish Crop Research Institute, Invergowrie, Dundee, United Kingdom.
Virology. 1998 Mar 15;242(2):303-13. doi: 10.1006/viro.1997.9025.
The proteins encoded by open reading frames (ORF) 3 and 4 of groundnut rosette umbravirus (GRV) were expressed in Nicotiana benthamiana as fusions with green fluorescent protein (GFP) from modified potato virus X (PVX) and tobacco mosaic virus (TMV) vectors. Regardless of which plant virus vector was used, GFP fused to the ORF3 protein accumulated in large cytoplasmic inclusion bodies and in nucleoli, whereas GFP fused to the ORF4 protein was found in cell walls close to plasmodesmata. Cell-to-cell movement of PVX requires three proteins encoded by the triple gene block (TGB) and also the coat protein (CP). However, when GRV ORF4 was substituted for the PVX CP gene, the hybrid virus was able to move normally in inoculated leaves but not into noninoculated leaves. In contrast, when GRV ORF4 was substituted for the TGB, or for both the TGB and the CP gene, movement of the hybrid viruses was limited to a few epidermal cells neighboring the infection site. Thus, the GRV ORF4 protein can replace the movement proteins of PVX for some of their functions.
花生丛簇伞形病毒（GRV）开放阅读框（ORF）3和4编码的蛋白质，在本氏烟草中作为与来自修饰马铃薯X病毒（PVX）和烟草花叶病毒（TMV）载体的绿色荧光蛋白（GFP）的融合蛋白进行表达。无论使用哪种植物病毒载体，与ORF3蛋白融合的GFP都在大的细胞质内含体和核仁中积累，而与ORF4蛋白融合的GFP则在靠近胞间连丝的细胞壁中发现。PVX的细胞间运动需要由三基因块（TGB）编码的三种蛋白质以及外壳蛋白（CP）。然而，当用GRV ORF4替代PVX CP基因时，杂交病毒能够在接种叶片中正常移动，但不能移动到未接种叶片中。相反，当用GRV ORF4替代TGB，或同时替代TGB和CP基因时，杂交病毒的移动仅限于感染部位附近的一些表皮细胞。因此，GRV ORF4蛋白可以部分替代PVX的移动蛋白行使其功能。
