Kleinow Tatjana, Tanwir Fariha, Kocher Cornelia, Krenz Björn, Wege Christina, Jeske Holger
Institute of Biology, Department of Molecular Biology and Plant Virology, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany.
Virology. 2009 Sep 1;391(2):212-20. doi: 10.1016/j.virol.2009.06.042. Epub 2009 Jul 22.
The geminivirus Abutilon mosaic virus (AbMV) encodes two proteins which are essential for viral spread within plants. The nuclear shuttle protein (NSP) transfers viral DNA between the nucleus and cytoplasm, whereas the movement protein (MP) facilitates transport between cells through plasmodesmata and long-distance via phloem. An inducible overexpression system for epitope-tagged NSP and MP in plants yielded unprecedented amounts of both proteins. Western blots revealed extensive posttranslational modification and truncation for MP, but not for NSP. Ultrastructural examination of Nicotiana benthamiana tissues showed characteristic nucleopathic alterations, including fibrillar rings, when epitope-tagged NSP and MP were simultaneously expressed in leaves locally infected with an AbMV DNA A in which the coat protein gene was replaced by a green fluorescent protein encoding gene. Immunogold labelling localized NSP in the nucleoplasm and in the fibrillar rings. MP appeared at the cell periphery, probably the plasma membrane, and plasmodesmata.
双生病毒苘麻花叶病毒（AbMV）编码两种对病毒在植物体内传播至关重要的蛋白质。核穿梭蛋白（NSP）在细胞核和细胞质之间转移病毒DNA，而运动蛋白（MP）则促进病毒通过胞间连丝在细胞间运输，并通过韧皮部长距离运输。一种用于在植物中诱导表达表位标记的NSP和MP的系统产生了前所未有的这两种蛋白质的量。蛋白质免疫印迹显示MP存在广泛的翻译后修饰和截短，但NSP没有。对本氏烟草组织的超微结构检查表明，当在局部感染了用绿色荧光蛋白编码基因替换了外壳蛋白基因的AbMV DNA A的叶片中同时表达表位标记的NSP和MP时，会出现特征性的核病变改变，包括纤维环。免疫金标记将NSP定位在核质和纤维环中。MP出现在细胞周边，可能是质膜和胞间连丝处。
