Rice dwarf phytoreovirus segment S6-encoded nonstructural protein has a cell-to-cell movement function
Rice dwarf phytoreovirus segment S6-encoded nonstructural protein has a cell-to-cell movement function
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DOI：
10.1128/jvi.78.10.5382-5389.2004
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发表时间：
2004-05-01
影响因子：
5.4
通讯作者：
Nelson, RS
中科院分区：
文献类型：
--
作者：
Li, Y;Bao, YM;Nelson, RS
水稻矮缩病毒（Rice dwarf virus，RDV）是植物呼肠孤病毒属（Phytoreovirus）的一种病毒，其基因组为双链RNA。支持这些病毒在宿主中细胞间运动的蛋白质尚未鉴定。使用微粒轰击来确定哪些开放阅读框（ORF）支持异源病毒的细胞间运动。将含有马铃薯X病毒（PVX）感染性克隆的质粒与含有RDV基因片段S1至S12的ORF的质粒共轰击到本氏烟草（Nicotiana benthamiana）叶片上，所述马铃薯X病毒（PVX）在细胞间移动中有缺陷并且表达β-葡萄糖醛酸酶或绿色荧光蛋白（GFP）。细胞到细胞的运动缺陷的PVX恢复与含有S6质粒的共轰击。在没有S6的情况下，没有其他基因片段支持运动。用烟草获得了相同的结果，烟草是一种允许较少病毒在其组织内感染和传播的宿主。S6支持移动缺陷型PVX在N.本萨米亚纳缺乏翻译起始密码子的突变体S6不能补充运动缺陷型PVX的细胞间运动。S6蛋白产物（Pns 6）增强的GFP融合在来自N.烟草通过免疫细胞化学方法，未融合的Pns 6定位于感染RDV的水稻叶片的胞间连丝上。因此，S6编码的蛋白质具有与其他病毒蛋白质相同的特征，这些蛋白质是其基因组细胞间运动所需的，因此可能是RDV细胞间运动所需的。
Rice dwarf virus (RDV) is a member of the genus Phytoreovirus, which is composed of viruses with segmented double-stranded RNA genomes. Proteins that support the intercellular movement of these viruses in the host have not been identified. Microprojectile bombardment was used to determine which open reading frames (ORFs) support intercellular movement of a heterologous virus. A plasmid containing an infectious clone of Potato virus X (PVX) defective in cell-to-cell movement and expressing either beta-glucuronidase or green fluorescent protein (GFP) was used for cobombardment with plasmids containing ORFs from RDV gene segments S1 through S12 onto leaves of Nicotiana benthamiana. Cell-to-cell movement of the movement-defective PVX was restored by cobombardment with a plasmid containing S6. In the absence of S6, no other gene segment supported movement. Identical results were obtained with Nicotiana tabacum, a host that allows fewer viruses to infect and spread within its tissue. S6 supported the cell-to-cell movement of the movement-defective PVX in sink and source leaves of N. benthamiana. A mutant S6 lacking the translation start codon did not complement the cell-to-cell movement of the movement-defective PVX. An S6 protein product (Pns6)-enhanced GFP fusion was observed near or within cell walls of epidermal cells from N. tabacum. By immunocytochemistry, unfused Pns6 was localized to plasmodesmata in rice leaves infected with RDV. S6 thus encodes a protein with characteristics identical to those of other viral proteins required for the cell-to-cell movement of their genome and therefore is likely required for the cell-to-cell movement of RDV.