Studies on the regulation of host-gene expression by Tomato mosaic virus movement protein.

为了研究植物病毒的运动蛋白（MPs）调控宿主基因表达的可能性，利用一种推定的转录辅激活因子NtMBF1建立了一个分析系统。NtMBF1是一种来自烟草的多蛋白桥接因子1同源物，可与来自番茄花叶病毒（ToMV）的MP结合。构建了6种质粒；(1)在含有乙烯反应元件（ERE）的启动子控制下，表达大肠杆菌β -葡萄糖苷酶（GUS）的报告质粒；(2)在花椰菜花叶病毒（CaMV）的35S启动子控制下，表达识别ERE的烟草转录激活子NtERF2的第一效应质粒；(3)在CaMV 35S启动子控制下，表达NtMBF1的第二效应质粒。(4)在CaMV 35S启动子控制下表达ToMV MP的第三效应质粒；(5)在CaMV 35S启动子控制下表达绿色荧光蛋白的控制质粒；(6)在CaMV 35S启动子控制下表达GUS的控制质粒，作为组成型报告子表达的控制。将这些质粒以不同的组合方式引入到烟草BY-2细胞原生质体中，并对GUS和GFP的积累进行了分析。结果表明，ToMV MP能够调控宿主基因的表达。这项研究使得未来研究是否不仅在培养细胞中而且在宿主植物中也会获得类似的结果变得更加有趣。

To examine the possibility that movement proteins(MPs) of plant viruses regulate gene expression of host genes, an analysis system was developed using a putative transcriptional coactivator, named NtMBF1,which is a multi protein bridging factor 1 homolog derived from Nicotiana tabacum and binds to the MP derived from Tomato mosaic virus(ToMV). For the assay, six kinds of plasmids were constructed ; (1)a reporter plasmid which expresses beta-glucronidase(GUS) derived from Escherichia coli under control of an ethylene responsive element(ERE)-containing promoter, (2)the first effecter plasmid which expresses a tobacco transcriptional activator NtERF2, which recognize ERE, under control of the 35S promoter derived from Cauliflower mosaic virus(CaMV), (3)the second effecter plasmid which expresses NtMBF1 under control of the CaMV 35S promoter, (4)the third effecter plasmid which expresses ToMV MP under control of the CaMV 35S promoter, (5)a control plasmid which expresses green fluorescent protein under control of the CaMV 35S promoter as an internal control, (6)a control plasmid which expresses GUS under control of the CaMV 35S promoter as a control for constitutive reporter expression. These plasmids were combined differently, introduced into protoplasts prepared from tobacco BY-2 cell culture and accumulation of GUS and GFP were analyzed. The results suggest that ToMV MP would regulate expression of the host genes. This study made it more interesting to examine in the future whether similar results will be obtained not only in cultured cells but also in host plants.