Requirements for intercellular and vascular transport of Potato virus X

PVX代表一组利用胞间连丝运输的独特机制的病毒。霍尔代病毒属、卡拉病毒属、本尼病毒属和波特克索病毒属的成员都含有一个高度保守的遗传模块，由三个重叠的开放阅读框架组成，称为三重基因块。TGB蛋白被命名为TGBp1、TGBp2和TGBp3，它们都是病毒从最初感染的细胞移动到邻近细胞所必需的。因此，对这一建议的研究对于开发一个解释这四个病毒属的胞间连丝运输机制的模型至关重要。大多数植物RNA病毒需要一个或两个病毒编码的运动蛋白来调节它们自己的胞间连丝运输，而PVX代表的是一组需要四种病毒蛋白的病毒：三重基因阻断蛋白(TGBp1、TGBp2和TGBp3)加上外壳蛋白(CP)。将进行研究，以确定TGB蛋白的功能，探索PVX蛋白与蛋白质之间的相互作用，确定“运动复合体”的性质，并研究细胞成分在介导PVX细胞间转运中的作用。从长远来看，将进行实验以确定参与病毒运动过程的每一步的病毒和宿主成分。这项提议有四个主要目标：1.确定TGBp1、TGBp2、TGBp3和/或CP是否在植物细胞中共存，表明这些蛋白质可能形成病毒运动所必需的复合体。2.利用体外技术确定TGBp1、TGBp2、TGBp3和/或CP是否相互作用。3.利用突变分析和细胞生物学技术确定TGBp2是否与TGBp1相互作用。确定PVX三重基因阻断和CP蛋白是否可以进入和/或离开支持病毒血管运动的血管系统。这项研究的结果将为植物的RNA和蛋白质运输以及细胞间通讯机制提供新的信息。植物病原体在细胞间和系统间的传播遵循一条已被命名为“RNA高速公路”的路径。“RNA高速公路”指的是分子从细胞到细胞的系统性运输，从维管系统进入和离开，以及通过相邻细胞之间的胞间连丝连接在植物中普遍传播。植物病毒(包括PVX)对于确定RNA通道、确定局部和系统基因沉默和防御机制以及研究胞间连丝的功能都是至关重要的。此外，PVX在农学上很重要，很少有研究表征PVX复制和系统传播的机制。这些类型的研究对于开发新的控制措施很重要。

PVX represents a group of viruses that utilize a unique mechanism for plasmodesmata transport. Members of the virus genera, Hordeivirus, Carlavirus, Benyvirus, and Potexvirus, all contain a highly conserved genetic module of three overlapping open reading frames, termed the triple gene block. The TGB proteins are named TGBp1, TGBp2, and TGBp3 and all are required for virus movement from the initially infected cell into adjacent cells. Thus, research in this proposal will be crucial for developing a model explaining the mechanism for plasmodesmata transport of these four virus genera. While most plant RNA viruses require one or two viral encoded movement proteins to mediate their own plasmodesmata transport, PVX represents a group of viruses that require four viral proteins: triple gene block proteins (TGBp1, TGBp2, and TGBp3) plus coat protein (CP). Research will be conducted to identify functions of the TGB proteins, to explore PVX protein-protein interactions, to determine the nature of the "movement complex", and to study the role of cellular components in mediating PVX cell-to-cell transport. In the long term, experiments will be conducted to identify the viral and host components that contribute to each step of the movement process.This proposal has four major objectives:1. Determine if TGBp1, TGBp2, TGBp3 and/or CP colocalize in plant cells, suggesting that these proteins might form a complex necessary for virus movement. 2. Determine if TGBp1, TGBp2, TGBp3 and/or CP interact using in vitro techniques. 3. Determine if TGBp2 interacts with TGBp1 using mutational analysis and cell biology techniques. Determine if the PVX triple gene block and CP proteins can enter and/or exit the vasculature in support of virus vascular movement . The results of this research will provide new information about RNA and protein trafficking as well as intercellular communication mechanisms in plants. Cell-to-cell and systemic spread of plant pathogens follows a path that has been named the "RNA highway". The "RNA highway" refers to the systemic transport of molecules from cell to cell, entry and exit from the vasculature, and general spread throughout the plant via plasmodesmata connections that occur between adjacent cells. Plant viruses (including PVX) have been crucial for defining the RNA highway, for defining mechanisms for local and systemic gene silencing and defense, and for studying functions of plasmodesmata. In addition, PVX is agronomically important and there have been few studies characterizing the mechanism for PVX replication and systemic spread. These types of studies are important for developing novel control measures.