植物病毒克服寄主细胞胞间连丝的限制，侵染邻近细胞的胞间运动，是植物病毒成功侵染寄主的最重要初始步骤。植物正单链RNA病毒编码运动蛋白，介导病毒的胞间运动。马铃薯卷叶病毒属辣椒脉黄病毒编码一个小分子量运动蛋白P4，介导病毒的胞间运动；然而，P4蛋白识别胞间连丝的分子机制，目前尚不明晰。申请者前期研究表明，辣椒脉黄病毒的运动蛋白P4，能够特异性识别并定位于寄主细胞的胞间连丝。在此基础上，本项目拟进一步鉴定P4蛋白识别的胞间连丝受体，并深入研究二者识别互作的分子机制。研究结果有望为揭示辣椒脉黄病毒P4蛋白介导病毒胞间运动的功能及其机理提供科学依据。也有助于认识正单链RNA病毒的小分子量移动蛋白介导病毒胞间运动的机理，以及为构建小分子量移动蛋白介导病毒胞间运动的理论模型提供理论基础。

Plant viruses usually encode movement protein to overcome the barrier of host cell plasmodesmata and infect adjacent cells, it is crucial step for plant viruses infecting host. Pepper vein yellows virus belongs to Polerovirus, which encodes movement protein P4. Our preliminary studies showed P4 protein specially recognized and located to the plasmodesmata. However, the receptors in plasmodesmata recognized by P4 protein, and recognition and interaction mechanism of P4 protein and receptors were still ambiguous. This project intends to use the integrated approaches of molecular biology, cell biology and biochemistry to isolate the receptors of P4 protein recognized, and reveal the interaction mechanism of P4 protein recognize the receptors, to understand the mechanism of cell-to-cell movement via plasmodesmata mediated by movement protein P4 of Pepper vein yellows virus. The scientific significance of this project will not only help to understand the mechanisms of cell-to-cell movement mediated by small molecular weight movement proteins of positive single strand RNA viruses, and also help to construct the theoretical model of cell-to-cell movement of plant viruses via plasmodesmata mediated by small molecular weight movement proteins.