SNARE蛋白VAMP721和VAMP722在生长素运输载体动态转运中的功能研究

SNARE蛋白介导了内膜系统中复杂的囊泡运输，实现了功能蛋白在胞内的动态转运。前人研究表明，植物细胞中生长素运输载体的动态转运调控了生长素在组织细胞中的流向和梯度分布。然而，有关SNARE蛋白介导生长素运输载体动态转运的分子机制缺乏相关研究。本项目针对前人工作的不足，以拟南芥为材料，着重展开三方面的研究：(1)观察分析SNARE VAMP721/VAMP722双突变体中生长素极性运输缺陷相关的表型；(2) 研究生长素运输载体在双突变体细胞中的亚细胞定位；(3) 探讨VAMP721和VAMP722蛋白参与生长素输运载体胞内转运的分子机理。在本项目研究中，拟采用新型荧光蛋白标记、光漂白恢复和荧光相关光谱等一些新方法、新技术，旨在揭示VAMP721和VAMP722蛋白介导的囊泡运输在生长素运输载体的极性定位和胞内转运中的作用，对进一步揭示生长素极性运输的分子机理具有重要的科学意义。

SNARE proteins mediate the complex vesicle trafficking by which the dynamic protein delivery is accomplished in endomembrane system of living cells. In plants, auxin flow and gradient in plant cell and tissue are modulated by the dynamic trafficking of auxin transporters. However, little information is known about the molecular mechanism of the dynamic trafficking of auxin transporters mediated by SNARE proteins. In the present study, we will investigate the function of Arabidopsis v-SNARE proteins VAMP721 and VAMP722 in the subcellular distribution and trafficking of auxin transporters by means of dynamic imaging in the living cells together with genetic approaches. First, we will analyze the phenotypes related to the defects in polar auxin transport by using VAMP721/VAMP722 homozygous double mutant. Then, we will determine the subcellular localization of auxin transporters in double mutant. Finally, we will further explore the mechanism for VAMP721 and VAMP722 involved in intracellular trafficking of auxin transporters. In the course of the investigation, some new methods and techniques including new fluorescent protein labeling, fluorescence recover after photobleaching and fluorescence correlation spectroscopy, will be used in this study with the aim of uncovering the function of vesicle trafficking mediated by VAMP721 and VAMP722 in the polar targeting and intracellular trafficking of auxin transporters. Surely, the results of this study will lay foundation for the further investigation of molecular mechanism for polar auxin transport in plant cells.