Role of the Arabidopsis TRAPPII tethering complex in protein sorting at the Trans-Golgi-Network

跨高尔基网络（TGN）是细胞表面信息流动和分类的主要枢纽。然而，TGN中蛋白质分选的分子机制尚不清楚。本提案的重点是在细胞分裂和光反应的背景下对TGN结构和功能的调节。拟南芥TRAPPII系结复合体被认为具有胍交换因子（GEF）调节Rab GTPase活性的功能，在细胞分裂和后高尔基转运中起着核心作用。我们已经通过蛋白质组学方法确定了TRAPPII复合体的相互作用伙伴。我们建议在细胞板上测试这些相互作用物的一个子集在蛋白质分选中的作用。我们还将研究TRAPPII蛋白组在环境刺激下的重新布线。我们的实验计划整合了分子遗传学，生理学，生物化学，蛋白质组学，计算和细胞生物学方法，包括超分辨率共聚焦实时成像显微镜和聚焦离子束/扫描电子显微镜，以研究TGN的结构和功能。所提出的实验结果将大大加深我们对TGN在驱动和微调植物生长和适应中的作用的理解。

The trans-Golgi network (TGN) is a major hub for the flow and sorting of information from and to the cell surface. The molecular mechanisms underlying protein sorting at the TGN, however, are poorly understood. The focus of this proposal is on the regulation of TGN structure and function in the context of cytokinesis and of light responses. The Arabidopsis TRAPPII tethering complex, thought to function as guanidine exchange factor (GEF) regulating Rab GTPase activity, is emerging as a central player in cytokinesis and in post-Golgi traffic. We have identified interaction partners of the TRAPPII complex via proteomic approaches. We propose to test the role of a subset of these interactors in protein sorting at the cell plate. We will also address rewiring of the TRAPPII proteome in response to environmental stimuli. Our experimental plan integrates molecular genetics, physiology, biochemistry, proteomics, computational and cell biological methods, including super-resolution confocal live imaging microscopy and focused ion beam/scanning electron microscopy, to address TGN structure and function. The outcome of the proposed experiments will considerably further our understanding of the role of the TGN in driving and fine tuning plant growth and adaptation.