Regulatory mechanisms of protein sorting in post-Golgi membrane trafficking

植物细胞后高尔基内膜系统的膜运输仍然知之甚少，尽管发育过程以及与环境的生物和非生物相互作用需要受体及其配体、转运蛋白和膜融合效应物的调节递送到质膜和从质膜取回。这项建议的主要目标是确定潜在的蛋白质分选后高尔基体贩运的监管机制。重点将是参与囊泡形成，货物选择或囊泡与靶膜融合的五个蛋白质家族的成员：调节ARF GT3活性的鸟嘌呤-核苷酸交换因子（ARF-GEFs），它们的ARF底物，介导货物分选形成囊泡的衔接蛋白（AP）复合物的μ-adaptin亚基，以及Rab GTPases和syntaxins，两者都有助于膜融合的特异性。实验方法包括亚细胞蛋白质定位，遗传或实验干扰蛋白质功能，并分析正常和破坏途径中可溶性和膜结合货物的运输。预期的结果也将为社区提供新的资源，如细胞内蛋白定位的标记。

Membrane trafficking in the post-Golgi endomembrane system of plant cells is still poorly understood, although developmental processes as well as biotic and abiotic interactions with the environment require regulated delivery to and retrieval from the plasma membrane of receptors and their ligands, transporters and membrane-fusion effectors. The main goal of this proposal is to identify regulatory mechanisms underlying protein sorting in post-Golgi trafficking. The focus will be on members of five protein families involved in vesicle formation, cargo selection or vesicle fusion with target membranes: guanine-nucleotide exchange factors regulating ARF GTPase activity (ARF-GEFs), their ARF substrates, the μ-adaptin subunits of adaptor protein (AP) complexes mediating cargo sorting into forming vesicles, and Rab GTPases and syntaxins both of which contribute to the specificity of membrane fusion. The experimental approaches include subcellular protein localisation, genetic or experimental interference with protein function, and analysis of trafficking of soluble and membrane-bound cargo in normal and disrupted pathways. The anticipated results will also provide the community with new resources such as markers for intracellular protein localisation.