Sorting and trafficking in the endosomal system

内体系统中的分选和运输

基本信息

批准号：
8144254
负责人：
Christopher G Burd
金额：
$ 34.79万
依托单位：
YALE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2000
资助国家：
美国
起止时间：
2000-09-01 至 2013-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8144254
关键词：
Address Adhesions Back Binding Biochemical Cell membrane Cell physiology Cell-Cell Adhesion Cells Cellular Structures Chemicals Chimeric Proteins Complex Controlled Environment Degradation Pathway Endosomes Environment Equilibrium Family Funding Genetic Genetic Screening Goals Golgi Apparatus Human Hydrolase Integral Membrane Protein Investigation Iron Kinetics Lead Lipids Lysosomes Mediating Metabolic Diseases Methodology Modeling Molecular Nutrient Nutritional status Organelles Pathway interactions Process Proteins Reaction Recycling Regulation Research Role SNAP receptor Saccharomyces cerevisiae Saccharomycetales Signal Transduction Sorting - Cell Movement Staging Stimulus Substrate Interaction System Testing Translating Vacuole Vesicle Work Yeasts cell motility developmental disease endosome membrane genetic analysis insight mutant nexin programs protein degradation public health relevance rab GTP-Binding Proteins receptor receptor recycling research study retrograde transport sorting nexins trafficking ubiquitin ligase

项目摘要

DESCRIPTION (provided by applicant): The broad goal of this project is to elucidate, in biochemical and cellular terms, a mechanism for regulated protein sorting within the endocytic pathway. The focus of the work in the upcoming funding period is on the export of cargo proteins from endosomes, a poorly characterized set of retrograde transport pathways that sort cargo to the Golgi apparatus. For some nutrient transporters, such as the yeast Fet3/Ftr1 reductive iron transporter, this step constitutes the initial stage of an endocytic recycling pathway that returns them to the plasma membrane for re-use. Model cargo proteins, including nutrient transporters, an acidic hydrolase sorting receptor, and SNARE proteins have been established to investigate these pathways and the genetic requirements for their trafficking have been determined. Proposed experiments will identify the structural features of cargo proteins that are necessary for retrograde sorting, and identify the components of the sorting machinery that recognize these signals. The research will focus on the roles of the retromer cargo sorting complex, an evolutionarily conserved complex of five proteins that are associated with endosome membranes, and sorting nexins, which are proposed to function as cargo receptors in endosome export pathways. Methodologies to be used include genetic analysis of trafficking in yeast mutant strains, kinetic analysis of protein turnover rates, biochemical characterization of interactions between cargo and the sorting machinery and between components of the sorting machinery. The studies will provide key insights into how cargo proteins are recognized in the endosomal system, how recognition is translated into export of cargo from endosomes, and how these molecular interactions are harnessed by the cell to modulate the composition of the plasma membrane. PUBLIC HEALTH RELEVANCE: Many aspects of cell physiology rely directly on the protein and lipid composition of the plasma membrane: nutrient acquisition, cell-cell recognition and signaling, cell-substrate adhesion, and cell motility. The molecular components of the plasma membrane are in a dynamic equilibrium with intracellular endosomes. The proposed studies will investigate mechanisms of protein sorting within endosomes that lead to their recycling back to the plasma membrane.

描述（由申请人提供）：该项目的总体目标是从生化和细胞角度阐明内吞途径中调节蛋白质分选的机制。即将到来的资助期的工作重点是从内体中输出货物蛋白，内体是一组特征不明的逆行运输途径，用于将货物分类到高尔基体。对于某些营养转运蛋白，例如酵母 Fet3/Ftr1 还原性铁转运蛋白，此步骤构成了内吞回收途径的初始阶段，将它们返回质膜以供再利用。已经建立了模型货物蛋白，包括营养物转运蛋白、酸性水解酶分选受体和 SNARE 蛋白来研究这些途径，并确定了其运输的遗传要求。拟议的实验将确定逆行分选所需的货物蛋白的结构特征，并确定识别这些信号的分选机器的组件。该研究将重点关注逆转录体货物分选复合物（一种与内体膜相关的五种蛋白质的进化保守复合物）和分选连接蛋白的作用，该复合物被认为在内体输出途径中充当货物受体。使用的方法包括酵母突变菌株运输的遗传分析、蛋白质周转率的动力学分析、货物与分选机械之间以及分选机械部件之间相互作用的生化特征。这些研究将为在内体系统中如何识别货物蛋白、如何将识别转化为从内体输出货物以及细胞如何利用这些分子相互作用来调节质膜的组成提供重要见解。公共健康相关性：细胞生理学的许多方面直接依赖于质膜的蛋白质和脂质组成：营养获取、细胞间识别和信号传导、细胞基质粘附和细胞运动。质膜的分子成分与细胞内的内体处于动态平衡。拟议的研究将研究内体中蛋白质分选的机制，从而导致蛋白质再循环回到质膜。