Molecular Genetics of Regulated Protein Delivery of the Plasma Membrane

质膜调控蛋白质传递的分子遗传学

基本信息

批准号：
7615535
负责人：
Chris Alan Kaiser
金额：
$ 30.27万
依托单位：
MASSACHUSETTS INSTITUTE OF TECHNOLOGY
依托单位国家：
美国
项目类别：
财政年份：
1998
资助国家：
美国
起止时间：
1998-02-01 至 2011-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7615535
关键词：
Address Adipocytes Affinity Amino Acid Permease Amino Acids Animal Model Binding Biochemical Biological Assay Carrier Proteins Cell membrane Cells Coated vesicle Code Complex Cues Culture Media Data Defect Dominant-Negative Mutation Endosomes Environment Fatty acid glycerol esters Funding GLUT4 gene GTP Binding Genetic Screening Genetic screening method Glucose Transporter Golgi Apparatus Guanosine Triphosphate Phosphohydrolases Insulin Integral Membrane Protein Knowledge Location Lysosomes Mass Spectrum Analysis Membrane Membrane Proteins Methods Modification Molecular Genetics Monomeric GTP-Binding Proteins Movement Muscle Cells Mutation Nitrogen Non-Insulin-Dependent Diabetes Mellitus Orthologous Gene Pathway interactions Physiological Plant Roots Procedures Process Protein Subunits Proteins RNA Interference Reading Recycling Regulation Relative (related person)Research Research Personnel Saccharomyces cerevisiae Signal Transduction Sorting - Cell Movement Source Starvation Structure Testing Time Ubiquitin Ubiquitination Vesicle Work Writing extracellular in vitro activity interest mutant receptor reconstitution response sensor small molecule trafficking

项目摘要

DESCRIPTION (provided by applicant): The activities of integral membrane proteins, such as transport proteins, are often regulated by intracellular sorting. Such sorting processes can produce rapid changes in the rate that a transporter is delivered to the plasma membrane in response to an intracellular signal and thus provide a way for a cell to alter its capacity to take up small molecules from the extracellular environment in response to regulatory cues. For example, the GLUT4 glucose transporter is delivered to the plasma membrane of fat and muscle cells in response to insulin, and defects in this regulated trafficking are thought to be a root cause of non insulin-dependent diabetes. Many aspects of the intracellular sorting of GLUT4 remain poorly understood at this time. Dr. Kaiser's research group proposes to continue to study regulated sorting of general amino acid permease (Gap1) in response to the nitrogen source in the growth medium. By studying amino acid permease sorting in the model organism S. cerevisiae it will be possible to elucidate the mechanisms responsible for regulated sorting in the late secretory pathway. Work in the previous funding period has shown that Gap 1 p sorting is controlled by the rate at which Gap1 p protein can recycle from the endosome to the plasma membrane and that this sorting step is controlled by the abundance of intracellular amino acids. A genetic screen for mutants defective in Gap1 p recycling identified a GTPase containing complex (GSE) that interacts with Gap 1 p so as to suggest that the GSE complex may form part of a vesicle coat for Gap 1 p trafficking. Building on these findings the proposal is to: (i) identify additional components of the GSE complex with the ultimate aim of reconstituting activity in vitro, (ii) determine the structure and function of the GTPase component of the GSE complex, including functional studies of the mammalian orthologs, and (iii) determine how the nitrogen source controls Gap1 p recycling. We have found that Gap1 p modification by ubiquitin is necessary for sorting from the Golgi to endosome. A final aim of the project is (iv) to understand how ubiquitination is regulated and to identify the cellular components required for recognition of the ubiquitin tag.

描述（由申请人提供）：整体膜蛋白（例如转运蛋白）的活性通常受细胞内分类调节。这样的排序过程可以在响应细胞内信号的响应中传递到质膜的速率快速变化，从而为细胞改变其能力，以改变其从细胞外环境中摄取小分子的能力，以响应调节性线索。例如，将GLUT4葡萄糖转运蛋白递送到脂肪和肌肉细胞的质膜中，响应胰岛素，并且该调节的运输中的缺陷被认为是非胰岛素依赖性糖尿病的根本原因。目前，GLUT4细胞内分类的许多方面仍然很少了解。 Kaiser博士的研究小组建议继续研究生长培养基中氮源的普通氨基酸渗透酶（GAP1）的调节分选。通过研究模型生物体中的氨基酸渗透酶分选S.酿酒酵母，可以阐明负责在晚分泌途径中调节分类的机制。在上一个资金期间的工作表明，GAP 1 P排序受到GAP1 P蛋白可以从内体回收到质膜的速率控制的速率，并且这种分类步骤受到丰富的细胞内氨基酸的控制。在GAP1 P回收中有缺陷的突变体的遗传筛选鉴定出含有与GAP 1 P相互作用的GTPase（GSE），以表明GSE复合物可能构成用于GAP 1 P运输的囊泡外套的一部分。在这些发现的基础上，提案是：（i）确定GSE复合体的其他组成部分，其最终目的是重新建立了体外活动，（ii）确定GSE复合物的GTPase成分的结构和功能，包括哺乳动物矫正力的功能研究，以及（iii）确定氮的控制方式。我们发现，泛素修饰GAP1 P修饰对于从高尔基体到内体的排序是必要的。该项目的最终目的是（iv）了解如何调节泛素化并确定识别泛素标签所需的细胞成分。