Biogenesis of transport vesicles coated by COPI

COPI 包被的运输囊泡的生物发生

• 批准号: 7807393
• 负责人: VICTOR W HSU
• 金额: $ 48.92万
• 依托单位: BRIGHAM AND WOMEN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-30 至 2010-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7807393
• 关键词: ADP-Ribosylation Factors; ARFGAP1; Affect; Binding; Biochemical; Biogenesis; Capsid Proteins; Cell membrane; Cells; Clathrin; Coat Protein Complex I; Complex; Coupled; Ear; Endocytosis; Event; Funding; GTPase-Activating Proteins; Goals; Golgi Apparatus; Guanine Nucleotide Exchange Factors; Image; In Transferrin; Investigation; Iron; Maps; Mediating; Membrane Proteins; Molecular; Monomeric GTP-Binding Proteins; Mutation; Parents; Pathologic; Pathway interactions; Point Mutation; Process; Proteins; Recovery; Regulation; Role; Sorting - Cell Movement; Transcription Factor AP-2 Alpha; Transferrin Receptor; Transport Vesicles; United States National Institutes of Health; Vesicle; insight; iron metabolism; novel; parent grant; protein function; public health relevance; response; uptake

DESCRIPTION (provided by applicant): We are submitting a revision to the parent R01 application (GM058615) in response to an NIH announcement (NOT-OD-09-058: NIH Announces the Availability of Recovery Act Funds for Competitive Revision Applications). The parent grant studies transport vesicles formed by the Coat Protein I (COPI) complex. This revision studies a new topic outside the scope of the parent grant, examining how a key COPI component, known as ARFGAP1, has a novel role in clathrin-mediated endocytosis. The clathrin AP2 complex participates in endocytosis from the plasma membrane, while COPI acts in transport from the Golgi to the ER and also among the Golgi stacks. These two coat complexes are the first ones identified, and have not been shown to share a common component despite having been intensely investigated for many years. We have now gathered evidence that ARFGAP1 acts in a subset of clathrin AP2-dependent transport, as defined by the endocytosis of transferrin receptor (TfR), and propose to further elucidate this process through two major approaches. First, using biochemical approaches, we will examine whether the interaction between AP2 and ARFGAP1 regulates the ability of either component in binding to TfR. We also seek insight into how ARFGAP1 interacts with AP2 by defining a minimal portion of ARFGAP1 that binds to the 1-ear domain, and also map how ARFGAP1 binds to the 1-ear domain. Second, we will pursue advanced imaging approaches to interrogate how the GAP activity affects vesicle formation and cargo sorting, and whether the interaction between ARFGAP1 and AP2 also affect these two events. We anticipate that potential results will contribute to a general understanding of mechanisms in vesicular transport. Moreover, because TfR endocytosis is essential for iron uptake, anticipated results will also contribute to a molecular understanding of how iron uptake is achieved, and how this process may become pathologic. PUBLIC HEALTH RELEVANCE: The function of proteins is critically regulated by their localization. This localization is achieved in part by transport pathways that act as highways within the cell. We propose to understand how a regulator of this process modulates the distribution of a surface protein known as the transferrin receptor. Our results will likely contribute to a basic understanding of transport mechanisms within the cell, and also shed insight into the regulation of iron metabolism.

描述（由申请人提供）：我们正在提交对父R 01申请（GM 058615）的修订，以响应NIH公告（NOT-OD-09-058：NIH宣布恢复法案资金可用于竞争性修订申请）。这项研究的目的是研究由外壳蛋白I（COPI）复合物形成的运输囊泡。这次修订研究了一个新的主题以外的母基金的范围，研究如何一个关键的COPI组成部分，被称为ARFGAP 1，在网格蛋白介导的内吞作用的新作用。网格蛋白AP 2复合物参与从质膜的内吞作用，而COPI作用于从高尔基体到ER的运输以及高尔基体堆叠之间的运输。这两个涂层复合物是第一个确定的，并没有显示出共享一个共同的组成部分，尽管已经深入研究了多年。我们现在已经收集到的证据表明，ARFGAP 1作用于网格蛋白AP 2依赖性运输的一个子集，如转铁蛋白受体（TfR）的内吞作用所定义的，并建议通过两种主要方法进一步阐明这一过程。首先，使用生物化学方法，我们将研究AP 2和ARFGAP 1之间的相互作用是否调节任一组分与TfR结合的能力。我们还通过定义ARFGAP 1与1-ear结构域结合的最小部分来深入了解ARFGAP 1如何与AP 2相互作用，并绘制ARFGAP 1如何与1-ear结构域结合的图谱。其次，我们将采用先进的成像方法来询问差距活性如何影响囊泡形成和货物分选，以及ARFGAP 1和AP 2之间的相互作用是否也影响这两个事件。我们预计，潜在的结果将有助于在囊泡运输机制的一般理解。此外，由于TfR内吞作用是铁摄取必不可少的，预期的结果也将有助于从分子上了解铁摄取是如何实现的，以及这个过程是如何成为病理性的。 公共卫生相关性：蛋白质的功能受到其定位的严格调节。这种定位部分是通过细胞内充当高速公路的运输途径实现的。我们建议了解如何调节这一过程的调节分布的表面蛋白称为转铁蛋白受体。我们的研究结果可能有助于对细胞内运输机制的基本理解，也有助于了解铁代谢的调节。