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）：我们正在提交对母 R01 申请 (GM058615) 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）。母基金研究由外壳蛋白 I (COPI) 复合物形成的运输囊泡。本次修订研究了母基金范围之外的一个新主题，研究了关键的 COPI 成分（称为 ARFGAP1）如何在网格蛋白介导的内吞作用中发挥新作用。网格蛋白 AP2 复合物参与质膜的内吞作用，而 COPI 则参与从高尔基体到内质网以及高尔基体堆叠之间的转运。这两种涂层复合物是第一个被识别的复合物，尽管经过多年的深入研究，但尚未显示出它们具有共同的成分。我们现在收集的证据表明，ARFGAP1 在网格蛋白 AP2 依赖性转运的一个子集中起作用，如转铁蛋白受体 (TfR) 的内吞作用所定义，并建议通过两种主要方法进一步阐明这一过程。首先，我们将使用生化方法检查 AP2 和 ARFGAP1 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 ARFGAP1 与 1-ear 结构域结合的最小部分来深入了解 ARFGAP1 如何与 AP2 相互作用，并绘制 ARFGAP1 如何与 1-ear 结构域结合。其次，我们将采用先进的成像方法来探究 GAP 活性如何影响囊泡形成和货物分选，以及 ARFGAP1 和 AP2 之间的相互作用是否也会影响这两个事件。我们预计潜在的结果将有助于对囊泡运输机制的一般理解。此外，由于 TfR 内吞作用对于铁的吸收至关重要，因此预期的结果也将有助于从分子角度了解铁的吸收是如何实现的，以及该过程如何变得病理性。 公共健康相关性：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充当细胞内高速公路的运输路径来实现的。我们建议了解该过程的调节剂如何调节称为转铁蛋白受体的表面蛋白的分布。我们的结果可能有助于对细胞内运输机制的基本了解，并有助于深入了解铁代谢的调节。