ARF regulators in endocytic transport

内吞转运中的 ARF 调节因子

• 批准号: 7805056
• 负责人: VICTOR W HSU
• 金额: $ 39.16万
• 依托单位: BRIGHAM AND WOMEN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-01 至 2013-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7805056
• 关键词: ADP-Ribosylation Factors; ARFGAP1; Binding; Biochemical; Bypass; Capsid Proteins; Cardiovascular system; Cell surface; Cells; Clathrin; Coat Protein Complex I; Complex; Coupled; Coupling; Crystallization; Defect; Disease; Endocytosis; Event; Funding; GTPase-Activating Proteins; Glucose Transporter; Goals; Guanine Nucleotide Exchange Factors; Immunologics; In Transferrin; In Vitro; Insulin; Insulin Signaling Pathway; Investigation; Lead; Link; Membrane; Molecular Conformation; Monomeric GTP-Binding Proteins; N Domain; Neurologic; Non-Insulin-Dependent Diabetes Mellitus; Oncogenic; Pathogenesis; Pathway interactions; Peptides; Phosphorylation; Process; Protein Kinase; Recycling; Role; Signal Transduction; Sorting - Cell Movement; Structure; System; Tertiary Protein Structure; Transferrin Receptor; Vesicle; blood glucose regulation; human disease; in vivo; insight; novel; protein distribution; protein function; protein transport; public health relevance

DESCRIPTION (provided by applicant): ADP-Ribosylation Factors (ARFs) regulate coat proteins, which act as the core cellular machinery in coupling vesicle formation and cargo sorting for vesicular transport. The ARF small GTPases are, in turn, regulated by guanine nucleotide exchange factors (GEFs) that catalyze ARF activation and GTPase-activating proteins (GAPs) that catalyze ARF deactivation. In the last funding period, we have been studying how three ARF regulators act in endocytic transport. First, we have identified an ARF GAP, known as ACAP1, to act as the core adaptor in a novel clathrin coat complex for endocytic recycling. We have also found that ACAP1 participates in both constitutive and regulated recycling, with its cargo binding explaining how both types of transport can be accomplished. Thus, we propose to further elucidate how ACAP1 acts in cargo sorting by taking combined biochemical and structural approaches. Second, we have identified Grp1 as the GEF that acts on ARF6 for the endocytic recycling of the glucose transporter type 4 (glut4), a process that is regulated by insulin. Thus, we propose to take combined morphologic and biochemical approaches to elucidate how this GEF may be targeted by insulin-induced signaling that regulates glut4 recycling. Third, we have found that ARFGAP1 is required for a subset of clathrin AP2-dependent transport, as defined by the endocytosis of transferrin receptor. Thus, we will further elucidate this role, examining how ARFGAP1 participates in cargo sorting and vesicle formation and also interrogating the role of its GAP activity. We anticipate that these results will shed key insights into mechanisms of endocytosis and recycling. Moreover, because defects in mechanisms that govern these transport pathways can cause and/or contribute to cardiovascular, immunologic, neurologic and oncogenic diseases, we further anticipate that our results will have broad ramifications to understanding and treating human diseases. 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 key components of these pathways function in regulating the distribution of proteins on the cell surface. This understanding will be broadly applicable to understanding human diseases, as many are now appreciated to arise because of defects in protein transport within the cell.

描述（由申请人提供）：ADP-核糖基化因子（ARF）调节外壳蛋白，外壳蛋白在偶联囊泡形成和囊泡运输的货物分选中充当核心细胞机制。反过来，ARF小GTPases又受到催化ARF激活的鸟嘌呤核苷酸交换因子（GEF）和催化ARF失活的GTPase-activating蛋白（GAP）的调节。在上一个资助期间，我们一直在研究三种ARF调节剂如何在内吞转运中起作用。首先，我们已经确定了一个ARF GAP，称为ACAP 1，作为核心适配器在一个新的网格蛋白外壳复合物的内吞再循环。我们还发现，ACAP 1参与了组成性和调节性再循环，其货物结合解释了这两种类型的运输如何完成。因此，我们建议进一步阐明如何ACAP 1的货物分拣采取结合生物化学和结构的方法。第二，我们已经确定Grp 1作为GEF，作用于ARF 6，用于葡萄糖转运蛋白4（GT 4）的内吞再循环，这是一个受胰岛素调节的过程。因此，我们建议采取形态学和生物化学相结合的方法来阐明这种GEF可能是由胰岛素诱导的信号调节α 4再循环的目标。第三，我们发现ARFGAP 1是网格蛋白AP 2依赖性转运的一个子集所必需的，如转铁蛋白受体的内吞作用所定义的。因此，我们将进一步阐明这一作用，研究ARFGAP 1如何参与货物分选和囊泡形成，并询问其GAP活性的作用。我们预计，这些结果将揭示内吞作用和回收机制的关键见解。此外，由于控制这些转运途径的机制缺陷可能导致和/或促成心血管、免疫、神经和致癌疾病，我们进一步预期我们的结果将对理解和治疗人类疾病产生广泛的影响。 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。我们建议了解这些途径的关键组成部分如何调节细胞表面蛋白质的分布。这种理解将广泛适用于理解人类疾病，因为现在认识到许多疾病是由于细胞内蛋白质转运的缺陷而产生的。