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（ARFS）调节外套蛋白，该蛋白充当耦合囊泡形成和货物分类的核心细胞机制，用于囊泡运输。 ARF小的GTPase反过来又受鸟嘌呤核苷酸交换因子（GEF）调节，这些鸟嘌呤核苷酸交换因子（GEF）催化ARF激活和GTPase激活蛋白（GAPS）催化ARF失活。在最后一个资金期间，我们一直在研究三个ARF调节器如何在内吞运输中起作用。首先，我们已经确定了一个称为ACAP1的ARF间隙，它是一种用于内吞回收的新型网状蛋白外套复合物中的核心适配器。我们还发现，ACAP1参与了构成和调节的回收利用，其货物结合解释了如何完成两种类型的运输。因此，我们建议通过采用合并的生化和结构方法来进一步阐明ACAP1如何在货物排序中作用。其次，我们将GRP1确定为对ARF6的GEF，用于4型葡萄糖转运蛋白的内吞回收（GLUT4），这一过程受胰岛素调节。因此，我们建议采用合并的形态和生化方法，以阐明如何通过调节GLUT4回收的胰岛素诱导的信号来靶向该GEF。第三，我们发现，克拉瑟蛋白AP2依赖性转运的子集需要ARFGAP1，这是由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角色，研究ARFGAP1如何参与货物分类和囊泡形成，并审问其间隙活性的作用。我们预计这些结果将为内吞和回收的机理提供关键的见解。此外，由于控制这些运输途径的机制的缺陷会导致和/或导致心血管，免疫学，神经系统疾病和致癌性疾病，因此我们进一步预计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：蛋白质的功能受其本地化的严格调节。这种定位是通过在电池内充当高速公路的运输途径来实现的。我们建议了解这些途径的关键成分如何在调节细胞表面的蛋白质分布中起作用。这种理解将广泛地适用于理解人类疾病，因为许多人现在因细胞内蛋白质转运的缺陷而受到赞赏。