The role of Rab1 GTPase and its activators in selective autophagy and neurodegenerative disease

Rab1 GTPase 及其激活剂在选择性自噬和神经退行性疾病中的作用

• 批准号: 9225579
• 负责人: Nava Segev
• 金额: $ 19.99万
• 依托单位: UNIVERSITY OF ILLINOIS AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-30 至 2018-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9225579
• 关键词: Affect; Alzheimer' s Disease; Amino Acids; Autophagocytosis; Cause of Death; Cell Line; Cell Survival; Cells; Complex; Cytoplasmic Granules; Cytoplasmic Protein; Disease; Endoplasmic Reticulum; Future; Generic Drugs; Goals; Guanosine Triphosphate Phosphohydrolases; Homologous Gene; Human; Human Cell Line; Integral Membrane Protein; Knock-in; Knock-out; Left; Lysosomes; Mammalian Cell; Membrane; Membrane Proteins; Mission; Mutate; Mutation; National Institute of Neurological Disorders and Stroke; Nerve Degeneration; Neurodegenerative Disorders; Normal Cell; Parkinson Disease; Pathway interactions; Pharmaceutical Preparations; Pharmacotherapy; Play; Process; Proteins; Quality Control; Quality of life; Recycling; Regulation; Research; Role; Small Interfering RNA; Stress; TRAPP transport protein particle; United States; Yeasts; abstracting; age related; alpha synuclein; base; design; knock-down; mutant; neuron loss; novel; overexpression; paralogous gene; protein aggregate; protein complex; rab GTP-Binding Proteins; research study; therapeutic target; tool; trafficking; tumorigenesis

Abstract Age-related neurodegenerative diseases (ND), which affect the lives of millions of people, are caused by a progressive loss of neuronal function. This loss is associated with the accumulation of aggregated proteins, such as α-synuclein in Parkinson's disease and APP in Alzheimer's disease. The pathogenic mechanisms underling these diseases, for which currently there are no cures, are not fully understood. Autophagy, a cellular recycling pathway, shuttles excess and damaged cellular components to the lysosome for degradation. We propose that constitutive selective autophagy pathways clear ND-related protein aggregates. In mammalian cells, autophagy has been extensively studied under stress conditions, but almost nothing is known about constitutive selective autophagy processes or their regulation in human cells. Here, we propose to extend our recent studies in yeast about two types of constitutive selective autophagy pathways and their regulation by the Rab1 yeast homolog, Ypt1, to human cells. Rab1 GTPase was implicated in ND and its activation was proposed to inhibit accumulation of ND-related aggregates. However, Rab1 regulates both secretion and autophagy and it is not clear through which process its activation affects ND. Moreover, Rab1 activation in secretion was implicated in oncogenesis. Thus, to elucidate through which process Rab1 affects ND, it is crucial to separate its functions in secretion and autophagy. In yeast, we succeeded in separating the functions of Ypt1 in secretion and autophagy using two approaches: generating autophagy-specific Ypt1 mutations and characterizing autophagy-specific Ypt1 activators. These activators stimulate Ypt1 in two constitutive selective autophagy pathways: clearance of excess membrane proteins and clearance of cytoplasmic protein complexes. Because all the players are conserved from yeast to human cells, we propose to determine whether our findings pertain to human cells. In Aim 1, we will attempt to generate autophagy-specific Rab1 mutations and in Aims 2-3, we will determine whether autophagy-selective activators stimulate Rab1 in two distinct constitutive selective autophagy pathways. If successful, these tools will be used in future experiments to determine whether autophagy- specific Rab1 modulation affects clearance of ND-related protein aggregates. Achieving the goals of this proposal and the future experiments would provide a novel regulation paradigm for clearance of ND-related protein aggregates. Moreover, identification of Rab1 regulators specific for constitutive selective autophagy would provide novel ND therapeutic targets, in line with the missions of the National Institute of Neurological Disorders and Stroke.

摘要 神经退行性疾病（ND）影响数百万人的生活， 由神经元功能的逐渐丧失引起。这种损失与积累有关 聚集的蛋白质，如帕金森病中的α-突触核蛋白和阿尔茨海默病中的APP 疾病这些疾病的致病机制，目前还没有 治疗，并没有完全理解。自噬是一种细胞循环途径， 受损的细胞成分被溶酶体降解。我们建议， 选择性自噬途径清除ND相关蛋白聚集体。在哺乳动物细胞中， 应激条件下的自噬已被广泛研究，但几乎一无所知 关于组成性选择性自噬过程或它们在人类细胞中的调节。这里我们 我建议扩展我们最近在酵母中关于两种类型的组成性选择性的研究 自噬途径和Rab 1酵母同源物Ypt 1对人类细胞的调节。 Rab 1 GT3与ND有关，其激活被认为抑制了 与ND相关的聚集体。然而，Rab 1既调节分泌又调节自噬， 明确其激活通过哪个过程影响ND。此外，Rab 1在分泌中的激活 与肿瘤发生有关因此，为了阐明Rab 1通过何种过程影响ND， 这对分离其分泌和自噬的功能至关重要。在酵母中，我们成功地 使用两种方法分离Ypt 1在分泌和自噬中的功能： 自噬特异性Ypt 1突变和表征自噬特异性Ypt 1激活剂。 这些激活剂在两种组成性选择性自噬途径中刺激Ypt 1： 过量的膜蛋白和细胞质蛋白复合物的清除。因为所有的 从酵母到人类细胞，我们建议确定我们的发现是否是保守的。 与人类细胞有关。在目标1中，我们将尝试产生自噬特异性Rab 1突变， 在目标2-3中，我们将确定自噬选择性激活剂是否刺激Rab 1， 两种不同的组成性选择性自噬途径。 如果成功，这些工具将用于未来的实验，以确定是否自噬- 特异性Rab 1调节影响ND相关蛋白聚集体的清除。实现 这项建议的目标和未来的实验将提供一个新的监管范式， ND相关蛋白聚集体的清除。此外，Rab 1调节子特异性的鉴定 对于组成性选择性自噬将提供新的ND治疗靶点，与 国家神经疾病和中风研究所的任务。