Tau-Mediated Regulation and Dysregulation of Protein Phosphatase 1

Tau 介导的蛋白磷酸酶 1 的调节和失调

• 批准号: 10320053
• 负责人: Nicholas M Kanaan
• 金额: $ 52.7万
• 依托单位: MICHIGAN STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-04-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10320053
• 关键词: Address; Affect; Affinity; Alzheimer' s Disease; Alzheimer' s disease related dementia; Automobile Driving; Axon; Axonal Transport; Binding; Biological Assay; Biology; Cell Culture Techniques; Cell Fractionation; Data; Deletion Mutation; Disease; FTD with parkinsonism; Functional disorder; Goals; Health; Healthcare; Human; Impairment; In Situ; Inherited; Injections; Knock-in; Knock-in Mouse; Knowledge; Lead; Ligation; Light; Link; Maps; Mass Spectrum Analysis; Mediating; Microscopy; Microtubule-Associated Proteins; Microtubules; Modeling; Modification; Molecular; Mus; Mutation; Nerve Degeneration; Neurons; Nuclear Protein Phosphatase; Oligonucleotides; Pathologic; Pathology; Pathway interactions; Phenotype; Phosphoric Monoester Hydrolases; Phosphorylation; Physiological; Play; Point Mutation; Protein Isoforms; Protein phosphatase; Regulation; Resolution; Role; Signal Pathway; Signal Transduction; Structure; Subcellular Fractions; Synapses; Tauopathies; Testing; Thinking; Toxic effect; Viral Vector; Work; axonal degeneration; delivery vehicle; in vivo; in vivo Model; insight; knock-down; mouse model; mutant; neurotoxicity; novel; pre-formed fibril; protein activation; protein protein interaction; small hairpin RNA; squid axon; tau Proteins; tau aggregation; tau function; tau mutation; Address; Affect; Affinity; Alzheimer' s Disease; Alzheimer' s disease related dementia; Automobile Driving; Axon; Axonal Transport; Binding; Biological Assay; Biology; Cell Culture Techniques; Cell Fractionation; Data; Deletion Mutation; Disease; FTD with parkinsonism; Functional disorder; Goals; Health; Healthcare; Human; Impairment; In Situ; Inherited; Injections; Knock-in; Knock-in Mouse; Knowledge; Lead; Ligation; Light; Link; Maps; Mass Spectrum Analysis; Mediating; Microscopy; Microtubule-Associated Proteins; Microtubules; Modeling; Modification; Molecular; Mus; Mutation; Nerve Degeneration; Neurons; Nuclear Protein Phosphatase; Oligonucleotides; Pathologic; Pathology; Pathway interactions; Phenotype; Phosphoric Monoester Hydrolases; Phosphorylation; Physiological; Play; Point Mutation; Protein Isoforms; Protein phosphatase; Regulation; Resolution; Role; Signal Pathway; Signal Transduction; Structure; Subcellular Fractions; Synapses; Tauopathies; Testing; Thinking; Toxic effect; Viral Vector; Work; axonal degeneration; delivery vehicle; in vivo; in vivo Model; insight; knock-down; mouse model; mutant; neurotoxicity; novel; pre-formed fibril; protein activation; protein protein interaction; small hairpin RNA; squid axon; tau Proteins; tau aggregation; tau function; tau mutation

Tau is a microtubule-associated protein that is abnormally phosphorylated and aggregates in Alzheimer’s disease (AD) and AD-related dementias, leading to its impaired functionality. No disease modifying treatment exists for these diseases, making them a significant healthcare priority. Though we have known for decades that several modifications are intimately associated with sporadic disease and mutations in tau directly cause inherited degenerative tauopathies, the precise molecular pathways engaged by pathological tau proteins to actively cause neurodegeneration are unknown. This knowledge gap remains a significant and critical problem that this proposal aims to address. Current thinking in the field suggests that disease-related tau modifications exert toxicity by disruption of microtubules and/or by enhancing tau aggregation. However, evidence from our group and others supports an alternative explanation. That is, tau acts to regulate signaling pathways and tau toxicity is due to an aberration of this function. Using the isolated axoplasm from squid giant axons, we discovered a functional signaling motif in the N-terminus of tau called the phosphatase-activating domain (PAD) that activates a protein phosphatase-1 (PP1)-dependent signaling cascade. We also identified that known pathological changes in tau (e.g. phosphorylation and oligomerization) alter tau’s structure leading to aberrant PAD-dependent activation of this pathway and axonal toxicity. We propose to focus on determining whether tau normally regulates PP1-dependent functions in neurons and on PP1-dependent pathways of tau toxicity. Our central hypothesis is that, through a PP1-dependent mechanism, tau normally regulates neuronal function and health, but in disease tau causes axonal, synaptic and/or neuronal toxicity through aberrations of this mechanism. In Aim 1, we will test the hypothesis that specific motifs within tau and PP1 are critical for the interaction with and activation of PP1 by tau proteins. We will use a combination of point mutations/deletions to map the specific domains in tau and PP1 isoforms that underlie tau’s ability to bind and activate PP1. In Aim 2, we will test the hypothesis that tau localizes with PP1 in specific subcellular compartments where it regulates PP1-dependent pathways. Here, we will use novel human tau-KI mouse primary neuron cultures and a combination of super-resolution microscopy, subcellular fraction and other protein-protein interaction assays to determine where in neurons tau and PP1 interact. Also, we will knockdown tau to determine its functional relationship to multiple PP1-dependent pathways in neurons. In Aim 3, we will test the hypothesis that disease forms of tau drive toxicity via PP1-dependent mechanisms. We will use a novel tau pre-formed fibril seeding model in the hTau-KI mice as well as the PS19 mutant tau mouse line to provide the critical in vivo translational insights for the tau-PP1 relationship and how disease forms of tau lead to PP1-dependent toxicity. Together, the proposed studies will fill critical gaps in our knowledge and will produce a significant impact by identifying important physiological and pathological roles for tau in regulating PP1 in neurons.

Tau是一种微管相关的蛋白 疾病（AD）和与AD相关的痴呆症，导致其功能受损。没有疾病修改治疗 这些疾病存在，使其成为重要的医疗保健优先事项。虽然我们已经知道数十年 几种修饰与零星疾病密切相关，而tau的突变直接引起 遗传的退化性tauopathies，病理学tau蛋白接纳的精确分子途径 积极引起神经退行性的原因是未知的。这个知识差距仍然是一个重大且关键的问题 该提议旨在解决。现场的当前思维表明与疾病相关的TAU修饰 通过微管的破坏和/或增强tau聚集来发挥毒性。但是，我们的证据 小组和其他人支持另一种解释。也就是说，tau可以调节信号通路和tau 毒性是由于此功能的畸变。使用鱿鱼巨型轴突中孤立的轴突，我们 在Tau的N端发现了一个功能信号基序，称为磷酸酶激活结构域 激活蛋白质磷酸酶-1（PP1）依赖性信号级联的（PAD）。我们还确定了 tau的已知病理变化（例如磷酸化和寡聚化）改变了tau的结构导致 该途径和轴突毒性的异常垫依赖性激活。我们建议专注于确定 tau是否通常调节神经元中的PP1依赖性功能和tau的PP1依赖性途径 毒性。我们的中心假设是，通过依赖PP1的机制，tau通常调节神经元 功能和健康 这种机制。在AIM 1中，我们将检验以下假设：Tau和Pp1中的特定基序对于 与tau蛋白与PP1的相互作用和激活。我们将使用点突变/删除的组合 绘制TAU和PP1同工型中的特定域，这些域是TAU结合和激活PP1的能力的基础。在AIM 2中， 我们将检验以下假设，即tau在特定的亚细胞室中与PP1定位的假设在该假说中调节它 pp1依赖性途径。在这里，我们将使用新颖的人tau-ki小鼠原发性神经元培养和 超分辨率显微镜，亚细胞分数和其他蛋白质 - 蛋白质相互作用测定的组合 确定tau和pp1相互作用的神经元中的位置。另外，我们将敲除tau以确定其功能 与神经元中多个依赖PP1的途径的关系。在AIM 3中，我们将检验疾病的假设 Tau的形式通过依赖PP1的机制驱动毒性。我们将使用一种新型的TAU预先形成的原纤维播种 HTAU-KI小鼠以及PS19突变体Tau小鼠系中的模型，以提供关键的体内翻译 tau-PP1关系的见解以及tau疾病形式如何导致pp1依赖性毒性。一起， 拟议的研究将填补我们知识的关键空白，并通过识别来产生重大影响 TAU在调节PP1中的重要物理和病理作用。