Tau structure and dynamics in Alzheimer's disease

阿尔茨海默病中的 Tau 结构和动力学

基本信息

批准号：
10659553
负责人：
Mei Hong
金额：
$ 51.02万
依托单位：
MASSACHUSETTS INSTITUTE OF TECHNOLOGY
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-08-15 至 2028-04-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10659553
关键词：
Acceleration Adopted Affect Alzheimer&apos s Disease Alzheimer&apos s disease model Alzheimer&apos s disease pathology Amyloid Axon Binding Biochemical Biological Assay Biomedical Research Brain C-terminal Charge Chemicals Complex Cryoelectron Microscopy Data Democracy Diagnosis Disease Dissociation Drug Design Electron Microscopy Epitopes Filament Future Heparin Human In Vitro Joints Label Length Light MAPT gene Measures Mediating Membrane Membrane Lipids Methods Microtubules Modernization Modification Molecular Molecular Conformation Molecular Structure Mus Mutation N-terminal NMR Spectroscopy Neurodegenerative Disorders Neurofibrillary Tangles Neurons Pathologic Pathology Phosphorylation Phosphorylation Site Post-Translational Protein Processing Process Proline-Rich Domain Property Proteins Recombinants Research Shapes Site Societies Staging Structure Surface Synaptic Membranes Tauopathies Tertiary Protein Structure Testing Therapeutic Intervention Toxic effect Wild Type Mouse Work cofactor drug discovery experimental study in vitro Model microscopic imaging mimetics molecular dynamics monomer mutant neuropathology neurotoxicity novel paired helical filament phospho-L-arginine prion-like reconstruction solid state solid state nuclear magnetic resonance tau Proteins tau aggregation tau interaction tau-1 unilamellar vesicle

项目摘要

Project Summary - Despite decades of research into Alzheimer's disease (AD), disease-modifying treatments for AD remain elusive. This is significantly due to challenges in understanding the molecular and structural basis of AD. One of the two hallmarks of AD is the neurofibrillary tangles formed by the intrinsically disordered microtubule (MT)-associated protein tau. Spreading of tau filaments in the brain is the basis of neuropathological staging of AD. AD tau is hyperphosphorylated, truncated, and decorated with other posttranslational modifications (PTMs). However, how these PTMs cause tau to dissociate from MTs and misfold into -sheet amyloids, and how tau crosses the lipid membrane to spread its pathology, is not known. AD paired helical filament (PHF) tau fibrils have a C-shaped -sheet core that encompasses part of the MT-binding repeats. But the majority of the protein, which contains most of the disease-relevant PTMs, is too disordered to be seen in cryo-electron microscopy data. Here we propose to employ solid-state NMR (ssNMR) spectroscopy, electron microscopy, mouse neuron toxicity assays, and other biochemical approaches to understand the molecular structures and dynamics of AD tau filaments, membrane-bound tau, and MT-bound tau. We hypothesize that specific charge-charge interactions underlie the varying conformations, dynamics and properties of tau when self-aggregated and when bound to its cellular partners. In the last four years, we demonstrated the feasibility of applying ssNMR to study the structures and dynamics of full-length tau fibrils formed in vitro and seeded by AD PHF tau. We will now apply this expertise to answer three questions. In Aim 1, we will investigate how phosphorylation and truncation cause AD PHF tau by determining the structures of phosphorylated tau (p-tau) fibrilized without anionic cofactors; searching for minimum constructs that replicate the AD PHF tau structure and properties; and characterizing the dynamic structures of the semi-mobile proline-rich region of tau. In Aim 2, we will investigate tau interactions with lipid membranes by measuring the conformation, dynamics and membrane insertion of monomeric tau bound to small and large unilamellar vesicles. We will determine the structures of membrane-induced tau aggregates, and probe how phosphorylation and truncation affect the structure and dynamics of membrane-bound tau. These experiments should shine light on how lipid membranes nucleate tau aggregates and how aggregated tau crosses the membrane. In Aim 3, we will investigate the structures of MT-bound tau as a function of phosphorylation, and probe how arginine-phosphate interactions in the R' domain affect tau binding to MTs. A joint study of the fibrillar, membrane-bound and MT-bound tau is crucial for understanding how tau converts from its intrinsically disordered structure to an aggregated structure that propagates in a prion-like manner. This understanding should inform the future design of drugs that interfere with this process.

项目摘要 - 尽管对阿尔茨海默病 (AD) 进行了数十年的研究，但疾病缓解 AD 的治疗方法仍然难以捉摸，这在很大程度上是由于理解分子和机制方面的挑战。 AD 的两个特征之一是由神经纤维形成的缠结。本质上无序的微管 (MT) 相关蛋白 tau 蛋白在大脑中的传播是 AD tau 神经病理学分期的基础是过度磷酸化、截短和修饰。其他翻译后修饰 (PTM) 然而，这些 PTM 如何导致 tau 与 MT 分离。并错误折叠成 -片状淀粉样蛋白，以及 tau 如何穿过脂质膜传播其病理学，目前尚不清楚已知 AD 配对螺旋丝 (PHF) tau 原纤维具有 C 形  片层核心，其中包含部分但大多数蛋白质（包含大部分与疾病相关的 PTM）会重复。太无序，无法在冷冻电子显微镜数据中看到。在这里，我们建议采用固态核磁共振。 (ssNMR) 光谱、电子显微镜、小鼠神经元毒性测定和其他生化分析了解膜结合 AD tau 丝的分子结构和动力学的方法我们捕获了不同电荷-电荷相互作用背后的特定电荷相互作用。 tau 自聚集和与其细胞结合时的构象、动力学和特性在过去四年中，我们展示了应用 ssNMR 来研究结构的可行性。以及体外形成并由 AD PHF tau 接种的全长 tau 原纤维的动力学，我们现在将应用它。在目标 1 中，我们将研究磷酸化和截短是如何引起的。 AD PHF tau，通过确定无阴离子辅助因子原纤维化的磷酸化 tau (p-tau) 的结构；寻找复制 AD PHF tau 结构和特性的最小构建体；在目标 2 中，我们将描述 tau 半移动富含脯氨酸区域的动态结构。通过测量构象、动力学和膜来研究 tau 与脂质膜的相互作用插入与小和大单层囊泡结合的单体 tau 我们将确定其结构。膜诱导的 tau 聚集体，并探讨磷酸化和截短如何影响结构以及膜结合 tau 蛋白的动力学，这些实验应该揭示脂质膜如何发挥作用。有核 tau 蛋白聚集以及聚集的 tau 蛋白如何穿过膜在目标 3 中，我们将研究 MT 结合 tau 蛋白的结构作为磷酸化的函数，并探讨精氨酸磷酸化的机制 R' 结构域中的相互作用影响 tau 与 MT 的结合。纤维状、膜结合和 MT 的联合研究。 MT 结合的 tau 对于理解 tau 如何从其本质上无序的结构转变为无序结构至关重要。这种以类似朊病毒的方式传播的聚合结构应该为未来提供信息。设计干扰这一过程的药物。