Activation of the 20S Proteasome to Normalize Tau Homeostasis

激活 20S 蛋白酶体使 Tau 稳态正常化

• 批准号: 9329344
• 负责人: Jason E Gestwicki
• 金额: $ 22.7万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-15 至 2019-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9329344
• 关键词: 26S proteasome; Acetylation; Acute; Address; Aging; Agonist; Allosteric Site; Alpha Cell; Alzheimer' s Disease; Apical; Binding; Binding Proteins; Biochemical; Biology; Bortezomib; Brain; C-terminal; Cell model; Cells; Chemicals; Disease; Electron Microscopy; Employee Strikes; Enzymes; Equilibrium; Excision; Family; Frontotemporal Dementia; Genetic; Goals; Homeostasis; Human; Human Activities; In Vitro; Individual; Knowledge; Lead; Lethal Dose 50; Libraries; Metabolic; Meteor; Methods; Microinjections; Microtubules; Modeling; Mutation; Neurodegenerative Disorders; Neurons; Nucleosome Core Particle; Pathway interactions; Patients; Peptides; Pharmaceutical Chemistry; Phosphorylation; Point Mutation; Post-Translational Protein Processing; Progressive Supranuclear Palsy; Proteasome Inhibitor; Proteins; Proteolysis; Quality Control; RNA Splicing; Reagent; Recombinant Proteins; Research; Resistance; Role; Safety; Series; Site; Source; Speed; Structure; System; Tauopathies; Time; Trypsin; Variant; Work; age related; analog; base; chymotrypsin; design; high reward; high risk; innovation; multicatalytic endopeptidase complex; mutant; new therapeutic target; novel strategies; overexpression; particle; small molecule; tau Proteins; tau aggregation; tau mutation

Project Summary/Abstract. Microtubule-binding protein tau (MAPT/tau) accumulates to cause a family of fifteen progressive neurodegenerative disorders, incluing frontotemporal dementia (FTD), progressive supranuclear palsy (PSP) and some forms of Alzheimer's disease (AD). The common feature of these untreatable, fatal diseases is that tau homeostasis is imbalanced, resulting in its accumulation and aggregation. Thus, a potential way to treat them is to enhance the flux of tau through the proteasome. During aging, the capacity of the proteasome pathway appears to deteriorate, potentially creating conditions that favor abnormal tau accumulation. It has recently been observed that many cells, including neurons, contain substantial pools of 20S proteasome that are not fully activated. We hypothesize that these “latent” pools could be mobilized to enhance tau turnover. Indeed, it is already known that microinjection of active proteasome or over-expression of proteasome subunits speeds the clearance of tau. Now, we propose to develop small molecules that are potent and selective agonists of the 20S proteasome. Towards this goal, we have used structure-based methods to identify small molecules that bind to the allosteric sites on the 20S proteasome that are responsible for “gating” the entry of substrates. NMR studies showed that the lead molecules bind to the intended sites and EM studies show that, consistent with the design, they “open” the 20S proteasome. Strikingly, we found that these molecules stimulate proteasome activity between 8 to 20-fold in vitro. The lead molecule also accelerated turnover of disease-associated tau in cell-based models, consistent with the model. The next critical step in this project is to (SA1) pursue the structure-guided, hit-to-lead optimization of the chemical series and (SA2) characterize the relationships between the 20S proteasome and tau homeostasis. This work is significant because it will provide new chemical probes for use in understanding tau homeostasis, potentially validating the 20S as a new drug target for tauopathies. The work is innovative because it employs cutting-edge computational, structural and experimental approaches to generate allosteric agonists of an important enzyme.

项目摘要/摘要。 微管结合蛋白 tau (MAPT/tau) 积累导致一个 15 人家族进行性进展 神经退行性疾病，包括额颞叶痴呆 (FTD)、进行性核上性麻痹 (PSP) 以及某些形式的阿尔茨海默病 (AD)。这些无法治愈的致命疾病的共同特征是 tau蛋白稳态失衡，导致其积累和聚集。因此，一种潜在的治疗方法 它们的目的是增强 tau 蛋白通过蛋白酶体的通量。在衰老过程中，蛋白酶体的能力 通路似乎恶化，可能创造有利于 tau 蛋白异常积累的条件。它有 最近观察到，包括神经元在内的许多细胞都含有大量的 20S 蛋白酶体， 没有完全激活。我们假设这些“潜在”池可以被调动来提高 tau 蛋白的周转率。 事实上，众所周知，活性蛋白酶体的显微注射或蛋白酶体亚基的过度表达 加速 tau 蛋白的清除。现在，我们建议开发有效且具有选择性的小分子 20S蛋白酶体激动剂。为了实现这一目标，我们使用基于结构的方法来识别小 与 20S 蛋白酶体上的变构位点结合的分子，负责“门控” 基材。 NMR 研究表明先导分子结合到预期位点，而 EM 研究表明， 与设计一致，他们“打开”了 20S 蛋白酶体。令人惊讶的是，我们发现这些分子 体外刺激蛋白酶体活性 8 至 20 倍。先导分子还加速了 基于细胞的模型中与疾病相关的 tau 蛋白，与模型一致。该项目的下一个关键步骤是 (SA1) 追求化学系列的结构导向、从命中到先导的优化，(SA2) 表征 20S 蛋白酶体和 tau 稳态之间的关系。这项工作意义重大，因为它将提供 用于了解 tau 稳态的新化学探针，有可能验证 20S 作为一种新药物 tau蛋白病的目标。这项工作具有创新性，因为它采用了尖端的计算、结构和 产生重要酶的变构激动剂的实验方法。