Chemical Probes and Chaperone-Accelerated Turnover of Tau

化学探针和分子伴侣加速 Tau 蛋白的周转

基本信息

批准号：
8519207
负责人：
Jason E Gestwicki
金额：
$ 19.38万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-08-01 至 2015-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8519207
关键词：
Alzheimer&apos s Disease Animal Model Appearance BAG1 gene Binding Binding Proteins Biology Cell model Cells Chemicals Co-Immunoprecipitations Collaborations Complex Critical Pathways Decision Making Disease Drug Targeting Equilibrium Event Excision Future Goals Heat shock proteins Homeostasis Impaired cognition In Vitro Individual Knowledge Laboratories Link Mass Spectrum Analysis Mediating Microtubules Modeling Molecular Molecular Chaperones Neurodegenerative Disorders Neurons Pathway interactions Patients Peptides Phosphorylation Post-Translational Protein Processing Process Proteins Quality Control Recruitment Activity Resistance Staging System Tauopathies Testing Time Triage Ubiquitin Variant Work base design in vitro Model infancy inhibitor/antagonist innovation insight multicatalytic endopeptidase complex neuron loss peptidomimetics programs protein complex research study tau Proteins tau aggregation tau mutation tool ubiquitin-protein ligase

项目摘要

DESCRIPTION (provided by applicant): Tau is a microtubule-binding protein that intrinsically disordered and abundantly expressed in neurons. Certain post-translationally modified forms of tau, such as hyper-phosphorylated and proteolyzed fragments, have been found to accumulate in more than fifteen neurodegenerative disorders, including Alzheimer's disease (AD). These "abnormal" tau variants are particularly prone to aggregation and their accumulation leads to proteotoxicity, neuron loss and cognitive impairment. Thus, strategies for accelerating the removal of abnormal tau are expected to protect against tauopathies. Cellular protein quality control (PQC) pathways, including molecular chaperones, have been shown to regulate tau homeostasis by controlling its post-translational modification, binding to microtubules and its turnover. However, the molecular details of this process are not yet clear. How do the chaperones distinguish between normal tau and aggregation-prone tau? Which chaperones and co-chaperones are critical for the triage decisions? What molecular events are critical during the earliest stages of tau degradation? The major goal of this project is to understand how the molecular chaperones and other components of PQC make the decision to degrade tau and its variants. Preliminary evidence suggests that the heat shock protein Hsp70 and Hsp90, in combination with some of their associated co-chaperones, detect the appearance of aggregation-prone tau and then make triage decisions to remove these proteins. Based on these studies, we hypothesize that a specific combination of chaperones and co-chaperones bind tau, distinguish between variants and then enact degradation programs. Towards probing that model, we propose two specific aims: (1) perform co-immunoprecipitation and mass spectrometry studies on normal, cycling tau and tau that has been acutely targeted for proteasomal degradation to identify proteins that are specifically associated with the degradation fate and (2) test whether specific Hsp40 co-chaperones selectively recruit Hsp70 to aggregation-prone tau variants. These studies are timely because they make use of new chemical probes that trigger the rapid (~ 10 min) and dramatic (~80%) degradation of tau by the ubiquitin-proteosome pathway. The Gestwicki laboratory has spent the past five years developing, characterizing and optimizing this suite of compounds and, together with the Dickey group, we have shown their activity in cellular and animal models of tauopathy. We propose that, because of their unusually rapid activities, these chemical probes will permit, for the first time, insight into the very earliest stages of the "decision" to degrade tau. Thus, we expect these aims will provide insight into how chaperone complexes discriminate between tau variants and how protein quality control components shuttle abnormal tau for degradation. The long-term goal of this work is to find new ways of treating AD and other tauopathies by understanding the critical pathways that control tau turnover.

描述（由申请人提供）：Tau是一种微管结合蛋白，在神经元中本质上无序且表达丰富。已经发现，某些经过翻译后修饰的Tau形式，例如高磷酸化和蛋白水解片段，它们会在包括阿尔茨海默氏病（AD）在内的15多种神经退行性疾病中积累。这些“异常” TAU变体特别容易出现聚集，它们的积累会导致蛋白质毒性，神经元丧失和认知障碍。因此，预计加速去除异常tau的策略有望防止tauopathies。细胞蛋白质质量控制（PQC）途径（包括分子伴侣）已被证明通过控制其翻译后修饰，与微管及其周转率结合来调节TAU稳态。但是，此过程的分子细节尚不清楚。伴侣如何区分正常的tau和容易发生的tau？哪些伴侣和伴侣对分类决策至关重要？在tau降解的最早阶段，哪些分子事件至关重要？该项目的主要目标是了解PQC的分子伴侣和其他组成部分如何决定降解Tau及其变体。初步证据表明，热休克蛋白HSP70和HSP90与它们的某些相关的伴侣结合使用，检测到容易发生的TAU的出现，然后做出分类决策以去除这些蛋白质。基于这些研究，我们假设伴侣和共伴侣的特定组合结合了tau，区分变体，然后颁布降解程序。要探究该模型，我们提出了两个具体的目的：（1）对正常，循环tau和tau进行共免疫沉淀和质谱研究，这些研究已被敏锐地针对蛋白酶体降解，以识别与降级命运特别相关的蛋白质，并（2）测试特定的HSP40 CO-CO-CONRECREDS SPPRORINE招募HSSP70是否针对特定的HSP40 Co-chareuit HSSP70。这些研究之所以及时，是因为它们利用了新的化学探针，这些探针触发了泛素 - 蛋白酶途径迅速（约10分钟）和急剧（〜80％）降解Tau。 Gestwicki实验室在过去的五年中一直在发展，表征和优化这套化合物，并与Dickey组一起展示了它们在Tauopathy的细胞和动物模型中的活性。我们建议，由于其异常快速的活动，这些化学探针将允许第一次时间，洞悉“决定”降级tau的最早阶段。因此，我们期望这些目标将提供有关伴侣伴侣如何区分tau变体以及蛋白质质量控制组件如何穿梭异常tau降解的洞察力的见解。这项工作的长期目标是通过了解控制tau更新的关键途径来找到新的方法来治疗AD和其他Tauopathies。