Probing the Role of Chaperone-TPR Complexes in Tau Proteostasis

探讨分子伴侣-TPR 复合物在 Tau 蛋白质稳态中的作用

基本信息

批准号：
10029781
负责人：
Charles Scott Craik
金额：
$ 224.04万
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：
2020
资助国家：
美国
起止时间：
2020-09-01 至 2024-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10029781
关键词：
Affinity Agonist Alzheimer&apos s Disease Alzheimer&apos s disease patient Animals Architecture Attention Binding Binding Sites Biochemical Brain C-terminal Cells Chemicals Client Collaborations Complex Cryoelectron Microscopy Crystallography Development Disease Engineering Ensure Enzymes Equilibrium FK506 binding protein 5 Genetic Goals Heat-Shock Proteins 70 Heat-Shock Proteins 90 Individual Laboratories Learning Libraries Location MAPT gene Maps Measures Modeling Modification Molecular Molecular Chaperones Nerve Degeneration Neurodegenerative Disorders Neurofibrillary Tangles Neurons PP5 protein-serine-threonine phosphatase Pathologic Peptide Library Peptide antibodies Peptidylprolyl Isomerase Phosphoric Monoester Hydrolases Phosphorylation Phosphotransferases Play Post-Translational Protein Processing Process Progressive Supranuclear Palsy Proline-Rich Domain Protein phosphatase Proteins Proteomics Quality Control Role Scanning Solubility Structure Tauopathies Tertiary Protein Structure Time Ubiquitination Work base combinatorial corticobasal degeneration design improved inhibitor/antagonist innovation new therapeutic target novel therapeutics protein aminoacid sequence protein protein interaction proteostasis recruit tau Proteins tau aggregation tau conformation tau phosphorylation tissue-factor-pathway inhibitor 2 ubiquitin-protein ligase

项目摘要

Abstract. A devastating class of untreatable, neurodegenerative disorders, which includes progressive supranuclear palsy (PSP), corticobasal degeneration (CBD) and Alzheimer’s disease (AD), are associated with accumulation of neurofibrillary tangles (NFTs) in the brain. These aggregates are primarily composed of microtubule-associated protein tau (MAPT/tau), which is heavily modified by post-translational modifications (PTMs). If we understood how neurons normally regulate tau’s PTMs, we might be able to find ways of restoring its delicate balance. The objective of this project is to understand how the molecular chaperones, heat shock protein 70 (Hsp70) and heat shock protein 90 (Hsp90), direct modifications on tau. Hsp70 and Hsp90 are known to bind key, aggregation-prone locations in tau. While these interactions improve the solubility of tau, they also recruit a number of critical PTM enzymes including: (i) the E3 ubiquitin ligase CHIP, (ii) the cis-trans prolyl isomerase FKBP51 and (iii) the protein phosphatase PP5. Specifically, each of these enzymes contains a tetratricopeptide repeat (TPR) domain, which has affinity for the conserved EEVD-CO2H motif at the C-termini of Hsp70 and Hsp90. Thus, we hypothesize that complexes between chaperones and TPR domains ultimately determines tau’s conformation and whether it is ubiquitinated or de-phosphorylated. Thanks to innovations in cryo-EM and recent breakthroughs in large-scale peptide libraries and antibody design, we are poised to use structural and chemical approaches to understand how chaperones coordinate with TPR proteins to modify tau. In preliminary studies, we have measured binding of the chaperone’s EEVD motifs to a panel of TPR domains, revealing unexpected selectivity of Hsp70 for PP5 and Hsp90 for FKBP51, as well as a key role for phosphorylation in tuning these affinities. We have also created a library of ~640,000 peptide sequences and used it to identify a potent (<10 nM) inhibitor of CHIP’s TPR domain that does not bind closely related TPRs. Finally, we have validated a structural approach to studying the Hsp70-CHIP-tau ternary complex, a project which has already uncovered a surprising, essential role for ADP. Guided by these exciting findings and fueled by a team-based approach, we propose to study how tau interacts with: (SA1) Hsp70/Hsp90-CHIP, (SA2) Hsp90-FKBP51 and (SA3) Hsp70-PP5. Through this effort, we aim to determine how molecular switches at the key protein interfaces tune the structure and modifications on tau. We anticipate that these studies could also revealing new drug targets for treating tauopathies.

摘要：一类毁灭性的、无法治愈的神经退行性疾病，其中包括进行性的。核上性麻痹 (PSP)、皮质基底节变性 (CBD) 和阿尔茨海默病 (AD) 与大脑中神经原纤维缠结（NFT）的积累主要由以下成分组成。微管相关蛋白 tau (MAPT/tau)，经过翻译后修饰大量修饰（PTM）如果我们了解神经元通常如何调节 tau 的 PTM，我们也许能够找到恢复的方法。该项目的目的是了解分子伴侣如何实现热休克。 tau 蛋白 70 (Hsp70) 和热休克蛋白 90 (Hsp90)、对 Hsp70 和 Hsp90 的直接修饰是已知的。结合 tau 中关键的、易于聚集的位置。虽然这些相互作用提高了 tau 的溶解度，但它们也招募许多关键的 PTM 酶，包括：(i) E3 泛素连接酶 CHIP，(ii) 顺反脯氨酰异构酶 FKBP51 和 (iii) 蛋白磷酸酶 PP5 具体来说，这些酶中的每一种都含有一个。四三肽重复 (TPR) 结构域，对 C 端保守的 EEVD-CO2H 基序具有亲和力因此，我们最终寻找伴侣和 TPR 结构域之间的复合物。确定 tau 的构象以及它是否被泛素化或去磷酸化，这要归功于 tau 的创新。冷冻电镜以及最近在大规模肽库和抗体设计方面取得的突破，我们准备使用结构和化学方法来了解分子伴侣如何与 TPR 蛋白协调修饰 tau。在初步研究中，我们测量了伴侣的 EEVD 基序与一组 TPR 结构域的结合，揭示了 Hsp70 对 PP5 和 Hsp90 对 FKBP51 的意外选择性，以及我们还创建了约 640,000 个肽序列的库，用它来鉴定 CHIP TPR 结构域的有效 (<10 nM) 抑制剂，该抑制剂不与密切相关的 TPR 结合。最后，我们验证了一种研究 Hsp70-CHIP-tau 三元复合物的结构方法，这是一个项目在这些令人兴奋的发现的指导和推动下，ADP 已经揭示了令人惊讶的重要作用。通过基于团队的方法，我们建议研究 tau 如何与以下相互作用：(SA1) Hsp70/Hsp90-CHIP，(SA2) Hsp90-FKBP51 和 (SA3) Hsp70-PP5 通过这项努力，我们的目标是确定分子如何开关。我们预计这些研究也可以调整 tau 蛋白的结构和修饰。揭示治疗tau蛋白病的新药物靶点。