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

• 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
• 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' s Disease; Alzheimer' 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

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.

抽象的。一类毁灭性的不可治疗的神经退行性疾病，其中包括渐进式 上麻痹（PSP），皮质型变性（CBD）和阿尔茨海默氏病（AD）与 大脑中神经原纤维缠结（NFT）的积累。这些聚集体主要由 微管相关蛋白tau（mapt/tau），通过翻译后修饰进行了大量修饰 （PTMS）。如果我们了解神经元通常如何调节Tau的PTM，我们也许可以找到恢复的方法 它微妙的平衡。该项目的目的是了解分子伴侣如何，热冲击 蛋白70（HSP70）和热休克蛋白90（HSP90），直接修饰Tau。 HSP70和HSP90是已知的 为了绑定钥匙，在tau中容易聚集的位置。尽管这些相互作用提高了tau的溶解度，但它们也 募集许多关键的PTM酶，包括：（i）E3泛素连接酶芯片，（ii）顺式trans prolyl 异构酶FKBP51和（iii）蛋白质磷酸酶PP5。具体而言，这些酶中的每一个都包含一个 四肽重复（TPR）域，该结构域与C-termini的配置的EEVD-CO2H基序有亲和力 HSP70和HSP90。这是我们假设伴侣和TPR域之间的复合物最终会 确定Tau的构象以及它是泛素化的还是去磷酸化的。感谢创新 冷冻EM和最近在大规模肽库和抗体设计中的突破，我们被毒用了 结构和化学方法了解伴侣如何与TPR蛋白进行修饰tau。 在初步研究中，我们测量了伴侣的EEVD基序与TPR域的结合， 揭示了pp5和hsp90对FKBP51的意外选择性，以及 调整这些亲和力时的磷酸化。我们还创建了一个约640,000个胡椒序列的库， 用它来识别CHIP的TPR结构域的潜在抑制剂（<10 nm），该抑制剂与与密切相关的TPR结合。 最后，我们验证了一种研究HSP70-CHIP-TAU三元综合体的结构方法，该项目是一个项目 这已经发现了ADP的惊喜，重要的角色。在这些令人兴奋的发现并加油的指导下 通过基于团队的方法，我们建议研究Tau​​如何与：（SA1）HSP70/HSP90-Chip，（SA2） HSP90-FKBP51和（SA3）HSP70-PP5。通过这项努力，我们旨在确定分子开关如何在 钥匙蛋白接口调整tau的结构和修饰。我们预计这些研究也可以 揭示了治疗tauopathies的新药物靶标。