Mechanism of Aggregation and Disaggregation of Huntingtin

亨廷顿蛋白的聚集和解聚机制

• 批准号: 9816571
• 负责人: Silvia Angelica Cervantes
• 金额: $ 4.5万
• 依托单位: UNIVERSITY OF SOUTHERN CALIFORNIA
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-18 至 2021-09-17
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9816571
• 关键词: Address; Affect; Automobile Driving; Binding; C-terminal; Cells; Code; DNA Sequence Alteration; Development; Disease; Disease Progression; Electron Spin Resonance Spectroscopy; Emotional; Exons; Family; Functional disorder; Genes; Huntington Disease; Huntington gene; Huntington protein; Individual; Knowledge; Lead; Learning; Length; Link; Mediating; Mental Health; Methods; Molecular; Molecular Chaperones; Molecular Conformation; Mutation; Neurodegenerative Disorders; Neurons; Onset of illness; Pathogenesis; Pathologic; Preparation; Process; Proteins; Psyche structure; Sampling; Sepharose; Site; Source; Structure; Techniques; Therapeutic; Time; Toxic effect; aggregation pathway; behavioral health; conformer; design; effective therapy; in vivo evaluation; innovation; insight; misfolded protein; monomer; mutant; physical conditioning; polyglutamine; prevent; protein function; protein misfolding; solid state nuclear magnetic resonance; stem

PROJECT SUMMARY/ABSTRACT Huntington's disease (HD) is a fatal neurodegenerative disorder affecting the physical, mental, and emotional state of approximately 1 in 10,000 individuals. There is no cure or effective treatment for this disease, a factor that stems directly from the lack of knowledge regarding the mechanism underlying this disorder. HD is caused by a genetic mutation in the polyglutamine (polyQ) domain of Huntingtin exon 1 (Htt_ex1). This mutation causes the polyQ tract to become pathologically expanded (>36Q), and for reasons that remain unknown, this expansion alters the function of the protein and causes it to become toxic and prone to misfolding and aggregation. In order to understand how a polyQ expansion leads to disease, I will utilize a combination of spectroscopic techniques to identify and characterize the molecular features that are affected in huntingtin (Htt) monomers and fibrils. Monomers and fibrils represent important conformers in the aggregation pathway and are prominent sources of toxicity. Specifically, I aim to investigate how the C-terminal domain of these conformers is affected by a polyQ expansion and whether this domain (C-terminus) facilitates the interaction of Htt and the chaperone DnaJB1. Mounting evidence, including recent findings from our lab, has alluded to the importance of this region in the overall organization of toxic Htt fibril species. Characterization of this region may therefore hold the key to understanding the mechanism of Htt aggregation and reveal potential targets for the disaggregation of fibrils. In aim 1, I will characterize the structure of mutant (>36Q) and wild type (<35Q) monomers using solid-state Nuclear Magnetic Resonance (ssNMR) and an innovative sample preparation method that allows for the trapping of Htt in its monomeric state. In doing so, I plan to uncover conformational changes that contribute to the pathogenesis of HD. In aim 2, I will utilize ssNMR and Electron Paramagnetic Resonance (EPR) to identify the sites that facilitate Htt fibril recognition by the chaperone DnaJB1. Identification of such sites will be key in understanding the mechanism underlying aggregate identification and disaggregation. Ultimately, my findings will allow for greater insight into the molecular features driving the mechanism of protein misfolding, disaggregation, and toxicity in Huntington's disease, and thereby provide key targets for the development of efficacious therapeutics.

项目总结/摘要 亨廷顿氏病（HD）是一种致命的神经退行性疾病，影响身体、精神和情绪 约为1/10，000人。这种疾病没有治愈或有效的治疗方法， 这直接源于对这种疾病的机制缺乏了解。HD是由 亨廷顿蛋白外显子1（Htt_ex1）的多聚谷氨酰胺（polyQ）结构域发生基因突变。这种突变 导致polyQ束病理性扩张（> 36 Q），由于未知的原因， 膨胀改变了蛋白质的功能，使其变得有毒，易于错误折叠， 聚合来为了了解polyQ扩增如何导致疾病，我将结合使用 光谱技术，以确定和表征亨廷顿蛋白（Htt）中受影响的分子特征 单体和原纤维。单体和原纤维代表聚集途径中的重要构象， 是毒性的主要来源。具体来说，我的目标是研究如何C-末端结构域的这些 构象异构体受polyQ扩增的影响，以及该结构域（C-末端）是否促进了 Htt和伴侣DnaJB 1。越来越多的证据，包括我们实验室最近的发现，都暗示了 该区域在有毒Htt原纤维种类的整体组织中的重要性。该区域的特征 因此，这可能是理解Htt聚集机制的关键，并揭示了Htt聚集的潜在靶点。 纤维的分解在目的1中，我将表征突变体（> 36 Q）和野生型（<35 Q）的结构。 使用固态核磁共振（ssNMR）和创新的样品制备技术 该方法允许将Htt捕获在其单体状态。在此过程中，我计划揭示构象 导致HD发病机制的变化。在目标2中，我将利用ssNMR和电子顺磁 共振（EPR）来鉴定促进Htt原纤维被伴侣DnaJB 1识别的位点。 识别这些网站将是关键，在了解机制的基础上聚集识别， 分解最终，我的研究结果将使我们更深入地了解驱动细胞凋亡的分子特征。 亨廷顿病中蛋白质错误折叠、解聚和毒性的机制，从而提供关键的 用于开发有效疗法的靶点。