Suppression of polyQ proteotoxicity by glutamine rich proteins

富含谷氨酰胺的蛋白质抑制 PolyQ 蛋白质毒性

• 批准号: 8256077
• 负责人: Katie Mayo
• 金额: $ 2.88万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-05 至 2013-09-04
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8256077
• 关键词: Amyloid; Benign; Biochemical; Cell Death; Cell Line; Cell Nucleus; Cell physiology; Cells; Characteristics; Collection; Data; Defense Mechanisms; Disease; Drug Metabolic Detoxication; Genetic Screening; Glutamine; Goals; Huntington Disease; Lead; Length; Link; Mammals; Mediating; Modeling; Molecular; Molecular Chaperones; Monitor; Neurodegenerative Disorders; Neurons; Organism; PC12 Cells; Pathway interactions; Process; Proteins; RNA Binding; Research; Resistance; Role; Saccharomyces cerevisiae; Senile Plaques; Series; Surface; System; Testing; Toxic effect; Visual; Yeasts; amyloid formation; base; cytotoxic; deletion analysis; disease characteristic; genetic manipulation; human Huntingtin protein; mutant; novel; polyglutamine; protein aggregation; research study; transcription factor

A key characteristic in numerous neurodegenerative diseases is the accumulation of amyloid- like aggregates. Although this topic has been highly studied, major controversy still surrounds the question of whether these amyloid inclusions cause the disease or represent a manifestation of a cytoprotective mechanism. Thus to gain an understanding of defense mechanisms against protein aggregation diseases, it is necessary to define the pathway by which amyloid-like aggregation occurs and how this process is regulated. Huntingtin (Htt), the disease associated protein in Huntington's disease (HD), will be used in order to study a cellular pathway for protection against aggregation prone cytotoxic proteins. This study will be carried out utilizing a Saccharomyces cerevisiae model of HD. Yeast is a reliable and useful model to study HD because key characteristics of the disease such as Htt inclusions and polyQ length dependent toxicity are recapitulated. Furthermore, a vast number of cellular processes are conserved from yeast to mammals thus making it a suitable organism in which to identify components of a pathway. Preliminary data in our lab from a screen for novel suppressors of Htt toxicity suggest a vital role for aggregation in the inhibition of toxicity. Several Q-rich proteins as well as an Hsp70/Hsp90 co-chaperone each suppress toxicity associated with an extended polyQ Htt fragment (Htt103Q) in yeast. This toxicity suppression correlates with an increase in the amount of SDS-resistant Htt103Q. The specific goals of the proposed research are (1) to determine the link between aggregation and Q-rich protein mediated suppression of Htt toxicity and (2) to define the cellular pathway by which protective facilitated aggregation occurs. These goals will be achieved by means such as visual and biochemical monitoring of aggregation and genetic manipulation of yeast in epistatic experiments. Data obtained during these studies will be applied to some neuronal models for HD including a PC12 cell line which inducibly expresses a mutant Htt fragment. Altogether, these studies will define basic principles for suppression of proteotoxicity of an amyloidogenic disease protein via aggregation. This information will uncover a pathway for organized facilitated assembly of proteotoxic species and how certain cellular factors, such as Q-rich proteins and molecular chaperones, modulate assembly.

许多神经退行性疾病的一个关键特征是淀粉样蛋白样聚集物的积累。尽管这个话题已经得到了深入的研究，但主要的争议仍然围绕着这些淀粉样蛋白内含物是否引起疾病或代表细胞保护机制的表现这一问题。因此，为了了解蛋白质聚集疾病的防御机制，有必要定义淀粉样蛋白聚集发生的途径以及如何调节该过程。亨廷顿蛋白 (Htt) 是亨廷顿病 (HD) 中的疾病相关蛋白，将用于研究防止易于聚集的细胞毒性蛋白的细胞途径。这项研究将利用 HD 的酿酒酵母模型进行。酵母是研究 HD 的可靠且有用的模型，因为它概括了该疾病的关键特征，例如 Htt 内含物和 PolyQ 长度依赖性毒性。此外，从酵母到哺乳动物，大量细胞过程是保守的，因此使其成为鉴定途径成分的合适生物体。我们实验室筛选新型 Htt 毒性抑制剂的初步数据表明，聚集在抑制毒性方面发挥着至关重要的作用。几种富含 Q 的蛋白质以及 Hsp70/Hsp90 共伴侣均能抑制酵母中与延长的 PolyQ Htt 片段 (Htt103Q) 相关的毒性。这种毒性抑制与 SDS 抗性 Htt103Q 数量的增加相关。拟议研究的具体目标是 (1) 确定聚集与富含 Q 蛋白介导的 Htt 毒性抑制之间的联系，以及 (2) 确定保护性促进聚集发生的细胞途径。这些目标将通过在上位实验中对酵母的聚集和遗传操作进行视觉和生化监测等手段来实现。这些研究期间获得的数据将应用于一些 HD 神经元模型，包括诱导表达突变 Htt 片段的 PC12 细胞系。总而言之，这些研究将定义通过聚集抑制淀粉样蛋白形成疾病蛋白的蛋白毒性的基本原理。这些信息将揭示蛋白质毒性物种有组织的促进组装的途径，以及某些细胞因子（例如富含 Q 的蛋白质和分子伴侣）如何调节组装。