Cellular Mechanisms of Aggregation of Abnormal Proteins

异常蛋白质聚集的细胞机制

• 批准号: 8034757
• 负责人: Michael Y Sherman
• 金额: $ 38.1万
• 依托单位: BOSTON UNIVERSITY MEDICAL CAMPUS
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-01 至 2013-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8034757
• 关键词: 14-3-3 Proteins; Atrophic; Biochemical; Biochemical Genetics; Cell Culture Techniques; Cells; Centrosome; Complex; Cytoprotection; Development; Disease; Elements; Exons; Failure; Genetic Screening; Health; Homologous Gene; Mammalian Cell; Modeling; Molecular; Molecular Chaperones; Motor; Neurodegenerative Disorders; Neurons; Organism; Performance; Play; Process; Proline-Rich Domain; Proteins; Resort; Role; SH3 Domains; Signal Transduction; Staging; Structure; Testing; Ubiquitin; Work; Yeast Model System; Yeasts; base; genetic analysis; human Huntingtin protein; human SNCAIP protein; improved; monomer; mouse model; multicatalytic endopeptidase complex; mutant; novel; polyglutamine; polypeptide; prevent; protein aggregate; protein aggregation; research study; small molecule

DESCRIPTION (provided by applicant): Failure of the ubiquitin proteasome machinery and molecular chaperones may result in aggregation of mutant or damaged polypeptides leading to various devastating diseases. However, special molecular machinery has evolved as a last line of defense to relieve proteotoxicity by transporting misfolded protein aggregates/oligomers to the centrosome-localized aggresome. The main objective of this proposal is to uncover the mechanisms of aggresome formation. The proposed work is based on our yeast model of aggregation of proteins with expanded polyglutamine (polyQ) domains. In the past, this model was used to identify small molecules that suppress polyQ aggregation, improve motor performance and reduce neuronal atrophy in a mouse model of HD. With this model, we have established that (a) aggresome formation both in yeast and mammalian cells requires transferable aggresome-targeting signals on substrate proteins, e.g. the proline-rich region (P-region) of exon 1 of huntingtin, (b) an SH3-domain protein Boi2 serves as a recognition element for the P-region aggresome- targeting signal, (c) a yeast 14-3-3 protein Bmh1 and components of the Cdc48/VCP-Ufd1-Nlp4 complex play an essential role in aggresome formation. We also established a cell culture model of aggresome formation to investigate the relevance for mammalian cells of aggresome components identified in yeast. In Aim 1 we will clarify how the aggresome machinery recognizes small polyQ aggregates/oligomers. We will establish the role of the SH3-domain protein Boi2 in the recognition of the aggregates in yeast, and will clarify whether Boi2 homologs function in mammalian cells to recognize huntingtin and other polyQ-containing pathological proteins. In Aim 2 we will establish the function of the 14-3-3 protein Bmh1 in early stages of aggresome formation in yeast, and will test whether 14-3-3 proteins play a general role in aggresome formation in mammalian cells. These experiments will help to clarify how the aggresome machinery distinguishes small aggregates/oligomers of abnormal polypeptides from soluble monomers. In Aim 3 using both biochemical and genetic approaches we will identify novel components involved in aggresome formation. As a result of this work, we plan to obtain sufficient information for understanding the mechanism of aggresome formation. PUBLIC HEALTH RELEVANCE Many devastating diseases, including major neurodegenerative disorders, are caused by accumulation of abnormal proteins. These abnormal species tend to aggregate, and here we will establish cellular mechanisms of protein aggregation. This work will uncover how organisms try to protect themselves from development of Hungtington's and certain other diseases.

描述（由申请人提供）：泛素蛋白酶体机械和分子伴侣的失败可能导致突变体或受损多肽的聚集，导致各种毁灭性疾病。然而，特殊的分子机制已作为最后的防御方法进化，以通过将错误折叠的蛋白质聚集体/低聚物转移到中心体积量化的杂物中来缓解蛋白毒性。该提案的主要目的是揭示分解形成的机制。所提出的工作基于我们与蛋白质聚集的酵母模型，该模型具有扩展的聚谷氨酰胺（PolyQ）结构域。过去，该模型用于鉴定抑制Polyq聚集，改善运动性能并减少HD小鼠模型中神经元萎缩的小分子。通过这种模型，我们已经确定（a）酵母和哺乳动物细胞中的散布形成都需要在底物蛋白上转移可转移的分散靶向信号，例如狩猎蛋白的外显子1的外显子1的脯氨酸区域（b）SH3-蛋白蛋白BOI2是P区域固定靶向信号的识别元素，（c）酵母14-3-3蛋白BMH1和CDCP-FUFD1-NLP4 Complent aggrow a a a a gramegr的重要作用。我们还建立了一种细分形成的细胞培养模型，以研究在酵母中鉴定出的分解成分的哺乳动物细胞的相关性。在AIM 1中，我们将阐明聚在一起的机械如何识别小型Polyq聚集体/低聚物。我们将确定SH3-域蛋白BOI2在酵母中聚集体识别中的作用，并阐明BOI2同源物在哺乳动物细胞中是否功能识别亨廷汀蛋白和其他含PolyQ的病理蛋白。在AIM 2中，我们将在酵母中分散形成的早期阶段建立14-3-3蛋白BMH1的功能，并将测试14-3-3蛋白在哺乳动物细胞中的散布形成中是否起一般作用。这些实验将有助于阐明好些机械如何区分异常多肽的小聚集体/低聚物与可溶性单体。在使用生化和遗传学方法的AIM 3中，我们将确定与整体形成有关的新成分。由于这项工作，我们计划获得足够的信息来了解整体形成的机制。公共卫生相关性许多破坏性疾病，包括主要的神经退行性疾病，都是由异常蛋白质的积累引起的。这些异常物种倾向于聚集，在这里我们将建立蛋白质聚集的细胞机制。这项工作将揭示生物如何试图保护自己免受洪廷顿和某些其他疾病的发展。