Pathway of Protein Misfolding Intiation in vivo

体内蛋白质错误折叠起始途径

• 批准号: 8060245
• 负责人: Janice Villali
• 金额: $ 4.84万
• 依托单位: BROWN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-01-15 至 2014-01-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8060245
• 关键词: Age; Alzheimer' s Disease; Appearance; Biogenesis; Bypass; C-terminal; Cell physiology; Complex; Disease; Environment; Event; Frequencies; Goals; Huntington Disease; In Vitro; Link; Mammals; Mining; Modeling; Molecular; Molecular Conformation; Neurodegenerative Disorders; Oligonucleotides; Parkinson Disease; Pathway interactions; Physiological; Prevention; Prion Diseases; Prions; Process; Protein Structure Initiative; Proteins; Quality Control; Research; Saccharomyces cerevisiae; System; Testing; Variant; conformer; in vivo; new therapeutic target; prevent; protein folding; protein misfolding; sup35

DESCRIPTION (provided by applicant): Neurodegenerative diseases, including Alzheimer's, Huntington's and Parkinson's Diseases and the Transmissible Spongiform Encephalopathies (prion diseases), have been linked to an unusual disease mechanism, in which alternative conformations of cellularly encoded proteins arise and subsequently direct the misfolding of normal conformers of the same protein to a like state. The spontaneous appearance of these disorders has been shown to increase with age, suggesting that cellular mechanisms exist to prevent the pathogenic misfolding pathways from initiating. Although the mechanism of conformational self-replication for these proteins has been well-studied, our mechanistic understanding of the initiation of this state lags far behind. Understanding the pathway that soluble, functional proteins take during this initial misfolding event can provide new therapeutic targets for the prevention and treatment of these diseases. The long-term goal of our research is to understand how the cellular environment regulates protein folding pathways to create both normal physiological and disease states. The objective of this proposal is to determine how a pathway of protein misfolding is initiated in vivo. For these studies, we will exploit the Sup35/[PSI+] prion system of Saccharomyces cerevisiae. While the mechanism by which Sup35 folding switches from the normal ([psi-]) to the misfolded ([PSI+]) pathway is still unknown, this process is dependent on presence of the misfolded form of another prion protein, Rnq1, or on a Sup35 variant with a non-native C- terminal extension. We hypothesize that these factors bypass the rate-limiting step for accumulation of misfolded Sup35, leading to [PSI+] appearance. To test this hypothesis, we will manipulate both the expressing levels of key players in the Sup35 misfolding pathway and the Sup35 sequence and link changes in the frequency of [PSI+] appearance to changes in the biogenesis of the Sup35 protein in vivo. By developing an understanding of how protein folding pathways can be modulated by their cellular environment, we will begin to reveal the molecular contributions of these processes to both normal cellular physiology and to the appearance and spread of diseases. PUBLIC HEALTH RELEVANCE: Severe neurodegenerative diseases, including Alzheimer's, Huntington's and Parkinson's Diseases as well as the Transmissible Spongiform Encephalopathies (prion diseases) have been linked to an unusual disease mechanism, in which alternative conformations of normal cellularly encoded proteins arise and subsequently direct the misfolding of normal conformers of the same protein to a like state. Understanding the pathway that soluble, functional proteins take during the initial misfolding event can provide new therapeutic targets for the prevention and treatment of these diseases.

描述（由申请人提供）：神经退行性疾病，包括阿尔茨海默病、亨廷顿病和帕金森病以及传染性海绵状脑病（朊病毒病），与一种不寻常的疾病机制有关，其中细胞编码蛋白的替代构象出现并随后导致错误折叠相同蛋白质的正常构象异构体到相似的状态。这些疾病的自发出现已被证明随着年龄的增长而增加，这表明细胞机制的存在可以防止致病性错误折叠途径的启动。尽管这些蛋白质的构象自我复制机制已得到充分研究，但我们对这种状态启动的机制理解还远远落后。了解可溶性功能蛋白在最初的错误折叠事件中所采取的途径可以为预防和治疗这些疾病提供新的治疗靶点。我们研究的长期目标是了解细胞环境如何调节蛋白质折叠途径以创造正常的生理和疾病状态。该提案的目的是确定蛋白质错误折叠途径如何在体内启动。对于这些研究，我们将利用酿酒酵母的 Sup35/[PSI+] 朊病毒系统。虽然 Sup35 折叠从正常 (ψ-]) 路径切换到错误折叠 ([PSI+]) 路径的机制仍不清楚，但该过程依赖于另一种朊病毒蛋白 Rnq1 的错误折叠形式的存在，或依赖于带有非本地 C 端扩展的 Sup35 变体。我们假设这些因素绕过了错误折叠的 Sup35 积累的限速步骤，导致 [PSI+] 的出现。为了检验这一假设，我们将操纵 Sup35 错误折叠途径中关键参与者的表达水平和 Sup35 序列，并将 [PSI+] 出现频率的变化与体内 Sup35 蛋白生物发生的变化联系起来。通过了解蛋白质折叠途径如何受细胞环境调节，我们将开始揭示这些过程对正常细胞生理学以及疾病的出现和传播的分子贡献。 公共健康相关性：严重的神经退行性疾病，包括阿尔茨海默病、亨廷顿病和帕金森病以及传染性海绵状脑病（朊病毒病）与一种不寻常的疾病机制有关，在这种机制中，正常细胞编码蛋白质会出现替代构象，并随后导致错误折叠相同蛋白质的正常构象异构体到相似的状态。了解可溶性功能蛋白在最初的错误折叠事件中所采取的途径可以为预防和治疗这些疾病提供新的治疗靶点。