A New E3 Ligase Implicated in Protein Quality Control and Neurodegeneration

一种与蛋白质质量控​​制和神经变性有关的新 E3 连接酶

• 批准号: 8292845
• 负责人: CLAUDIO A.P. JOAZEIRO
• 金额: $ 41.45万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-01-15 至 2016-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8292845
• 关键词: Afferent Neurons; Alzheimer' s Disease; Amyotrophic Lateral Sclerosis; Animal Model; Basic Science; Binding; Biochemical; Biochemistry; Biological; Biological Assay; Biological Process; Cells; Cellular biology; Defect; Development; Disease; Disease model; Drug Delivery Systems; Eukaryota; Eukaryotic Cell; Exhibits; Gene Expression; Genes; Genetic; Goals; Homologous Gene; Human; Huntington Disease; In Vitro; Intervention; Lead; Mammalian Cell; Mammals; Mass Spectrum Analysis; Mediating; Messenger RNA; Modeling; Modification; Molecular; Molecular Chaperones; Molecular Genetics; Motor Neurons; Mus; Mutation; Names; Nerve Degeneration; Neurodegenerative Disorders; Organism; Orthologous Gene; Paralysed; Parkinson Disease; Pathogenesis; Pathway interactions; Poly(A) Tail; Prevalence; Process; Production; Proteins; Public Health; Quality Control; Reaction; Regulation; Reporting; Research; Research Design; Research Proposals; Ribosomes; Role; Saccharomycetales; Signal Transduction; Specific qualifier value; System; Terminator Codon; Testing; Tissues; To specify; Translations; Ubiquitin; Ubiquitination; Work; Yeasts; base; early onset; gene discovery; gene function; mRNA Decay; mouse model; novel; novel therapeutics; polypeptide; protein aggregate; protein aggregation; protein degradation; reconstitution; tissue culture; ubiquitin-protein ligase; yeast genetics

DESCRIPTION (provided by applicant): Background and relevance: The goal of this basic research proposal is to better understand the causes of neurodegenerative disorders at the molecular level. Among the best known examples are Alzheimer's, Parkinson's and Huntington's diseases, and Amyotrophic Lateral Sclerosis (ALS). Neurodegenerative diseases are incurable and debilitating conditions with increasing prevalence, and without their pathogenic mechanisms being elucidated in sufficient detail, our ability to generate a rationale for corrective therapeutc interventions is greatly limited. We had previously characterized a novel mouse model of neurodegeneration caused by mutation of the LISTER gene. Consistent with an important biological function, this gene is conserved in all organisms from yeast to humans. Accordingly, we have been utilizing various models to discover the gene function and how defects in this function may lead to the disease. The LISTER gene encodes a protein that acts as an E3 ubiquitin ligase, named Listerin. More recently, using yeast we discovered a function for Listerin that is consistent with a role in neurodegeneration in mammals: it functions in a process known as protein quality control whereby aberrant proteins are targeted for degradation. Specifically, it targets are proteins encoded by defective mRNA lacking stop codons ("non-stop proteins"). Listerin functions by tagging those aberrant proteins with molecules of ubiquitin (ubiquitination), which often acts as a destruction signal. Mutation of Listerin causes those toxic proteins to accumulate. With the proposed research we plan to specify the features of Listerin-mediated ubiquitination and expand the findings towards disease. Objective/Hypothesis: Our main hypotheses are that (a) Listerin acts in protein quality control by ubiquitinating non-stop polypeptides stalled in ribosomes, and (b) defective Listerin-mediated degradation leads to the formation of protein aggregates and inclusions, which are hallmarks of neurodegeneration. The Specific Aims are to characterize Listerin's function in non-stop protein degradation, to investigate the extent of conservation of Listerin's function in protein quality control, and to investigate how defects in this function lead to neurodegeneration. Our long-term objective is to help elucidate molecular mechanisms involved in the pathogenesis of human neurodegenerative disease. Study design: We will use biochemistry and yeast molecular genetics to specify how the E3 recognizes its specific target substrates; mammalian tissue culture and biochemistry to investigate the regulation of non-stop protein degradation by mammalian Listerin and biochemistry and cell biology to study the consequences of non-stop protein accumulation in cells. PUBLIC HEALTH RELEVANCE: The goal of this basic research proposal is to characterize the function of a new gene implicated in neurodegeneration, and its role in disease. The better understanding of the causes of neurodegenerative disorders at the molecular level is expected to open the way to the development of new therapeutic rationale and approaches (e.g., by discovering new drug targets).

描述（由申请人提供）：背景和相关性：这项基础研究建议的目的是更好地了解分子层面神经退行性疾病的原因。最著名的例子包括阿尔茨海默氏症，帕金森氏症和亨廷顿疾病，以及肌萎缩性侧面硬化症（ALS）。神经退行性疾病是无法治愈的，并且会因患病率的增加而使衰弱的疾病不足，并且没有足够细节阐明其致病机制，我们有能力为纠正疗法的干预措施产生基本原理。我们以前曾表征由李斯特基因突变引起的新型神经变性的小鼠模型。与重要的生物学功能一致，该基因在从酵母到人类的所有生物中都保存。因此，我们一直在利用各种模型来发现基因功能以及该功能中的缺陷如何导致该疾病。李斯特基因编码一种用作E3泛素连接酶的蛋白质，称为李斯特蛋白。最近，使用酵母，我们发现了李斯特蛋白的功能，该功能与哺乳动物中神经变性中的作用一致：它在称为蛋白质质量控​​制的过程中起作用，从而使异常的蛋白质靶向降解。具体而言，它的靶标是缺乏终止密码子（“非停车蛋白”）的缺陷mRNA编码的蛋白质。李斯特蛋白通过用泛素分子（泛素化）标记那些异常蛋白的功能， 通常充当破坏信号。李斯特蛋白的突变会导致这些有毒蛋白积聚。通过拟议的研究，我们计划指定李斯特蛋白介导的泛素化的特征，并将发现扩大到疾病。目的/假设：我们的主要假设是（a）李斯特蛋白通过泛素化核糖体中停滞的非停滞多肽来对蛋白质质量控​​制作用，以及（b）李斯特蛋白介导的降解有缺陷导致蛋白质聚集物和夹杂蛋白的形成，这是神经脱发的标志。具体的目的是表征李斯特蛋白在不间断蛋白质降解中的功能，以研究李斯特蛋白在蛋白质质量控​​制中功能的保护程度，并研究该功能中缺陷如何导致神经变性。我们的长期目标是帮助阐明与人神经退行性疾病发病机理有关的分子机制。研究设计：我们将使用生物化学和酵母分子遗传学来指定E3如何识别其特定靶标底物；哺乳动物组织培养和生物化学研究了哺乳动物李斯特蛋白和生物化学和细胞生物学对非停滞蛋白质降解的调节，以研究细胞中不停滞蛋白的后果。 公共卫生相关性：这项基础研究建议的目的是表征与神经变性有关的新基因的功能及其在疾病中的作用。对分子水平上神经退行性疾病的原因的更好理解预计将为发展新的治疗原理和方法开发（例如，通过发现新的药物靶标）开辟道路。