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：该基础研究提案的目标是在分子水平上更好地了解神经退行性疾病的原因。其中最著名的例子是阿尔茨海默病、帕金森病、亨廷顿病以及肌萎缩侧索硬化症 (ALS)。神经退行性疾病是无法治愈且令人衰弱的疾病，且患病率不断增加，如果没有足够详细地阐明其致病机制，我们为纠正性治疗干预提供理论依据的能力将受到极大限制。我们之前已经描述了一种由 LISTER 基因突变引起的神经变性的新型小鼠模型。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体中都是保守的。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的缺陷如何导致疾病。 LISTER 基因编码一种充当 E3 泛素连接酶的蛋白质，名为 Listerin。最近，我们利用酵母发现了李施德林的功能，该功能与哺乳动物神经退行性疾病中的作用一致：它在称为蛋白质质量控​​制的过程中发挥作用，从而将异常蛋白质作为降解的目标。具体来说，它的目标是由缺乏终止密码子的缺陷 mRNA 编码的蛋白质（“非终止蛋白”）。李施德林通过用泛素分子标记那些异常蛋白质（泛素化）来发挥作用， 这通常充当破坏信号。李施德林的突变会导致这些有毒蛋白质积聚。通过拟议的研究，我们计划明确李施德林介导的泛素化的特征，并将研究结果扩展到疾病领域。目的/假设：我们的主要假设是（a）李斯特菌通过泛素化核糖体中停滞的不间断多肽来发挥蛋白质质量控​​制作用，以及（b）有缺陷的李斯特菌介导的降解导致蛋白质聚集体和内含物的形成，这是其标志神经退行性变。具体目标是表征李斯特林在不间断蛋白质降解中的功能，研究李斯特林在蛋白质质量控​​制中功能的保守程度，并研究该功能的缺陷如何导致神经变性。我们的长期目标是帮助阐明人类神经退行性疾病发病机制的分子机制。研究设计：我们将利用生物化学和酵母分子遗传学来具体说明E3如何识别其特定的目标底物；哺乳动物组织培养和生物化学研究哺乳动物李斯特菌对不间断蛋白质降解的调节，生物化学和细胞生物学研究细胞中不间断蛋白质积累的后果。 公共健康相关性：这项基础研究提案的目标是表征与神经退行性变相关的新基因的功能及其在疾病中的作用。在分子水平上更好地了解神经退行性疾病的原因有望为开发新的治疗原理和方法（例如，通过发现新的药物靶点）开辟道路。