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：本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氏症、帕金森氏症和亨廷顿氏症以及肌萎缩性侧索硬化症（ALS）。神经退行性疾病是不可治愈的和使人衰弱的疾病，其患病率不断增加，并且在没有足够详细地阐明其致病机制的情况下，我们产生纠正治疗干预的基本原理的能力受到很大限制。我们先前描述了一种由LISTER基因突变引起的神经退行性变的新型小鼠模型。与一个重要的生物学功能相一致，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这种功能的缺陷如何导致疾病。LISTER基因编码一种蛋白质，作为E3泛素连接酶，命名为Listerin。最近，使用酵母，我们发现了Listerin的功能，这与哺乳动物神经变性的作用一致：它在一个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。具体而言，它靶向由缺乏终止密码子的缺陷mRNA编码的蛋白质（“非终止蛋白质”）。李斯特蛋白通过用泛素分子标记这些异常蛋白质（泛素化）发挥作用， 这通常是一种破坏信号。李斯特菌的突变导致这些有毒蛋白质的积累。通过拟议的研究，我们计划详细说明李斯特蛋白介导的泛素化的特征，并将发现扩展到疾病。目的/假设：我们的主要假设是：（a）李斯特蛋白通过泛素化停滞在核糖体中的非终止多肽来控制蛋白质的质量，以及（B）有缺陷的李斯特蛋白介导的降解导致蛋白质聚集体和包涵体的形成，这是神经变性的标志。具体目的是表征Listerin在不停止蛋白质降解中的功能，研究Listerin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参与人类神经退行性疾病发病机制的分子机制。研究设计：我们将使用生物化学和酵母分子遗传学来详细说明E3如何识别其特定的靶底物;哺乳动物组织培养和生物化学来研究哺乳动物李斯特蛋白和生物化学和细胞生物学对不停止蛋白质降解的调节，以研究细胞中不停止蛋白质积累的后果。 公共卫生相关性：这项基础研究计划的目标是描述一种与神经退行性变有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理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开辟道路（例如，通过发现新的药物靶点）。