UBIQUITINATED PROTEIN DEGRADATION AND NEURODEGENERATION

泛素化蛋白质降解和神经变性

• 批准号: 6450689
• 负责人: PATRICIA BOYLE ROCKWELL
• 金额: $ 5.95万
• 依托单位: HUNTER COLLEGE
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-04-01 至 2002-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6450689
• 关键词: animal tissue; apoptosis; brain cell; cell line; covalent bond; electron microscopy; embryo /fetus tissue /cell culture; gel mobility shift assay; immunofluorescence technique; laboratory rat; mesencephalon; neural degeneration; northern blottings; physiologic stressor; polymerase chain reaction; proteasome; protein binding; protein degradation; protein structure function; radionuclides; ubiquitin; western blottings

Inclusions containing ubiquitinated proteins are a hallmark of many neurological disorders such as Alzheimer's (AD), Parkinson's (PD), and Huntington's diseases. Covalent binding of ubiquitin to proteins is known to mark them for degradation of the ubiquitin/proteasome pathways. This ATP-dependent pathway plays a major role in the breakdown of abnormal proteins, which should be rapidly removed. Although the relationship between accumulation of ubiquitinated proteins and neurodegeneration is poorly understood, recently identified mutations in ubiquitin and in an enzyme of the ubiquitin/proteasome pathway were found to be closely associated with sporadic AD and familial PD, respectively. We propose that ubiquitin-protein aggregates must result from a malfunction or overload of the ubiquitin/proteasome pathway or from structural changes in protein substrates halting their degradation, and that failure to eliminate ubiquitinated proteins disrupts cellular hemostasis contributing to degeneration. Therefore, it is of the utmost importance to identify stress conditions that jeopardize the functioning of the ubiquitin/proteasome pathway and lead to accumulation of ubiquitinated proteins in neuronal cells. The goals of this project are: (i) to identify stress conditions that interfere with the proper functioning of the ubiquitin/proteasome pathway and understand the biochemical mechanisms by which they disrupt homeostasis; (ii) to study genetic regulatory pathways affected by these conditions and establish how they change expression of enzymes of the ubiquitin/proteasome pathway as well as of related proteins involved in the pathological process; (iii) test the therapeutic effectiveness of antioxidants and inhibitors of some of these regulated pathways, in preventing accumulation of ubiquitinated proteins and neurodegeneration. To better understand the role played by the ubiquitin/proteasome pathway in neurodegeneration we will establish a stable neuronal cell line in which the activity of its proteolytic moiety, the 20S proteasome, is compromised by a mutation in the active site of one of its catalytic subunits. The proposed studies will yield insights into a poorly understood aspect of neurodegeneration, and more specifically, identify novel therapeutic targets for prevention of the accumulation of ubiquitinated proteins in stressed neuronal cells. As part of the MBRS SCORE program, this proposal will enhance the efforts of the Departments of Biological Sciences and Chemistry in Hunter College of CUNY to expose participating students to biomedical research addressing current questions in the field of Neurodegenerative Disorders. A new course, designated Molecular Aspects of Disease will be offered. One of the topics to be addressed by invited speakers will be "Molecular Aspects of Neurodegenerative disorders".

包含泛素化蛋白质的内含物是许多神经系统疾病如阿尔茨海默病（AD）、帕金森病（PD）和亨廷顿病的标志。已知泛素与蛋白质的共价结合标记它们的泛素/蛋白酶体途径的降解。这种ATP依赖性途径在异常蛋白质的分解中起着重要作用，这些异常蛋白质应该被迅速去除。虽然泛素化蛋白的积累和神经退行性变之间的关系知之甚少，最近发现的泛素和泛素/蛋白酶体途径的酶的突变分别与散发性AD和家族性PD密切相关。我们提出，泛素-蛋白质聚集体必须由泛素/蛋白酶体途径的故障或过载或蛋白质底物的结构变化停止其降解引起，并且未能消除泛素化蛋白质破坏细胞止血，从而导致变性。因此，它是至关重要的，以确定应力条件下，危及泛素/蛋白酶体途径的功能，并导致在神经元细胞中的泛素化蛋白质的积累。该项目的目标是：（一）确定干扰泛素/蛋白酶体途径正常运作的应激条件，并了解它们破坏体内平衡的生化机制;（二）研究受这些条件影响的遗传调节途径，并确定它们如何改变泛素/蛋白酶体途径的酶以及病理过程所涉及的相关蛋白质的表达;（iii）测试抗氧化剂和这些调节途径中的一些的抑制剂在防止泛素化蛋白质的积累和神经变性方面的治疗效果。为了更好地了解泛素/蛋白酶体途径在神经退行性变中所起的作用，我们将建立一个稳定的神经元细胞系，其中其蛋白水解部分的活性，20 S蛋白酶体，受到其催化亚基的活性位点突变的影响。 拟议的研究将深入了解神经退行性变的一个鲜为人知的方面，更具体地说，确定新的治疗靶点，以预防应激神经元细胞中泛素化蛋白的积累。作为MBRS SCORE计划的一部分，该提案将加强纽约市立大学亨特学院生物科学和化学系的努力，使参与的学生接触到解决神经退行性疾病领域当前问题的生物医学研究。将开设一门新的课程，名为疾病的分子方面。其中一个主题将由特邀演讲者解决将是“神经退行性疾病的分子方面”。