Nascent SOD1 in Amyotrophic Lateral Sclerosis

肌萎缩侧索硬化症中的新生 SOD1

• 批准号: 7791079
• 负责人: Peter JOHN HART
• 金额: --
• 依托单位: SOUTH TEXAS VETERANS HEALTH CARE SYSTEM
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-10-01 至 2013-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7791079
• 关键词: 3-Dimensional; Address; Adopted; Affect; Affinity; Age; Aging-Related Process; Amino Acid Substitution; Amino Acids; Amyotrophic Lateral Sclerosis; Antioxidants; Behavior; Binding; Binding Sites; Biochemistry; Cessation of life; Child; Complex; Consultations; Copper; Cultured Cells; DNA Sequence Rearrangement; Data; Defect; Degenerative Disorder; Dimensions; Disease; Dissociation; Disulfides; Enzymes; Event; Exercise; Failure; Familial Amyotrophic Lateral Sclerosis; Family; Future; Gel Chromatography; Generations; Genes; Health Sciences; Hospitals; Human; Inherited; Ions; Iraq; Laboratories; Lead; Lesion; Letters; Light; Link; Measurement; Mediating; Metalloproteins; Metals; Methods; Military Personnel; Modeling; Molecular; Molecular Chaperones; Molecular Conformation; Motion; Motor Neuron Disease; Motor Neurons; Mus; Mutation; Neurodegenerative Disorders; Neurons; Paralysed; Parents; Pathway interactions; Patients; Population; Post-Translational Protein Processing; Process; Proline; Proteins; Relative (related person); Reporting; Resolution; SOD1 gene; Sampling; Site; Solutions; Spinal Cord; Structure; Study Section; Temperature; Testing; Texas; Therapeutic; Therapeutic Agents; Time; Toxic effect; Transgenic Mice; Translating; United States; Universities; Variant; Veterans; War; Work; X ray diffraction analysis; X-Ray Crystallography; X-Ray Diffraction; analytical ultracentrifugation; base; cofactor; conformer; copper zinc superoxide dismutase; design; disease-causing mutation; disulfide bond; gain of function; gel electrophoresis; human tissue; in vivo; interest; melting; molecular mass; mouse model; mutant; oxidation; polypeptide; protein aggregation; protein misfolding; public health relevance; relating to nervous system; research study; sedimentation equilibrium; sedimentation velocity; tool

DESCRIPTION (provided by applicant): Mutations in human copper-zinc superoxide dismutase (SOD1) cause an inherited form of the fatal neurodegenerative disease amyotrophic lateral sclerosis (ALS, Lou Gehrig's disease, motor neuron disease). With increasing age, insoluble forms of mutant SOD1 progressively accumulate in neural tissues of human ALS patients and in spinal cords of transgenic mice expressing these polypeptides, suggesting that SOD1- linked ALS is a protein misfolding and aggregation disorder. Understanding the molecular basis for how the pathogenic mutations give rise to SOD1 folding intermediates that are prone to aggregation is therefore of keen interest. A critical step on the folding pathway occurs when the nascent SOD1 polypeptide is posttranslationally modified by the copper chaperone for SOD1 (CCS), a helper protein that inserts the catalytic copper cofactor and oxidizes the SOD1 intrasubunit disulfide bond. CCS recognizes and binds to nascent, but not mature SOD1, suggesting that the newly translated form exists in a conformation distinct from the mature form. Recent studies reveal that pathogenic SOD1 proteins coming from aggregates isolated from cultured cells and from the spinal cords of transgenic mice tend to be metal-deficient and/or lacking the disulfide bond. These observations suggest the hypothesis that the disease-causing mutations may enhance levels of SOD1 folding intermediates by hindering CCS-mediated SOD1 maturation. The experiments outlined in this project are designed to probe the structure and dynamics of nascent SOD1 and to examine its interaction with CCS. Successful completion of the Aims contained herein will address the following questions: 1) What are the structural determinants that are responsible for the recognition of nascent SOD1 by CCS? 2) Is the functional SOD1/CCS complex heterodimeric, heterotetrameric, or some other higher order oligomer? 3) What are the structural details of the nascent SOD1/CCS complex in three dimensions? 4) What factors govern the interconversion of the nascent and mature SOD1 conformations in the absence of CCS? 5) How do the ALS mutations affect the interconversion of the nascent and mature conformations? Answers to these questions are prerequisites for the design of therapeutic agents aimed inhibiting pathogenic SOD1 aggregation in ALS. 1 PUBLIC HEALTH RELEVANCE: Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative disorder linked to the aging process. Military personnel who served in the first U.S.-Iraq war, have developed sporadic (noninherited) ALS upon their return more frequently than found in the United States population as a whole. Familial ALS (fALS) is passed from parent to child over generations, and the underlying genetic defects were entirely unknown until it was discovered that some ALS families possess mutations in the gene encoding the antioxidant enzyme copper- zinc superoxide dismutase (SOD1). Importantly, the manifestations of sporadic and familial ALS are nearly clinically indistinguishable, suggesting that the underlying molecular causes for the two forms of the disease are related. This proposal investigates SOD1-linked ALS because understanding the molecular basis for motor neuron death in familial cases could lead to therapeutic avenues applicable to sporadic forms of the disease, both of which are expected to increasingly affect the veteran population as it continues to age.

描述（由申请人提供）： 人铜锌超氧化物歧化酶（SOD1）中的突变引起致命神经退行性疾病肌萎缩性侧面硬化症的遗传形式（ALS，Lou Gehrig病，运动神经元疾病）。随着年龄的增长，突变体SOD1的不溶性形式逐渐积聚在人类ALS患者的神经组织以及表达这些多肽的转基因小鼠的脊髓中，这表明SOD1链接的ALS是一种蛋白质错误折叠和聚集障碍。因此，了解病原突变如何产生容易聚集的SOD1折叠中间体的分子基础是敏锐的关注。折叠途径的关键步骤是当新生的SOD1多肽后通过铜伴侣在转化后修饰SOD1（CCS）（CCS），SOD1（CCS）是一种辅助催化铜辅因子并氧化SOD1 Intrasubunit二硫化物的蛋白质。 CCS识别并结合了新生但不成熟的SOD1，表明新翻译的形式存在于与成熟形式不同的构象中。最近的研究表明，从培养细胞分离的聚集体和转基因小鼠的脊髓的致病SOD1蛋白往往是金属缺陷型和/或缺乏二硫键。这些观察结果表明，通过阻碍CCS介导的SOD1成熟来提高SOD1折叠中间体的水平。该项目中概述的实验旨在探测新生SOD1的结构和动力学，并检查其与CCS的相互作用。成功完成此处包含的目标将解决以下问题：1）CCS负责识别新生SOD1的结构决定因素是什么？ 2）功能性SOD1/CCS复合物异二聚体，异次术或其他高阶低聚物？ 3）在三个维度上，新生SOD1/CCS复合物的结构细节是什么？ 4）哪些因素决定了在没有CCS的情况下新生和成熟的SOD1构象的互连？ 5）ALS突变如何影响新生和成熟构象的互连？这些问题的答案是设计旨在抑制ALS致病SOD1聚集的治疗剂的先决条件。 1 公共卫生相关性： 肌萎缩性侧索硬化症（ALS）是与衰老过程有关的进行性神经退行性疾病。在美国伊拉克第一次战争中服役的军事人员在返回时发展了零星（非秘书）ALS，比在整个美国人口中更频繁地发展。家族性ALS（fals）从父母传给了几代人，而潜在的遗传缺陷是完全未知的，直到发现某些ALS家族在编码抗氧化酶的铜锌超氧化物歧化酶（SOD1）的基因中具有突变。重要的是，零星和家族性ALS在临床上几乎无法区分，这表明该疾病两种形式的潜在分子原因是相关的。该提案研究了SOD1连接的ALS，因为了解家族病例中运动神经元死亡的分子基础可能会导致适用于该疾病零星形式的治疗途径，这两种疾病都预计随着年龄的增长，这两种疾病都会越来越多地影响退伍军人人群。