Nascent SOD1 in Amyotrophic Lateral Sclerosis

肌萎缩侧索硬化症中的新生 SOD1

• 批准号: 8397508
• 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 2014-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8397508
• 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

描述（由申请人提供）： 人类铜锌超氧化物歧化酶（SOD 1）的突变会导致一种遗传形式的致命性神经退行性疾病肌萎缩侧索硬化症（ALS，Lou Gehrig病，运动神经元病）。随着年龄的增长，不溶性形式的突变体SOD 1逐渐积累在人类ALS患者的神经组织和表达这些多肽的转基因小鼠的脊髓中，这表明SOD 1连接的ALS是一种蛋白质错误折叠和聚集障碍。因此，了解致病突变如何产生易于聚集的SOD 1折叠中间体的分子基础是非常感兴趣的。折叠途径上的关键步骤发生在新生的SOD 1多肽被SOD 1的铜分子伴侣（CCS）后修饰时，CCS是一种插入催化铜辅因子并氧化SOD 1亚基内二硫键的辅助蛋白。CCS识别并结合到新生的，但不是成熟的SOD 1，这表明新翻译的形式存在于不同于成熟形式的构象。最近的研究表明，致病性SOD 1蛋白来自从培养细胞和转基因小鼠脊髓分离的聚集体，往往是金属缺陷和/或缺乏二硫键。这些观察结果表明，致病突变可能通过阻碍CCS介导的SOD 1成熟来提高SOD 1折叠中间体的水平。本项目中概述的实验旨在探索新生SOD 1的结构和动力学，并研究其与CCS的相互作用。成功完成本文所包含的目标将解决以下问题：1）CCS识别新生SOD 1的结构决定因素是什么？2)功能性SOD 1/CCS复合物是异二聚体、异四聚体还是其他更高级的寡聚体？3)新生的SOD 1/CCS复合物在三维空间中的结构细节是什么？4)在没有CCS的情况下，什么因素控制新生和成熟SOD 1构象的相互转化？5)ALS突变如何影响新生和成熟构象的相互转化？对这些问题的回答是设计旨在抑制ALS中致病性SOD 1聚集的治疗剂的先决条件。1