Investigating the Activation Mechanism of SARM1 during Axon Degeneration

轴突变性过程中 SARM1 激活机制的研究

• 批准号: 10649519
• 负责人: Janneke Doedee
• 金额: $ 3.24万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10649519
• 关键词: Active Sites; Affect; Alzheimer' s Disease; Animal Model; Axon; Biological Assay; Biotin; Biotinylation; Brain; Caenorhabditis elegans; Catalysis; Cells; Cessation of life; Characteristics; Chimeric Proteins; Clinical; Co-Immunoprecipitations; Complement; Cyclic ADP-Ribose; Data; Development; Disease; Drug Design; Enzymes; Etiology; Event; Family Dasypodidae; Functional disorder; Generations; Goals; Homologous Gene; Human; Huntington Disease; Hydrolase; In Vitro; Injury; Interleukin Receptor; Interleukin-1; Interleukins; Investigation; Kinetics; Knock-out; Knowledge; Label; Length; Ligase; Liquid substance; MAPK10 gene; Mass Spectrum Analysis; Mediating; Mediator; Molecular; Morphology; Motor; Multiple Sclerosis; Mutate; Myelin Sheath; Neurodegenerative Disorders; Neurons; Niacinamide; Nicotinamide adenine dinucleotide; Orthologous Gene; Outcome Study; PINK1 gene; Parkinson Disease; Pathway interactions; Periodicity; Peripheral Nervous System Diseases; Phase Transition; Physiological; Play; Process; Proteins; Regulation; Role; Running; SAM Domain; Solid; Sterility; Structure; Substrate Specificity; TRAF6 gene; Tertiary Protein Structure; Therapeutic; Traumatic Brain Injury; Validation; Wallerian Degeneration; Work; axon injury; axonal degeneration; effective therapy; enzyme mechanism; experimental study; inhibitor; insight; knock-down; prevent; restraint; targeted treatment; therapeutic development; therapeutic target

PROJECT SUMMARY After injury, axons begin to die via a process that is characterized by axonal fragmentation and disintegration of myelin sheath. This process is often termed Wallerian degeneration after Augustus Waller. Wallerian-like degeneration, which is morphologically similar to Wallerian degeneration, is associated with the early stages of many neurodegenerative diseases, including as Alzheimer’s, Huntington’s, and Parkinson’s Diseases. Wallerian degeneration was long thought to occur passively, but the discovery of proteins that actively prevent or promote degeneration negated this idea. One such protein is SARM1. SARM1 is a NAD+ hydrolase that cleaves NAD+ to nicotinamide, ADPR, and cyclic ADPR; generation of these products ultimately leads to axonal degeneration. Moreover, SARM1 knockout delays degeneration in animal models of Wallerian-like diseases, including traumatic brain injury and peripheral neuropathy. Given the critical role of SARM1 in Wallerian-like diseases, the central hypothesis of this proposal is that SARM1 inhibition would prevent the pathophysiology of axon degeneration associated with neurodegenerative diseases. However, development of SARM1 inhibitors is limited by the lack of knowledge surrounding the regulation, structure, and mechanism of this enzyme. As such, the goal of this proposal is to understand SARM1 regulation in the context of Wallerian degeneration, and this goal will be achieved by pursing the following Specific Aims. Aim 1 focuses on identifying proteins that regulate SARM1 activity. Proximity dependent labeling will also be used to identify proteins that interact with SARM1. The impact of SARM1 interacting proteins on NAD+ hydrolase activity and SARM1-mediated axon degeneration will also be assessed. These experiments will identify intermolecular events that regulate SARM1 during axon degeneration. Aim 2 will focus on understanding the structure and function of TIR-1, the C. elegans ortholog of SARM1. Here, we will solve the TIR-1 structure and characterize the enzymatic mechanism of this enzyme. These studies will complement recent structural and kinetic studies of SARM1 and will yield insights into the intramolecular characteristics of SARM1/TIR-1 that contribute to its degenerative capacity. Investigation into the regulation of SARM1, both inter- and intramolecularly, is a rapidly growing field in the context of neurodegenerative diseases. As such, completion of this work will significantly enhance our understanding of the fundamental molecular mechanisms that control axonal degeneration. These studies will yield insights into the role of SARM1 in axon degeneration, which will have broad implications in the development of therapeutics for neurodegenerative diseases.

项目摘要 受伤后，轴突开始通过以轴突碎片和瓦解为特征的过程死亡 髓鞘。该过程通常被称为奥古斯都·沃勒（Augustus Waller）之后的沃勒（Wallerian）变性。像沃勒利一样 变性在形态上与沃勒利的变性相似，与早期阶段有关 许多神经退行性疾病，包括阿尔茨海默氏症，亨廷顿和帕金森氏病。沃勒里安 长期以来，人们认为退化是被动地发生的，但是发现积极预防或促进的蛋白质的发现 退化否定了这个想法。一种这样的蛋白质是SARM1。 SARM1是将NAD+切割至的NAD+水解酶 烟酰胺，ADPR和循环ADPR；这些产品的产生最终导致轴突变性。 此外，SARM1淘汰 创伤性脑损伤和周围神经病。鉴于SARM1在类似Wallerian的疾病中的关键作用， 该提议的中心假设是SARM1抑制作用将防止轴突的病理生理 与神经退行性疾病有关的变性。但是，SARM1抑制剂的开发是有限的 由于缺乏围绕该酶调节，结构和机制的知识。因此，目标 该提议是在沃勒堕胎的背景下了解SARM1调节，这一目标将 可以通过追求以下特定目标来实现。 AIM 1专注于识别调节SARM1的蛋白质 活动。接近性依赖性标签也将用于识别与SARM1相互作用的蛋白质。影响 SARM1相互作用的NAD+水解酶活性和SARM1介导的轴突变性的蛋白质也将是 评估。这些实验将确定在轴突变性过程中调节SARM1的分子间事件。 AIM 2将专注于理解TIR-1的结构和功能，即SARM1的秀丽隐杆线虫直系同源物。这里， 我们将解决TIR-1结构，并表征该酶的酶促机理。这些研究会 补充SARM1的最新结构和动力学研究，并将对分子内产生见解 SARM1/TIR-1的特征有助于其退化能力。调查调节 SARM1，分子间和分子内都是在神经退行性疾病的背景下快速生长的领域。 因此，这项工作的完成将显着增强我们对基本分子的理解 控制轴突变性的机制。这些研究将对SARM1在轴突中的作用产生见解 堕落，这将对神经退行性理论的发展具有广泛的影响 疾病。