Investigating the Activation Mechanism of SARM1 during Axon Degeneration

轴突变性过程中 SARM1 激活机制的研究

基本信息

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
项目类别：
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&apos 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

项目摘要

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.

项目概要受伤后，轴突开始通过轴突碎裂和解体的过程死亡这个过程通常被称为奥古斯都·沃勒样的沃勒变性。变性在形态上与华勒变性相似，与早期阶段有关。许多神经退行性疾病，包括阿尔茨海默病、亨廷顿病和帕金森病。长期以来，人们认为退化是被动发生的，但主动预防或促进蛋白质的发现 SARM1 是一种 NAD+ 水解酶，可将 NAD+ 裂解为 NAD+。烟酰胺、ADPR 和环状 ADPR；这些产物的产生最终导致轴突变性。此外，SARM1 敲除可延缓华勒样疾病动物模型的退化，包括鉴于 SARM1 在华勒样疾病中的关键作用，该提案的中心假设是 SARM1 抑制会阻止轴突的病理生理学然而，SARM1 抑制剂的开发有限。由于缺乏有关这种酶的调节、结构和机制的知识，因此，目标。该提案的目的是了解华勒变性背景下的 SARM1 调节，这一目标将通过追求以下具体目标来实现目标 1 侧重于识别调节 SARM1 的蛋白质。邻近依赖性标记也将用于识别与 SARM1 相互作用的蛋白质。 SARM1 相互作用蛋白对 NAD+ 水解酶活性和 SARM1 介导的轴突变性的影响也将这些实验将鉴定在轴突变性期间调节 SARM1 的分子间事件。目标 2 将重点了解 TIR-1（SARM1 的线虫直系同源物）的结构和功能。我们将解析 TIR-1 的结构并表征该酶的酶促机制。最近对 SARM1 的结构和动力学研究将产生对分子内的补充见解 SARM1/TIR-1 的特性有助于其退化能力的调节。 SARM1，无论是分子间还是分子内，都是神经退行性疾病背景下快速发展的领域。因此，这项工作的完成将显着增强我们对基本分子的理解。这些研究将深入了解 SARM1 在轴突中的作用。变性，这将对神经变性疗法的开发产生广泛的影响疾病。