Phosphatidylinositol 3-Phosphate in the Regulation of Autophagic Membrane Remodeling

磷脂酰肌醇 3-磷酸在自噬膜重塑调节中的作用

• 批准号: 10700167
• 负责人: Ting-Sung Hsieh
• 金额: $ 12.5万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-07 至 2024-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10700167
• 关键词: Acute; Address; Advisory Committees; Architecture; Automobile Driving; Autophagocytosis; Autophagosome; Award; Binding; Biochemical; Biogenesis; Biological; Biological Assay; Biophysics; Cell physiology; Cells; Chemicals; Coupled; Data; Diabetes Mellitus; Diffusion; Disease; Endoplasmic Reticulum; Ensure; Environment; Event; Functional disorder; Future; Generations; Genetic; Goals; In Vitro; Intracellular Membranes; Lead; Legionella; Legionella pneumophila; Link; Lipids; Lysosomes; Malignant Neoplasms; Mediating; Medical center; Membrane; Membrane Biology; Methods; Modeling; Molecular; N-terminal; Nerve Degeneration; Organelles; Outcome; PIK3CG gene; Pathologic Processes; Pathway interactions; Pattern; Phase; Phosphatidylinositols; Phosphoric Monoester Hydrolases; Phosphotransferases; Physiological Processes; Play; Proteins; Reaction; Regulation; Research; Research Personnel; Research Training; Role; Scientist; Shapes; Site; Structure; System; Testing; Theoretical model; Therapeutic; Training; Tubular formation; Vesicle; Vps34 Phosphatidylinositol 3 Kinase; biophysical techniques; career; career development; chronic infection; human disease; in silico; innovation; live cell imaging; membrane model; novel therapeutic intervention; optogenetics; pathogen; pathogenic bacteria; phosphatidylinositol 3-phosphate; phosphatidylinositol-3-phosphatase; protein degradation; quantitative imaging; reconstitution; recruit; research and development; skills; spatiotemporal; success; tool

PROJECT SUMMARY/ABSTRACT Autophagy is a fundamental cellular process mediating lysosome-dependent degradation of proteins, organelles, and intracellular pathogens. Dysfunction of autophagy is associated with many diseases, including cancer, neurodegeneration, diabetes, and chronic infections. Better elucidation of the molecular mechanisms for autophagy may inspire new therapeutic approaches to these diseases. Autophagy initiation occurs at endoplasmic reticulum (ER) subdomains enriched with phosphatidylinositol 3-phosphate (PI3P). Autophagy is blocked when depleting or inactivating VPS34, the phosphatidylinositol (PI) 3-kinase responsible for PI3P synthesis during autophagy. Nevertheless, how PI3P contributes to membrane remodeling events crucial for autophagosome biogenesis remains elusive. Much is also unknown about how PI3P synthesis and turnover are orchestrated at autophagy initiation sites. Dr. Hsieh recently discovered that the Legionella PI 3-kinase MavQ generates PI3P on the ER and drives membrane remodeling. He also found that MavQ is coupled with the Legionella PI 3-phosphatase SidP to spatiotemporally modulate PI3P levels at ER subdomains, inducing vesicle/tubule budding. The striking similarity between this pathological process and autophagy initiation prompts Dr. Hsieh to dissect the molecular and physical factors that PI3P brings for autophagic membrane remodeling. Moreover, the current technical hurdles in tackling this question can mostly be cleared by using MavQ and SidP as tools. In Dr. Hsieh’s proposed research, Aim 1 will develop optogenetic methods to control PI3P generation in the cell and determine how PI3P regulates autophagic membrane remodeling using live-cell imaging and systematic genetic perturbations. Aim 2 will combine in vitro biophysical assays, optogenetic control, and quantitative imaging to elucidate how PI3P domain formation leads to membrane remodeling. Aim 3 will reconstitute a reaction-diffusion system in vitro and use this system to determine how PI 3-kinases and phosphatases drive the formation of PI3P-enriched membrane subdomains. Dr. Hsieh’s career goal is to become a leader in cell biophysics and membrane biology, focusing on physiological and pathological processes involving membrane remodeling. Training during the award period will prepare him to lead an independent research group using cell biological, biochemical, and biophysical approaches to understand the mechanistic basis of autophagic membrane remodeling. UT Southwestern Medical Center provides an excellent environment to aid Dr. Hsieh’s proposed research and career development. Dr. Hsieh has also set up an advisory committee consisting of leading scientists with complementary research expertise. Under their guidance, Dr. Hsieh will receive the necessary research training, such as preparing and using various model membrane systems, and further develop professional skills during the award period. These will significantly facilitate Dr. Hsieh's transition into an independent investigator and ensure his future success.

项目总结/摘要 自噬是介导蛋白质、细胞器 和细胞内病原体。自噬功能障碍与许多疾病有关，包括癌症， 神经变性、糖尿病和慢性感染。更好地阐明了 自噬可能会激发这些疾病的新治疗方法。自噬起始发生在 富含磷脂酰肌醇3-磷酸（PI 3 P）的内质网（ER）亚结构域。自噬是 当消耗或失活VPS 34时阻断，VPS 34是负责PI 3 P的磷脂酰肌醇（PI）3-激酶， 自噬过程中的合成尽管如此，PI 3 P如何促进膜重塑事件对于 自噬体的生物发生仍然是难以捉摸的。关于PI 3 P的合成和周转是如何进行的， 在自噬的起始位点进行协调。谢博士最近发现军团菌PI 3-激酶MavQ 在ER上产生PI 3 P并驱动膜重塑。他还发现，MavQ与 军团菌PI 3-磷酸酶SidP时空调节ER亚结构域的PI 3 P水平，诱导 囊泡/小管出芽。这种病理过程和自噬启动之间惊人的相似性 促使Hsieh博士剖析PI 3 P为自噬膜带来的分子和物理因素 重塑此外，目前解决这一问题的技术障碍大多可以通过使用 MavQ和SidP作为工具。在Hsieh博士提出的研究中，Aim 1将开发光遗传学方法来控制 细胞中PI 3 P的产生，并使用活细胞确定PI 3 P如何调节自噬膜重塑。 成像和系统遗传扰动。目的2将联合收割机与体外生物物理学测定、光遗传学 对照和定量成像来阐明PI 3 P结构域形成如何导致膜重塑。目的 3将在体外重建反应扩散系统，并使用该系统来确定PI 3-激酶和 磷酸酶驱动富含PI 3 P的膜亚结构域的形成。谢博士的职业目标是成为 细胞生物物理学和膜生物学的领导者，专注于生理和病理过程 包括膜重塑在获奖期间的培训将使他准备领导一个独立的 研究小组使用细胞生物学、生物化学和生物物理方法来了解其机制 自噬膜重塑的基础。UT西南医学中心提供了一个良好的环境 以帮助谢博士的研究和职业发展。谢博士还成立了一个咨询委员会 由具有互补研究专长的顶尖科学家组成。在他们的指导下，谢博士将 接受必要的研究培训，例如准备和使用各种模型膜系统，以及 在获奖期间进一步发展专业技能。这将大大促进谢博士的 转型为独立调查员，确保他未来的成功。