Defining the Nucleophagy Mechanism: Opening New Doors for Aging Research

定义核吞噬机制：为衰老研究打开新的大门

• 批准号: 9761417
• 负责人: Charles Patrick Lusk
• 金额: $ 20.94万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-15 至 2020-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9761417
• 关键词: 3-Dimensional; Aging; Artificial Membranes; Attention; Automobile Driving; Autophagocytosis; Autophagosome; Biological Models; Bulla; Cell Nucleus; Cells; Cellular biology; Collaborations; Communication; Complement; Complex; Coupling; Cytoplasm; Cytosol; Data; Degradation Pathway; Disease; Electron Microscopy; Event; Fluorescence; Functional disorder; Funding Mechanisms; Goals; Homeostasis; Human; Impairment; In Vitro; Intermediate Filaments; Investigation; Lamins; Lead; Link; Lipids; Longevity; Lysosomes; Mechanics; Mediating; Melia; Membrane; Membrane Proteins; Mitochondria; Modeling; Molecular; Morphology; Mutation; Neurodegenerative Disorders; Nuclear; Nuclear Envelope; Nuclear Inner Membrane; Nuclear Lamina; Nuclear Outer Membrane; Nuclear Protein; Organelles; Pathogenicity; Pathway interactions; Phenotype; Physiological; Positioning Attribute; Process; Proteins; Quality Control; Research; Role; Saccharomyces cerevisiae; Signal Transduction; Structural defect; Structure; System; Technology; Testing; TimeLine; Ursidae Family; Vacuole; Yeasts; age related; biological adaptation to stress; gene function; high risk; in vivo; insight; light microscopy; novel; protein aggregate; proteostasis; reconstitution; reconstruction; scaffold; synergism; tomography; tool; yeast two hybrid system

Project Summary Over the last 10 years, the lysosome-mediated degradation pathway macroautophagy has gained prominence in the study of aging-related disorders and extension of lifespan. Macroautophagy is an essential cellular pathway responsible for the elimination of cytosolic proteins, lipids and organelles, and as such, the field has focused upon the role of macroautophagy in clearing protein aggregates or dysfunctional organelles (such as mitochondria) that specifically accumulate in the cytoplasm. Increasingly however, protein accumulation and organelle dysfunction are observed to occur within the nucleus, apparently shielded from cytoplasmic processes by the double-membraned nuclear envelope. Furthermore, links between aging and nuclear envelope structural defects are emerging, including nuclear envelopathies caused by mutations in the envelope scaffolding lamins. How the cell responds to these nuclear insults is not well understood, but intriguingly, lamins appear to be subject to macroautophagy-dependent turnover. Thus, it is clear that we must refocus our attention on how nuclear quality control is executed and specifically on the mechanism(s) that governs nuclear content turnover in cytoplasmic autophagosomes. Thus, in this proposal, we focus on the fundamental question of how cytoplasmic autophagy machinery and nuclear envelope remodeling are coordinated. Using S. cerevisiae, where discovery of the molecular machinery driving nuclear autophagy is the most mature, we will reveal each of the complex membrane dynamics events that occur to move nuclear envelope fragments away from the nucleus and eventually into the vacuole for degradation. We will then establish the mechanism of membrane remodeling, using fully reconstituted systems that maintain the topologic identity of each of the two nuclear envelope membranes. Importantly, within these reconstituted systems we will also introduce molecular mimics of the growing autophagosome and recapitulate the formation of the nuclear envelope-autophagosome interface that governs sequestration of nuclear envelope fragments. With the completion of this project, we will further our mechanistic understanding of a key underappreciated macroautophagic process and further our understanding of how nuclear autophagy can impact aging-impaired proteostasis.

项目概要 在过去的十年中，溶酶体介导的降解途径巨自噬引起了人们的关注 研究与衰老相关的疾病和延长寿命。巨自噬是一种重要的细胞自噬 负责消除胞浆蛋白、脂质和细胞器的途径，因此，该领域已 重点关注巨自噬在清除蛋白质聚集物或功能失调的细胞器（例如 线粒体），专门积累在细胞质中。然而，蛋白质积累和 观察到细胞器功能障碍发生在细胞核内，显然不受细胞质的影响 由双膜核膜处理。此外，衰老与核之间的联系 包膜结构缺陷正在出现，包括由基因突变引起的核包膜病。 信封脚手架层压板。细胞如何应对这些核损伤尚不清楚，但是 有趣的是，核纤层蛋白似乎受到巨自噬依赖性周转的影响。因此，很明显，我们必须 将我们的注意力重新集中在核质量控制的执行方式上，特别是核质量控制的机制上。 控制细胞质自噬体中的核内容物周转。因此，在本提案中，我们重点关注 细胞质自噬机制和核膜重塑如何发生的基本问题 协调。使用酿酒酵母，发现驱动核自噬的分子机制是 最成熟的，我们将揭示发生在核运动中的每一个复杂的膜动力学事件 包膜碎片远离细胞核，最终进入液泡降解。我们随后将 建立膜重塑机制，使用完全重构的系统来维持 两个核膜的拓扑特性。重要的是，在这些重组中 我们还将引入生长中的自噬体的分子模拟物并概括其形成 控制核膜碎片隔离的核膜-自噬体界面。 随着这个项目的完成，我们将进一步加深对一个被低估的关键机制的理解 巨自噬过程并进一步了解核自噬如何影响衰老受损 蛋白质稳态。