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.

项目摘要 在过去的十年中，溶酶体介导的降解途径大量噬菌体变得突出 在研究与衰老有关的疾病和寿命的扩展中。宏观哲学是必不可少的细胞 负责消除胞质蛋白，脂质和细胞器的途径，因此该领域具有 侧重于大型噬菌学在清除蛋白质聚集体或功能失调细胞器中的作用（例如 线粒体特异性积聚在细胞质中。然而，蛋白质的积累越来越多 观察到细胞器功能障碍发生在细胞核内，显然是从细胞质中屏蔽的 双重核包膜的过程。此外，衰老与核之间的联系 包膜结构缺陷正在出现，包括由突变引起的核神经 信封脚手架层。细胞如何应对这些核侮辱，但没有很好地理解 有趣的是，lamins似乎受到大自发性依赖性周转率的约束。因此，很明显我们必须 我们重点关注我们如何执行核质量控制，尤其是关于如何执行核质量控制的机制 控制细胞质自噬小体的核含量周转。因此，在此提案中，我们专注于 细胞质自噬机械和核包络重塑的基本问题是 协调。使用酿酒酵母，发现驱动核自噬的分子机械的发现是 最成熟的，我们将揭示移动核的每一个复杂的膜动态事件 包络片段从细胞核中移开，最终进入液泡以降解。然后我们会 使用完全重构的系统来确定膜重塑的机理 两个核包膜膜中的每一个的拓扑认同。重要的是，在这些重组中 系统我们还将引入生长自噬体的分子模仿并概括地层 控制核包络片段的隔离的核包膜 - 自助体界面。 随着该项目的完成，我们将进一步了解对关键的机械理解 大自大的过程，进一步了解我们对核自噬如何影响衰老损害的理解 蛋白毒酸。