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10年里，溶酶体介导的降解途径巨型自噬得到了显著的重视。 在衰老相关疾病和延长寿命的研究中。巨噬细胞自噬是一种重要的细胞 负责消除胞浆蛋白、脂类和细胞器的途径，因此，场 侧重于巨型自噬在清除蛋白质聚集体或功能失调的细胞器(如 线粒体)，特异性地聚集在细胞质中。然而，蛋白质的积累和 细胞器功能障碍发生在细胞核内，显然不受细胞质的影响。 双膜核膜的突起。此外，老龄化和核能之间的联系 包膜结构缺陷正在出现，包括由基因突变引起的核包膜 信封脚手架夹板。细胞如何应对这些核侮辱还不是很清楚，但 有趣的是，Lamins似乎受到依赖于宏观自噬的更替的影响。因此，很明显，我们必须 重新将注意力集中在核质量控制是如何执行的，特别是在机制上(S) 控制细胞质自噬小体中的核内容周转。因此，在本提案中，我们将重点放在 细胞质自噬机制和核膜重塑的基本问题 协调一致。使用酿酒酵母，其中驱动核自噬的分子机制的发现是 最成熟的，我们将揭示每一个复杂的膜动力学事件，这些事件发生在移动原子核 包膜碎片离开细胞核，最终进入液泡进行降解。到时候我们会的 建立膜重塑的机制，使用完全重组的系统来维持 两种核膜的拓扑学同一性。重要的是，在这些重组的 系统，我们还将介绍不断增长的自噬小体的分子模拟，并概述形成过程。 核膜-自噬体界面上控制核膜碎片的隔离。 随着这个项目的完成，我们将进一步从机制上理解一个被忽视的关键 巨噬细胞自噬过程和我们对核自噬如何影响衰老受损的理解 蛋白质平衡。