The mechanism of nuclear autophagy

核自噬机制

• 批准号: 10688323
• 负责人: Charles Patrick Lusk
• 金额: $ 34.32万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-30 至 2024-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10688323
• 关键词: Aging; Attention; Automobile Driving; Autophagocytosis; Autophagosome; Binding; Biochemical; Biological Models; Cell Aging; Cell Nucleus; Cells; Complement; Cytoplasm; Cytosol; Data; Degradation Pathway; Disease; Dynamin; Electron Microscopy; Elements; Engineering; Event; Fluorescence; Functional disorder; Goals; Homeostasis; Human; Impairment; In Vitro; Individual; Intermediate Filaments; Kinetics; Lamins; Light; Link; Lipids; Longevity; Lysosomes; Mechanics; Mediating; Membrane; Membrane Proteins; Microscopy; Mitochondria; Mitotic; Modeling; Molecular; Mutation; Neurodegenerative Disorders; Nuclear; Nuclear Envelope; Nuclear Inner Membrane; Nuclear Lamina; Nuclear Outer Membrane; Nuclear Protein; Organelles; Pathogenicity; Pathway interactions; Phenotype; Physical condensation; Physiological; Process; Proteins; Publishing; Quality Control; Role; Saccharomyces cerevisiae; Signal Transduction; Site; Structural defect; System; Testing; TimeLine; Yeasts; age related; biological adaptation to stress; insight; light microscopy; membrane assembly; novel; nucleocytoplasmic transport; protein aggregation; proteostasis; receptor; reconstitution; recruit; scaffold

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 and associated integral inner nuclear membrane proteins. How the cell responds to these nuclear insults is not well understood, but there is emerging evidence that components of the nuclear envelope and the nucleus are 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 and where we have generated substantial preliminary and recently published data, we will test an exciting “outside-in” model of nucleophagy. This model invokes a novel translumenal bridge that spans the nuclear envelope membranes and connects the cytosol to the nucleus. This proposal will thus fully define the molecular components that make up this nucleophagy pathway and place these factors within an ultrastructural timeline. Elements of this pathway will then be reconstituted using fully engineered in vitro systems in order to collectively provide critical molecular insight into the key membrane remodeling events necessary to remove nuclear contents while maintaining nuclear integrity. With the completion of this project, we will further our mechanistic understanding of a key underappreciated macroautophagic process and open doors to define 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自噬已经得到了重视 研究衰老相关疾病和延长寿命。巨自噬是一种重要的细胞 负责消除胞质蛋白质、脂质和细胞器的途径，因此，该领域具有 专注于大自噬在清除蛋白质聚集体或功能失调的细胞器（如 线粒体），其特异性地积聚在细胞质中。然而，越来越多的蛋白质积累和 观察到细胞器功能障碍发生在细胞核内，显然与细胞质屏蔽 由双层膜核膜突起。此外，衰老和核武器之间的联系 包膜结构缺陷正在出现，包括由细胞膜蛋白突变引起的细胞核病变。 包膜支架核纤层蛋白和相关的整合内核膜蛋白。细胞如何反应 对这些核侮辱的认识还不清楚，但有新的证据表明，核武器的组成部分， 被膜和细胞核受到大自噬依赖性周转。因此，很明显，我们必须 重新关注如何执行核质量控制，特别是 控制细胞质自噬体中的核内容物周转。因此，在本提案中，我们将重点放在 细胞质自噬机制和核膜重塑是如何 协调一致。利用S.酿酒酵母，在那里发现的分子机制驱动核自噬是 最成熟的，我们已经产生了大量的初步和最近公布的数据，我们将测试一个 令人兴奋的“由外向内”的噬核模型。该模型调用了一种新颖的跨腔桥， 核膜连接细胞质和细胞核。因此，这项建议将充分界定 这些分子组成了这种噬核途径，并将这些因子置于超微结构中。 时间轴。然后将使用完全工程化的体外系统重建该途径的元件， 共同提供了关键的分子洞察力的关键膜重塑事件所必需的去除 同时保持核完整性。随着该项目的完成，我们将进一步 一个关键的未被重视的宏自噬过程的机械理解，并打开大门，以确定如何 核自噬可影响衰老受损的蛋白质稳态。