Dissecting new mechanisms of lysosome quality control in health and disease

剖析健康和疾病中溶酶体质量控制的新机制

• 批准号: 10594038
• 负责人: Rushika Miriam Perera
• 金额: $ 36.2万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-04-01 至 2026-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10594038
• 关键词: Acceleration; Acute; Affinity; Aging; Architecture; Autophagocytosis; Binding; Biochemical; Biochemistry; Biogenesis; Biological Assay; C-terminal; C2 Domain; Calcium; Catabolism; Cell Membrane Permeability; Cell Proliferation; Cell membrane; Cell physiology; Cells; Characteristics; Chemicals; Coupled; Cytoplasm; DYSF gene; Data; Dedications; Defect; Degenerative Disorder; Dependence; Digestion; Disease; Disease Progression; Dissection; Endowment; Ensure; Family; Family member; Fluorescent Probes; Goals; Golgi Apparatus; Growth; Health; Homeostasis; Impairment; In Vitro; Lipid Bilayers; Lysosomes; Maintenance; Malignant Neoplasms; Malignant neoplasm of pancreas; Mass Spectrum Analysis; Measurement; Measures; Mechanical Stress; Mediating; Membrane; Membrane Proteins; Metabolic; Metabolism; Mitochondria; Morphology; Muscular Dystrophies; Mutation; Myoblasts; Normal Cell; Nutrient; Organelles; Pancreatic Ductal Adenocarcinoma; Pathogenesis; Pathway interactions; Phospholipids; Phosphotransferases; Process; Property; Protein Family; Proteins; Proteomics; Quality Control; Reaction; Recycling; Resistance; Role; Route; Signal Transduction; Skeletal Muscle; Stress; Testing; Transmembrane Domain; cell type; comparative; coping; detection of nutrient; in vivo; insight; lysosome membrane; member; metabolomics; mutant; novel; pancreatic ductal adenocarcinoma cell; preservation; programs; repaired; resilience; response; seal; trafficking; transcription factor; tumor growth

PROJECT SUMMARY Lysosomes function as critical nodes for macromolecular recycling, metabolic rewiring, and pro-growth signaling in cells. Accordingly, defects in lysosome function underlie degenerative diseases and aging while hyperactivation of lysosomes are associated with cancer. Prior studies have shown that highly aggressive Pancreatic ductal adenocarcinoma (PDA) cells upregulate lysosome biogenesis and activity to facilitate degradation, clearance and recycling of incoming cargo material delivered by increased rates of autophagy and macropinocytosis. Whether qualitative differences endow PDA lysosomes with unique structural and functional properties to cope with a higher demand for substrate clearance remains unknown. To answer this question, we have conducted the first comparative proteomics analysis of lysosomes isolated from PDA versus normal cells and have identified members of the Ferlin family of membrane repair factors, Myoferlin and Dysferlin, as selectively enriched on the membrane of PDA lysosomes. We propose that Ferlin proteins confer increased protection against lysosomal membrane stress in PDA cells. Ferlin proteins are normally localized on the plasma membrane of cell types subjected to heightened mechanical stress, such as skeletal muscle, where they facilitate repair of the lipid bilayer. Accordingly, mutations in DYSF are associated with two forms of muscular dystrophy whereby impaired membrane resealing compromises myoblast maturation, fusion and plasma membrane repair. Therefore, we hypothesize that PDA cells hijack and repurpose Ferlin proteins at the lysosome membrane to protect the integrity of this organelle. In support of this hypothesis, our preliminary findings show that PDA lysosomes are more resistant to acute chemically induced membrane permeabilization relative to normal cells. Mechanistically, lysosome localization of MYOF is necessary and sufficient for maintenance of lysosome quality control and its suppression leads to profound defects in lysosome morphology, PDA cell proliferation and in vivo tumor growth. The goal of this study is to investigate how MYOF functions to protect the lysosome membrane in mechanistic detail and to determine the impact of blocking lysosome quality control on cellular metabolism, pro-growth signaling and disease progression. In summary, our discovery and proposed studies will be the first to determine a novel function for Ferlin proteins at the lysosome membrane and provide insight into how enhanced lysosome quality control regulates cellular homeostasis and disease pathogenesis.

项目摘要 溶酶体充当大分子回收，代谢重新布和促增长的关键节点 细胞中的信号传导。因此，溶酶体功能缺陷是退化性疾病和衰老的基础 溶酶体的过度激活与癌症有关。先前的研究表明，高度侵略性 胰腺导管腺癌（PDA）细胞上调溶酶体生物发生和活性，以促进 自动噬和增加的货物降解，清除和回收货物的降解和回收 大型细胞增多症。定性差异是否具有独特的结构和功能性的PDA溶酶体 应对底物清除需求较高的属性尚不清楚。要回答这个问题，我们 已经对从PDA与正常细胞分离的溶酶体进行了首次比较蛋白质组学分析 并确定了膜维修因素的Ferlin家族成员，Myoferlin和Dysferlin， 有选择地富集PDA溶酶体的膜。我们建议Ferlin蛋白赋予 对PDA细胞中溶酶体膜应激的保护增加。 FERLIN蛋白通常位于受增强的细胞类型的质膜上 机械应力，例如骨骼肌，在那里促进脂质双层的修复。因此，突变 在DYSF中，有两种形式的肌肉营养不良，从而损害膜重新密封 损害肌细胞成熟，融合和质膜修复。因此，我们假设PDA 细胞在溶酶体膜上劫持和重新利用Ferlin蛋白，以保护该细胞器的完整性。在 对这一假设的支持，我们的初步发现表明，PDA溶酶体对急性更具耐药性 化学诱导的膜通透性相对于正常细胞。从机械上讲，溶酶体定位 Myof的含量是必要的，足以维持溶酶体质量控制及其抑制作用导致 溶酶体形态，PDA细胞增殖和体内肿瘤生长的深刻缺陷。目标的目标 研究是为了调查MyOF如何通过机械细节和到保护溶酶体膜的功能 确定阻断溶酶体质量控制对细胞代谢，促增长信号和的影响 疾病进展。总而言之，我们的发现和拟议的研究将是第一个确定新颖的研究 Ferlin蛋白在溶酶体膜上的功能，并洞悉溶酶体质量的增强 控制调节细胞稳态和疾病发病机理。