Nutrient transport, membrane trfficking, and mTORC1 signaling at lysosomes.

溶酶体的营养转运、膜转运和 mTORC1 信号传导。

• 批准号: 9274990
• 负责人: Michael H. Overholtzer
• 金额: $ 33.83万
• 依托单位: SLOAN-KETTERING INST CAN RESEARCH
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2019-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9274990
• 关键词: Alpha Cell; Amino Acid Transporter; Amino Acids; Amino Sugars; Anabolism; Autophagocytosis; Breast Carcinoma; Cell Compartmentation; Cell Culture Techniques; Cell Proliferation; Cell Survival; Cells; Colon Carcinoma; Complex; Cultured Cells; Cyclic AMP-Dependent Protein Kinases; Cytosol; Data; Digestion; Excision; FRAP1 gene; Genetic Translation; Glucose; Glucose Transporter; Growth Factor; Homeostasis; Human; Lipids; Lysosomes; Malignant Neoplasms; Mediating; Mediator of activation protein; Membrane; Modeling; Nutrient; Pathway interactions; Phagocytes; Phagocytosis; Phagosomes; Phosphorylation; Phosphotransferases; Proteins; Proteomics; Pyruvate; Recovery; Recruitment Activity; Recycling; Regulation; Reporting; Research; Role; Signal Pathway; Signal Transduction; Source; Stable Isotope Labeling; Starvation; System; Therapeutic; Vacuole; base; experimental study; leukemia; loss of function; lung Carcinoma; lysosome membrane; macrophage; novel; programs; public health relevance; sugar; therapeutic target; trafficking; uptake

DESCRIPTION (provided by applicant): The end stages of the cellular engulfment mechanisms phagocytosis and entosis, which mediate the uptake of exogenous substrates, and autophagy, which mediates the engulfment of intracellular substrates, involve lysosomal digestion of engulfed cargo and export of catabolites to the cytosol for use in biosynthesis. Despite the critical role of these pathways for the removal of targeted substrates, and the importance lysosome- mediated digestion for the actual clearance and recycling of engulfed material, little is known about how the lysosomal processing of engulfed cargo and export of degraded components is regulated. We have found that the mTORC1 protein kinase, a regulator of mRNA translation and autophagy, and the lipid kinase PIKfyve, are required for a program of phagosome fission that shrinks large lysosomal vacuoles as internalized cargo is degraded, which reminiscent of the recently described autophagic lysosome reformation (ALR) program that functions similarly during autophagy. Vacuole fission is associated with nutrient recovery that rescues engulfing cells from the effects of amino acid or glucose/pyruvate starvation, and reactivates mTORC1. Reactivated mTOR recruits specifically to large lysosomal vacuoles harboring degrading cells and controls their fission. The proposed research will identify amino acid and sugar transporters acting at lysosomes that mediate nutrient recovery and mTORC1 activation, and will identify mTOR and PIKfyve-regulated proteins that control the fission of lysosomal vacuoles.

描述（由申请人提供）：细胞吞噬机制的最终阶段，即介导外源底物摄取的吞噬作用和内吞作用，以及介导细胞内底物吞噬的自噬，涉及溶酶体消化被吞噬的物质并将分解代谢物输出到细胞质中用于生物合成。尽管这些途径对于去除目标底物起着关键作用，并且溶酶体介导的消化对于吞没物质的实际清除和回收也很重要，但人们对如何调节吞没物质的溶酶体处理和降解成分的输出知之甚少。我们发现，mTORC1 蛋白激酶（mRNA 翻译和自噬的调节因子）和脂质激酶 PIKfyve 是吞噬体裂变程序所必需的，该程序会随着内化货物的降解而缩小大溶酶体液泡，这让人想起最近描述的自噬溶酶体重组（ALR）程序，其在自噬过程中的功能类似。液泡裂变与营养恢复相关，营养恢复可将吞噬细胞从氨基酸或葡萄糖/丙酮酸饥饿的影响中拯救出来，并重新激活 mTORC1。重新激活的 mTOR 专门招募含有降解细胞的大溶酶体液泡并控制其裂变。拟议的研究将鉴定作用于溶酶体的氨基酸和糖转运蛋白，介导营养回收和 mTORC1 激活，并将鉴定控制溶酶体液泡裂变的 mTOR 和 PIKfyve 调节蛋白。

项目成果

Leucine retention in lysosomes is regulated by starvation.

• DOI: 10.1073/pnas.2114912119
• 发表时间: 2022-02-08
• 期刊: Proceedings of the National Academy of Sciences of the United States of America
• 影响因子: 11.1
• 作者: Bandyopadhyay U;Todorova P;Pavlova NN;Tada Y;Thompson CB;Finley LWS;Overholtzer M
• 通讯作者: Overholtzer M