Regulation of TOR Signaling and Autophagy in Drosophila

果蝇 TOR 信号传导和自噬的调控

基本信息

批准号：
8473223
负责人：
Thomas P. Neufeld
金额：
$ 30.35万
依托单位：
UNIVERSITY OF MINNESOTA
依托单位国家：
美国
项目类别：
财政年份：
2001
资助国家：
美国
起止时间：
2001-03-01 至 2015-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8473223
关键词：
1-Phosphatidylinositol 3-Kinase Address Adverse effects Aging Animals Antithymoglobulin Apoptosis Area Autophagocytosis Awareness Biochemical Caspase Cell Culture Techniques Cell Death Cell Death Signaling Process Cell Survival Cell physiology Cells Cessation of life Complement Complex Cyclic AMP-Dependent Protein Kinases Cytoplasm Defect Development Dimerization Disease Drosophila genus Environment Eukaryotic Cell Event Feedback Genes Genetic Genetic Screening Goals Grant Growth Factor Guanosine Triphosphate Phosphohydrolases Health Human Image Infection Inflammatory Injury Ischemia Knock-out Lead Life Link Lysosomes Malignant Neoplasms Mammalian Cell Mediating Mediator of activation protein Methods Modeling Multiprotein Complexes Mutation Myopathy Nerve Degeneration Nutrient Organelles Organism Pathway interactions Phosphoproteins Phosphorylation Phosphorylation Site Phosphotransferases Physiological Play Process Protein Kinase Proteins Proteomics Reagent Recycling Regulation Role Signal Pathway Signal Transduction Signaling Molecule Sirolimus Source Starvation Stress System Testing Therapeutic Vesicle Work Yeasts aged base cell growth cofactor detection of nutrient fly gene discovery genetic manipulation in vivo interest novel nutrition overexpression public health relevance research study response stem trafficking

项目摘要

DESCRIPTION (provided by applicant): The long term goal of this project is to understand the regulation and physiological roles of autophagy, a process by which proteins, organelles and bulk cytoplasm are sequestered within autophagic vesicles and delivered to the lysosome for degradation. This process plays several distinct, vital roles in the cell, acting to recycle aged or damaged components, to provide a source of nutrients in response to starvation, and in some cases to initiate cell death. These cellular functions underlie the impact of autophagy on a broad range of human illnesses. Fundamental questions regarding autophagy remain to be addressed, including how autophagy is regulated by nutrients and other signals, how substrates are selectively targeted for degradation, and how autophagy can promote either cell survival or cell death in different contexts. The proposed studies will use genetic, biochemical and imaging-based approaches in the Drosophila system to help define mechanisms of autophagy regulation and its functions in an intact organism. Recent studies in Drosophila and mammalian cells have delineated key factors in a conserved signaling pathway that inhibits autophagy under favorable nutrient conditions. The central component of this nutrient-sensing pathway, the Ser/Thr protein kinase Target of Rapamycin (TOR), was shown to control the activity of a multicomponent complex containing the autophagy related kinase Atg1 and the phosphoprotein Atg13. Specific aims of this project are to: 1) test potential models of Atg1/13 complex regulation, including the effects of phosphorylation, multimerization, and association with novel inhibitory cofactors. Potential roles of PKA in this regulation as well as the function of the Atg1-related kinase Ulk3 will be characterized. 2) investigate mechanisms and consequences of a novel self-reinforcing feedback signal by which Atg1 inhibits TOR signaling. 3) investigate mechanisms by which Atg1 overexpression leads to autophagy-dependent cell death. As preliminary indicate of a role for Jun kinase (Jnk) signaling, the mechanisms of autophagy induction by Jnk and the roles of autophagy in endogenous Jnk-mediated death will be explored. 4) identify and characterize the functions of novel autophagy regulators and substrates through genetic and proteomic screens. Experiments in these aims were selected for their likelihood of having a high impact on key questions important to the field of autophagy. This proposal makes use of recently developed reagents including knockouts of several autophagy-related (Atg) genes, in vivo markers of autophagic activity, and novel methods of genetic manipulation. Information gained from studies of autophagy in Drosophila will provide an important whole- animal complement to mammalian cell culture-based studies.

描述（由申请人提供）：该项目的长期目标是了解自噬的调节和生理作用，该过程通过将蛋白质，细胞器和大量细胞质隔离在自噬囊泡中，并传递到溶酶体中以降解。该过程在细胞中起着几种不同的至关重要的作用，其作用是回收老化或损坏的成分，以响应饥饿而提供营养来源，在某些情况下可以启动细胞死亡。这些细胞功能是自噬对广泛人类疾病的影响的基础。有关自噬的基本问题仍有待解决，包括如何通过营养和其他信号调节自噬，如何选择性地靶向降解底物，以及自噬如何在不同情况下促进细胞存活或细胞死亡。拟议的研究将在果蝇系统中使用遗传，生化和基于成像的方法，以帮助定义自噬调节机制及其在完整生物体中的功能。果蝇和哺乳动物细胞的最新研究已在保守的信号传导途径中描述了关键因素，该途径在有利的营养条件下抑制自噬。该营养感应途径的中心成分是雷帕霉素（TOR）的Ser/Thr蛋白激酶靶标，可控制含有自噬相关激酶ATG1和磷酸蛋白ATG13的多组分复合物的活性。该项目的具体目的是：1）测试ATG1/13复合调节的潜在模型，包括磷酸化，多聚化以及与新型抑制性辅助因子的关联的影响。 PKA在该调节中的潜在作用以及与ATG1相关激酶ULK3的功能。 2）研究一种新型自我增强反馈信号的机制和后果，ATG1抑制TOR信号传导。 3）研究ATG1过表达导致自噬依赖性细胞死亡的机制。由于初步表明JUN激酶（JNK）信号的作用，将探索JNK自噬诱导的机制以及自噬在内源性JNK介导的死亡中的作用。 4）通过遗传和蛋白质组学筛选确定并表征新型自噬调节剂和底物的功能。这些目标的实验是因为它们可能对对自噬领域重要的关键问题产生高影响。该建议利用了最近开发的试剂，包括几种自噬相关（ATG）基因的敲除，自噬活性的体内标记以及遗传操纵的新方法。从果蝇自噬的研究中获得的信息将为基于哺乳动物细胞培养的研究提供重要的全动物补充。