A tRNA synthetase is an amino acid sensor for TOR in plants

tRNA 合成酶是植物中 TOR 的氨基酸传感器

• 批准号: 10705030
• 负责人: Jacob O Brunkard
• 金额: $ 32.1万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-15 至 2027-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10705030
• 关键词: Affinity Chromatography; Amino Acids; Amino Acyl-tRNA Synthetases; Arabidopsis; Binding; Biochemical; Biological Assay; Biological Models; Biology; Biomedical Research; Catalysis; Cells; Complex; Cues; Development; Disease; EIF-2alpha; Eukaryota; Evolution; Foundations; Future; Genetic; Genomics; Goals; Growth; Growth and Development function; Health; Heart; Homeostasis; Human; In Vitro; Investigation; Knowledge; Label; Leucine; Longevity; Malignant Neoplasms; Maps; Mediating; Mediation; Metabolic; Metabolic Diseases; Metabolism; Methodology; Methods; Modeling; Molecular; Morbidity - disease rate; Mutate; Mutation; Nitrogen; Nutrient; Nutrient availability; Outcome; Pathway interactions; Phosphotransferases; Physiological; Physiology; Plants; Protein Kinase; Proteins; Proteomics; Regulation; Reporting; Reproducibility; Role; Signal Pathway; Signal Transduction; Signal Transduction Pathway; Sirolimus; Solid; System; Techniques; Testing; Therapeutic; Transfer RNA; Translations; United States; Variant; Work; age related; detection of nutrient; experimental study; genetic approach; human disease; improved; in vivo; innovation; leucine-tRNA; mRNA Translation; metabolomics; mortality; novel; protein protein interaction; sensor; targeted treatment; therapeutic target; yeast two hybrid system

PROJECT SUMMARY TARGET OF RAPAMYCIN (TOR) is a deeply conserved protein kinase that regulates eukaryotic metabolism. TOR senses and integrates upstream signals, especially nutrient availability, to coordinate metabolism and promote growth only when conditions are favorable. TOR dysregulation causes or contributes to a broad range of human diseases, including cancers, age-related health disorders, and metabolic disorders, which are the major causes of morbidity and mortality in the United States. Therefore, a major goal for biomedical research is to develop therapeutic treatments that specifically target components of the TOR signaling network without broadly disrupting metabolism and homeostasis in healthy cells that rely on TOR. Recently, there have been significant advances to that goal with the discovery of several putative amino acid sensors for TOR. Conflicting reports about the relative contributions, importance, and molecular mechanisms of these sensors have stymied these advances, however. This project uses an innovative approach to bring fresh perspective to these ongoing debates by shifting focus to the other major eukaryotic lineage, plants. In my lab’s ongoing work to elucidate the TOR signaling network in plants, I discovered a novel amino acid sensor for TOR, an aminoacyl tRNA synthetase (aaRS). This aaRS is necessary to maintain TOR activity and sufficient to stimulate TOR in plant cells. Using a combination of biochemical, molecular, genetic, and systems-level approaches, I propose to precisely define how the aaRS activates TOR in plant cells through three independent aims. In Aim 1, I propose to mutate key enzymatic residues and structural features of the aaRS to determine the molecular features it requires to activate TOR. In Aim 2, I propose to map the signal transduction pathway mediating aaRS-TOR activation using robust orthogonal interactomic approaches. Putative signal transduction components will then be validated using reciprocal assays and functional genetics to comprehensively define how aaRS-TOR interactors contribute to TOR regulation. In Aim 3, I propose to establish the selective sensitivity of TOR for specific amino acids and determine whether the aaRS is a bona fide amino acid sensor for TOR. Taken together, these three aims will define the molecular mechanisms underlying the putative amino acid-aaRS-TOR signaling axis and open new directions for future research on metabolic regulation in eukaryotes. Moreover, this pathway will serve as a model for understanding how tRNA synthetases have evolved functions beyond translation in signal transduction pathways and illuminate how the complex TOR signaling network evolved to integrate diverse physiological cues in humans. Long-term, our findings will make significant contributions to a major goal of contemporary biomedical research: fine-tuning TOR signaling networks to improve and lengthen healthy human lifespans.

项目摘要 雷帕霉素（Tor）的靶标是一种深处保守的蛋白激酶，可调节真核。 代谢。 tor感觉并整合上游信号，尤其是营养的可用性，以协调 新陈代谢并促进条件有利时才促进生长。导致失调或 促成广泛的人类疾病，包括癌症，与年龄有关的健康障碍以及 代谢疾病，这是美国发病率和死亡率的主要原因。 因此，生物医学研究的主要目标是开发治疗性治疗 TOR信号网络的目标成分，而不会大致破坏新陈代谢和 健康细胞中依赖Tor的稳态。最近，这取得了重大进展 通过为Tor发现了几种推定的氨基酸传感器的目标。关于有关的报告 这些传感器的相对贡献，重要性和分子机制已阻碍了这些 但是，进步。该项目采用创新方法来为这些带来新的视角 正在进行的辩论通过将重点转移到其他主要真核血统的植物中。 在我的实验室正在进行的工作中阐明植物中的TOR信号网络，我发现了一个新颖的氨基 Tor的酸传感器，氨基酰基TRNA合成酶（AARS）。该AAR是维持TOR的必要条件 活性且足以刺激植物细胞中的TOR。结合生化，分子， 遗传和系统级方法，我建议精确定义AARS如何激活TOR 植物细胞通过三个独立目标。在AIM 1中，我建议突变关键酶残留物和 AARS的结构特征确定激活TOR所需的分子特征。目标 2，我建议使用鲁棒绘制介导AARS-TOR激活的信号传输途径 正交相互作用方法。然后将验证推定的信号转导组件 使用相互测定和功能遗传学来全面定义AARS-TOR相互作用者 有助于TOR调节。在AIM 3中，我建议建立Tor对特定的选择性敏感性 氨基酸并确定AARS是否是TOR的真正的氨基酸传感器。 综上所述，这三个目标将定义假定氨基的分子机制 酸性信号传导轴和开放新方向，用于未来关于代谢调节的研究 真核生物。此外，该途径将作为了解tRNA合成酶的模型 在信号翻译途径中的翻译超出翻译的发展功能，并阐明了如何 复杂的TOR信号网络演变为整合人类中的潜水员物理线索。长期， 我们的发现将为当代生物医学研究的主要目标做出重大贡献： 微调TOR信号网络，以改善和延长健康的人类寿命。