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 雷帕霉素靶蛋白（TOR）是一种高度保守的蛋白激酶， 新陈代谢. TOR感知并整合上游信号，尤其是养分供应， 只有在条件有利的情况下才能促进新陈代谢和生长。TOR失调导致或 导致广泛的人类疾病，包括癌症、与年龄有关的健康障碍， 代谢紊乱，这是美国发病率和死亡率的主要原因。 因此，生物医学研究的一个主要目标是开发治疗方法， 靶向TOR信号网络的组分，而不广泛破坏代谢， 依赖于TOR的健康细胞的稳态。最近，在这方面取得了重大进展， 目标是发现几种推定的TOR氨基酸传感器。关于美国的 这些传感器的相对贡献、重要性和分子机制阻碍了这些研究。 然而，进步。该项目采用创新的方法，为这些 通过将焦点转移到另一个主要的真核生物谱系--植物， 在我的实验室正在进行的阐明植物中TOR信号网络的工作中，我发现了一种新的氨基， TOR的酸传感器，氨酰tRNA合成酶（阿尔斯）。该阿尔斯对于维持TOR是必要的 活性和足以刺激植物细胞中的TOR。利用生物化学，分子， 遗传学和系统水平的方法，我建议精确地定义阿尔斯如何激活TOR， 植物细胞通过三个独立的目标。在目标1中，我建议突变关键的酶残基， 分析阿尔斯的结构特征以确定其激活TOR所需的分子特征。在Aim中 2，我建议使用鲁棒的方法来映射介导aaRS-TOR激活的信号转导通路。 正交相互作用方法。然后将验证假定的信号转导组分 使用相互测定和功能遗传学来全面定义aaRS-TOR相互作用物 有助于监管。在目标3中，我建议建立TOR对特异性 氨基酸，并确定阿尔斯是否是真正的TOR氨基酸传感器。 综合起来，这三个目标将定义潜在的假定氨基的分子机制。 acid-aaRS-TOR信号轴，为未来研究代谢调控开辟了新的方向。 真核生物此外，这一途径将作为一个模型，了解如何tRNA合成酶 在信号转导途径中已经进化出了超越翻译的功能，并阐明了 复杂的TOR信号网络进化为整合人类的各种生理线索。长期来看， 我们的发现将为当代生物医学研究的一个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。