Spatial and temporal regulation of nutrient sensing

营养传感的时空调节

• 批准号: 10797729
• 负责人: Kuang Shen
• 金额: $ 20万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2027-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10797729
• 关键词: Amino Acids; Behavior; Biological Process; Catabolism; Cell Proliferation; Cells; Complex; Cryo-electron tomography; Environment; Eukaryotic Cell; FRAP1 gene; Guanosine Triphosphate Phosphohydrolases; In Vitro; Membrane; Molecular; Molecular Conformation; Nutrient; Nutrient availability; Outcome; Process; Reaction; Regulation; Research; Series; Signal Transduction; Surface; System; Visualization; biophysical tools; cell growth; detection of nutrient; insight; novel; protein complex; reconstitution; recruit; single-molecule FRET; therapeutic development; transmission process

Project Summary / Abstract Cells need to sense the nutrient availability to adjust their survival strategy. In eukaryotic cells, the mechanistic Target of Rapamycin Complex 1 (mTORC1) is a key regulator of cell growth and proliferation. Upon activation in a nutrient-rich environment, mTORC1 triggers anabolic reactions and inhibits catabolism. Amino acid signals are transmitted to mTORC1 through a series of protein complexes that ultimately converge on the Rag GTPases, a heterodimeric GTPase that recruits mTORC1 to the lysosomal surface. However, the molecular mechanisms of how these protein complexes dynamically transmit the amino acid signal are still elusive. In this proposal, we aim to develop biophysical tools to study the dynamics of the amino acid sensing process. Specifically, we aim to use single molecule FRET to study the conformational dynamics of the Rag GTPase heterodimer and its regulators (Project 1). Further, we plan to reconstitute an in vitro system to recapitulate Rag-dependent amino acid sensing on a membrane surface (Project 2), and use cryo-electron tomography (cryo-ET) to visualize the signaling complexes in their native environment (Project 3). The outcomes will yield novel insights into this important biological process and provide guidance to the development of therapeutic strategies.

项目摘要/摘要 细胞需要感知营养的可获得性来调整它们的生存策略。在真核细胞中， 雷帕霉素复合体的机械靶点1(MTORC1)是细胞生长和增殖的关键调控因子。 当在营养丰富的环境中被激活时，mTORC1会触发合成代谢反应并抑制分解代谢。 氨基酸信号通过一系列最终会聚的蛋白质复合体传递给mTORC1 在RAG GTP酶上，一种异源二聚体GTP酶，将mTORC1招募到溶酶体表面。然而， 这些蛋白质复合体如何动态传递氨基酸信号的分子机制仍然存在 难以捉摸。在这项建议中，我们的目标是开发生物物理工具来研究氨基酸传感的动力学 进程。具体地说，我们的目标是使用单分子FRET来研究RAG的构象动力学 GTP酶异源二聚体及其调节因子(项目1)。此外，我们计划重建体外系统，以 在膜表面概括RAG依赖的氨基酸感测(项目2)，并使用冷冻电子 断层摄影术(冷冻-ET)，以可视化其自然环境中的信号复合体(项目3)。这个 结果将对这一重要的生物过程产生新的见解，并为 制定治疗策略。

项目成果

A New Crosslinking Assay to Study Guanine Nucleotide Binding in the Gtr Heterodimer of S. cerevisiae.

• DOI: 10.1080/21541248.2022.2141019
• 发表时间: 2022-01
• 期刊: Small GTPases

Redundant electrostatic interactions between GATOR1 and the Rag GTPase heterodimer drive efficient amino acid sensing in human cells.

• DOI: 10.1016/j.jbc.2023.104880
• 发表时间: 2023-07
• 期刊: JOURNAL OF BIOLOGICAL CHEMISTRY
• 影响因子: 4.8
• 作者: Doxsey, Dylan D.;Tettoni, Steven D.;Egri, Shawn B.;Shen, Kuang
• 通讯作者: Shen, Kuang