Regulation of Protein Synthesis by Glucose

葡萄糖对蛋白质合成的调节

• 批准号: 10252815
• 负责人: Paul A Roberson
• 金额: $ 6.64万
• 依托单位: PENNSYLVANIA STATE UNIV HERSHEY MED CTR
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10252815
• 关键词: 5' -AMP-activated protein kinase; Adenosine Monophosphate; Aging; Amino Acids; Animal Husbandry; Binding; Biological Models; Branched-Chain Amino Acids; Carbohydrates; Cell Culture Techniques; Cell Fractionation; Cells; Chronic; Co-Immunoprecipitations; Complement; Complex; Consumption; Cyclic AMP-Dependent Protein Kinases; Data; Disease; Dissociation; Electroporation; FRAP1 gene; Family; Fasting; Fluorescence Resonance Energy Transfer; Future; Glucose; Glycogen; Growth; Hexokinase 2; Immunoprecipitation; Knowledge; Leucine; Mediating; Metabolism; Methods; Microscopy; Molecular; Molecular Biology Techniques; Morbidity - disease rate; Muscle; Muscle Proteins; Nutrient; Nutrient Depletion; Oral Administration; Pharmacologic Substance; Plasmids; Play; Protein Biosynthesis; Protein Family; Protein Kinase; Proteins; Rattus; Regulation; Research; Rodent Model; Role; Scientist; Signal Pathway; Signal Transduction; Skeletal Muscle; Techniques; Testing; base; cell growth; deprivation; experience; experimental study; gain of function; glucose metabolism; glycogenolysis; improved; in vivo; knock-down; loss of function; mitochondrial membrane; molecular marker; muscle form; novel; overexpression; protein complex; protein expression; sensor; skeletal muscle metabolism; skeletal muscle wasting; stable cell line; training opportunity

PROJECT SUMMARY/ABSTRACT Skeletal muscle loss is associated with aging and various disease states. The mechanistic Target of Rapamycin in Complex 1 (mTORC1) is a protein kinase that acts to upregulate skeletal muscle protein synthesis and thereby promote muscle growth. Adenosine monophosphate-activated protein kinase (AMPK), a nutrient sensor, inhibits mTORC1 during nutrient depletion and thereby inhibits cellular growth. Similarly, the Sestrin family of proteins (Sestrins1-3) are leucine sensors that act to suppress mTORC1 by binding to and inhibiting the mTORC1 activating complex referred to as GAP activity toward Rags (GATOR2). Interestingly, the Sestrins bind not only to GATOR2 but also AMPK, suggesting that they may mediate leucine-induced activation of mTORC1 through multiple mechanisms. In novel preliminary studies presented herein, I show that the Sestrins mediate not only leucine, but also glucose signaling to mTORC1. However, which of the three Sestrins mediates glucose-induced regulation of mTORC1 is unknown. Moreover, whether glucose-induced activation of mTORC1 is mediated through the Sestrin-GATOR2 complex and/or the Sestrin-AMPK complex is unexplored. Previous studies have shown that AMPK is not only regulated by glucose but that it also regulates glucose metabolism, e.g. it upregulates hexokinase 2 (HKII) expression, suppresses glycogen synthesis, and promotes glycogenolysis. In novel preliminary studies presented herein, I show a specific interaction of Sestrin3 with AMPK and also show that Sestrin3 associates with HKII. Based on these findings, I propose to test the hypothesis that glucose acts through Sestrin3 and HKII to both stimulate mTORC1 activity and promote glycogenolysis. By using knockdown and overexpression cell culture and rodent models as well as advanced microscopy techniques I will elucidate the mechanisms through which glucose acts to modulate skeletal muscle protein synthesis and glucose metabolism. It is anticipated that delineation of the molecular markers associated with glucose-mediated stimulation of skeletal muscle metabolism will provide novel targets for future studies as well as targets for pharmaceutical manipulation.

项目总结/摘要 骨骼肌损失与衰老和各种疾病状态有关。雷帕霉素的作用机制 在复合物1中（mTORC 1）是一种蛋白激酶，其作用是上调骨骼肌蛋白质合成，从而 促进肌肉生长。腺苷一磷酸激活蛋白激酶（AMPK），一种营养传感器， mTORC 1在营养耗尽期间，从而抑制细胞生长。类似地，Sestrin蛋白质家族 （Sestrins 1 -3）是亮氨酸传感器，其通过结合并抑制mTORC 1来抑制mTORC 1 活化复合物，称为GAP对Rags的活性（GATOR 2）。有趣的是，塞斯特林不仅 GATOR 2和AMPK，这表明它们可能介导亮氨酸诱导的mTORC 1激活， 多重机制在本文提出的新的初步研究中，我表明Sestrin不仅介导 亮氨酸，而且葡萄糖信号传导至mTORC 1。然而，这三种Sestrin介导葡萄糖诱导的 mTORC 1的调节是未知的。此外，葡萄糖诱导的mTORC 1激活是否是介导的 通过Sestrin-GATOR 2复合物和/或Sestrin-AMPK复合物的作用尚未探索。先前的研究 表明AMPK不仅受葡萄糖调节，而且还调节葡萄糖代谢，例如， 上调己糖激酶2（HKII）表达，抑制糖原合成，并促进糖原分解。在 本文提出的新的初步研究，我显示了Sestrin 3与AMPK的特异性相互作用， Sestrin 3与HKII有联系。基于这些发现，我提议检验葡萄糖 通过Sestrin 3和HKII刺激mTORC 1活性并促进糖原分解。通过使用 敲低和过表达细胞培养和啮齿动物模型以及先进的显微镜 我将阐明葡萄糖调节骨骼肌的机制 蛋白质合成和葡萄糖代谢。预计分子标记物的描绘 与葡萄糖介导的骨骼肌代谢刺激相关的蛋白质将为未来的研究提供新的靶点。 研究以及药物操作的目标。