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.

项目摘要/摘要 骨骼肌的丧失与年龄和各种疾病状态有关。雷帕霉素的作用靶点 在复合体1中(MTORC1)是一种蛋白激酶，作用于上调骨骼肌蛋白质合成，从而 促进肌肉生长。一种营养感受器一磷酸腺苷激活的蛋白激酶(AMPK)抑制 MTORC1在营养耗竭期间，从而抑制细胞生长。同样，Sestrin蛋白家族 (Sestrins1-3)是亮氨酸传感器，通过结合和抑制mTORC1来抑制mTORC1 激活被称为针对RAG的GAP活性的复合体(GATOR2)。有趣的是，塞斯特林家族不仅 GATOR2和AMPK，提示它们可能通过介导亮氨酸诱导的mTORC1激活 多种机制。在这里提出的新的初步研究中，我表明Sestrins不仅在 亮氨酸，但也有葡萄糖信号转导mTORC1。然而，这三种七叶皂苷中的哪一种是介导葡萄糖诱导的 MTORC1的调控尚不清楚。此外，葡萄糖诱导的mTORC1激活是否通过 通过Sestrin-GATOR2复合体和/或Sestrin-AMPK复合体尚未被发现。之前的研究已经 研究表明，AMPK不仅受葡萄糖的调节，而且还调节葡萄糖的代谢，例如 上调己糖激酶2(HKII)的表达，抑制糖原合成，促进糖原分解。在……里面 在这里提出的新的初步研究，我显示了Sestrin3与AMPK的特定相互作用，并显示了 Sestrin3与HKII有关联。基于这些发现，我建议检验葡萄糖起作用的假设 通过Sestrin3和HKII刺激mTORC1活性，促进糖原分解。通过使用 敲除和过度表达细胞培养和啮齿动物模型以及高级显微镜 技术I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。预计分子标记的描绘 与葡萄糖介导的骨骼肌代谢相关的刺激将为未来提供新的靶点 药物操纵的研究和目标。