Regulation and Function of hVps34 in Insulin Signaling

hVps34 在胰岛素信号传导中的调节和功能

• 批准号: 7036859
• 负责人: Jonathan M. Backer
• 金额: $ 30.57万
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-03-06 至 2010-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7036859
• 关键词: aminoacid; biological signal transduction; enzyme activity; glucose; guanine nucleotide binding protein; insulin; laboratory rabbit; mTOR protein; mass spectrometry; membrane proteins; nuclear proteins; phosphatidylinositol 3 kinase; phosphorylation; protein kinase; protein protein interaction; protein structure function; ribosomal proteins

DESCRIPTION (provided by applicant): Diabetes is a major public health problem in the United States and the world, with a huge societal cost in both human and financial terms. Phosphoinositide 3-kinases (PI 3-kinases) are lipid kinases that play an essential role in insulin action. While the function of p85/p110 PI 3-kinases in insulin responsive cells is well documented, the Class III PI 3-kinase, hVps34, also plays a significant role in insulin action. In this application, exciting new evidence is presented that links hVps34 to two nutrient sensing systems in mammalian cells: the AMP-activated Protein Kinase (AMPK), which regulates the utilization of alternative energy sources under low-nutrient conditions, and p70 S6-kinase (S6K), a key regulator of insulin-stimulated protein synthesis. Data presented in this application show that overexpression of hVps34 activates S6K, and that inhibition of hVps34 blocks insulin stimulation of S6K. In addition, hVps34 is inhibited by either glucose or amino acid starvation, conditions that also inhibit S6K. Finally, it is shown that hVps34 is inhibited by activation of AMPK. These novel data suggest that hVps34 plays an important role in nutrient sensing in mammalian cells; this is explored in four specific aims. Aim 1 examines the regulation of hVps34 by amino acids and glucose starvation, and will identify changes in hVps34 phosphorylation (using mass spectrometry-based methods) and in hVps34-associated proteins that occurs in starved cells. Aim 2 studies the role of AMPK in the inhibition of hVps34 in glucose-starved cells, and the mechanism of hVps34 regulation by AMPK. Aim 3 explores potential mechanisms of hVps34 signaling to S6K, including interactions with mTOR, Cdc42, and CISK. Finally, Aim 4 examines the function of the hVps34-associated protein beclin- 1. These studies explore the mechanism of beclin-1-hVps34 association, and the role of beclin-1 in hVps34- dependent vesicular trafficking and activation of S6K. Overall, these studies will have important implications for our understanding of the function and regulation of hVps34, and its role in insulin action and diabetes.

描述（由申请人提供）：糖尿病是美国和世界上一个主要的公共卫生问题，在人力和财力方面都有巨大的社会成本。磷酸肌醇 3-激酶（PI 3-激酶）是在胰岛素作用中起重要作用的脂质激酶。虽然p85/p110 PI 3-激酶在胰岛素应答细胞中的功能已被充分证明，但III类PI 3-激酶hVps 34在胰岛素作用中也起重要作用。在这项应用中，令人兴奋的新证据表明，链接hVps 34到两个营养传感系统在哺乳动物细胞：AMP激活的蛋白激酶（AMPK），它调节利用替代能源在低营养条件下，和p70 S6激酶（S6 K），胰岛素刺激的蛋白质合成的关键调节。本申请中提供的数据显示hVps 34的过表达激活S6 K，并且hVps 34的抑制阻断S6 K的胰岛素刺激。此外，hVps 34被葡萄糖或氨基酸饥饿抑制，这些条件也抑制S6 K。最后，显示hVps 34被AMPK的活化抑制。这些新的数据表明，hVps 34在哺乳动物细胞的营养传感中起着重要的作用，这是在四个具体的目标进行了探讨。目的1研究氨基酸和葡萄糖饥饿对hVps 34的调节，并将鉴定hVps 34磷酸化（使用基于质谱的方法）和饥饿细胞中发生的hVps 34相关蛋白的变化。目的2研究AMPK在葡萄糖饥饿细胞中对hVps 34的抑制作用，探讨AMPK对hVps 34的调控机制。目的3探讨hVps 34信号转导S6 K的可能机制，包括与mTOR、Cdc 42和CISK的相互作用。最后，目的4检查hVps 34相关蛋白beclin- 1的功能。这些研究探索了beclin-1-hVps 34缔合的机制，以及beclin-1在hVps 34依赖的囊泡运输和S6 K活化中的作用。总的来说，这些研究将对我们理解hVps 34的功能和调节及其在胰岛素作用和糖尿病中的作用具有重要意义。