Regulation and Function of hVps34 in Insulin Signaling

糖尿病是美国和世界的主要公共卫生问题，在全球范围内造成巨大的社会成本 无论是从人力方面还是从财务方面来说。磷脂酰肌醇3-激酶(PI-3-Kinase)是一种脂类激酶，发挥着重要的作用 在胰岛素作用中起重要作用。而p85/p110PI3-激酶在胰岛素反应细胞中的功能良好 文献证明，III型PI 3-激酶，hVps34，在胰岛素作用中也起着重要作用。在这 应用，提出了令人兴奋的新证据，将hVps34与两个营养传感系统联系在一起 哺乳动物细胞：AMP激活的蛋白激酶(AMPK)，它调节替代物的利用 低营养条件下的能源和胰岛素的关键调节因子p70 S6-激酶(S6K)- 刺激蛋白质合成。本申请中提供的数据显示hVps34的过度表达 激活S6K，抑制hVps34阻断胰岛素对S6K的刺激。此外，hVps34被抑制 通过葡萄糖或氨基酸饥饿，也抑制S6K的条件。结果表明，hVps34是 被AMPK激活所抑制。这些新的数据表明hVps34在营养中起着重要的作用。 在哺乳动物细胞中的感知；这在四个特定的目标中进行了探索。目标1研究hVps34的调节 通过氨基酸和葡萄糖饥饿，并将确定hVps34磷酸化的变化(使用质量 基于光谱学的方法)和饥饿细胞中出现的hVps34相关蛋白。目标2研究 AMPK在抑制葡萄糖饥饿细胞hVps34中的作用及其机制 AMPK的监管。目标3探索hVps34信号转导S6K的潜在机制，包括相互作用 使用mTOR、CDC42和Cisk。最后，Aim 4研究了hVps34相关蛋白的功能。 1.这些研究探索了beclin-1-hVps34的结合机制，以及beclin-1在hVps34中的作用。 S6K依赖的囊泡运输和激活。总体而言，这些研究将产生重要影响。 以帮助我们了解hVps34的功能和调节，以及它在胰岛素作用和糖尿病中的作用。

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 an 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), an 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.