DOWNSTREAM ELEMENTS IN IRS 1 SIGNALING--P55PIK

IRS 1 信号中的下游元件 - P55PIK

• 批准号: 2654524
• 负责人: Morris F. White
• 金额: $ 22.17万
• 依托单位: JOSLIN DIABETES CENTER
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-02-27 至 2001-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2654524
• 关键词: 3T3 cells; CHO cells; adipocytes; apoptosis; biological signal transduction; epidermal growth factor; fasting; gene expression; gene targeting; genetic regulation; glucose metabolism; immunofluorescence technique; insulin receptor; insulin sensitivity /resistance; insulinlike growth factor; laboratory mouse; laboratory rat; neurogenesis; neurotrophic factors; obesity; phosphatidylinositol 3 kinase; protein structure function; site directed mutagenesis; sulfides; tissue /cell culture

This revised proposal (DK47308-01A2) entitled Downstream elements in IRS-1 signaling: p55/PIK focuses on a novel protein discovered in our laboratory by cDNA expression screening with a [32/P]IRS-1 probe. IRS-1 is an essential component for insulin signaling that becomes phosphorylated on multiple tyrosine residues during activation of the insulin receptor kinase, as well as the receptors for IGF-1, IL-4 and growth hormone. We suspect that important insulin signals are engaged when the phosphorylated tyrosine residues associate with high affinity to cellular signaling proteins which contain Src homology-2 domains (SH2-proteins). The p55/PIK is a newly discovered SH2-protein which shares characteristics with p85, a principle regulatory element linking phosphatidylinositol-3 kinase to IRS-1 and other growth factor receptors. A full understanding of the IRS- 1 signaling system and the elements it interacts with is scientifically and clinically important because diabetes is a contemporary health problem that affects about 2% of the world population and over 14 million Americans. Whereas 10% of these individuals suffer from an absolute lack of insulin (IDDM), most are diabetic because their cells do not respond fully to normal or elevated amounts of circulating insulin (NIDDM). A molecular basis for insulin signaling will provide new therapeutic opportunities for NIDDM patients and improved strategies for the tight control of individuals with IDDM. This proposal introduces a new element in the insulin signaling system called p55/PIK, that appears to link the insulin receptor/IRS-1 to the PI 3-kinase and possibly other downstream signaling molecules. Based on growing literature pointing to the important of PI 3-kinase signaling, and glucose uptake in particular, p55/PIK is expected to play an important role in the cellular insulin response. This proposal will establish over the next five years the role of p55/PIK in the insulin signaling cascade and explore the role of p55/PIK in the regulation of glucose metabolism, neuronal development and apoptosis. The following specific aims are proposed: 1. The expression and function of p55/PIK will be determined in tissues from rats and mice under normal conditions and during fasting, obesity and insulin resistance. 2. The function of p55/PIK in cultured P19 neuronal cells will be investigated. 3. Structure/function analysis of p55/PIK will be conducted by site- directed mutagenesis and overexpression in cultured cells, including CHO, P19 neurons and 3T3-L1 adipocytes. 4. The gene for p55/PIK will be disrupted in mice, and the effect of on glucose homeostatis will be evaluated in the resulting animals.

该修订的提案（DK47308-01A2）题为IRS-1中的下游元素 信号传导：p55/pik专注于我们实验室发现的新蛋白质 通过[32/p] IRS-1探针筛选cDNA表达筛选。 IRS-1是一个 胰岛素信号传导的必需成分，该信号被磷酸化 胰岛素受体激活期间多个酪氨酸残基 激酶以及IGF-1，IL-4和生长激素的受体。 我们 怀疑当磷酸化时参与重要的胰岛素信号 酪氨酸残基与细胞信号高亲和力相关 含有SRC同源性-2结构域（SH2-蛋白）的蛋白质。 p55/pik 是一种新发现的SH2-蛋白质，与P85共享特征， 将磷脂酰肌醇-3激酶与 IRS-1和其他生长因子受体。 对IRS的充分理解 1信号系统及其相互作用的元素是科学的 而且在临床上很重要，因为糖尿病是当代健康问题 这影响了大约2％的世界人口，超过1400万 美国人。 这些人中有10％的人绝对缺乏 胰岛素（IDDM）的大多数是糖尿病患者，因为它们的细胞不反应 完全达到正常或升高的循环胰岛素（NIDDM）。 一个 胰岛素信号的分子基础将提供新的治疗 NIDDM患者的机会，并改善了紧张的策略 控制IDDM的个体。 该建议在胰岛素信号系统中引入了一个新元素 称为p55/pik，似乎将胰岛素受体/IRS-1连接到PI 3-激酶，可能是其他下游信号分子。 基于 越来越多的文献指出了PI 3-激酶信号的重要性，并且 尤其是葡萄糖吸收，p55/pik有望发挥重要作用 在细胞胰岛素反应中的作用。 该提议将建立 接下来的五年p55/pik在胰岛素信号级联中的作用 并探讨p55/pik在调节葡萄糖代谢中的作用， 神经元发育和凋亡。 以下具体目的是 建议的： 1。将在组织中确定p55/pik的表达和功能 在正常条件下和禁食期间，肥胖症的大鼠和小鼠 和胰岛素抵抗。 2。p55/pik在培养的P19神经元细胞中的功能将是 调查。 3。p55/pik的结构/功能分析将通过位点进行 - 培养细胞中的定向诱变和过表达，包括 CHO，P19神经元和3T3-L1脂肪细胞。 4。p55/pik的基因将在小鼠中破坏，以及对 葡萄糖稳态将在由此产生的动物中进行评估。