Role of Forkhead Proteins in Insulin Action

叉头蛋白在胰岛素作用中的作用

• 批准号: 7563957
• 负责人: DOMENICO ACCILI
• 金额: $ 40.47万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-01-01 至 2010-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7563957
• 关键词: 1-Phosphatidylinositol 3-Kinase; Abbreviations; Acetylation; Acetyltransferase; Acute Promyelocytic Leukemia; Address; Adipocytes; Animals; Binding Proteins; Biological; Biological Assay; Biology; Boxing; Catalytic Domain; Cell Differentiation process; Cells; Chimeric Proteins; Cloning; Cultured Cells; DNA Binding; Data; Diabetes Mellitus; Disease; Drug Delivery Systems; EP300 gene; Enzymes; Equilibrium; Exclusion; Family; Funding; Gene Expression; Gene Expression Regulation; Gene Targeting; Genetic; Genetic Transcription; Gluconeogenesis; Goals; Grant; Hand; Hepatic; Histone Deacetylase; Human; Insulin; Insulin Receptor; Kinetics; Knock-in Mouse; Laboratories; Link; Liver; Lysine; Maps; Mediating; Mediator of activation protein; Metabolic; Metabolic Diseases; Metabolism; Methods; Mus; Nuclear; Oxidative Stress; Pancreas; Pathway interactions; Phosphorylation; Physiological; Post-Translational Protein Processing; Protein-Serine-Threonine Kinases; Proteins; Proto-Oncogenes; Pyruvate; Pyruvates; Regulation; Research Personnel; Role; Signal Transduction; Site; Testing; Therapeutic; Transcription Coactivator; Transgenic Mice; Transgenic Organisms; Work; base; cell type; cellular imaging; forkhead protein; gain of function; glucose production; glucose-6-phosphatase; glycogenolysis; hepatic gluconeogenesis; in vivo; inorganic phosphate; insulin signaling; mutant; notch protein; novel; programs; promoter; protein degradation; protein protein interaction; research study; transcription factor

The mechanism of insulin action on gene expression is a key question in biology, with important ramifications for the treatment of diabetes and metabolic disorders. Studies supported by this grant have established a role for the O sub-family of Forkhead transcription factors in insulin regulation of gene expression. During the past funding cycle, we have demonstrated that FoxOl is the principal insulin- dependent transcription factor in the regulation of hepatic gluconeogenesis and pancreatic (3 cell mass. We have shown that: /, phosphorylation is the main mechanism by which insulin inhibits FoxOl by promoting its nuclear exclusion; ii, FoxOl expression can single-handedlyconfer insulin regulation on the expression of Glucose-6-phosphatase, the rate-limiting enzyme in glycogenolysis; Hi,FoxOl interacts with Pgcla to stimulate gluconeogenesis; iv, FoxOl links insulin signaling to Pdxl regulation of |3cell mass. We now present preliminarydata extending the gamut of FoxO functions to regulation of cell differentiation and protection against oxidative stress, while also expanding the repertoire of FoxO target genes. We demonstrate that these functions are based on two novel modes of FoxO action: acetylation-dependent 'targeting to nuclear Pml bodies, and protein/protein interactions with the Notch effector Csl. The latter observation indicates that FoxOl functions as a coactivator, and not only as a transcription factor. It also bridges together two important signalingpathways, the PI 3-kinase and the Hesl pathways. In the next five years, we will endeavor to integrate this new information in the mechanism of FoxOl action and its role in metabolic disorders. We propose to study: in Aiml, how phosphorylation- and acetylation-mediated mechanisms are integrated in vivo to determine the kineticsof FoxOl sub-cellularlocalization in physiologic conditions and disease states; in Aim 2, how acetylation-dependent sub-nucleartargeting of FoxOl regulates metabolism in liver, pancreatic (3 cells and adipocytes; and in Aim 3, how the balance between the coactivator and transcription functions of Foxol is determined. The studies will be carried out with genetic loss- and gain-of-function experiments in transgenic mice and cultured cells, using methods that have been fully implemented in the Pi's laboratory. The ultimate goal of this work is to find a therapeutic approach to modifying FoxOl function. Indeed, while FoxOl is an extremely attractive biological target to treat diabetes and metabolic diseases, it is largely intractable as a drug target. Therefore, it is hoped that by identifying mechanisms of action and interacting partners, new ways to modulate its function can be found.

胰岛素对基因表达的作用机制是生物学中的一个关键问题，具有重要意义。 对治疗糖尿病和代谢紊乱的影响。此项资助支持的研究 建立了 Forkhead 转录因子 O 亚家族在胰岛素基因调节中的作用 表达。在过去的融资周期中，我们已经证明 FoxOl 是主要的胰岛素 肝脏糖异生和胰腺（3细胞团）调节中的依赖转录因子。我们 已经表明：/，磷酸化是胰岛素通过促进其抑制 FoxOl 的主要机制 核排除； ii，FoxOl表达可以单独赋予胰岛素对表达的调节作用 葡萄糖-6-磷酸酶，糖原分解的限速酶；你好，FoxOl 与 Pgcla 交互 刺激糖异生； iv，FoxOl将胰岛素信号转导与|3细胞质量的Pdxl调节联系起来。我们现在 目前初步数据将 FoxO 功能范围扩展到细胞分化的调节和 防止氧化应激，同时还扩展了 FoxO 靶基因的库。我们 证明这些功能基于 FoxO 作用的两种新模式：乙酰化依赖性 '靶向核Pml体，以及与Notch效应器Csl的蛋白质/蛋白质相互作用。后者 观察表明FoxO1作为共激活因子发挥作用，而不仅仅是作为转录因子。它还 连接两个重要的信号传导途径：PI 3 激酶和 Hesl 途径。在接下来的五年里 多年来，我们将努力将这些新信息整合到 FoxOl 的作用机制及其在 代谢紊乱。我们建议研究：在 Aiml 中，磷酸化和乙酰化如何介导 体内整合机制以确定 FoxOl 生理学亚细胞定位的动力学 条件和疾病状态；在目标 2 中，FoxOl 的乙酰化依赖性亚核靶向如何调节 肝脏、胰腺（3 细胞和脂肪细胞）的代谢；目标 3 中，如何平衡 确定了 Foxol 的共激活子和转录功能。这些研究将通过遗传进行 使用已被证实的方法在转基因小鼠和培养细胞中进行功能丧失和获得的实验 完全在 Pi 的实验室中实施。这项工作的最终目标是找到一种治疗方法 修改 FoxOl 函数。事实上，虽然 FoxOl 是治疗糖尿病的一个极具吸引力的生物靶点 和代谢疾病，它作为药物靶点在很大程度上是棘手的。因此，希望通过识别 作用机制和相互作用的伙伴，可以找到调节其功能的新方法。