Role of Forkhead Proteins in Insulin Action

叉头蛋白在胰岛素作用中的作用

基本信息

批准号：
7195746
负责人：
DOMENICO ACCILI
金额：
$ 39.45万
依托单位：
COLUMBIA UNIVERSITY HEALTH SCIENCES
依托单位国家：
美国
项目类别：
财政年份：
2000
资助国家：
美国
起止时间：
2000-06-01 至 2010-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7195746
关键词：
1-Phosphatidylinositol 3-Kinase Abbreviations Acetylation Acetyltransferase Acute Promyelocytic Leukemia Address Adipocytes Animals Beta Cell Binding Proteins Biological Biological Assay Biology Boxing Catalytic Domain Cell Differentiation process Cells Chimeric Proteins Cloning Condition 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 Pathway interactions Phosphorylation Physiological Post-Translational Protein Processing Protein-Serine-Threonine Kinases Proteins Proto-Oncogenes Pyruvate Pyruvates Rate Regulation Research Personnel Role Signal Pathway Signal Transduction Site Structure of beta Cell of islet 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

项目摘要

DESCRIPTION (provided by applicant): 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 FoxO1 is the principal insulin-dependent transcription factor in the regulation of hepatic gluconeogenesis and pancreatic beta cell mass. We have shown that: i, phosphorylation is the main mechanism by which insulin inhibits FoxO1 by promoting its nuclear exclusion; ii, FoxO1 expression can single-handedly confer insulin regulation on the expression of Glucose-6-phosphatase, the rate-limiting enzyme in glycogenolysis; iii, FoxO1 interacts with Pgc1alpha to stimulate gluconeogenesis; iv, FoxO1 links insulin signaling to Pdx1 regulation of beta cell mass. We now present preliminary data 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 FoxO1 functions as a coactivator, and not only as a transcription factor. It also bridges together two important signaling pathways, the PI 3-kinase and the Hes1 pathways. In the next five years, we will endeavor to integrate this new information in the mechanism of FoxO1 action and its role in metabolic disorders. We propose to study: in Aim 1, how phosphorylation- and acetylation-mediated mechanisms are integrated in vivo to determine the kinetics of FoxO1 sub-cellular localization in physiologic conditions and disease states; in Aim 2, how acetylation-dependent sub-nuclear targeting of FoxO1 regulates metabolism in liver, pancreatic beta cells and adipocytes; and in Aim 3, how the balance between the coactivator and transcription functions of Foxo1 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 FoxO1 function. Indeed, while FoxO1 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.

描述（由申请人提供）：胰岛素作用对基因表达的机制是生物学中的关键问题，对治疗糖尿病和代谢性疾病的治疗产生了重要影响。该赠款支持的研究已经确立了叉头转录因子的O子家庭在基因表达调节中的作用。在过去的资金周期中，我们证明了FOXO1是肝糖异生和胰腺β细胞量调节的主要胰岛素依赖性转录因子。我们已经表明：i，磷酸化是胰岛素通过促进其核排斥抑制FOXO1的主要机制； II，FOXO1表达可以单手赋予胰岛素调节，以调节葡萄糖-6-磷酸酶的表达，葡萄糖-6-磷酸酶是糖基解体中速率限制酶。 III，FOXO1与PGC1Alpha相互作用以刺激糖异生。 IV，FOXO1将胰岛素信号传导与Beta细胞质量的PDX1调节联系起来。现在，我们提供了初步数据，将FOXO功能的范围扩展到调节细胞分化和防止氧化应激的保护，同时还扩大了Foxo靶基因的曲目。我们证明这些功能基于Foxo作用的两种新型模式：乙酰化依赖性靶向核PML体，以及与Notch效应子CSL的蛋白质/蛋白质相互作用。后一个观察结果表明FOXO1起着共激活因子的作用，而不仅仅是转录因子。它还桥接了两个重要的信号通路，即PI 3-激酶和HES1途径。在接下来的五年中，我们将努力将这些新信息纳入FOXO1动作机制及其在代谢疾病中的作用。我们建议研究：在AIM 1中，如何将磷酸化和乙酰化介导的机制整合到体内，以确定生理状况和疾病状态下FOXO1亚细胞定位的动力学；在AIM 2中，FOXO1的乙酰化依赖性亚核靶向如何调节肝脏，胰腺β细胞和脂肪细胞的代谢；在AIM 3中，如何确定FOXO1的共激活因子和转录函数之间的平衡。这些研究将使用已在PI实验室中完全实施的转基因小鼠和培养细胞的遗传损失和功能获得实验进行。这项工作的最终目标是找到一种修改FOXO1功能的治疗方法。实际上，尽管FOXO1是治疗糖尿病和代谢疾病的极具吸引力的生物学靶标，但它在很大程度上是棘手的药物靶标。因此，希望通过识别行动机制和互动伙伴，可以找到调节其功能的新方法。