TUG-mediated GLUT4 glucose transporter trafficking and regulation by post-transla

TUG 介导的 GLUT4 葡萄糖转运蛋白转运和翻译后调节

• 批准号: 8254918
• 负责人: Jonathan Philip Belman
• 金额: $ 4.68万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-16 至 2013-09-15
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8254918
• 关键词: 14-3-3 Proteins; Acetylation; Adipocytes; Adipose tissue; Affect; Americas; Binding; Blood Glucose; Cell membrane; Cell physiology; Cell surface; Cells; Cellular biology; Characteristics; Coiled-Coil Domain; Complex; Data; Defect; Disease; Doctor of Philosophy; Dominant-Negative Mutation; Epidemic; Exocytosis; GLUT 4 protein; GLUT4 gene; Genetic; Glucose; Glucose Transporter; Goals; Golgi Apparatus; Health; Hyperglycemia; Insulin; Insulin Resistance; Insulin Signaling Pathway; Intervention; Intracellular Membranes; Investigation; Light; Mediating; Mediator of activation protein; Mentors; Microtubules; Modeling; Morbidity - disease rate; Motor; Muscle; Non-Insulin-Dependent Diabetes Mellitus; Pathogenesis; Plasma; Play; Process; Property; Proteins; Public Health; Publishing; RNA Interference; Regulation; Research; Role; Site; Subcellular structure; System; Testing; Tissues; Vesicle; base; glucose uptake; insight; insulin sensitivity; mortality; mutant; prevent; protein transport; research study; response; trafficking; trans-Golgi Network; uptake

DESCRIPTION (provided by applicant): Type 2 diabetes is one of the most common diseases in America and carries an enormous impact on public health, having reached epidemic proportions worldwide. Type 2 diabetes is characterized by a defective response to insulin, which prevents normal uptake of post-prandial glucose into muscle and adipose tissue and contributes to hyperglycemia and long-term complications. Glucose transporter 4 (GLUT4) is the major insulin responsive glucose transporter. Translocation of GLUT4 from intracellular membranes to the cell surface is required for insulin to enhance glucose uptake, and defects in this process in this process contribute to type 2 diabetes pathogenesis. Much research has indicated the importance of insulin signaling pathways in this defect but increasing evidence points to a role in GLUT4 trafficking itself. However, the precise mechanisms controlling GLUT4 trafficking are largely unclear. Tether containing a UBX domain for GLUT4 (TUG) was discovered by my mentor and shown to be an important regulator of GLUT4 trafficking, essential for intracellular retention of GLUT4 within cells not stimulated by insulin. Although the TUG C-terminus is necessary for this retention, it is not known how TUG performs this function. The goal of my PhD thesis and this proposal is to study how the TUG C-terminus mediates intracellular retention of GLUT4 and how acetylation of the TUG C-terminus modulates its function. As part of this, we look to test our favored model that, based on both preliminary and published data, hypothesizes TUG to function in an intracellular anchoring mechanism for GLUT4 involving the trans-Golgi network (TGN) protein GCC185, a known mediator of vesicle trafficking. Further, we propose that acetylation of TUG is important for this anchoring function. We will test these hypotheses with two Specific Aims. In the first Aim, I will employ genetic knockdown of GCC185 to test if this disrupts intracellular sequestration of GLUT4 in unstimulated 3T3-L1 adipocytes. In the second Aim, I will study how TUG acetylation modulates its function, and will test the hypotheses that acetylation controls the size of the insulin- responsive GLUT4 pool and is required for TUG to bind to GCC185. We will investigate other candidate anchors already identified by our lab and other functions of TUG acetylation as needed. The results of this research will elucidate how GLUT4 traffics within cells, and will enhance the understanding of how insulin sensitivity may be controlled by acetylation. These are important questions for type 2 diabetes, and may also have more fundamental significance for cell biology and physiology.

描述(申请人提供)：2型糖尿病是美国最常见的疾病之一，对公众健康具有巨大的影响，已在全球范围内流行。2型糖尿病的特点是对胰岛素的反应有缺陷，这会阻止餐后葡萄糖正常摄取到肌肉和脂肪组织，并导致高血糖和长期并发症。葡萄糖转运蛋白4(GLUT4)是胰岛素反应的主要葡萄糖转运蛋白。胰岛素需要GLUT4从细胞内膜到细胞表面的转位来增强葡萄糖的摄取，而这一过程中的缺陷导致了2型糖尿病的发病。许多研究已经表明胰岛素信号通路在这一缺陷中的重要性，但越来越多的证据表明，GLUT4交易本身也起到了作用。然而，控制GLUT4贩运的确切机制在很大程度上尚不清楚。含有GLUT4 UBX结构域的系绳(TUG)是由我的导师发现的，并被证明是GLUT4运输的重要调节因子，对于GLUT4在不受胰岛素刺激的细胞内的滞留是必不可少的。尽管TUG的C-末端对于这种保持是必要的，但TUG如何执行这一功能尚不清楚。我的博士论文和这项建议的目的是研究TUG C末端如何介导GLUT4在细胞内的滞留，以及TUG C末端的乙酰化如何调节其功能。作为这项工作的一部分，我们希望测试我们青睐的模型，该模型基于初步和已发表的数据，假设TUG在GLUT4的细胞内锚定机制中发挥作用，涉及跨高尔基网络(TGN)蛋白GCC185，GCC185是一种已知的囊泡运输中介。此外，我们认为TUG的乙酰化对这种锚定功能是重要的。我们将用两个具体的目标来检验这些假设。在第一个目标中，我将使用GCC185的基因敲除来测试这是否扰乱了未受刺激的3T3-L1脂肪细胞中GLUT4的细胞内隔离。在第二个目标中，我将研究TUG乙酰化如何调节其功能，并将检验以下假设：乙酰化控制胰岛素反应性GLUT4池的大小，并要求TUG与GCC185结合。我们将研究我们实验室已经确定的其他候选锚点，并根据需要研究TRAG乙酰化的其他功能。这项研究的结果将阐明GLUT4是如何在细胞内运输的，并将加强对胰岛素敏感性如何通过乙酰化来控制的理解。这些都是2型糖尿病的重要问题，也可能对细胞生物学和生理学具有更基本的意义。