Molecular Mechanisms of Arrestin-Domain Containing Proteins in Metabolism

含有抑制蛋白结构域的蛋白质在代谢中的分子机制

基本信息

批准号：
10320336
负责人：
RICHARD T LEE
金额：
$ 42.25万
依托单位：
HARVARD UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-01-01 至 2024-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10320336
关键词：
Address Amino Acid Sequence Amino Acid Substitution Amino Acids Arrestins Binding Biochemical Biochemistry C-terminal Carrier Proteins Cells Collaborations Crystallization Cysteine Data Diabetes Mellitus Disease Family Family member Fructose G Protein-Coupled Receptor Signaling Glucose Glucose Clamp Glucose Transporter High Fat Diet In Vitro Insulin Insulin Receptor Investigation Laboratories Link Manuscripts Metabolic Metabolism Molecular Mus Mutation Obesity Oxidation-Reduction Paper Pathway interactions Play Prediabetes syndrome Proteins Reporting Role SLC2A1 gene Structure TXN gene TXNIP gene Tail Testing Tissues United States Visual arrestin 1 beta-arrestin blood glucose regulation experimental study glucose metabolism glucose uptake glucose-regulated proteins human male improved in vivo insulin sensitivity insulin signaling member metabolic abnormality assessment metabolic phenotype molecular imaging mouse model

项目摘要

The arrestin superfamily is composed of two subfamilies: the classical visual/beta-arrestins that were first identified as regulators of G-protein coupled receptor signaling, and the more ancient branch of arrestin domain-containing proteins that are sometimes called the “alpha-arrestins”. Recently, the roles of some members of the alpha-arrestin family have been revealed in mammalian metabolism. The most studied member of the alpha-arrestin family is thioredoxin interacting protein (TXNIP), which regulates glucose and fructose metabolism. Arrestin domain-containing 4 (ARRDC4) is a member of the alpha-arrestin family that has not been subject to extensive investigation. The arrestin domains of ARRDC4 show 41% amino acid sequence similarity to TXNIP; therefore, ARRDC4 might be expected to have functions similar to TXNIP. However, we have shown that TXNIP is the only member of the family that binds covalently to thioredoxin. Consistent with our biochemistry studies, the recently solved crystal structure revealed that the cysteine 247 residue of TXNIP is essential for binding covalently to thioredoxin. Furthermore, we have reported that mice with deletion of TXNIP have improved insulin sensitivity, indicating a potential like between redox state and glucose metabolism through thioredoxin. Here we show new unpublished experiments revealing that mice with global deletion of arrdc4 have improved insulin sensitivity. We also show improved insulin signaling in metabolic tissues from mice with deletion of arrdc4. Our preliminary data demonstrate that the ARRDC4 protein interacts directly with glucose transporter protein 4 (GLUT4) in insulin-stimulated conditions. Furthermore, we present a new mouse model with mutation of C247 of TXNIP and show that this single amino acid change in TXNIP improves insulin sensitivity in mice fed a High Fat Diet. In this project, we will use these new discoveries and mouse models to understand how arrestin domain-containing proteins regulate glucose metabolism in vivo and at the molecular mechanism level. Our Specific Aims are: Specific Aim 1 will test the hypothesis that alpha-arrestin protein ARRDC4 regulates insulin-stimulated glucose uptake in vivo. Specific Aim 2 will investigate the molecular mechanisms of alpha arrestin domain-containing protein interactions with glucose transporters and insulin receptor. Specific Aim 3 will test the hypothesis that TXNIP can regulate insulin sensitivity through thioredoxin-independent mechanisms and identify the target tissue responsible.

逮捕蛋白超家族由两个亚家族组成：首先被确定为G蛋白耦合受体信号传导的调节剂的经典视觉/β-art蛋白，以及有时称为“ alpha-arrpha-arrpha-arrpha-arrpha-arrpha-arrpha-arrpha-arrpha-arpha的蛋白质”的更古老的分支。最近，哺乳动物代谢中已经揭示了Alpha-arrestin家族的一些成员的作用。 α-arrestin家族中研究的最多的成员是硫氧还蛋白相互作用的蛋白（TXNIP），可调节葡萄糖和果糖代谢。含毒素域的4（ARRDC4）是尚未接受广泛调查的Alpha-arrestin家族的成员。 ARRDC4的阻止素结构域显示41％的氨基酸序列与TXNIP相似。因此，可能期望ARRDC4具有类似于TXNIP的功能。但是，我们已经表明TXNIP是该家族中唯一与硫氧还蛋白共价结合的家族成员。与我们的生物化学研究一致，最近解决的晶体结构表明，TXNIP的半胱氨酸247居住对于与硫氧还蛋白共价结合至关重要。此外，我们报道了删除TxNIP的小鼠提高了胰岛素敏感性，表明氧化还原态和葡萄糖之间的潜力通过硫氧还蛋白的代谢。在这里，我们展示了新的未发表的实验，表明具有全球缺失ARDC4的小鼠具有提高胰岛素敏感性。我们还显示了删除ARDC4的小鼠的代谢组织中胰岛素信号的改善。我们的初步数据表明，在胰岛素刺激的条件下，ARRDC4蛋白与葡萄糖转运蛋白4（GLUT4）直接相互作用。此外，我们提出了一种新的小鼠模型，该模型具有TXNIP C247突变的新小鼠模型，并表明TXNIP中这种单个氨基酸的变化可改善喂养高脂饮食的小鼠的胰岛素敏感性。在这个项目中，我们将使用这些新发现和小鼠模型来了解含毒素结构域的蛋白如何调节体内和分子机理水平的葡萄糖代谢。我们的具体目的是：具体目标1将检验以下假设：α-钟甲蛋白ARRDC4调节体内胰岛素刺激的葡萄糖摄取。具体的目标2将研究含有alpha阻滞蛋白结构域蛋白质的分子机制与葡萄糖转运蛋白和胰岛素受体的相互作用。具体目标3将检验以下假设：TXNIP可以通过硫氧还蛋白独立的机制调节胰岛素敏感性，并确定负责的靶组织。