Analyzing the role of TXNIP as a universal regulator of glucose transport

分析 TXNIP 作为葡萄糖转运通用调节剂的作用

• 批准号: 10238864
• 负责人: Ning Wu
• 金额: $ 39.9万
• 依托单位: VAN ANDEL RESEARCH INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-15 至 2022-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10238864
• 关键词: 1-Phosphatidylinositol 3-Kinase; 5' -AMP-activated protein kinase; Acute; Adipocytes; Adipose tissue; Affect; Arrestins; Biochemical; Biological; Biological Assay; Biological Process; Cancerous; Carrier Proteins; Cell membrane; Cells; Clathrin; Defect; Disease; Endocytosis; Environment; Event; Exercise; Family; Foundations; Future; G-Protein-Coupled Receptors; GLUT 4 protein; GLUT-1 protein; GLUT-2 protein; GLUT-3 protein; Glucose; Glucose Transporter; Growth; Growth Factor; Human; Hyperlipidemia; Hyperphagia; Hypoglycemia; In Vitro; Insulin; Investigation; Knockout Mice; Knowledge; Learning; Lipids; Location; Malignant Neoplasms; Maps; Mediating; Metabolic; Metabolic stress; Metabolic syndrome; Mitogen-Activated Protein Kinases; Modeling; Movement; Mus; Muscle; Muscle Fibers; Nutrient; Organism; Pathway interactions; Peripheral; Phenotype; Phosphatidylinositols; Phosphorylation; Phosphorylation Site; Phosphotransferases; Physiological; Play; Post-Translational Protein Processing; Postabsorptive Hypoglycemia; Proteins; Proto-Oncogene Proteins c-akt; Regulation; Reporting; Role; SLC2A1 gene; Sequence Homology; Signal Transduction; Site; Stress; Structure; Symptoms; System; TXNIP gene; Testing; Tissues; Up-Regulation; Vitamin D; age related; blood glucose regulation; cell growth; cell type; extracellular; glucose metabolism; glucose transport; glucose uptake; human disease; human old age (65+); in vivo; insight; insulin regulation; knockout animal; member; metabolic phenotype; metabolic profile; prevent; protein degradation; protein transport; prototype; response; solute; therapy development; tumor growth; upstream kinase

PROJECT SUMMARY Glucose is one of the most highly regulated metabolites for nearly all organisms. In humans, misregulation of glucose metabolism plays a role in many diseases, from systemic metabolic syndrome to cancerous cell growth. This proposal focuses on the glucose transporters (GLUTs) in the solute carrier family 2 (SLC2), which includes the well-known transporters GLUT1, GLUT2, GLUT3, and GLUT4. These transporters facilitate the movement of glucose across the cell membrane following concentration gradients in an energy-independent manner. Since GLUTs serve as gates between the cell and the extracellular environment, their activity must be tightly controlled by both signaling events and metabolite levels. Despite their key roles in the major metabolic tissues, very little is known about GLUT protein-level regulation. Insulin regulation of GLUT4 is the notable exception, but even in this case, many mechanistic details (such as insulin-dependent inhibition of GLUT4 endocytosis) remain unknown. We discovered that an α-arrestin protein, TXNIP (thioredoxin interacting protein), acts as an adaptor between GLUT1 and the clathrin-dependent endocytosis machinery, facilitating GLUT1 endocytosis. The interaction between TXNIP and GLUT1 is signal-dependent: phosphorylation of TXNIP by AMPK (AMP-activated kinase) dissociates TXNIP from GLUT1, preventing GLUT1 endocytosis, thus leading to a rapid increase in glucose influx. Given the sequence and structural homology among the GLUTs, together with signal-induced post- translational modifications found on the TXNIP protein, we aim to show that TXNIP is a universal regulatory node evolved for modulating acute glucose flux response. Specific Aim 1 will analyze the regulation of TXNIP on GLUTs, using GLUT1 as the prototype and developing a detailed map of its interaction through various biochemical assays. The information we learn about GLUT1 will be tested on other GLUTs, particularly GLUT4, to verify the role of TXNIP as a common adaptor for all GLUTs. In this Aim, we will also examine the role of lipids in TXNIP-GLUT interactions to build a foundation for future investigation of GLUT protein trafficking. Specific Aim 2 will focus on the upstream regulation of TXNIP by cell signaling events, particularly growth factor stimulation. We intend to identify upstream kinases and their phosphorylation sites on TXNIP; we also plan to test the effect of this regulation in vivo, using insulin regulation of glucose uptake in muscle and adipose tissue as the model. Muscle- and adipose-specific TXNIP knock-out mice will be generated to examine their metabolic profile. Combined understanding of the upstream and downstream regulatory mechanisms of TXNIP should provide greater insight into how glucose metabolism can be misregulated in human diseases.

项目总结 葡萄糖是几乎所有生物体中最受调控的代谢物之一。在人类中，错误的调节 从全身性代谢综合征到癌细胞，葡萄糖代谢在许多疾病中都起着作用 成长。这项建议集中在溶质载体家族2(SLC2)中的葡萄糖转运体(GLUT)，它 包括广为人知的转运蛋白GLUT1、GLUT2、GLUT3和GLUT4。这些传输器促进了 不依赖能量的浓度梯度下葡萄糖在细胞膜上的移动 举止。由于谷氨酸是细胞和细胞外环境之间的大门，它们的活性必须是 受到信号事件和代谢物水平的严格控制。尽管它们在主要新陈代谢中扮演着关键角色 组织中，对过量蛋白质水平的调控知之甚少。胰岛素对GLUT4的调节作用值得注意 例外，但即使在这种情况下，许多机制细节(如胰岛素依赖的GLUT4抑制 内吞作用)仍不清楚。 我们发现，α-arrestin蛋白TXNIP(硫氧还蛋白相互作用蛋白)在 Glut1和依赖于笼蛋白的内吞机制，促进GLUT1内吞。互动 TXNIP和GLUT1之间的信号依赖：AMPK对TXNIP的磷酸化 使TXNIP与GLUT1解离，防止GLUT1内吞，从而导致血糖迅速增加 涌入。鉴于GLUG之间的序列和结构同源性，以及信号诱导的后 在TXNIP蛋白上发现翻译修饰，我们的目的是证明TXNIP是一个通用的调节因子 结节的进化是为了调节急性葡萄糖流量反应。 具体目标1将以GLUT1为原型，分析TXNIP对GLUTS的调节作用，并开发出 通过各种生化分析显示其相互作用的详细图谱。我们了解的关于GLUT1的信息将 在其他GLUT上进行测试，特别是GLUT4，以验证TXNIP作为所有GLUT的通用适配器的作用。 在这个目标中，我们还将研究脂类在TXNIP-GLUT相互作用中的作用，为未来奠定基础 调查供过于求的蛋白质贩运。具体目标2将重点放在细胞对TXNIP的上游调控 信号事件，特别是生长因子刺激。我们打算识别上游的蛋白激酶及其 TXNIP上的磷酸化位点；我们还计划通过胰岛素调节，在体内测试这种调节的效果 以肌肉和脂肪组织的葡萄糖摄取为模型。肌肉和脂肪特异性TXNIP基因敲除 将产生小鼠来检查它们的代谢情况。结合对上游和 TXNIP的下游调节机制应该能更好地了解葡萄糖代谢如何 在人类疾病中受到不合理的监管。

项目成果

Excess dietary carbohydrate affects mitochondrial integrity as observed in brown adipose tissue.

• DOI: 10.1016/j.celrep.2021.109488
• 发表时间: 2021-08-03
• 期刊: Cell reports
• 影响因子: 8.8
• 作者: Waldhart AN;Muhire B;Johnson B;Pettinga D;Madaj ZB;Wolfrum E;Dykstra H;Wegert V;Pospisilik JA;Han X;Wu N
• 通讯作者: Wu N