ARRDC4 与 GLUT1 的相互作用介导缺血性心脏中的代谢应激。
Interaction of ARRDC4 With GLUT1 Mediates Metabolic Stress in the Ischemic Heart.
机构信息
Department of Molecular, Cellular & Biomedical Sciences, City University of New York School of Medicine, City College of New York, New York, New York (Y.N., N.M., G.K., J.Y.).
Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts (P.P., J.Y.).
出版信息
Circ Res. 2022 Sep 2;131(6):510-527. doi: 10.1161/CIRCRESAHA.122.321351. Epub 2022 Aug 11.
BACKGROUND
An ancient family of arrestin-fold proteins, termed alpha-arrestins, may have conserved roles in regulating nutrient transporter trafficking and cellular metabolism as adaptor proteins. One alpha-arrestin, TXNIP (thioredoxin-interacting protein), is known to regulate myocardial glucose uptake. However, the in vivo role of the related alpha-arrestin, ARRDC4 (arrestin domain-containing protein 4), is unknown.
METHODS
We first tested whether interaction with GLUTs (glucose transporters) is a conserved function of the mammalian alpha-arrestins. To define the in vivo function of ARRDC4, we generated and characterized a novel knockout (KO) mouse model. We then analyzed the molecular interaction between arrestin domains and the basal GLUT1.
RESULTS
ARRDC4 binds to GLUT1, induces its endocytosis, and blocks cellular glucose uptake in cardiomyocytes. Despite the closely shared protein structure, ARRDC4 and its homologue TXNIP operate by distinct molecular pathways. Unlike TXNIP, ARRDC4 does not increase oxidative stress. Instead, ARRDC4 uniquely mediates cardiomyocyte death through its effects on glucose deprivation and endoplasmic reticulum stress. At baseline, -KO mice have mild fasting hypoglycemia. -KO hearts exhibit a robust increase in myocardial glucose uptake and glycogen storage. Accordingly, deletion of improves energy homeostasis during ischemia and protects cardiomyocytes against myocardial infarction. Furthermore, structure-function analyses of the interaction of ARRDC4 with GLUT1 using both scanning mutagenesis and deep-learning identify specific residues in the C-terminal arrestin-fold domain as the interaction interface that regulates GLUT1 function, revealing a new molecular target for potential therapeutic intervention against myocardial ischemia.
CONCLUSIONS
These results uncover a new mechanism of ischemic injury in which ARRDC4 drives glucose deprivation-induced endoplasmic reticulum stress leading to cardiomyocyte death. Our findings establish ARRDC4 as a new scaffold protein for GLUT1 that regulates cardiac metabolism in response to ischemia and provide insight into the therapeutic strategy for ischemic heart disease.
背景
一种名为α-arrestin 的古老 arrestin 折叠蛋白家族可能作为衔接蛋白在调节营养转运体和细胞代谢中具有保守作用。已知一种α-arrestin，即 TXNIP（硫氧还蛋白相互作用蛋白），可调节心肌葡萄糖摄取。然而，相关的α-arrestin ARRDC4（arrestin 结构域包含蛋白 4）的体内作用尚不清楚。
方法
我们首先测试了哺乳动物α-arrestin 是否具有与 GLUTs（葡萄糖转运体）相互作用的保守功能。为了定义 ARRDC4 的体内功能，我们生成并表征了一种新型 KO 小鼠模型。然后，我们分析了 arrestin 结构域与基础 GLUT1 之间的分子相互作用。
结果
ARRDC4 与 GLUT1 结合，诱导其内吞，并阻断心肌细胞中的细胞葡萄糖摄取。尽管蛋白质结构非常相似，但 ARRDC4 和其同源物 TXNIP 通过不同的分子途径发挥作用。与 TXNIP 不同，ARRDC4 不会增加氧化应激。相反，ARRDC4 通过对葡萄糖剥夺和内质网应激的影响，独特地介导心肌细胞死亡。在基础状态下，-/-小鼠有轻度空腹低血糖。-/- 心脏表现出心肌葡萄糖摄取和糖原储存的显著增加。因此，缺失可改善缺血期间的能量稳态并保护心肌细胞免受心肌梗死。此外，使用扫描诱变和深度学习对 ARRDC4 与 GLUT1 的相互作用进行结构-功能分析，确定了 C 末端 arrestin 折叠结构域中的特定残基作为调节 GLUT1 功能的相互作用界面，揭示了针对心肌缺血的潜在治疗干预的新分子靶点。
结论
这些结果揭示了一种新的缺血性损伤机制，其中 ARRDC4 驱动葡萄糖剥夺诱导的内质网应激导致心肌细胞死亡。我们的发现确立了 ARRDC4 作为 GLUT1 的新支架蛋白，可调节心脏对缺血的代谢反应，并为缺血性心脏病的治疗策略提供了深入了解。
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