Insulin-responsive compartments containing GLUT4 in 3T3-L1 and CHO cells: Regulation by amino acid concentrations
Insulin-responsive compartments containing GLUT4 in 3T3-L1 and CHO cells: Regulation by amino acid concentrations
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DOI：
10.1128/mcb.21.14.4785-4806.2001
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发表时间：
2001-07-01
影响因子：
5.3
通讯作者：
Lodish, HF
中科院分区：
文献类型：
--
作者：
Bogan, JS;Mckee, AE;Lodish, HF
在脂肪和肌肉中，胰岛素通过将GLUT 4葡萄糖转运蛋白从专门的细胞内区室快速动员到质膜来刺激葡萄糖摄取。我们描述了一种方法来量化GLUT 4在质膜的相对比例，使用流式细胞术来测量对应于细胞表面的荧光强度的比率和单个活细胞中标记的GLUT 4报告基因的总量。使用该试验，我们证明了3 T3-L1和CHO细胞都含有细胞内隔室，胰岛素可快速动员GLUT 4，并且在这两种细胞类型中，当它们相同地培养时，重新分布到质膜的初始幅度和动力学相似。通过培养条件调节GLUT 4靶向CHO细胞中的高度胰岛素响应区室。特别是，我们发现氨基酸通过雷帕霉素敏感途径调节GLUT 4在这个动力学定义的隔室中的分布。氨基酸还调节3 T3-L1脂肪细胞中胰岛素刺激的易位的幅度。我们的研究结果表明，葡萄糖和氨基酸代谢之间的新联系。
In fat and muscle, insulin stimulates glucose uptake by rapidly mobilizing the GLUT4 glucose transporter from a specialized intracellular compartment to the plasma membrane. We describe a method to quantify the relative proportion of GLUT4 at the plasma membrane, using flow cytometry to measure a ratio of fluorescence intensities corresponding to the cell surface and total amounts of a tagged GLUT4 reporter in individual living cells. Using this assay, we demonstrate that both 3T3-L1 and CHO cells contain intracellular compartments from which GLUT4 is rapidly mobilized by insulin and that the initial magnitude and kinetics of redistribution to the plasma membrane are similar in these two cell types when they are cultured identically. Targeting of GLUT4 to a highly insulin responsive compartment in CHO cells is modulated by culture conditions. In particular, we find that amino acids regulate distribution of GLUT4 to this kinetically defined compartment through a rapamycin-sensitive pathway. Amino acids also modulate the magnitude of insulin-stimulated translocation in 3T3-L1 adipocytes. Our results indicate a novel link between glucose and amino acid metabolism.