Omata W, Shibata H, Suzuki Y, Tanaka S, Suzuki T, Takata K, Kojima I
Department of Cell Biology, Gunma University, Maebashi, Japan.
Biochem Biophys Res Commun. 1997 Dec 18;241(2):401-6. doi: 10.1006/bbrc.1997.7810.
We have investigated the subcellular distribution of GLUT4 by immunofluorescence microscopy after transfection with wild-type or mutant dynamin cDNA into Chinese hamster ovary cells expressing insulin receptor and GLUT4. In the basal state, GLUT4 was distributed exclusively within the cells in the cells overexpressing wild-type dynamin (CHOIR-GLUT4-WT) but was located at the cell surface in the cells overexpressing mutant dynamin (CHOIR-GLUT4-K44E). Insulin induced subcellular shift of GLUT4 to the cell surface in CHOIR-GLUT4-WT cells but had little effect in CHOIR-GLUT4-K44E cells. When insulin-stimulated cells were treated with wortmannin, GLUT4 was redistributed within the cells in CHOIR-GLUT4-WT cell, whereas it remained at the cell surface in CHOIR-GLUT4-K44E cell. These results suggest that dynamin is a regulatory GTPase in endocytosis of GLUT4.
我们通过免疫荧光显微镜研究了在中国仓鼠卵巢细胞中过表达胰岛素受体和GLUT4后，野生型或突变型发动蛋白cDNA转染对GLUT4亚细胞分布的影响。在基础状态下，GLUT4仅分布于过表达野生型发动蛋白的细胞（CHOIR-GLUT4-WT）内，但位于过表达突变型发动蛋白的细胞（CHOIR-GLUT4-K44E）的细胞表面。胰岛素诱导CHOIR-GLUT4-WT细胞中GLUT4向细胞表面的亚细胞移位，但对CHOIR-GLUT4-K44E细胞几乎没有影响。当用渥曼青霉素处理胰岛素刺激的细胞时，GLUT4在CHOIR-GLUT4-WT细胞内重新分布，而在CHOIR-GLUT4-K44E细胞中仍保留在细胞表面。这些结果表明发动蛋白是GLUT4内吞作用中的一种调节性GTP酶。
