Backer J M, Kahn C R, White M F
Joslin Diabetes Center, Department of Medicine, Brigham and Women's Hospital, Boston, MA 02215.
Proc Natl Acad Sci U S A. 1989 May;86(9):3209-13. doi: 10.1073/pnas.86.9.3209.
The relation between insulin-stimulated autophosphorylation of the insulin receptor and internalization of the receptor was studied in Fao rat hepatoma cells. Treatment of Fao cells with 2,4-dinitrophenol for 45 min depleted cellular ATP by 80% and equally inhibited insulin-stimulated receptor autophosphorylation, as determined by immunoprecipitation of surface-iodinated or [32P]phosphate-labeled cells with anti-phosphotyrosine antibody. In contrast, internalization of the insulin receptor and internalization and degradation of 125I-labeled insulin by 2,4-dinitrophenol-treated cells were normal. These data show that autophosphorylation of the insulin receptor is not required for the receptor-mediated internalization of insulin in Fao cells and suggest that insulin receptor recycling is independent of autophosphorylation.
在Fao大鼠肝癌细胞中研究了胰岛素刺激的胰岛素受体自磷酸化与受体内化之间的关系。用2,4-二硝基苯酚处理Fao细胞45分钟，使细胞内ATP耗竭80%，并同样抑制胰岛素刺激的受体自磷酸化，这是通过用抗磷酸酪氨酸抗体对表面碘化或[32P]磷酸盐标记的细胞进行免疫沉淀来确定的。相比之下，2,4-二硝基苯酚处理的细胞中胰岛素受体的内化以及125I标记胰岛素的内化和降解是正常的。这些数据表明，在Fao细胞中，胰岛素受体介导的胰岛素内化不需要胰岛素受体的自磷酸化，提示胰岛素受体的再循环独立于自磷酸化。
