EPIDERMAL GROWTH-FACTOR TRIGGERS THE TRANSLOCATION OF INSULIN-RESPONSIVE GLUCOSE-TRANSPORTER (GLUT4)

In a novel cell line we developed for direct, sensitive detection of i nsulin-responsive glucose transporter (GLUT4) on the cell surface, we considered that insulin-activated phosphatidylinositol 3-kinase (PI 3- kinase) may be involved in the signaling pathway of insulin-stimulated GLUT4 translocation. We report here evidence that epidermal growth fa ctor (EGF), which stimulates PI 3-kinase activity, also triggers GLUT4 translocation in Chinese hamster ovary (CHO) cells stably overexpress ing the EGF receptor. The EGF-dependent GLUT4 translocation is possibl y mediated by two independent pathways: one by PI 3-kinase and the oth er by protein kinase C (PKC); the PI 3-kinase-mediated pathway predomi nates. Triggering of the GLUT4 translocation is not specific for insul in, rather it may be a common property of growth factors which activat e PI 3-kinase. (C) 1994 Academic Press, Inc.