Microtubule Network Is Required for Insulin Signaling through Activation of Akt/Protein Kinase B: EVIDENCE THAT INSULIN STIMULATES VESICLE DOCKING/FUSION BUT NOT INTRACELLULAR MOBILITY*

摘要: Abstract The microtubule network has been shown to be required for insulin-dependent GLUT4 redistribution; however, the precise molecular function not elucidated. In this article, we used fluorescence recovery after photobleaching (FRAP) evaluate role of microtubules in intracellular vesicle mobility. A comparison rate (t½), and maximum recovered (Fmax) was made between basal insulin-treated cells with or without nocodazole treatment disrupt microtubules. We found that mobility fluorescently tagged (HA-GLUT4-GFP) high cells. Mobility increased by insulin treatment. Basal dependent upon an intact network. Using a constitutively active Akt signal redistribution, microtubule-based obligatory plasma membrane insertion. Our findings suggest organize insulin-signaling complex provide surface vesicles. data do support requirement long range movement vesicles insulin-mediated redistribution cell surface. Taken together, these model which signaling targets docking and/or fusion rather than trafficking