Figure 2.

Growth factor attenuates Glut1 internalization and promotes Rab11a-dependent recycling of intracellular Glut1. (A) FLAG-Glut1 cells were cultured in IL3 or withdrawn from IL3 for 6 h. Cells were stained with anti-FLAG antibody, washed, and cultured at 37°C for indicated times before staining with fluorescent secondary antibody. (B and C) FLAG-Glut1 cells were transiently transfected with control or dominant-negative Rab11a (Rab11aS25N/dnRab11a) vector and cultured in IL3 or in the absence of IL3 for 6 h. (B) Total FLAG-Glut1 expression levels were measured by immunoblot with actin as a loading control. Total levels of FLAG were normalized to actin and are shown below the immunoblot. (C) Surface FLAG-Glut1 levels were measured by flow cytometry and normalized to total FLAG expression. Mean and SD of triplicate samples are shown. Asterisk (*) indicates p < 0.005 within the experiment.