FIG. 5.

Translocation of GLUT4 can bypass Akt signaling in HCMV-infected cells. (A) Akt signaling is not involved in the activation of GLUT4 expression in HCMV-infected cells. Serum-starved HFs were pretreated with 1 μM AKTi for 1 h. Then, the cells were either mock treated or infected with HCMV in serum-free medium in the presence or absence of 1 μM AKTi. Whole-cell extracts were prepared at 48 hpi, and GLUT4, phospho-Akt S473, MIEPs, and actin protein levels were determined by Western analysis. (B) Translocation of GLUT4 can bypass Akt signaling in HCMV-infected cells. Results of fluorescence microscopy analysis of the cellular localization of HA-GLUT4-GFP in HFs are shown. At 2 hpi, mock- or HCMV-infected HFs were electroporated with the HA-GLUT4-GFP reporter plasmid. At 48 hpi the cells were serum starved for 4 h and then either left untreated or treated with insulin and AKTi as described in detail in Materials and Methods. GFP fluorescence (green) is a measure of total GLUT4 expression. Immunofluorescence staining for the HA tag (red) is a measure of GLUT4 on the cell surface. The nuclei were stained with DAPI (blue).