Fig. 4. PKB[KD]-GLUT4 and Myr-PKB[KD] act as dominant-negative
inhibitors of insulin-stimulated IRAP-GFP translocation in 3T3-L1 adipocytes.
3T3-L1 adipocytes were microinjected with plasmids encoding IRAP-GFP (A-C) and
either kinase-inactive PKB (A; PKB[KD]), kinase-inactive PKB fused to
the N-terminus of GLUT4 (B; PKB[KD]-Glut4) or kinase-inactive
myristoylated PKB (C; Myr-PKB[KD]). 16 hours later the cells were
serum starved for 2 hours and then incubated in the presence of insulin at 100
nM for 30 minutes. The cells were then fixed and stained with anti-HA
antibodies to visualise the PKB constructs (as indicated). Bars, 10 µm. The
arrow in C indicates a cell that expresses IRAP-GFP but little detectable
Myr-PKB[KD] and which still responds to insulin, unlike its neighbour
which co-expresses significant amounts of Myr-PKB[KD].