Fig. 4.

Forskolin-stimulated PKA activity at the plasma membrane (AKAR3-CAAX) and cytosol (AKAR3-NES) in AN3 CA cells co-expressing AKAR3 and either full-length (WT) gravin-V5/His or ΔPKA gravin which lacks the PKA binding domain. Representative confocal micrographs show the distribution of transfected gravin-V5/His constructs in fixed cells immunolabeled with a gravin antibody. Graphs A,B show that while WT gravin expression increased forskolin-stimulated PKA activity levels at the plasma membrane, this increase was not observed in cells expressing (ΔPKA) gravin. Graphs C,D show that the gravin-mediated decrease in cytosolic PKA activity levels was not observed in cells expressing ΔPKA gravin. One-way ANOVA with Holm-Sidak post hoc tests revealed significant differences between treatments as indicated by asterisks (p < 0.05); error bars denote SD. Scale bar = 10 μm