Fluorescent images illustrating the effect of changes in gravin distribution on PKA RII distribution in HEC-1-A (A–J) and AN3 CA cells (K–T) after PMA treatment. PMA treatment did not affect PKA RII-ECFP distribution in cells expressing PKA RII-ECFP alone (A, F, K, P). Similarly, PKA RII-ECFP did not change distribution after PMA treatment in cells co-expressing PKA RII-ECFP and gravin-EGFP lacking the PKA RII binding domain (Δ-PKA gravin; D, I; E, J; N, S; O, T), although the gravin construct underwent redistribution to a vesicular compartment. In cells co-expressing full length gravin-EGFP and PKA RII-ECFP however, the gravin and PKA RII constructs both underwent redistribution from the cell periphery in response to PMA treatment and colocalized in the juxtanuclear region of the cells (B, G; C, H; L, Q; M, R). Arrows point to the vesicular membranes to where the PKA RII-ECFP redistributed. Scale bar, 20 µm.