Figure 2

Confocal microscopy analyses of probes translocation. A. Immunocytochemistry analyses of βarr2-AEQ localization in HeLa cells, either co-transfected with β₂AR (right panels) or with an empty vector (left panels), in control condition (upper panels) and upon 40 μM isoprenaline stimulation (1 min) in KRB/EGTA (lower panels). After 1 minute of isoprenaline stimulation, the typical re-localization at the plasma membrane, in almost 80% of the cells, was observed only for βarr2-AEQ co-expressed with β₂AR (lower right panel) because the expression of the endogenous receptors targets of βarr2 is very low in these cells. B. PKCβII-AEQ localization in HeLa cells before (cytosolic, left panel) and after 5 minutes of 1 μM PMA treatment in KRB/EGTA (plasma membrane, right panel). After PMA stimulation almost all (≥ 95%) of the cells showed a PKCβII-AEQ plasma membrane translocation.