FIGURE 3.

Membrane colocalization of CaM with A_2A or D₂ receptors. Co-transfected HEK-293 cells were washed and resuspended for 2.5 h in HBSS buffer containing 1.26 mm CaCl₂ (A–D and I–L) or in a Ca⁺²-free HBSS buffer containing 1 mm EDTA (E–H). A, E, and I, confocal microscopy images of HEK-293T cells expressing (from left to right in each panel) CaMYFP (0.6 μg of cDNA), A_2ARRluc (1 μg of cDNA), or D₂RRluc (1 μg of cDNA). B–D, F–H, and J–L, confocal microscopy images of HEK-293T cells co-transfected with the above described amounts of cDNA for CaMYFP and A_2ARRluc (B, F, and J), CaMYFP and D₂RRluc (C, G, and K), or CaMYFP and A₁RRluc (1 μg of cDNA) (D, H, and L). Ionomycin-treated cells (10 min prior to fixation) are shown in I–L. CaM was identified by YFP fluorescence (green images), and receptor-Rluc constructs were identified by immunocytochemistry (using a monoclonal anti-Rluc primary antibody and a cyanine-3-conjugated secondary antibody). Colocalization (yellow) is shown in the right panels.