Fig. 6. GABA_B receptors interact with caveolin 1. (a) Cells labeled with an anti-GABA_B receptor antibody (red) and an anti-caveolin 1 antibody (green). Colocalization is seen as a yellow fluorescence. Bar, 10 µm. (b) 2D cytofluorogram. Colocalized pixels are visualized in blue. (c,d) Immunogold labeling in the transmission electron microscopy confirms the colocalization of GABA_B receptors (15 nm gold partcles) and caveolin 1 (10 nm gold particles). Bars, 50 nm. (e) Proteins from Paramecium primaurelia cells (line 1) and human endothelial lysate (line 2) were subjected to SDS-PAGE and western blotting. Two protein bands with estimated molecular masses of 24 and 21 kDa were detected with an anti-caveolin 1 antibody, corresponding to the and ß splicing forms, respectively. The position of the molecular mass marker is shown on the right.