Figure 3

Visualization of GPCRs by auto-fluorescent proteins. Commonly, AFPs are fused to the C-terminus of the GPCR (A). Localization of hY₁R-EYFP in HEK293 cells (B; receptor in yellow, nuclei in blue, bar represents 10 μm). Receptor expression as well as membrane and subcellular GPCR localization can be easily followed, since the fluorescence is generated in vivo and no additional labeling is reqired. Localization of human Y₅ receptor C-terminally fused to ECFP in HEK293 cells stably expressing hY₁R-EYFP (C; hY₅R in green, hY₁R in red, bar represents 10 μm). The spectral properties of AFPs allow receptor co-expression and co-localization studies.