Fig. 2. A. Resonance energy transfer between F₁₈ and R₁₈ labeled membranes.

A representative fluorescence emission scan showing an increase in R₁₈ emission (λ_em=592, blue line) with a concomitant decrease in F₁₈ emission (λ_em=524, pink line) during the fusion of two labeled membrane species. In this particular experiment fusion between F₁₈-labeled COS cell intracellular membranes (expressing FLAG-peripherin constructs) and R₁₈-labeled bovine ROS plasma membrane was measured FRET as described above in the Methods All fusion assays were carried out at room temperature under dim light. B. Fusion between R₁₈-PM and F₁₈-target membranes. FRET- based fusion assays were used to follow fusion between R₁₈-PM and membrane(s) isolated from Control (mock-transfected COS cells) and cells expressing P/rds, ROM-1 or P/rds + ROM-1 in co-transfection analyses. Control target membranes, phosphatiodylcholine LUV (PC LUV), disk lipid extract LUV (DL LUV) or cos cell membrane extract LUV (CS) were prepared as described in the methods. The results show the % fusion at 2 min (black bars), 5 min, (light-gray bars) and 10 minutes, (dark gray bars). All assays were compared to fusion between R₁₈-PM and F₁₈–disks (indicated as disks). Fusion was initiated with the addition of R₁₈-PM to F₁₈-target membranes in 96 well plates at RT. Data represent mean +/+ SE of three independent preparations each done in at least duplicate.