FIGURE 4.

Effect of 11-cis-retinoids on expressed human rod and cone opsin activities. Transducin activation by expressed human (A) rod, (B) red cone, (C) green cone, and (D) blue cone opsins (open circles) with 11-cis-retinol (filled circles) and with retinal (triangles). At 5.5 min, the samples with 11-cis-retinoids were illuminated for 12 s, and only opsins with 11-cis-retinal showed a light-dependent increase in transducin activation. Each sample was assayed in triplicate and averaged; error bars reflect mean ± S.E. and often were smaller than the symbol size. At 5.5 min, samples with 11-cis-retinal and 11-cis-retinol were illuminated with light for 12 s as described under “Experimental Procedures” and illustrated in the figure with the vertical line.