Figure 6. Time course of 9-cis-retinal treatment in Rpe65^−/− mice on photoreceptor specific proteins and the inhibitory effect of a protease inhibitor mixture on M-opsin degradation in Rpe65^−/− mice and wild-type mice at three weeks in retinal explants. A: The M-opsin, S-opsin, GNAT2, GNAT1, and rhodopsin levels treated with 0.5 nM 9-cis-retinal for 6, 12, or 24 h are shown with immunoblot in Rpe65^−/− mice. B: Quantitative analysis of effect of 9-cis-retinal on the M-opsin protein level. Histograms indicate mean±SD (n=6), **p<0.01. Western blots were performed to analyze the expression of M-opsin protein in the retina-RPE choroids treated with a protease inhibitor mixture (20 μM pepstatin A, 30 μM E64d, and 10μM MG-132) for 12 h in Rpe65^−/− mice (C) and wild-type mice (D).