Figure 3.

FATP4 functions as a mixed-type inhibitor of RPE65. A, Synthesis of 11cROL from atROL added into the media of 293T-C cells transfected with the indicated amounts of LRAT and constant amounts of RPE65 plus FATP4 or pRK5. A representative immunoblot shows similar expression levels of RPE65 in the transfected cells. B, Relative inhibition rate of 11cROL synthesis by FATP4 in A. Note that the inhibition rate was reduced as the amount of transfected LRAT increased. The immunoblot shows different expression levels of LRAT in the transfected cells. C, Synthesis of 11cROL from varying concentrations of the atRP substrate incubated with homogenates of Sf9 cells expressing RPE65 plus EGFP or FATP4. D, Relative inhibition rate of RPE65 activity by FATP4 in C. Note that the inhibition rate was reduced as the concentration of atRP substrate increased. E, Lineweaver–Burk plot for a dataset from a series of isomerase assays using varying concentrations of the atRP substrate and Sf9 cells infected with RPE65 baculovirus (MOI = 4) and the indicated deferent MOI of FATP4 baculovirus. F, Immunoblots show expression levels of FATP4 and RPE65 in the baculovirus-infected Sf9 cells that were used for isomerase assays in E. G, Effects of long-chain (palmitoyl; 16:0) and very long-chain (lignoceroyl; 24:0) fatty acyl-CoA on the synthesis of 11cROL in an in vitro isomerase assay. Error bars indicate SD (n = 3).