Figure 2.

FATP4 had no effect on synthesis of atRE and 11cRAL but inhibited synthesis of 11cROL. A, RDH5, but not FATP4 or ELOVL1, oxidized 11cROL to 11cRAL. The 293T-LRC cells transfected with the indicated plasmids were incubated with atROL. The 11cRAL in the cells was converted to syn- and anti-retinaloxime isomers by hydroxylamine treatment and was measured by HPLC. B, LRAT assay showing synthesis of atRE from atROL incubated for the indicated times with the cells transfected with pRK5 (control) or FATP4 plasmid. C, Dose-dependent inhibition of 11cROL synthesis by FATP4 in living cells. Synthesis of 11cROL (left y-axis) and atRE (right y-axis) from atROL in 293T-LRC cells transfected with the indicated amounts of FATP4 plasmid were measured by HPLC. A representative immunoblot shows expression levels of FATP4 in the transfected cells. D, In vitro isomerase assay showing synthesis of 11cROL from atRP substrate incubated with homogenates of Sf9 cells infected with the indicated recombinant baculoviruses. A representative immunoblot shows similar expression levels of RPE65 in the baculovirus-infected cells. Error bars indicate SD (n = 4).