Figure 1. Faa1 and Faa4 are involved in the import of LCBs.

(a) Structures of DHS, SPH, and PHS. (b–e,g) BY4741 (wild-type; WT) cells were incubated with [³H]DHS [(b), 20 μM; (d), indicated concentration] or [³H]palmitic acid (PAL) [(c), 20 μM] for the indicated time period (b,c) or for 5 min (d). BY4741, 6477 (faa1Δ), 833 (faa4Δ), and AOY13 (faa1Δ faa4Δ; ΔΔ) cells were labeled with 20 μM [³H]palmitic acid for 30 min or 20 μM [³H]DHS for 5 min (e). BY4741 and AOY13 cells were labeled with 20 μM [³H]DHS, [³H]SPH, or [³H]PHS for 5 min (g). Radioactivities associated with cells, medium, and glass test tubes were counted by a liquid scintillation counter, and those associated with cells are expressed as a percentage of the total radioactivity. Values represent the means ± SDs of three independent experiments, and statistically significant differences are indicated (t-test; *p < 0.05; **p < 0.01) (e,g). (f) BY4741 and AOY13 cells were labeled with 0.2 μCi [³H]DHS for 60 min. Lipids were extracted, separated by TLC, and detected by autoradiography. Cer, ceramide; PE, phosphatidylethanolamine; PC, phosphatidylcholine; PS, phosphatidylserine; PI, phosphatidylinositol; IPC, inositol phosphorylceramide; MIPC, mannosylinositol phosphorylceramide; M(IP)₂C, mannosyldiinositol phosphorylceramide. (h) TNY42 (FAA1-GFP) and TNY51 (FAA4-GFP) cells were subjected to fluorescence microscopic observation using a DM5000B microscope (Leica Microsystems, Wetzlar, Germany). Bar, 4 μm.