Fig. 4

L168S ELOVL4 localizes properly to the Endoplasmic Reticulum (ER) but is deficient in Very Long Chain Saturated fatty acid synthesis. A ARPE-19 cells transduced with WT mouse ELOVL4 and L168S mouse ELOVL4 MYC constructs were immunostained for MYC (red) and CALNEXIN (green). WT and L168S colocalizes with ER transmembrane marker Calnexin (Scale bar, 10 µm) indicating their localization to the ER necessary for their biochemical activity. B Accumulation of 24:0 (lignoceric fatty acid) in HEK293 cells expressing L168S mutant protein. HEK293 cells overexpressing WT, L168S and control cells (GFP and UT) were supplemented with 24:0 SFA for 72 h. C L168S showed enzymatic activity by making higher amounts of 28:0, 30:0 and 32:0 compared to GFP controls. However, L168S synthesized lower levels of VLC-SFA levels compared to WT. Results are the mean ± SD (n = 3). Statistical significance was assessed for B and C by ANOVA with Tukey’s post-hoc test. *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001; ns not significant in comparison with WT