Fig. 2. DIESL drives TAG accumulation in the absence of TMX1.
a, Schematic representation of the DGAT pathway (green box) and the putative TMX1-inhibited pathway (orange box). FA, fatty acid or fatty acyl. b, Set-up of the modifier screens used to identify the regulators of each pathway. c, Fishtail plots of lipid droplet screens in WT HAP1 cells treated with oleic acid (OA) (left) and in ∆TMX1 HAP1 cells (right). Significant positive and negative regulators are coloured light blue and orange, respectively; larger dots indicate the genes of interest. d, Difference in mutational index (log2-transformed) between the two screens for every gene with at least 30 insertions in each screen. e, Immunoblot of TMX1 in WT, ∆DIESL and DGAT DKO HAP1 cells transduced with a synthetic guide RNA targeting TMX1 (sgTMX1). f, Ultrastructural analysis of lipid droplets (red arrowheads) in WT and ∆DIESL cells after loss of TMX1. Scale bar, 1 μm. g, Lipid droplets, visualized by BODIPY 665/676, in WT, ∆DIESL and DGAT DKO cells transduced with the indicated sgRNA or treated with 200 µM oleic acid for 24 h. sgCTRL is a control sgRNA. Scale bars, 10 μm. h, TLC analysis of neutral lipids (left) and quantification of TAG (right) in DGAT DKO HAP1 cells also lacking DIESL and/or TMX1. Bars represent mean ± s.e.m. of n = 3 independent experiments (two-way ANOVA, Bonferroni correction).