The C-terminal domain is required for LD targeting of APOE. (A) Schematic of the APOE truncation constructs used in this experiment. (B) Western blot of lysates from TRAE3-H cell transfected with the indicated APOE truncation construct. Each construct was expressed and appeared at the expected molecular weight. Predicted molecular weights for each construct are as follows: FL: 63.94 kD, ΔSS FL: 62.03 kD, N: 51.83 kD, ΔSS N: 49.92 kD, C: 39.28 kD, C ΔSS: 37.36 kD. (C) Representative confocal slices of TRAE3-H cells transfected with the indicated construct, stained for LDs with BODIPY 665/676, and treated with 400 µM OA for 5 h. “O” denotes no enrichment of signal on the LD surface, “+” indicates partial enrichment, and “++” indicates full enrichment. (D) Quantification of LD targeting of each construct. The LD intensity ratio was calculated by dividing the mean mEm fluorescence intensity on LDs by the mean mEm fluorescence intensity of the rest of the cell. Letters indicate pairwise significance groups. Conditions denoted with the same letter have no statistically significant difference. N = 40 cells per condition. Each data point represents one cell. Data were collected and pooled from three independent experiments. P-values were calculated via Dunn’s Test for pairwise multiple comparisons. FL, full-length APOE. N-term., N-terminal domain of APOE. C-term., C-terminal domain of APOE. ΔSS, construct has the N-terminal signal peptide deleted. Source data are available for this figure: SourceData F4.