TG synthesis enzymes in U2OS cultured with OA for 1 d. (A) BiFC (green) of NLSx3-GFP_1–10 and GFP₁₁-tagged enzymes. Nucleus, blue. (B) GFP-tagged enzymes (green) in nuclear LDs (arrowheads). LDs, red; nucleus, blue. (C) The effect of ACSL RNAi on nuclear LDs. The number of nuclei counted: 40 (control), 44 (ACSL1), 39 (ACSL3), or 40 (ACSL4). Pooled data from three independent experiments. Kruskal–Wallis ANOVA test followed by Dunn’s test, ***, P < 0.001. (D) The effect of GPAT3 and GPAT4 RNAi on nuclear LDs. The number of nuclei counted: 51 (control), 52 (GPAT3+GPAT4). Pooled data from three independent experiments. Mann–Whitney test; ***, P < 0.001. (E) The effect of GFP-DGAT2 and GFP-PK-DGAT2 expression on nuclear LDs in U2OS after knockdown of endogenous DGAT2. The number of nuclei counted: 48 (GFP-DGAT2), 45 (GFP-PK-DGAT2). Pooled data from three independent experiments. Mann–Whitney test; ***, P < 0.001. (F) Appearance of red Dendra2-LPCAT1 signal in nuclear LDs (arrowheads) after photoconversion in the cytoplasm (rectangular area). Selected frames from Video 3 are shown. (G) Disappearance of GFP-ACSL3 from nuclear LDs (arrowheads). Selected frames from Video 5 are shown. Scale bars, 10 µm; 2 µm (inset).