Figure 3.

Ethanolamine-mediated rescue of respiratory growth of CL-deficient cells is independent of PE biosynthesis. A, 10-fold serial dilutions of WT, ect1Δ, taz1Δ, and ect1Δtaz1Δ cells were seeded on to the indicated media, and images were captured after 2 days of growth on SC glucose and 7 days on SC ethanol ± 2 mm Etn at 37 °C. Data are representative of at least three independent experiments. B, total cellular PE levels of the indicated strains grown in SC ethanol ± 2 mm Etn. Data are expressed as mean ± S.D. (n = 3); *, p < 0.05, NS, not significant. C, 10-fold serial dilutions of WT, eki1Δcki1Δ, taz1Δ, eki1Δcki1Δtaz1Δ. D, WT, hnm1Δ, taz1Δ, and hnm1Δtaz1Δ cells were seeded onto the indicated media, and images were captured after 2 days of growth on SC glucose and 7 days on SC ethanol ± 2 mm Etn at 37 °C. Data are representative of at least three independent experiments. E, box plots of relative intracellular Etn abundance from WT, hnm1Δ, taz1Δ, and hnm1Δtaz1Δ grown in SC ethanol ± Etn. Etn levels were measured by LC-MS and expressed as peak intensity in arbitrary units (A.U.). Box plots show individual data points, median, first, and third quartiles, and greatest values within 1.5 inter-quartile range. Data are representative of at least three independent experiments. Data are expressed as mean ± S.D. (n = 3). F, WT and hnm1Δ cells were labeled with 1 μCi of [¹⁴C]Etn for 24 h, and radioactive Etn counts were measured in cpm (CPM) and expressed as % of WT. Data are expressed as mean ± S.D. (n = 3); ***, p < 0.001. G, growth of taz1Δhnm1Δ cells in SC ethanol with indicated concentrations of Etn (0–10 mm) was monitored by measuring absorbance at 600 nm at 72 h, and EC₅₀ values for Etn were calculated using GraphPad Prism. Data are expressed as mean ± S.D. (n = 3). H, WT cells, grown in presence or absence of 10 mm choline, were radiolabeled with 1 μCi of [¹⁴C]Etn for 24 h, and intracellular radioactivity was measured and expressed as % of WT intensity. Data are expressed as mean ± S.D. (n = 3); ***, p < 0.001. I, 10-fold serial dilutions of WT, taz1Δ, and crd1Δ cells were seeded onto the indicated media, and images were captured after 2 days of growth on SC glucose and 7 days on SC ethanol ± Cho at 37 °C. Data are representative of at least three independent experiments.