Gpc d9

Deuterated isotope tracking was performed by addition of 2 mM choline-d₉ (Sigma-Aldrich) in 50 ml of THB; 3.7 mM GPC-d₉ (Toronto Research Chemicals) was added to 15 ml of THB to yield a final concentration of 130 μM. Cultures were grown in 5% CO₂ at 37°C for 18 h before 10 ml of choline-d₉ culture or 5 ml of GPC-d₉ culture was removed for metabolite extraction and the remaining culture was pelleted for lipid extraction. LysoPC(20:0) was obtained from Avanti Polar Lipids. Cultures were supplemented with 2 mg of lysoPC per 15 ml of THB, unless otherwise stated, and incubated overnight at 37°C in 5% CO₂. Lipid extractions were performed as described above.