Category: membrane
Membrane phospholipid biosynthesis from glycerol-3-phosphate via phosphatidic acid (PA) intermediate. PA → diacylglycerol (DAG; also a signaling molecule, see inositol_phosphate_signaling) → choline/ethanolamine/serine/inositol head-group attachment (Kennedy pathway: CDP-choline / CDP-ethanolamine activation). PEMT (phosphatidylethanolamine N-methyltransferase, hepatic) provides ~30% of phosphatidylcholine via 3 sequential methylations from SAM. Choline supplementation (alpha-GPC, citicoline) feeds the Kennedy pathway. Phospholipid imbalance (low PC/PE ratio) is associated with NAFLD progression. Lysophosphatidylcholine + lysophosphatidic acid are bioactive lipid mediators.