Phosphatidylcholine ismade in the liver via the CDP-choline pathway and via the conversion of phosphatidylethanolamine
to phosphatidylcholine by 3 transmethylation reactions from AdoMet catalyzed by phosphatidylethanolamine
N-methyltransferase (PEMT). PEMT is a 22.3 kDa integral transmembrane protein of the endoplasmic
reticulumand mitochondria-associatedmembranes.