Phosphatidylcholine (PC) is a phospholipid that plays a role in methylation biochemistry.
PC is the precursor of phosphatidylethanolamine methyltransferase (PEMT) which catalyzes the conversion of phosphatidylethanolamine (PE) to PC.
The PEMT enzyme requires S-adenosylmethionine (SAM) as a methyl donor and generates phosphatidylcholine (PC) and S-adenosylhomocysteine (SAH) as products.
PC is also a component of cell membrane, which is important for the activity of enzymes that catalyze the methylation and demethylation of DNA, such as DNMTs (DNA methyltransferases) and TET enzymes. These enzymes are responsible for the addition or removal of methyl groups from DNA, which can affect the expression of genes.