Interactions among pathways for phosphatidylcholine metabolism, CTP synthesis and secretion through the Golgi apparatus

Phosphatidylcholine is the major phospholipid in eukaryotic cells, It serve s as a structural component of cell membranes and a reservoir of several li pid messengers. Recent studies in yeast and mammalian systems have revealed interrelationships between the two pathways of phosphatidylcholine metabol ism, and between these pathways and those for CTP synthesis and secretion v ia the Golgi, These processes involve the regulation of the CDP-choline and phosphatidylethanolamine-methylation pathways of phosphatidylcholine synth esis, CTP synthetase, phospholipase D and the phospholipid-transfer protein Sec14p.