title: Rate-limiting steps in the cytidine pathway for the synthesis of phosphatidylcholine and phosphatidylethanolamine.
abstract: An analysis of the available data on the cytidine pathway for the synthesis of phosphatidylcholine and phosphatidylethanolamine, by the logic derived from the theoretical principles of metabolic regulation, shows that the first two reactions catalysed by choline (ethanolamine) kinase and phosphocholine (phosphoethanolamine) cytidylyltransferase are rate-limiting, whereas the phosphocholine (phosphoethanolamine) transferase step is near equilibrium in rat liver.
mesh_terms: D000818:Animals; D002797:Choline Kinase / Q000378:metabolism; D003562:Cytidine / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000378:metabolism; D009713:Nucleotidyltransferases / Q000378:metabolism; D010713:Phosphatidylcholines / Q000096:biosynthesis*; D010714:Phosphatidylethanolamines / Q000096:biosynthesis*; D011117:Polyribonucleotide Nucleotidyltransferase / Q000378:metabolism; D051381:Rats
chemical_list: D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D003562:Cytidine; D002797:Choline Kinase; D009713:Nucleotidyltransferases; D011117:Polyribonucleotide Nucleotidyltransferase