title: Role of reversible phosphorylation of acetyl-CoA carboxylase in long-chain fatty acid synthesis.
abstract: Acetyl-CoA carboxylase, the rate-limiting enzyme in the biogenesis of long-chain fatty acids, is regulated by phosphorylation and dephosphorylation. The major phosphorylation sites that affect carboxylase activity and the specific protein kinases responsible for phosphorylation of different sites have been identified. A form of acetyl-CoA carboxylase that is independent of citrate for activity occurs in vivo. This active form of carboxylase becomes citrate-dependent upon phosphorylation under conditions of reduced lipogenesis. Therefore, phosphorylation-dephosphorylation of acetyl-CoA carboxylase is the enzyme's primary short-term regulatory mechanism; this control mechanism together with cellular metabolites such as CoA, citrate, and palmitoyl-CoA serves to fine-tune the synthesis of long-chain fatty acids under different physiological conditions.
authors.affiliation: Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907.
authors.forename: K H
authors.initials: KH
authors.lastname: Kim
authors.forename: F
authors.initials: F
authors.lastname: López-Casillas
authors.forename: D H
authors.initials: DH
authors.lastname: Bai
authors.forename: X
authors.initials: X
authors.lastname: Luo
authors.forename: M E
authors.initials: ME
authors.lastname: Pape
mesh_terms: D000103:Acetyl-CoA Carboxylase / Q000378:metabolism*; D000818:Animals; D002951:Citrates / Q000502:physiology; D004789:Enzyme Activation; D005227:Fatty Acids / Q000096:biosynthesis*; D008025:Ligases / Q000378:metabolism*; D010749:Phosphoprotein Phosphatases / Q000378:metabolism; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism
chemical_list: D002951:Citrates; D005227:Fatty Acids; D011494:Protein Kinases; D010749:Phosphoprotein Phosphatases; D008025:Ligases; D000103:Acetyl-CoA Carboxylase