Roles of phosphatidate phosphatase enzymes in lipid metabolism.
Phosphatidate phosphatase (PAP) enzymes catalyze the dephosphorylation of phosphatidate, yielding diacylglycerol and inorganic phosphate. In eukaryotic cells, PAP activity has a central role in the synthesis of phospholipids and triacylglycerol through its product diacylglycerol, and it also generates and/or degrades lipid-signaling molecules that are related to phosphatidate. There are two types of PAP enzyme, Mg(2+) dependent (PAP1) and Mg(2+) independent (PAP2), but only genes encoding PAP2 enzymes had been identified until recently, when a gene (PAH1) encoding a PAP1 enzyme was found in Saccharomyces cerevisiae. This discovery has revealed a molecular function of the mammalian protein lipin, a deficiency of which causes lipodystrophy in mice. With molecular information now available for both types of PAP, the specific roles of these enzymes in lipid metabolism are being clarified.
Carman
George M
GM
Department of Food Science, Cook College, New Jersey Agricultural Experiment Station, Rutgers University, 65 Dudley Road, New Brunswick, NJ 08901, USA. carman@aesop.rutgers.edu
Han
Gil-Soo
GS
D000818:Animals; D020134:Catalytic Domain; D005786:Gene Expression Regulation; D006801:Humans; D050356:Lipid Metabolism; D008055:Lipids / Q000737:chemistry; D008060:Lipodystrophy / Q000473:pathology; D008274:Magnesium / Q000737:chemistry; D051379:Mice; D008954:Models, Biological; D009154:Mutation; D000073718:Pancreatitis-Associated Proteins; D010711:Phosphatidate Phosphatase / Q000502:physiology*; D010743:Phospholipids / Q000737:chemistry; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D015398:Signal Transduction
D008055:Lipids; D000073718:Pancreatitis-Associated Proteins; D010743:Phospholipids; C000612141:REG3A protein, human; D010711:Phosphatidate Phosphatase; D008274:Magnesium