Acyl-CoA:diacylglycerol acyltransferase: molecular biology, biochemistry and biotechnology.
Triacylglycerol (TG) is a storage lipid which serves as an energy reservoir and a source of signalling molecules and substrates for membrane biogenesis. TG is essential for many physiological processes and its metabolism is widely conserved in nature. Acyl-CoA:diacylglycerol acyltransferase (DGAT, EC 2.3.1.20) catalyzes the final step in the sn-glycerol-3-phosphate pathway leading to TG. DGAT activity resides mainly in two distinct membrane bound polypeptides, known as DGAT1 and DGAT2 which have been identified in numerous organisms. In addition, a few other enzymes also hold DGAT activity, including the DGAT-related acyl-CoA:monoacylglycerol acyltransferases (MGAT). Progress on understanding structure/function in DGATs has been limited by the lack of detailed three-dimensional structural information due to the hydrophobic properties of theses enzymes and difficulties associated with purification. This review examines several aspects of DGAT and MGAT genes and enzymes, including current knowledge on their gene structure, expression pattern, biochemical properties, membrane topology, functional motifs and subcellular localization. Recent progress in probing structural and functional aspects of DGAT1 and DGAT2, using a combination of molecular and biochemical techniques, is emphasized. Biotechnological applications involving DGAT enzymes ranging from obesity therapeutics to oilseed engineering are also discussed.
Agricultural Lipid Biotechnology Program, Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada T6H 2P5. qin.liu@ualberta.ca
Qin
Q
Liu
Rodrigo M P
RM
Siloto
Richard
R
Lehner
Scot J
SJ
Stone
Randall J
RJ
Weselake
D000818:Animals; D001419:Bacteria / Q000201:enzymology; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D051048:Diacylglycerol O-Acyltransferase / Q000737:chemistry / Q000145:classification / Q000378:metabolism*; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism; D005658:Fungi / Q000201:enzymology; D010944:Plants / Q000201:enzymology; D017434:Protein Structure, Tertiary; D013379:Substrate Specificity; D014280:Triglycerides / Q000096:biosynthesis*
D001426:Bacterial Proteins; D005656:Fungal Proteins; D014280:Triglycerides; D051048:Diacylglycerol O-Acyltransferase