CGI-58/ABHD5 is a coenzyme A-dependent lysophosphatidic acid acyltransferase.
Mutations in human CGI-58/ABHD5 cause Chanarin-Dorfman syndrome (CDS), characterized by excessive storage of triacylglycerol in tissues. CGI-58 is an alpha/beta-hydrolase fold enzyme expressed in all vertebrates. The carboxyl terminus includes a highly conserved consensus sequence (HXXXXD) for acyltransferase activity. Mouse CGI-58 was expressed in Escherichia coli as a fusion protein with two amino terminal 6-histidine tags. Recombinant CGI-58 displayed acyl-CoA-dependent acyltransferase activity to lysophosphatidic acid, but not to other lysophospholipid or neutral glycerolipid acceptors. Production of phosphatidic acid increased with time and increasing concentrations of recombinant CGI-58 and was optimal between pH 7.0 and 8.5. The enzyme showed saturation kinetics with respect to 1-oleoyl-lysophosphatidic acid and oleoyl-CoA and preference for arachidonoyl-CoA and oleoyl-CoA. The enzyme showed slight preference for 1-oleoyl lysophosphatidic acid over 1-palmitoyl, 1-stearoyl, or 1-arachidonoyl lysophosphatidic acid. Recombinant CGI-58 showed intrinsic fluorescence for tryptophan that was quenched by the addition of 1-oleoyl-lysophosphatidic acid, oleoyl-CoA, arachidonoyl-CoA, and palmitoyl-CoA, but not by lysophosphatidyl choline. Expression of CGI-58 in fibroblasts from humans with CDS increased the incorporation of radiolabeled fatty acids released from the lipolysis of stored triacylglycerols into phospholipids. CGI-58 is a CoA-dependent lysophosphatidic acid acyltransferase that channels fatty acids released from the hydrolysis of stored triacylglycerols into phospholipids.
Montero-Moran
Gabriela
G
Rutgers Center for Lipid Research, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA.
Caviglia
Jorge M
JM
McMahon
Derek
D
Rothenberg
Alexis
A
Subramanian
Vidya
V
Xu
Zhi
Z
Lara-Gonzalez
Samuel
S
Storch
Judith
J
Carman
George M
GM
Brasaemle
Dawn L
DL
D051103:1-Acylglycerol-3-Phosphate O-Acyltransferase / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D000214:Acyl Coenzyme A / Q000378:metabolism*; D000217:Acyltransferases / Q000378:metabolism*; D020816:Amino Acid Motifs; D000818:Animals; D002478:Cells, Cultured; D015870:Gene Expression; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D050356:Lipid Metabolism / Q000235:genetics; D008052:Lipid Metabolism, Inborn Errors / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D008246:Lysophospholipids / Q000378:metabolism*; D051379:Mice; D056510:Position-Specific Scoring Matrices; D011485:Protein Binding; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D013379:Substrate Specificity; D013577:Syndrome
D000214:Acyl Coenzyme A; D008246:Lysophospholipids; D011994:Recombinant Proteins; D000217:Acyltransferases; D051103:1-Acylglycerol-3-Phosphate O-Acyltransferase; C439972:ABHD5 protein, human; C492986:Abhd5 protein, mouse; C018764:2-acylglycerophosphate acyltransferase