title: A 10-kDa acyl-CoA-binding protein (ACBP) from Brassica napus enhances acyl exchange between acyl-CoA and phosphatidylcholine.
abstract: The gene encoding a 10-kDa acyl-CoA-binding protein (ACBP) from Brassica napus was over-expressed in developing seeds of Arabidopsis thaliana. Biochemical analysis of T(2) and T(3) A. thaliana seeds revealed a significant increase in polyunsaturated fatty acids (FAs) (18:2(cisDelta9,12) and 18:3(cisDelta9,12,15)) at the expense of very long monounsaturated FA (20:1(cisDelta11)) and saturated FAs. In vitro assays demonstrated that recombinant B. napus ACBP (rBnACBP) strongly increases the formation of phosphatidylcholine (PC) in the absence of added lysophosphatidylcholine in microsomes from DeltaYOR175c yeast expressing A. thaliana lysophosphatidylcholine acyltransferase (AthLPCAT) cDNA or in microsomes from microspore-derived cell suspension cultures of B. napus L. cv. Jet Neuf. rBnACBP or bovine serum albumin (BSA) were also shown to be crucial for AthLPCAT to catalyse the transfer of acyl group from PC into acyl-CoA in vitro. These data suggest that the cytosolic 10-kDa ACBP has an effect on the equilibrium between metabolically active acyl pools (acyl-CoA and phospholipid pools) involved in FA modifications and triacylglycerol bioassembly in plants. Over-expression of ACBP during seed development may represent a useful biotechnological approach for altering the FA composition of seed oil.
authors.affiliation: Agricultural Lipid Biotechnology Program, Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada.
authors.forename: Olga P
authors.initials: OP
authors.lastname: Yurchenko
authors.forename: Cory L
authors.initials: CL
authors.lastname: Nykiforuk
authors.forename: Maurice M
authors.initials: MM
authors.lastname: Moloney
authors.forename: Ulf
authors.initials: U
authors.lastname: Ståhl
authors.forename: Antoni
authors.initials: A
authors.lastname: Banaś
authors.forename: Sten
authors.initials: S
authors.lastname: Stymne
authors.forename: Randall J
authors.initials: RJ
authors.lastname: Weselake
mesh_terms: D008243:1-Acylglycerophosphocholine O-Acyltransferase / Q000235:genetics / Q000378:metabolism; D000214:Acyl Coenzyme A / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D029688:Brassica napus / Q000378:metabolism*; D026261:Diazepam Binding Inhibitor / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000378:metabolism; D008861:Microsomes / Q000378:metabolism; D010713:Phosphatidylcholines / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D012639:Seeds / Q000235:genetics / Q000378:metabolism
chemical_list: D000214:Acyl Coenzyme A; D026261:Diazepam Binding Inhibitor; D005231:Fatty Acids, Unsaturated; D010713:Phosphatidylcholines; D008243:1-Acylglycerophosphocholine O-Acyltransferase