Lysophosphatidic acid acyltransferase from meadowfoam mediates insertion of erucic acid at the sn-2 position of triacylglycerol in transgenic rapeseed oil.
Abstract
Lysophosphatidic acid acyltransferase acylates the sn-2 hydroxyl group of lysophosphatidic acid to form phosphatidic acid, a precursor to triacylglycerol. A cDNA encoding lysophosphatidic acid acyltransferase was isolated from developing seeds of meadowfoam (Limnanthes alba alba). The cDNA encodes a 281-amino acid protein with a molecular mass of 32 kD. The cDNA was expressed in developing seeds of transgenic high-erucic-acid rapeseed (Brassica napus) using a napin expression cassette. Erucic acid was present at the sn-2 position of triacylglycerols from transgenic plants but was absent from that position of seed oil extracted from control plants. Trierucin was present in the transgenic oil. Alteration of the sn-2 erucic acid composition did not affect the total erucic acid content. These experiments demonstrate the feasibility of using acyltransferases to alter the stereochemical composition of transgenic seed oils and also represent a necessary step toward increasing the erucic acid content of rapeseed oil.
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- Cao YZ, Oo KC, Huang AH. Lysophosphatidate Acyltransferase in the Microsomes from Maturing Seeds of Meadowfoam (Limnanthes alba). Plant Physiol. 1990 Nov;94(3):1199–1206.[PMC free article] [PubMed] [Google Scholar]
- Claros MG, von Heijne G. TopPred II: an improved software for membrane protein structure predictions. Comput Appl Biosci. 1994 Dec;10(6):685–686. [PubMed] [Google Scholar]
- Coleman J. Characterization of Escherichia coli cells deficient in 1-acyl-sn-glycerol-3- phosphate acyltransferase activity. J Biol Chem. 1990 Oct 5;265(28):17215–17221. [PubMed] [Google Scholar]
- Coleman J. Characterization of the Escherichia coli gene for 1-acyl-sn-glycerol-3-phosphate acyltransferase (plsC). Mol Gen Genet. 1992 Mar;232(2):295–303. [PubMed] [Google Scholar]
- James DW, Jr, Lim E, Keller J, Plooy I, Ralston E, Dooner HK. Directed tagging of the Arabidopsis FATTY ACID ELONGATION1 (FAE1) gene with the maize transposon activator. Plant Cell. 1995 Mar;7(3):309–319.[PMC free article] [PubMed] [Google Scholar]
- Jones A, Davies HM, Voelker TA. Palmitoyl-acyl carrier protein (ACP) thioesterase and the evolutionary origin of plant acyl-ACP thioesterases. Plant Cell. 1995 Mar;7(3):359–371.[PMC free article] [PubMed] [Google Scholar]
- Knutzon DS, Lardizabal KD, Nelsen JS, Bleibaum JL, Davies HM, Metz JG. Cloning of a coconut endosperm cDNA encoding a 1-acyl-sn-glycerol-3-phosphate acyltransferase that accepts medium-chain-length substrates. Plant Physiol. 1995 Nov;109(3):999–1006.[PMC free article] [PubMed] [Google Scholar]
- Laurent P, Huang AH. Organ- and development-specific acyl coenzyme a lysophosphatidate acyltransferases in palm and meadowfoam. Plant Physiol. 1992 Aug;99(4):1711–1715.[PMC free article] [PubMed] [Google Scholar]
- Nagiec MM, Wells GB, Lester RL, Dickson RC. A suppressor gene that enables Saccharomyces cerevisiae to grow without making sphingolipids encodes a protein that resembles an Escherichia coli fatty acyltransferase. J Biol Chem. 1993 Oct 15;268(29):22156–22163. [PubMed] [Google Scholar]
Abstract
Lysophosphatidic acid acyltransferase acylates the sn-2 hydroxyl group of lysophosphatidic acid to form phosphatidic acid, a precursor to triacylglycerol. A cDNA encoding lysophosphatidic acid acyltransferase was isolated from developing seeds of meadowfoam (Limnanthes alba alba). The cDNA encodes a 281-amino acid protein with a molecular mass of 32 kD. The cDNA was expressed in developing seeds of transgenic high-erucic-acid rapeseed (Brassica napus) using a napin expression cassette. Erucic acid was present at the sn-2 position of triacylglycerols from transgenic plants but was absent from that position of seed oil extracted from control plants. Trierucin was present in the transgenic oil. Alteration of the sn-2 erucic acid composition did not affect the total erucic acid content. These experiments demonstrate the feasibility of using acyltransferases to alter the stereochemical composition of transgenic seed oils and also represent a necessary step toward increasing the erucic acid content of rapeseed oil.