Research article - Peer-reviewed, 2021
Camelina sativa phosphatidylcholine:diacylglycerol cholinephosphotransferase-catalyzed interconversion does not discriminate between substrates
Demski, Kamil; Jeppson, Simon; Stymne, Sten; Lager, IdaAbstract
Phosphatidylcholine:diacylglycerol cholinephosphotransferases (PDCT) regulate the fatty acid composition of seed oil (triacylglycerol, TAG) by interconversion of diacylglycerols (DAG) and phosphatidylcholine (PtdCho). PtdCho is the substrate for polyunsaturated fatty acid biosynthesis, as well as for a number of unusual fatty acids. By the action of PDCT, these fatty acids can be transferred into the DAG pool to be utilized in TAG biosynthesis by the action of acyl-CoA:DAG and phospholipid:diacylglycerol acyltransferases. Despite its importance in regulating seed oil composition, biochemical characterization of PDCT enzymes has been lacking. We characterized Camelina sativa PDCT in microsomal preparations of a yeast strain expressing Camelina PDCT and lacking the capacity of producing TAG. Camelina PDCT was specific for PtdCho and the sn-1,2 enantiomer of DAG and could not utilize ceramide. The interconversion reaches equilibrium within 15 min of incubation, indicating that only distinct pools of DAG and PtdCho were available for exchange. However, the pool sizes of DAG and PtdCho involved in the exchange were not fixed but increased with the amount of exogenous DAG or PtdCho added. Camelina PDCT showed about the same selectivity for di-oleoyl, di-linoleoyl, and di-linolenoyl species in both PtdCho and DAG substrates, suggesting that no unidirectional transfer of particular unsaturated substrates occurred. Camelina PDCT had a good activity with erucoyl-DAG as a substrate despite low erucic acid levels in PtdCho in plant species accumulating a high amount of this fatty acid in the seed oil.Keywords
acyltransferase; Camelina; diacylglycerol; PDCT; phosphatidylcholine; seed oilPublished in
Lipids2021, volume: 56, number: 6, pages: 591-602
Publisher: WILEY
Authors' information
Swedish University of Agricultural Sciences, Department of Plant Breeding
Jeppsson, Simon
Swedish University of Agricultural Sciences, Department of Plant Breeding
Swedish University of Agricultural Sciences, Department of Plant Breeding
Swedish University of Agricultural Sciences, Department of Plant Breeding
UKÄ Subject classification
Biochemistry and Molecular Biology
Publication Identifiers
DOI: https://doi.org/10.1002/lipd.12322
URI (permanent link to this page)
https://res.slu.se/id/publ/113486