In vivo and in vitro evidence for biochemical coupling of reactions catalyzed by lysophosphatidylcholine acyltransferase and diacyglycerol acyltransferase

Simple item page
dc.contributor.authorGreer, Michael S.
dc.contributor.authorPan, Xue
dc.contributor.authorWeselake, Randall J.
dc.contributor.authorChen, Guanqun
dc.contributor.authorZou, Jitao
dc.contributor.authorCaldo, Kristian Mark P.
dc.contributor.authorKazachkov, Michael
dc.date.accessioned2025-05-01T11:56:32Z
dc.date.available2025-05-01T11:56:32Z
dc.date.issued2015
dc.descriptionSeed oils of flax (Linum usitatissimum L.) and many other plant species contain substantial amounts of polyunsaturated fatty acids (PUFAs). Phosphatidylcholine (PC) is the major site for PUFA synthesis. The exact mechanisms of how these PUFAs are channeled from PC into triacylglycerol (TAG) needs to be further explored. By using in vivo and in vitro approaches, we demonstrated that the PC deacylation reaction catalyzed by the reverse action of acyl-CoA:lysophosphatidylcholine acyltransferase (LPCAT) can transfer PUFAs on PC directly into the acyl-CoA pool, making these PUFAs available for the diacylglycerol acyltransferase (DGAT)-catalyzed reaction for TAG production. Two types of yeast mutants were generated for in vivo and in vitro experiments, respectively. Both mutants provide a null background with no endogenous TAG forming capacity and an extremely low LPCAT activity. In vivo experiments showed that co-expressing flax DGAT1-1 and LPCAT1 in the yeast quintuple mutant significantly increased 18-carbon PUFAs in TAG with a concomitant decrease of 18-carbon PUFAs in phospholipid. We further showed that after incubation of sn-2-[14C]acyl-PC, formation of [14C]TAG was only possible with yeast microsomes containing both LPCAT1 and DGAT1-1. Moreover, the specific activity of overall LPCAT1 and DGAT1-1 coupling process exhibited a preference for transferring 14C-labeled linoleoyl or linolenoyl than oleoyl moieties from the sn-2 position of PC to TAG. Together, our data support the hypothesis of biochemical coupling of the LPCAT1-catalyzed reverse reaction with the DGAT1-1-catalyzed reaction for incorporating PUFAs into TAG. This process represents a potential route for enriching TAG in PUFA content during seed development in flax.
dc.identifier.doihttps://doi.org/10.7939/R30R9MH8W
dc.language.isoen
dc.relationhttp://dx.doi.org/10.1074/jbc.M115.654798
dc.relation.isversionofPan, X., Chen, G., Kazachkov, M., Greer, M. S., Caldo, K. M., Zou, J., & Weselake, R. J. (2015). In vivo and in vitro evidence for biochemical coupling of reactions catalyzed by lysophosphatidylcholine acyltransferase and diacyglycerol acyltransferase. Journal of Biological Chemistry, 290(29), 18068-18078. http://dx.doi.org/10.1074/jbc.M115.654798
dc.rights© 2015 by The American Society for Biochemistry and Molecular Biology, Inc.
dc.subjectPhosphatidylcholine
dc.subjectFlax
dc.subjectDGAT
dc.subjectTriacylglycerol
dc.subjectPolyunsaturated Fatty Acid (PUFA)
dc.subjectYeast
dc.subjectTriacylglycerol Biosynthesis
dc.subjectLinum usitatissimum
dc.subjectPhospholipid Metabolism
dc.subjectLPCAT
dc.titleIn vivo and in vitro evidence for biochemical coupling of reactions catalyzed by lysophosphatidylcholine acyltransferase and diacyglycerol acyltransferase
dc.typehttp://purl.org/coar/resource_type/c_6501 http://purl.org/coar/version/c_970fb48d4fbd8a85
ual.jupiterAccesshttp://terms.library.ualberta.ca/public

Files

Original bundle

Now showing 1 - 1 of 1
Thumbnail Image
Name:
JBC_290_29_18068.pdf
Size:
1.46 MB
Format:
Adobe Portable Document Format
Download

Collections

Journal Articles (Agricultural, Food and Nutritional Science)