Isoforms of acyl-CoA:diacylglycerol acyltransferase2 differ substantially in their specificities toward erucic acid
Kamil Demski , Simon Jeppson , Ida Lager , Agnieszka Misztak , Katarzyna Jasieniecka-Gazarkiewicz , Małgorzata Waleron , Sten Stymne , Antoni Banaś
AbstractIn most oilseeds, two evolutionarily unrelated acyl-CoA:diacylglycerol acyltransferase (DGAT) enzymes, DGAT1 and DGAT2, are the main contributors to the acylation of diacylglycerols in the synthesis of triacylglycerol. DGAT1 and DGAT2 are both present in the important crop oilseed rape (Brassica napus), with each type having four isoforms. We studied the activities of DGAT isoforms during seed development in microsomal fractions from two oilseed rape cultivars: edible, low-erucic acid (22:1) MONOLIT and nonedible high-erucic acid MAPLUS. Whereas the speciﬁc activities of DGATs were similar with most of the testedacyl-CoAsubstratesinbothcultivars,MAPLUShad6-to14-foldhigheractivitywith22:1-CoAthandidMONOLIT.Thus, DGAT isoforms with different acyl-CoA speciﬁcities are differentially active in the two cultivars. We characterized the acyl-CoA speciﬁcities of all DGAT isoforms in oilseed rape in the microsomal fractions of yeast cells heterologously expressing these enzymes. All four DGAT1 isoforms showed similar and broad acyl-CoA speciﬁcities. However, DGAT2 isoforms had much narrower acyl-CoA speciﬁcities: two DGAT2 isoforms were highly active with 22:1-CoA, while the ability of the other two isoforms to use this substrate was impaired. These ﬁndings elucidate the importance, which a DGAT isoform with suitable acylCoA speciﬁcity may have, when aiming for high content of a particular fatty acid in plant triacylglycerol reservoirs.
|Journal series||Plant Physiology, ISSN 0032-0889, e-ISSN 1532-2548, (N/A 140 pkt)|
|Publication size in sheets||0.55|
|ASJC Classification||; ;|
|Score||= 140.0, 28-01-2020, ArticleFromJournal|
|Publication indicators||: 2017 = 1.598; : 2018 = 6.305 (2) - 2018=7.024 (5)|
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