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Molecular and biochemical characterizations of the monoacylglycerol lipase gene family of Arabidopsis thaliana
Author(s) -
Kim Ryeo Jin,
Kim Hae Jin,
Shim Donghwan,
Suh Mi Chung
Publication year - 2016
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.13146
Subject(s) - monoacylglycerol lipase , biochemistry , lipase , chemistry , biology , enzyme , endocannabinoid system , receptor
Summary Monoacylglycerol lipase ( MAGL ) catalyzes the last step of triacylglycerol breakdown, which is the hydrolysis of monoacylglycerol ( MAG ) to fatty acid and glycerol. Arabidopsis harbors over 270 genes annotated as ‘lipase’, the largest class of acyl lipid metabolism genes that have not been characterized experimentally. In this study, computational modeling suggested that 16 Arabidopsis putative MAGL s (At MAGL s) have a three‐dimensional structure that is similar to a human MAGL . Heterologous expression and enzyme assays indicated that 11 of the 16 encoded proteins indeed possess MAG lipase activity. Additionally, At MAGL 4 displayed hydrolase activity with lysophosphatidylcholine and lysophosphatidylethanolamine ( LPE ) substrates and At MAGL 1 and 2 utilized LPE as a substrate. All recombinant At MAGL s preferred MAG substrates with unsaturated fatty acids over saturated fatty acids and At MAGL 8 exhibited the highest hydrolase activities with MAG containing 20:1 fatty acids. Except for At MAGL 4, −14 and −16, all At MAGL s showed similar activity with both sn ‐1 and sn ‐2 MAG isomers. Spatial, temporal and stress‐induced expression of the 16 At MAGL genes was analyzed by transcriptome analyses. At MAGL : eYFP fusion proteins provided initial evidence that At MAGL 1, −3, −6, ‐7, −8, −11, −13, −14 and −16 are targeted to the endoplasmic reticulum and/or Golgi network, At MAGL 10, −12 and −15 to the cytosol and At MAGL 2, −4 and −5 to the chloroplasts. Furthermore, At MAGL 8 was associated with the surface of oil bodies in germinating seeds and leaves accumulating oil bodies. This study provides the broad characterization of one of the least well‐understood groups of Arabidopsis lipid‐related enzymes and will be useful for better understanding their roles in planta .