title: Molecular Characterization of Two Lysophospholipid:acyl-CoA Acyltransferases Belonging to the MBOAT Family in Nicotiana benthamiana.
abstract: In the remodeling pathway for the synthesis of phosphatidylcholine (PC), acyl-CoA-dependent lysophosphatidylcholine (lysoPC) acyltransferase (LPCAT) catalyzes the reacylation of lysoPC. A number of genes encoding LPCATs have been cloned and characterized from several plants in recent years. Using Arabidopsis and other plant LPCAT sequences to screen the genome database of Nicotiana benthamiana, we identified two cDNAs encoding the putative tobacco LPCATs (NbLPCAT1 and NbLPCAT2). Both of them were predicted to encode a protein of 463 amino acids with high similarity to LPCATs from other plants. Protein sequence features such as the presence of at least eight putative transmembrane regions, four highly conserved signature motifs and several invariant residues indicate that NbLPCATs belong to the membrane bound O-acyltransferase family. Lysophospholipid acyltransferase activity of NbLPCATs was confirmed by testing lyso-platelet-activating factor (lysoPAF) sensitivity through heterologous expression of each full-length cDNA in a yeast mutant Y02431 (lca1△) disrupted in endogenous LPCAT enzyme activity. Analysis of fatty acid profiles of phospholipids from the NbLPCAT-expressing yeast mutant Y02431 cultures supplemented with polyunsaturated fatty acids suggested more incorporation of linoleic acid (18:2n6, LA) and α-linolenic acid (18:3n3, ALA) into PC compared to yeast mutant harbouring empty vector. In vitro enzymatic assay demonstrated that NbLPCAT1had high lysoPC acyltransferase activity with a clear preference for α-linolenoyl-CoA (18:3), while NbLPCAT2 showed a high lysophosphatidic acid (lysoPA) acyltransferase activity towards α-linolenoyl-CoA and a weak lysoPC acyltransferase activity. Tissue-specific expression analysis showed a ubiquitous expression of NbLPCAT1 and NbLPCAT2 in roots, stems, leaves, flowers and seeds, and a strong expression in developing flowers. This is the first report on the cloning and characterization of lysophospholipid acyltransferases from N. benthamiana.
authors.affiliation: Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan, 430062, China.
authors.forename: Donghui
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Intercollegiate Faculty of Biotechnology of University of Gdansk and Medical University of Gdansk, 80-822, Gdansk, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Jasieniecka-Gazarkiewicz
authors.affiliation: Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan, 430062, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Wan
authors.affiliation: Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan, 430062, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Luo
authors.affiliation: Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan, 430062, China.
authors.forename: Yinbo
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Intercollegiate Faculty of Biotechnology of University of Gdansk and Medical University of Gdansk, 80-822, Gdansk, Poland.
authors.forename: Antoni
authors.initials: A
authors.lastname: Banas
authors.affiliation: Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan, 430062, China.
authors.forename: Mulan
authors.initials: M
authors.lastname: Jiang
authors.affiliation: Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan, 430062, China.
authors.forename: Yangmin
authors.initials: Y
authors.lastname: Gong
mesh_terms: D008243:1-Acylglycerophosphocholine O-Acyltransferase / Q000235:genetics* / Q000378:metabolism*; D000102:Acetyl-CoA C-Acyltransferase / Q000235:genetics* / Q000378:metabolism*; D003001:Cloning, Molecular; D008246:Lysophospholipids / Q000378:metabolism; D005810:Multigene Family; D016366:Open Reading Frames; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D014026:Nicotiana / Q000201:enzymology* / Q000235:genetics
chemical_list: D008246:Lysophospholipids; D010940:Plant Proteins; D000102:Acetyl-CoA C-Acyltransferase; D008243:1-Acylglycerophosphocholine O-Acyltransferase