Publications

• Caenorhabditis elegans mboa-7, a member of the MBOAT family, is required for selective incorporation of polyunsaturated fatty acids into phosphatidylinositol.

  Lee H.C., Inoue T., Imae R., Kono N., Shirae S., Matsuda S., Gengyo-Ando K., Mitani S., Arai H.

  Phosphatidylinositol (PI) is a component of membrane phospholipids, and it functions both as a signaling molecule and as a compartment-specific localization signal in the form of polyphosphoinositides. Arachidonic acid (AA) is the predominant fatty acid in the sn-2 position of PI in mammals. LysoP ... >> More

  Phosphatidylinositol (PI) is a component of membrane phospholipids, and it functions both as a signaling molecule and as a compartment-specific localization signal in the form of polyphosphoinositides. Arachidonic acid (AA) is the predominant fatty acid in the sn-2 position of PI in mammals. LysoPI acyltransferase (LPIAT) is thought to catalyze formation of AA-containing PI; however, the gene that encodes this enzyme has not yet been identified. In this study, we established a screening system to identify genes required for use of exogenous polyunsaturated fatty acids (PUFAs) in Caenorhabditis elegans. In C. elegans, eicosapentaenoic acid (EPA) instead of AA is the predominant fatty acid in PI. We showed that an uncharacterized gene, which we named mboa-7, is required for incorporation of PUFAs into PI. Incorporation of exogenous PUFA into PI of the living worms and LPIAT activity in the microsomes were greatly reduced in mboa-7 mutants. Furthermore, the membrane fractions of transgenic worms expressing recombinant MBOA-7 and its human homologue exhibited remarkably increased LPIAT activity. mboa-7 encodes a member of the membrane-bound O-acyltransferase family, suggesting that mboa-7 is LPIAT. Finally, mboa-7 mutants had significantly lower EPA levels in PI, and they exhibited larval arrest and egg-laying defects. << Less

  Mol. Biol. Cell 19:1174-1184(2008) [PubMed] [EuropePMC]

  This publication is cited by 3 other entries.

• Lysophospholipid acyltransferases and arachidonate recycling in human neutrophils.

  Gijon M.A., Riekhof W.R., Zarini S., Murphy R.C., Voelker D.R.

  The cycle of deacylation and reacylation of phospholipids plays a critical role in regulating availability of arachidonic acid for eicosanoid production. The major yeast lysophospholipid acyltransferase, Ale1p, is related to mammalian membrane-bound O-acyltransferase (MBOAT) proteins. We expressed ... >> More

  The cycle of deacylation and reacylation of phospholipids plays a critical role in regulating availability of arachidonic acid for eicosanoid production. The major yeast lysophospholipid acyltransferase, Ale1p, is related to mammalian membrane-bound O-acyltransferase (MBOAT) proteins. We expressed four human MBOATs in yeast strains lacking Ale1p and studied their acyl-CoA and lysophospholipid specificities using novel mass spectrometry-based enzyme assays. MBOAT1 is a lysophosphatidylserine (lyso-PS) acyltransferase with preference for oleoyl-CoA. MBOAT2 also prefers oleoyl-CoA, using lysophosphatidic acid and lysophosphatidylethanolamine as acyl acceptors. MBOAT5 prefers lysophosphatidylcholine and lyso-PS to incorporate linoleoyl and arachidonoyl chains. MBOAT7 is a lysophosphatidylinositol acyltransferase with remarkable specificity for arachidonoyl-CoA. MBOAT5 and MBOAT7 are particularly susceptible to inhibition by thimerosal. Human neutrophils express mRNA for these four enzymes, and neutrophil microsomes incorporate arachidonoyl chains into phosphatidylinositol, phosphatidylcholine, PS, and phosphatidylethanolamine in a thimerosal-sensitive manner. These results strongly implicate MBOAT5 and MBOAT7 in arachidonate recycling, thus regulating free arachidonic acid levels and leukotriene synthesis in neutrophils. << Less

  J. Biol. Chem. 283:30235-30245(2008) [PubMed] [EuropePMC]

  This publication is cited by 26 other entries.

• Drosophila lysophospholipid acyltransferases are specifically required for germ cell development.

  Steinhauer J., Gijon M.A., Riekhof W.R., Voelker D.R., Murphy R.C., Treisman J.E.

  Enzymes of the membrane-bound O-acyltransferase (MBOAT) family add fatty acyl chains to a diverse range of protein and lipid substrates. A chromosomal translocation disrupting human MBOAT1 results in a novel syndrome characterized by male sterility and brachydactyly. We have found that the Drosoph ... >> More

  Enzymes of the membrane-bound O-acyltransferase (MBOAT) family add fatty acyl chains to a diverse range of protein and lipid substrates. A chromosomal translocation disrupting human MBOAT1 results in a novel syndrome characterized by male sterility and brachydactyly. We have found that the Drosophila homologues of MBOAT1, Oysgedart (Oys), Nessy (Nes), and Farjavit (Frj), are lysophospholipid acyltransferases. When expressed in yeast, these MBOATs esterify specific lysophospholipids preferentially with unsaturated fatty acids. Generating null mutations for each gene allowed us to identify redundant functions for Oys and Nes in two distinct aspects of Drosophila germ cell development. Embryos lacking both oys and nes show defects in the ability of germ cells to migrate into the mesoderm, a process guided by lipid signals. In addition, oys nes double mutant adult males are sterile due to specific defects in spermatid individualization. oys nes mutant testes, as well as single, double, and triple mutant whole adult animals, show an increase in the saturated fatty acid content of several phospholipid species. Our findings suggest that lysophospholipid acyltransferase activity is essential for germline development and could provide a mechanistic explanation for the etiology of the human MBOAT1 mutation. << Less

  Mol. Biol. Cell 20:5224-5235(2009) [PubMed] [EuropePMC]

  This publication is cited by 16 other entries.