title: Analysis of ATP-citrate lyase and malic enzyme mutants of Yarrowia lipolytica points out the importance of mannitol metabolism in fatty acid synthesis.
abstract: The role of the two key enzymes of fatty acid (FA) synthesis, ATP-citrate lyase (Acl) and malic enzyme (Mae), was analyzed in the oleaginous yeast Yarrowia lipolytica. In most oleaginous yeasts, Acl and Mae are proposed to provide, respectively, acetyl-CoA and NADPH for FA synthesis. Acl was mainly studied at the biochemical level but no strain depleted for this enzyme was analyzed in oleaginous microorganisms. On the other hand the role of Mae in FA synthesis in Y. lipolytica remains unclear since it was proposed to be a mitochondrial NAD(H)-dependent enzyme and not a cytosolic NADP(H)-dependent enzyme. In this study, we analyzed for the first time strains inactivated for corresponding genes. Inactivation of ACL1 decreases FA synthesis by 60 to 80%, confirming its essential role in FA synthesis in Y. lipolytica. Conversely, inactivation of MAE1 has no effects on FA synthesis, except in a FA overaccumulating strain where it improves FA synthesis by 35%. This result definitively excludes Mae as a major key enzyme for FA synthesis in Y. lipolytica. During the analysis of both mutants, we observed a negative correlation between FA and mannitol level. As mannitol and FA pathways may compete for carbon storage, we inactivated YlSDR, encoding a mannitol dehydrogenase converting fructose and NADPH into mannitol and NADP+. The FA content of the resulting mutant was improved by 60% during growth on fructose, demonstrating that mannitol metabolism may modulate FA synthesis in Y. lipolytica.
authors.affiliation: INRA, UMR1319 Micalis, F-78350 Jouy-en-Josas, France; AgroParisTech, UMR Micalis, Jouy-en-Josas, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Dulermo
authors.affiliation: INRA, UMR1319 Micalis, F-78350 Jouy-en-Josas, France; AgroParisTech, UMR Micalis, Jouy-en-Josas, France; Department of Biotechnology and Food Microbiology, Wroclaw University of Environmental and Life Sciences, Chełmońskiego 37/41, 51-630 Wroclaw, Poland.
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Lazar
authors.affiliation: INRA, UMR1319 Micalis, F-78350 Jouy-en-Josas, France; AgroParisTech, UMR Micalis, Jouy-en-Josas, France.
authors.forename: Rémi
authors.initials: R
authors.lastname: Dulermo
authors.affiliation: INRA, UMR1319 Micalis, F-78350 Jouy-en-Josas, France; AgroParisTech, UMR Micalis, Jouy-en-Josas, France; Department of Biotechnology and Food Microbiology, Wroclaw University of Environmental and Life Sciences, Chełmońskiego 37/41, 51-630 Wroclaw, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Rakicka
authors.affiliation: INRA, UMR1319 Micalis, F-78350 Jouy-en-Josas, France; AgroParisTech, UMR Micalis, Jouy-en-Josas, France.
authors.forename: Ramedane
authors.initials: R
authors.lastname: Haddouche
authors.affiliation: INRA, UMR1319 Micalis, F-78350 Jouy-en-Josas, France; AgroParisTech, UMR Micalis, Jouy-en-Josas, France. Electronic address: jean-marc.nicaud@grignon.inra.fr.
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Nicaud
mesh_terms: D001275:ATP Citrate (pro-S)-Lyase / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D000105:Acetyl Coenzyme A / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism*; D005632:Fructose / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D050356:Lipid Metabolism / Q000235:genetics; D008291:Malate Dehydrogenase / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D008353:Mannitol / Q000378:metabolism; D008354:Mannitol Dehydrogenases / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D009249:NADP / Q000378:metabolism; D010957:Plasmids / Q000737:chemistry / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D025062:Yarrowia / Q000235:genetics / Q000378:metabolism*
chemical_list: D005227:Fatty Acids; D005656:Fungal Proteins; D011994:Recombinant Proteins; D005632:Fructose; D008353:Mannitol; D009249:NADP; D000105:Acetyl Coenzyme A; D008354:Mannitol Dehydrogenases; D008291:Malate Dehydrogenase; C030574:malate dehydrogenase (decarboxylating); D001275:ATP Citrate (pro-S)-Lyase
keywords: ATP-citrate lyase; Lipid; Malic enzyme; Mannitol; Mannitol dehydrogenase; Yarrowia lipolytica