title: Functional roles of the fatty acid desaturases encoded by KlOLE1, FAD2 and FAD3 in the yeast Kluyveromyces lactis.
abstract: Functional properties of cell membranes depend on their composition, particularly on the relative amount of saturated, unsaturated and polyunsaturated fatty acids present in the phospholipids. The aim of this study was to investigate the effect of cell membrane composition on cell fitness, adaptation and stress response in Kluyveromyces lactis. To this purpose, we have deleted the genes FAD2 and FAD3 encoding Δ12 and ω3 desaturases in Kluyveromyces lactis, thus generating mutant strains with altered fatty acid composition of membranes. These strains were viable and able to grow in stressing conditions like hypoxia and low temperature. Deletion of the Δ9 desaturase-encoding gene KlOLE1 resulted in lethality, suggesting that this enzyme has an essential role in this yeast. Transcription of the desaturase genes KlOLE1, FAD2 and FAD3 and cellular localization of the corresponding enzymes, have been studied under hypoxia and cold stress. Our findings indicate that expression of these desaturase genes and membrane composition were modulated by hypoxia and temperature stress, although the changes induced by these and other assayed conditions did not dramatically affect the general cellular fitness.
authors.affiliation: Department of Biology and Biotechnology C. Darwin, Sapienza Università di Roma, p.le Aldo Moro 5, 00185, Roma, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: De Angelis
authors.affiliation: Department of Biology and Biotechnology C. Darwin, Sapienza Università di Roma, p.le Aldo Moro 5, 00185, Roma, Italy.|Pasteur Institute Cenci-Bolognetti Foundation, Viale Regina Elena 291, 00161 Roma, Italy.
authors.forename: Teresa
authors.initials: T
authors.lastname: Rinaldi
authors.affiliation: Department of Biology and Biotechnology C. Darwin, Sapienza Università di Roma, p.le Aldo Moro 5, 00185, Roma, Italy.
authors.forename: Angela
authors.initials: A
authors.lastname: Cirigliano
authors.affiliation: Department of Environmental Biology, Sapienza Università di Roma, Roma, Italy.
authors.forename: Cristiano
authors.initials: C
authors.lastname: Bello
authors.affiliation: Department of Environmental Biology, Sapienza Università di Roma, Roma, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Reverberi
authors.affiliation: Department of Life Sciences, Università di Modena e Reggio Emilia, Via Università, 4, 41121, Modena, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Amaretti
authors.affiliation: Department of Biology and Biotechnology C. Darwin, Sapienza Università di Roma, p.le Aldo Moro 5, 00185, Roma, Italy.
authors.forename: Arianna
authors.initials: A
authors.lastname: Montanari
authors.affiliation: Department of Biology and Biotechnology C. Darwin, Sapienza Università di Roma, p.le Aldo Moro 5, 00185, Roma, Italy.
authors.forename: Rosa
authors.initials: R
authors.lastname: Santomartino
authors.affiliation: Department of Life Sciences, Università di Modena e Reggio Emilia, Via Università, 4, 41121, Modena, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Raimondi
authors.affiliation: Department of Biochemistry and Structural Biology, Universidad Nacional Autónoma de México, Mexico.
authors.forename: Alicia
authors.initials: A
authors.lastname: Gonzalez
authors.affiliation: Department of Biology and Biotechnology C. Darwin, Sapienza Università di Roma, p.le Aldo Moro 5, 00185, Roma, Italy.
authors.forename: Michele M
authors.initials: MM
authors.lastname: Bianchi
mesh_terms: D000693:Anaerobiosis; D002462:Cell Membrane / Q000378:metabolism; D058639:Cold-Shock Response / Q000502:physiology*; D004721:Endoplasmic Reticulum / Q000201:enzymology; D004734:Energy Metabolism / Q000235:genetics / Q000502:physiology*; D044943:Fatty Acid Desaturases / Q000235:genetics* / Q000378:metabolism; D005285:Fermentation / Q000235:genetics / Q000502:physiology; D017353:Gene Deletion; D007716:Kluyveromyces / Q000201:enzymology* / Q000235:genetics; D013230:Stearoyl-CoA Desaturase
chemical_list: D044943:Fatty Acid Desaturases; D013230:Stearoyl-CoA Desaturase; C040448:delta-12 fatty acid desaturase; C029627:delta-9 fatty acid desaturase; C078565:omega-3 fatty acid desaturase