title: Deletion of genes encoding fatty acid desaturases leads to alterations in stress sensitivity in Pichia pastoris.
abstract: Unsaturated fatty acids (UFAs) are key compounds which have important roles in maintaining cell membrane physiological functions and the adaption to tough conditions. Defects of fatty acid desaturases will change cellular UFA constitution. Pichia pastoris GS115 has four fatty acid desaturase genes, namely FAD9A, FAD9B, FAD12 and FAD15. Their products catalyze the synthesis of three kinds of UFAs, oleic acid (catalyzed by Fad9A and Fad9B), linoleic acid (catalyzed by Fad12) and α-linolenic acid (catalyzed by Fad15), respectively. In this study, we found that deletion of FAD12 led to increased resistance to oxidative stress. Cellular lipid peroxidation levels declined in the fad12Δ mutant upon H2O2 treatment. Cellular fatty acids compositions were changed with the increased expression of FAD9A. On the other hand, deletion of FAD9A resulted in increased tolerance to the plasma membrane (PM) damage agent SDS, and PM deformation was not detected in the fad9AΔ mutant under this stress. Our results showed that UFAs are related to cell adaption to adverse environmental changes.
authors.affiliation: Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, Nankai University, 300071 Tianjin, PR China.
authors.forename: Meng
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, Nankai University, 300071 Tianjin, PR China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, Nankai University, 300071 Tianjin, PR China.
authors.forename: Qilin
authors.initials: Q
authors.lastname: Yu
authors.affiliation: Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, Nankai University, 300071 Tianjin, PR China.
authors.forename: Jiwei
authors.initials: J
authors.lastname: Mao
authors.affiliation: Tianjin Traditional Chinese Medicine University, 300193 Tianjin, PR China.
authors.forename: Biao
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, Nankai University, 300071 Tianjin, PR China.
authors.forename: Laijun
authors.initials: L
authors.lastname: Xing
authors.affiliation: Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, Nankai University, 300071 Tianjin, PR China nklimingchun@163.com.
authors.forename: Mingchun
authors.initials: M
authors.lastname: Li
mesh_terms: D044943:Fatty Acid Desaturases / Q000235:genetics / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D017353:Gene Deletion; D006861:Hydrogen Peroxide / Q000633:toxicity; D015227:Lipid Peroxidation; D018384:Oxidative Stress; D010843:Pichia / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D012967:Sodium Dodecyl Sulfate / Q000633:toxicity; D013312:Stress, Physiological
chemical_list: D005231:Fatty Acids, Unsaturated; D012967:Sodium Dodecyl Sulfate; D006861:Hydrogen Peroxide; D044943:Fatty Acid Desaturases
keywords: Pichia pastoris; fatty acid desaturase; oxidative stress; plasma membrane damage