title: Lipid homeostasis is involved in plasma membrane and endoplasmic reticulum stress in Pichia pastoris.
abstract: Maintaining cellular lipid composition is essential for many cell processes. Our previous study has demonstrated that Spt23 is an important transcription factor within the cell and responsible for the regulation of fatty acid desaturase genes. Disruption of SPT23 results in increased lipid saturation. In the present study, we found that lipid saturation caused by SPT23 deletion exhibited a growth defect under ethanol stress and increased chitin contents. Ergosterol synthesis-related genes were up-regulated to protect cells from plasma membrane damage in the presence of ethanol. The cell wall stress caused by increased chitin contents could not be attenuated by up-regulation of phospholipids synthesis-related genes in spt23Δ. Besides, lipid saturation induced expression of unfolded protein response (UPR) genes and reactive oxygen species (ROS) accumulation followed by activation of the cellular antioxidant system, which is associated with endoplasmic reticulum functions. Taken together, our data suggested that lipid homeostasis has a close connection with cell responses to both plasma membrane stress and endoplasmic reticulum stress.
authors.affiliation: Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of Life Science, Nankai University, Tianjin, 300071, PR China.
authors.forename: Meng
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of Life Science, Nankai University, Tianjin, 300071, PR China.
authors.forename: Qilin
authors.initials: Q
authors.lastname: Yu
authors.affiliation: Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of Life Science, Nankai University, Tianjin, 300071, PR China.
authors.forename: Chen
authors.initials: C
authors.lastname: Liang
authors.affiliation: Tianjin Traditional Chinese Medicine University, Tianjin, 300193, PR China.
authors.forename: Biao
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of Life Science, Nankai University, Tianjin, 300071, PR China. Electronic address: nklimingchun@163.com.
authors.forename: Mingchun
authors.initials: M
authors.lastname: Li
mesh_terms: D002462:Cell Membrane / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D002473:Cell Wall / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D002686:Chitin / Q000096:biosynthesis; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism; D059865:Endoplasmic Reticulum Stress; D004875:Ergosterol / Q000096:biosynthesis; D000431:Ethanol / Q000494:pharmacology; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D006706:Homeostasis / Q000235:genetics*; D050356:Lipid Metabolism / Q000187:drug effects / Q000235:genetics*; D010743:Phospholipids / Q000096:biosynthesis; D010843:Pichia / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000819:agonists / Q000378:metabolism; D015534:Trans-Activators / Q000172:deficiency / Q000235:genetics*; D056811:Unfolded Protein Response
chemical_list: D005656:Fungal Proteins; D010743:Phospholipids; D017382:Reactive Oxygen Species; D015534:Trans-Activators; D002686:Chitin; D000431:Ethanol; D004875:Ergosterol
keywords: Endoplasmic reticulum; Lipid saturation; Plasma membrane; Reactive oxygen species; Spt23; Unfolded protein response