title: Overexpression of OLE1 Enhances Cytoplasmic Membrane Stability and Confers Resistance to Cadmium in Saccharomyces cerevisiae.
abstract: The heavy metal cadmium is widely used and released into the environment, posing a severe threat to crops and humans. Saccharomyces cerevisiae is one of the most commonly used organisms in the investigation of environmental metal toxicity. We investigated cadmium stress and the adaptive mechanisms of yeast by screening a genome-wide essential gene overexpression library. A candidate gene, OLE1, encodes a delta-9 desaturase and was associated with high anti-cadmium-stress activity. The results demonstrated that the expression of OLE1 was positively correlated with cadmium stress tolerance and induction was independent of Mga2p and Spt23p (important regulatory factors for OLE1). Moreover, in response to cadmium stress, cellular levels of monounsaturated fatty acids were increased. The addition of exogenous unsaturated fatty acids simulated overexpression of OLE1, leading to cadmium resistance. Such regulation of OLE1 in the synthesis of unsaturated fatty acids may serve as a positive feedback mechanism to help cells counter the lipid peroxidation and cytoplasmic membrane damage caused by cadmium.
  
  
  
  A S. cerevisiae gene encoding a delta-9 desaturase, OLE1, was associated with high anti-cadmium-stress activity. The data suggest that the regulation of OLE1 in the synthesis of unsaturated fatty acids may serve as a positive feedback mechanism to help yeast cells counter the lipid peroxidation and cytoplasmic membrane damage caused by cadmium. The discovery of OLE1 involvement in membrane stability may indicate a novel defense strategy against cadmium stress.
authors: College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai, China.
authors: Zhijia
authors: Z
authors: Fang
authors: College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai, China.
authors: Zhongxiang
authors: Z
authors: Chen
authors: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China.
authors: Song
authors: S
authors: Wang
authors: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China ship@ecust.edu.cn zhiweih@dhu.edu.cn.
authors: Ping
authors: P
authors: Shi
authors: Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, Qinghai Province, China.
authors: Yuhu
authors: Y
authors: Shen
authors: College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai, China.
authors: Youshang
authors: Y
authors: Zhang
authors: College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai, China.
authors: Junhua
authors: J
authors: Xiao
authors: College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai, China ship@ecust.edu.cn zhiweih@dhu.edu.cn.
authors: Zhiwei
authors: Z
authors: Huang
mesh_terms: D002104:Cadmium / Q000494:pharmacology*; D002462:Cell Membrane / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D005229:Fatty Acids, Monounsaturated / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000096:biosynthesis / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal / Q000187:drug effects; D016681:Genome, Fungal; D015227:Lipid Peroxidation; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics*; D013230:Stearoyl-CoA Desaturase / Q000235:genetics* / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D005229:Fatty Acids, Monounsaturated; D005231:Fatty Acids, Unsaturated; D002104:Cadmium; D013230:Stearoyl-CoA Desaturase; C029627:delta-9 fatty acid desaturase
keywords: OLE1; cadmium; cytoplasmic membrane; delta-9 desaturase; unsaturated fatty acids