論文

査読有り
2009年1月

Eicosapentaenoic Acid Plays a Beneficial Role in Membrane Organization and Cell Division of a Cold-Adapted Bacterium, Shewanella livingstonensis Ac10

JOURNAL OF BACTERIOLOGY
  • Jun Kawamoto
  • ,
  • Tatsuo Kurihara
  • ,
  • Kentaro Yamamoto
  • ,
  • Makiko Nagayasu
  • ,
  • Yasushi Tani
  • ,
  • Hisaaki Mihara
  • ,
  • Masashi Hosokawa
  • ,
  • Takeshi Baba
  • ,
  • Satoshi B. Sato
  • ,
  • Nobuyoshi Esaki

191
2
開始ページ
632
終了ページ
640
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1128/JB.00881-08
出版者・発行元
AMER SOC MICROBIOLOGY

Shewanella livingstonensis Ac10, a psychrotrophic gram-negative bacterium isolated from Antarctic seawater, produces eicosapentaenoic acid (EPA) as a component of phospholipids at low temperatures. EPA constitutes about 5% of the total fatty acids of cells grown at 4 degrees C. We found that five genes, termed orf2, orf5, orf6, orf7, and orf8, are specifically required for the synthesis of EPA by targeted disruption of the respective genes. The mutants lacking EPA showed significant growth retardation at 4 degrees C but not at 18 degrees C. Supplementation of a synthetic phosphatidylethanolamine that contained EPA at the sn-2 position complemented the growth defect. The EPA-less mutant became filamentous, and multiple nucleoids were observed in a single cell at 4 degrees C, indicating that the mutant has a defect in cell division. Electron microscopy of the cells by high-pressure freezing and freeze-substitution revealed abnormal intracellular membranes in the EPA-less mutant at 4 degrees C. We also found that the amounts of several membrane proteins were affected by the depletion of EPA. While polyunsaturated fatty acids are often considered to increase the fluidity of the hydrophobic membrane core, diffusion of a small hydrophobic molecule, pyrene, in the cell membranes and large unilamellar vesicles prepared from the lipid extracts was very similar between the EPA-less mutant and the parental strain. These results suggest that EPA in S. livingstonensis Ac10 is not required for bulk bilayer fluidity but plays a beneficial role in membrane organization and cell division at low temperatures, possibly through specific interaction between EPA and proteins involved in these cellular processes.

リンク情報
DOI
https://doi.org/10.1128/JB.00881-08
J-GLOBAL
https://jglobal.jst.go.jp/detail?JGLOBAL_ID=200902271830899362
PubMed
https://www.ncbi.nlm.nih.gov/pubmed/19011019
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000262117700020&DestApp=WOS_CPL
ID情報
  • DOI : 10.1128/JB.00881-08
  • ISSN : 0021-9193
  • eISSN : 1098-5530
  • J-Global ID : 200902271830899362
  • PubMed ID : 19011019
  • Web of Science ID : WOS:000262117700020

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