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Title: Lipid engineering reveals regulatory roles for membrane fluidity in yeast flocculation and oxygen-limited growth

Abstract

Cells modulate lipid metabolism in order to maintain membrane homeostasis. In this paper, we use a metabolic engineering approach to manipulate the stoichiometry of fatty acid unsaturation, a regulator of cell membrane fluidity, in Saccharomyces cerevisiae. Unexpectedly, reduced lipid unsaturation triggered cell-cell adhesion (flocculation), a phenomenon characteristic of industrial yeast but uncommon in laboratory strains. We find that ER lipid saturation sensors induce expression of FLO1 – encoding a cell wall polysaccharide binding protein – independently of its canonical regulator. In wild-type cells, Flo1p-dependent flocculation occurs under oxygen-limited growth, which reduces unsaturated lipid synthesis and thus serves as the environmental trigger for flocculation. Transcriptional analysis shows that FLO1 is one of the most highly induced genes in response to changes in lipid unsaturation, and that the set of membrane fluidity-sensitive genes is globally activated as part of the cell's long-term response to hypoxia during fermentation. Finally, our results show how the lipid homeostasis machinery of budding yeast is adapted to carry out a broad response to an environmental stimulus important in biotechnology.

Authors:
 [1];  [2];  [3];  [4];  [2]
  1. Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Technical Univ. of Darmstadt (Germany)
  2. Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Univ. of California, Berkeley, CA (United States)
  3. Technical Univ. of Darmstadt (Germany)
  4. Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Technical Univ. of Denmark, Lyngby (Denmark)
Publication Date:
Research Org.:
Univ. of California, Berkeley, CA (United States); Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Technical Univ. of Darmstadt (Germany)
Sponsoring Org.:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23); National Science Foundation (NSF); German Research Foundation (DFG)
OSTI Identifier:
1393229
DOE Contract Number:
AC02-05CH11231; MCB-1330914; MCB-1341894; BE1181/10-1
Resource Type:
Journal Article
Resource Relation:
Journal Name: Metabolic Engineering; Journal Volume: 41
Country of Publication:
United States
Language:
English
Subject:
47 OTHER INSTRUMENTATION; fatty acid unsaturation; membrane fluidity; yeast flocculation; oxygen-limited growth; hypoxia; fermentation

Citation Formats

Degreif, Daniel, de Rond, Tristan, Bertl, Adam, Keasling, Jay D., and Budin, Itay. Lipid engineering reveals regulatory roles for membrane fluidity in yeast flocculation and oxygen-limited growth. United States: N. p., 2017. Web. doi:10.1016/j.ymben.2017.03.002.
Degreif, Daniel, de Rond, Tristan, Bertl, Adam, Keasling, Jay D., & Budin, Itay. Lipid engineering reveals regulatory roles for membrane fluidity in yeast flocculation and oxygen-limited growth. United States. doi:10.1016/j.ymben.2017.03.002.
Degreif, Daniel, de Rond, Tristan, Bertl, Adam, Keasling, Jay D., and Budin, Itay. Sat . "Lipid engineering reveals regulatory roles for membrane fluidity in yeast flocculation and oxygen-limited growth". United States. doi:10.1016/j.ymben.2017.03.002.
@article{osti_1393229,
title = {Lipid engineering reveals regulatory roles for membrane fluidity in yeast flocculation and oxygen-limited growth},
author = {Degreif, Daniel and de Rond, Tristan and Bertl, Adam and Keasling, Jay D. and Budin, Itay},
abstractNote = {Cells modulate lipid metabolism in order to maintain membrane homeostasis. In this paper, we use a metabolic engineering approach to manipulate the stoichiometry of fatty acid unsaturation, a regulator of cell membrane fluidity, in Saccharomyces cerevisiae. Unexpectedly, reduced lipid unsaturation triggered cell-cell adhesion (flocculation), a phenomenon characteristic of industrial yeast but uncommon in laboratory strains. We find that ER lipid saturation sensors induce expression of FLO1 – encoding a cell wall polysaccharide binding protein – independently of its canonical regulator. In wild-type cells, Flo1p-dependent flocculation occurs under oxygen-limited growth, which reduces unsaturated lipid synthesis and thus serves as the environmental trigger for flocculation. Transcriptional analysis shows that FLO1 is one of the most highly induced genes in response to changes in lipid unsaturation, and that the set of membrane fluidity-sensitive genes is globally activated as part of the cell's long-term response to hypoxia during fermentation. Finally, our results show how the lipid homeostasis machinery of budding yeast is adapted to carry out a broad response to an environmental stimulus important in biotechnology.},
doi = {10.1016/j.ymben.2017.03.002},
journal = {Metabolic Engineering},
number = ,
volume = 41,
place = {United States},
year = {Sat Mar 18 00:00:00 EDT 2017},
month = {Sat Mar 18 00:00:00 EDT 2017}
}
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