Defects in triacylglycerol lipolysis affect synthesis of triacylglycerols and steryl esters in the yeast.

Claudia Schmidt, Karin Athenstaedt, Barbara Koch, Birgit Ploier, Martina Korber, Günther Zellnig, Günther Daum*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Tgl3p, Tgl4p and Tgl5p are the major triacylglycerol lipases of the yeast Saccharomyces cerevisiae catalyzing degradation of triacylglycerols stored in lipid droplets. Previous results from our laboratory (Athenstaedt and Daum, 2005, J. Biol. Chem. 280, 37301–37309) demonstrated that a yeast strain lacking all three triacylglycerol lipases accumulates not only triacylglycerols at high amount, but also steryl esters. Here we show a metabolic link between synthesis and mobilization of non-polar lipids. In particular, we demonstrate that a block in tri-acylglycerol degradation in a tgl3∆tgl4∆tgl5∆ triple mutant lacking all major triacylglycerol lipases causes marked changes in non-polar lipid synthesis. Under these conditions formation of triacylglycerols is reduced, whereas steryl ester synthesis is enhanced as shown by quantification of non-polar lipids, in vivo labeling of lipids using [14C]oleic acid and [14C]acetic acid as precursors, and enzyme analyses in vitro. In summary, this study demonstrates that triacylglycerol metabolism and steryl ester metabolism are linked processes. The importance of balanced storage and degradation of these components for lipid homeostasis in the yeast is highlighted.
Original languageEnglish
Pages (from-to)1393-1402
JournalBiochimica et Biophysica Acta - Molecular and Cell Biology of Lipids
Volume1841
DOIs
Publication statusPublished - 2014

Fields of Expertise

  • Human- & Biotechnology

Treatment code (Nähere Zuordnung)

  • Basic - Fundamental (Grundlagenforschung)

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