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Quantitative modeling of triacylglycerol homeostasis in yeast – metabolic requirement for lipolysis to promote membrane lipid synthesis and cellular growth
Author(s) -
Zanghellini Jürgen,
Natter Klaus,
Jungreuthmayer Christian,
Thalhammer Armin,
Kurat Christoph F.,
GoggFassolter Gabriela,
Kohlwein Sepp D.,
von Grünberg HansHennig
Publication year - 2008
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/j.1742-4658.2008.06681.x
Subject(s) - lipolysis , biochemistry , fatty acid , lipid droplet , lipid metabolism , yeast , flux (metallurgy) , chemistry , metabolism , metabolic flux analysis , membrane , biology , microbiology and biotechnology , adipose tissue , organic chemistry
Triacylglycerol metabolism in Saccharomyces cerevisia e was analyzed quantitatively using a systems biological approach. Cellular growth, glucose uptake and ethanol secretion were measured as a function of time and used as input for a dynamic flux‐balance model. By combining dynamic mass balances for key metabolites with a detailed steady‐state analysis, we trained a model network and simulated the time‐dependent degradation of cellular triacylglycerol and its interaction with fatty acid and membrane lipid synthesis. This approach described precisely, both qualitatively and quantitatively, the time evolution of various key metabolites in a consistent and self‐contained manner, and the predictions were found to be in excellent agreement with experimental data. We showed that, during pre‐logarithmic growth, lipolysis of triacylglycerol allows for the rapid synthesis of membrane lipids, whereas d e nov o fatty acid synthesis plays only a minor role during this growth phase. Progress in triacylglycerol hydrolysis directly correlates with an increase in cell size, demonstrating the importance of lipolysis for supporting efficient growth initiation.