Systems Level Analysis of the Yeast Osmo-Stat
Journal article, 2016

Adaptation is an important property of living organisms enabling them to cope with environmental stress and maintaining homeostasis. Adaptation is mediated by signaling pathways responding to different stimuli. Those signaling pathways might communicate in order to orchestrate the cellular response to multiple simultaneous stimuli, a phenomenon called crosstalk. Here, we investigate possible mechanisms of crosstalk between the High Osmolarity Glycerol (HOG) and the Cell Wall Integrity (CWI) pathways in yeast, which mediate adaptation to hyper- and hypo-osmotic challenges, respectively. We combine ensemble modeling with experimental investigations to test in quantitative terms different hypotheses about the crosstalk of the HOG and the CWI pathways. Our analyses indicate that for the conditions studied i) the CWI pathway activation employs an adaptive mechanism with a variable volume-dependent threshold, in contrast to the HOG pathway, whose activation relies on a fixed volume-dependent threshold, ii) there is no or little direct crosstalk between the HOG and CWI pathways, and iii) its mainly the HOG alone mediating adaptation of cellular osmotic pressure for both hyper- as well as hypo-osmotic stress. Thus, by iteratively combining mathematical modeling with experimentation we achieved a better understanding of regulatory mechanisms of yeast osmo-homeostasis and formulated new hypotheses about osmo-sensing.


Soheil Rastgou Talemi

German Cancer Research Center (DKFZ)

Otto von Guericke Universitaet Magdeburg

Carl Fredrik Tiger

University of Gothenburg

Mikael Andersson

University of Gothenburg

Roja Babazadeh

University of Gothenburg

Niek Welkenhuysen

University of Gothenburg

Edda Klipp

Humboldt University of Berlin

Stefan Hohmann

Chalmers, Biology and Biological Engineering

University of Gothenburg

J. Schaber

Otto von Guericke Universitaet Magdeburg

Scientific Reports

2045-2322 (ISSN)

Vol. 6 Article Number: 30950 -

Subject Categories

Biological Sciences



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9/6/2018 1