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A thermodynamic model of monovalent cation homeostasis in the yeast Saccharomyces cerevisiae

Citation

Gerber, S and Frohlich, M and Lichtenberg-Frate, H and Shabala, S and Shabala, L and Klipp, E, A thermodynamic model of monovalent cation homeostasis in the yeast Saccharomyces cerevisiae, PLoS Computational Biology, 12, (1) Article e1004703. ISSN 1553-7358 (2016) [Refereed Article]


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Copyright Statement

Copyright: 2016 Gerber et al. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) http://creativecommons.org/licenses/by/4.0/

DOI: doi:10.1371/journal.pcbi.1004703

Abstract

Cationic and heavy metal toxicity is involved in a substantial number of diseases in mammals and crop plants. Therefore, the understanding of tightly regulated transporter activities, as well as conceiving the interplay of regulatory mechanisms, is of substantial interest. A generalized thermodynamic description is developed for the complex interplay of the plasma membrane ion transporters, membrane potential and the consumption of energy for maintaining and restoring specific intracellular cation concentrations. This concept is applied to the homeostasis of cation concentrations in the yeast cells of S. cerevisiae. The thermodynamic approach allows to model passive ion fluxes driven by the electrochemical potential differences, but also primary or secondary active transport processes driven by the inter- play of different ions (symport, antiport) or by ATP consumption (ATPases). The model - confronted with experimental data - reproduces the experimentally observed potassium and proton fluxes induced by the external stimuli KCl and glucose. The estimated phenomenological constants combine kinetic parameters and transport coefficients. These are in good agreement with the biological understanding of the transporters thus providing a better understanding of the control exerted by the coupled fluxes. The model predicts the flux of additional ion species, like e.g. chloride, as a potential candidate for counterbalancing positive charges. Furthermore, the effect of a second KCl stimulus is simulated, predicting a reduced cellular response for cells that were first exposed to a high KCl stimulus compared to cells pretreated with a mild KCl stimulus. By describing the generalized forces that are responsible for a given flow, the model provides information and suggestions for new experiments. Furthermore, it can be extended to other systems such as e.g. Candida albicans, or selected plant cells.

Item Details

Item Type:Refereed Article
Keywords:yeast, ion transport, homeostasis
Research Division:Biological Sciences
Research Group:Physiology
Research Field:Animal Physiology - Biophysics
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Environmental Sciences
Author:Shabala, S (Professor Sergey Shabala)
Author:Shabala, L (Dr Lana Shabala)
ID Code:107585
Year Published:2016
Web of Science® Times Cited:2
Deposited By:Tasmanian Institute of Agriculture
Deposited On:2016-03-18
Last Modified:2017-11-02
Downloads:56 View Download Statistics

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