Potassium Starvation in Yeast: Mechanisms of Homeostasis Revealed by Mathematical Modeling
Figure 2
Regulation of potassium starvation.
(A) The tracking approach to detect potential regulators of homeostasis. Parameters which are constant in the minimal model are now considered as input functions. A parameter is called a potential regulator if it can be chosen to recover (“track”) the experimental time courses. (B,C) The predicted activity changes for Pma1 (B) and the bicarbonate reaction system (C) in response to potassium starvation. (D) Time course of ATPase activity for Pma1. (E) Time course of gene expression for the NCE103 gene encoding carbonic anhydrase in the wild type strain. Confirmatory qRT-PCR measurements yield a fold increase of the mRNA level in the wild type after 60 minutes of potassium starvation. For comparison, the expression in non-starved trk1,2 double mutant with respect to the wild type strain is depicted. The mRNA levels for NCE103 in trk1,2 double mutants growing at
are higher by a factor of
compared to the wild type strain (qRT-PCR measurements).