FIGURE 8: Schematic model proposed for Hrk1 involvement in S. cerevisiae adaptation and tolerance to acetic acid stress. The model depicts the proposed mechanisms of S. cerevisiae adaptation to acetic acid-induced stress that are modulated by Hrk1 based on the results presented here complemented by results from previously published studies. This model focuses on the ion fluxes across the plasma membrane and does not take into account their intracellular distribution.