Fig. 6: Protein kinase A post-starvation reactivation enables aggregate dissolution.

a Representative images of Hsp104-GFP aggregates in the presence of Rp-cAMPS (protein kinase A inhibitor), pfk2Δ strain and both, at indicated times of the recovery period are displayed, and compared to the control. This experiment was performed in three technical replicates for each of the three biological replicates. The black bar represents 8 µm. b Percentage of cells bearing at least one aggregate during the recovery in 2% glucose in the presence of Rp-cAMPS, pfk2Δ, and both. c In control conditions (2% glucose), during the recovery from starvation in 0.02% glucose, ATP levels increase, and median aggregate diameter is decreased. d In the presence of Rp-cAMPS and in pfk2Δ, there is no restoration of ATP level during the recovery period, despite the presence of 2% glucose. Median aggregate diameter fails to decrease during the recovery period. e Percentage of cells with aggregates increases in 0.02% glucose, both with cytosolic acidification, as well as at pH 7. In b–e, n = 1100 of cells were screened for aggregates starting from three independent exponential yeast cultures for each condition. Bar height represents mean ± SD from three separate cultures, each performed in triplicate. The mean of three technical replicates for each biological replicate is displayed as single data points. ***p < 0.001; **p < 0.01; *p < 0.05 (one-way ANOVA plus Tukey post hoc). Representative images of cells in different regimes of pH and glucose. The images are representative of three biological replicates, each in three technical replicates. Roundness of the aggregates was quantified using the Shape descriptors plugin for ImageJ. Bar height represents mean ± SD from three separate cultures, each performed in triplicate. Individual data points are given for the roundness of each analyzed aggregate. N = 90, 164, 95, and 96 aggregates for the conditions of 2% and 0.02% glucose, 0.02% glucose pH 7, and 2% glucose pH 5.5, respectively. ***p < 0.001; **p < 0.01; *p < 0.05 (one-way ANOVA plus Tukey post hoc). The black bar represents 8 µm.