Figures and data
The lifespan extension of SUL1Δ mutant is not caused by changes in sulfate transport/metabolism.
(A) Deletion of SUL1 gene significantly extended the replicative lifespan of yeast S. cerevisiae. Numbers in parentheses indicate the average life span and the number of cells measured. **: P < 0.01. (B) Lifespan is not altered by three targeted genetic interventions that change sulfate transport/metabolism: a. mutation of the amino acid residue of SUL1 (E427Q) that abolishes the activity of sulfate transport; b. inactivation of MET3, the key enzymes of SAP; c. deletion of SUL2 (a homolog of SUL1). Survival curves for the WT and SUL1E427Q, MET3Δ or SUL2Δ strains are shown.
Common longevity pathways may contribute to the RLS extension of SUL1 deletion mutant.
(A) Volcano plot of the DEG between the SUL1Δ and WT strains. The transcriptomics analysis was performed in the SUL1Δ and WT strains. Log10 of the P values is plotted against the Log2 FC of the FPKM. (B) Biological processes enriched in the DEGs between the SUL1Δ and WT strains. The up-regulated genes (P < 0.1, Log2 FC > 0.5) and the down-regulated genes (P < 0.1, Log2 FC < -0.5) were used for the analysis. (C) Heatmaps showing changes of stress response (left) and amino acid biosynthetic and ribosome biogenesis genes (right). (D) Association analysis of the potential transcription factors and the DEGs in the enriched biological processes (See Methods).
SUL1 deletion inhibits the PKA pathway and increases the translocation of MSN2 into nucleus.
(A) The mRNA levels of several stress response genes and trehalose synthesis. ns: not significant; *: P < 0.05. (B) The concentrations of trehalose and glycogen in WT and SUL1Δ strains. *: P < 0.05; **: P < 0.01. (C) Representative images of EGFP-labeled endogenous MSN2 in WT and SUL1Δ strains during the exponential growth phase. BF: bright field. Scale bars: 10 μm. (D) The ratio of the mean fluorescence intensity of MSN2-EGFP in the nucleus vs. that of the total cell. Bars represent mean ± SD, n = 100. ***: P < 0.001. (E) Representative time-lapse images of MSN2-EGFP in WT and SUL1Δ strains. Scale bars: 5 μm. (F) The normalized nuclear/cytoplasmic fluorescence intensity ratio of MSN2-EGFP as a function of age in the WT and SUL1Δ strains (number of cells WT: n = 80; SUL1Δ: n = 80). (G) Comparison of the nuclear/cytoplasmic mean fluorescence intensity ratio of MSN2-EGFP as a function of age in WT and SUL1Δ strains. Bars represent mean ± SD, n = 80. ns: not significant; *: P < 0.05; **: P < 0.01; ***: P < 0.001; ****: P < 0.0001.
SUL1 deletion raises cellular autophagy level.
(A) Heatmap showing changes of autophagy-related genes in WT and SUL1Δ strains. (B) Representative time-lapse images of ATG8-EGFP in WT and SUL1Δ strains. Scale bars: 5 μm. (C) The normalized fluorescence intensity of ATG8-EGFP as a function of age in the WT and the SUL1Δ strains. Each colored curve represents a single cell. (number of cells: WT n = 80; SUL1Δ n = 80). (D) Distribution of the fluorescence intensity of ATG8-EGFP as a function of age in the WT and SUL1Δ strains. Bars represent mean ± SD, number of cells n = 80. ns: not significant; *: P < 0.05; **: P < 0.01. (E) Representative time-lapse images of ATG8-EGFP in WT and SUL1Δ strains grown in complete synthetic medium (2% glucose) or in glucose restriction medium (0.05% glucose) at the indicated times. Scale bars: 5 μm. (F) Distribution of the fluorescence intensity of ATG8-EGFP in WT and SUL1Δ strains grown in complete synthetic medium (2% glucose) or in glucose restriction medium (0.05% glucose) at indicated times. Bars represent mean ± SD; WT: n = 35; SUL1Δ: n = 44. **: P < 0.01; ****: P < 0.0001.
The effect of SUL1 deletion on longevity is partially mediated by MSN2 and ATG8.
(A-B) Replicative life span of MSN2 and ATG8 deletion mutants in WT and SUL1Δ strains. The median lifespan is displayed on the graph. (C) A schematic illustrating a mechanistic model of how the deletion of SUL1 extends lifespan. SUL1 deletion leads to decreased PKA activity, resulting in increased nuclear translocation of MSN2 (and consequently increased general stress response), autophagy, trehalose, and decreased ribosome biogenesis. The cumulative impact of these downstream effects collectively contributes to the extension of lifespan. R: PKA regulatory subunit; C: PKA catalytic subunit.
