Research Paper Volume 13, Issue 8 pp 10989—11009

Translational control of gene expression by eIF2 modulates proteostasis and extends lifespan

Effect of nutrient deprivation and temperature on translation and lifespan. (A) Translation rate of WT and eIF2α.S52A (S52A) cells measured by 35S-methionine/cysteine metabolic labelling. Coomassie staining shows the total protein levels loaded in each lane (bottom panel). Cells were grown in standard conditions (3% glucose YES medium at 30° C, Control) or low glucose (0.1% Glc) YES medium and at 20° C or 35° C prior to labelling. Cells were metabolically labelled, as previously described. (B) Longevity assay of WT and eIF2α.S52A (S52A) cells cultivated under conditions described in A). Serial dilutions (1/5) of cells were plated onto YES-Agar plates at the exponential phase (Control) or several days after reaching stationary phase of growth, as indicated, and incubated at 30° C for 2-3 days. (C) Longevity assay of cells shifted from 3% to 0.1% glucose YES medium during exponential growth phase. Left panel: eIF2α.S52A cells growing in 3% glucose (black boxes) were shifted to 0.1% glucose YES medium (white boxes) at indicated times. Right panel: eIF2α.S52A cells growing in 0.1% glucose YES medium were shifted to 3% glucose by addition of glucose at the indicated times. WT and eIF2α.S52A cells grown in 3% or 0.1% glucose YES medium during the whole experiment were used as control. Serial dilutions of cells were plated as described in panel (B). Data information: (A–C) Representative results from three independent experiments.

Figure 3. Effect of nutrient deprivation and temperature on translation and lifespan. (A) Translation rate of WT and eIF2α.S52A (S52A) cells measured by 35S-methionine/cysteine metabolic labelling. Coomassie staining shows the total protein levels loaded in each lane (bottom panel). Cells were grown in standard conditions (3% glucose YES medium at 30° C, Control) or low glucose (0.1% Glc) YES medium and at 20° C or 35° C prior to labelling. Cells were metabolically labelled, as previously described. (B) Longevity assay of WT and eIF2α.S52A (S52A) cells cultivated under conditions described in A). Serial dilutions (1/5) of cells were plated onto YES-Agar plates at the exponential phase (Control) or several days after reaching stationary phase of growth, as indicated, and incubated at 30° C for 2-3 days. (C) Longevity assay of cells shifted from 3% to 0.1% glucose YES medium during exponential growth phase. Left panel: eIF2α.S52A cells growing in 3% glucose (black boxes) were shifted to 0.1% glucose YES medium (white boxes) at indicated times. Right panel: eIF2α.S52A cells growing in 0.1% glucose YES medium were shifted to 3% glucose by addition of glucose at the indicated times. WT and eIF2α.S52A cells grown in 3% or 0.1% glucose YES medium during the whole experiment were used as control. Serial dilutions of cells were plated as described in panel (B). Data information: (AC) Representative results from three independent experiments.