Figure 3. Loss of yeast Maf1 reduces but loss of C. elegans MAFR-1 enhances stress tolerance.

A. Loss of Maf1 sensitizes yeast cells to oxidative stress activator hydrogen peroxide (H₂O₂). Yeast cells in log phase (OD₆₀₀ = 0.6) were treated without and with 1 mM of H₂O₂ for 30 min then immediately washed with YPD medium. Live cells were counted through colony formation assay. Error bars show the SEM of survival rate from 3 separate experiments. Student's t-test: **p < 0.001. B. Loss of Maf1 sensitizes yeast cells to heat stress. Yeast cells in log phase (OD₆₀₀ = 0.6) were incubated at 30°C (control) or 50°C (heat shock) for 30 min. Live cells were counted through colony formation assay. Error bars show the SEM of survival rate from 3 separate experiments. Student's t-test: **p < 0.001. C. Loss of MAFR-1 in C. elegans increases resistance to H₂O₂. Young adult worms were treated with 10 mM H₂O₂ on agar plate and survival was measured at each time point. Chi-square test: **p < 0.001. D. Loss of MAFR-1 in C. elegans increases resistance to heat. Young adult worms were raised in 30°C and survival at indicated time points was plotted. Chi-square test: **p < 0.001. E. Knocking down mafr-1 expression by RNAi increases lifespan. Worms were fed bacteria expressing double strand RNA (dsRNA) of mafr-1 gene fragment (mafr-1 RNAi) or empty vector (Control RNAi) from hatch. Chi-square test: ***p < 0.0001. F. The extended lifespan of mafr-1 mutant is due to the loss of MAFR-1. Lifespan extension in mafr-1 mutant animals is prevented by expression of MAFR-1::GFP, which did not affect lifespan of WT control. Chi-square test: **p < 0.001, ns, not significant.