Deficiency Increases the Sensitivity of Yeast to Oxidative Stress and Shortens Replicative Lifespan by Inhibiting Catalase Activity.

Yeast , a subunit of the cytosolic iron-sulfur (Fe/S) protein assembly (CIA) machinery which is responsible for the maturation of Fe/S proteins, has been reported to participate in the oxidative stress response. However, the underlying molecular mechanisms remain unclear. In this study, we constructed a heterozygous mutant yeast strain and found that deficiency in yeast cells impaired oxidative stress resistance as evidenced by increased sensitivity to hydrogen peroxide (HO) and cumene hydroperoxide (CHP). Mechanistically, the mRNA levels of catalase A and catalase T as well as the total catalase activity were significantly reduced in -deficient cells. In contrast, overexpression of or in -deficient cells significantly increased the intracellular catalase activity and enhanced the resistance ability against HO and CHP. In addition, deficiency diminished the replicative capacity of yeast cells as evidenced by the shortened replicative lifespan, which can be restored by overexpression, but not by , in the -deficient cells. These results suggest that , in a catalase-dependent manner, plays an essential role in enhancing the resistance of yeast cells to oxidative stress and increasing the replicative capacity of yeast cells.