Sulfiredoxin Protein Is Critical for Redox Balance and Survival of Cells Exposed to Low Steady-state Levels of H2O2*

Abstract

Background: Sulfiredoxin catalyzes the reactivation of hyperoxidized peroxiredoxins, which are peroxidases. Results: Under low steady-state levels of H 2 O 2 ([H 2 O 2 ]ss), loss of function of sulfiredoxin leads to redox imbalance and sensitizes cells to apoptosis. Conclusion: Sulfiredoxin functions as a critical antioxidant for redox balance and survival of cells exposed to low [H 2 O 2 ]ss. Significance: Sulfiredoxin may serve as a cell survival factor even in the presence of low [H 2 O 2 ]ss.