Dose-dependent mitochondrial H2O2 signaling drives toxicity or stress adaptation and longevity in fission yeast

Using fission yeast, we controlled and monitored intracellular H 2 O 2 to study its spatiotemporal signaling.Localized mitochondrial H 2 O 2 reached the nucleus and, depending on intensity, either enhanced stress resistance and longevity or impaired mitochondrial function.These findings define a quantitative framework for mitochondrial redox signaling and its impact on cellular fitness.