Decreased cellular permeability to H2O2 protects Saccharomyces cerevisiae cells in stationary phase against oxidative stress.
The higher resistance of stationary-phase Saccharomyces cerevisiae to H2O2 when compared with exponential phase is well characterized, but the molecular mechanisms underlying it remain mostly unknown. By applying the steady-state H2O2-delivery model, we show that (a) cellular permeability to H2O2 is five times lower in stationary--than in exponential phase; (b) cell survival to H2O2 correlates with H2O2 cellular gradients for a variety of cells; and, (c) cells in stationary phase are predicted to be more susceptible to intracellular H2O2 than in exponential phase. In conclusion, limiting H2O2 diffusion into cells is a key protective mechanism against extracellular H2O2.
Sousa-Lopes
A
A
Grupo de Bioquímica dos Oxidantes e Antioxidantes, Centro de Química e Bioquímica, P-1749-016 Lisboa, Portugal.
Antunes
F
F
Cyrne
L
L
Marinho
H S
HS
D002453:Cell Cycle / Q000502:physiology; D002463:Cell Membrane Permeability / Q000502:physiology*; D002470:Cell Survival; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D016877:Oxidants / Q000494:pharmacology*; D018384:Oxidative Stress; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000187:drug effects / Q000502:physiology*
D016877:Oxidants; D006861:Hydrogen Peroxide