Saccharomyces cerevisiae can import iron through a high-affinity system 
consisting of the Ftr1/Fet3-mediated reductive pathway and the 
siderophore-mediated non-reductive one. Expression of components of the 
high-affinity system is controlled by the Aft1 transcriptional factor. In this 
study we show that, upon oxidative stress, Aft1 is transitorily internalized 
into the nucleus, followed by transcription activation of components of its 
regulon. In these conditions, the mRNA levels of the genes of the non-reductive 
pathway become increased, while those of FTR1 and FET3 remain low because of 
destabilization of the mRNAs. Consequently, the respective protein levels also 
remain low. Such mRNA destabilization is mediated by the general 5'-3' mRNA 
decay pathway and is independent of the RNA binding protein Cth2. Yeast cells 
are hypersensitive to peroxides in growth conditions where only the 
high-affinity reductive pathway is functional for iron assimilation. On the 
contrary, peroxide does not affect growth when iron uptake occurs exclusively 
through the non-reductive pathway. This reinforces the idea that upon oxidative 
stress S. cerevisiae cells redirect iron assimilation through the non-reductive 
pathway to minimize oxidative damage by the ferrous ions, which are formed 
during iron import through the Ftr1/Fet3 complexes.