Arabidopsis thaliana FRATAXIN (AtFH) IS INVOLVED IN IRON HOMEOSTASIS AND OXIDATIVE STRESS

RODRIGUEZ-COLMAN, M. J.; GÓMEZ-CASATI, D.; LAMATTINA, L.; EDUARDO JULIAN ZABALETA; MARTIN, M.

Rosario

Congreso; 42th Reunion Anual de SAIB; 2006

Iron is an essential cofactor for many reactions in the cell; in particular, it is present in heme and FeS proteins. Moreover, mitochondria contain the machinery for FeS cluster biogenesis and export into the cytosol. However, excess iron can generate via Fenton reaction highly toxic-free radicals generating oxidative damage to the cell. Nitric oxide (NO) can attenuate the Fenton oxidative damage preventing the formation of oxidants by scavenging either iron or superoxide limiting hydroxyl radical formation. Thus, plants employ a sophisticated homeostasis mechanism to control cellular iron. Frataxin is a mitochondrial protein that is conserved throughout evolution. The function of frataxin is still essentially unknown. It has been postulated that this protein is an essential protein in plants, required for full activity of mitochondrial Fe-S proteins and plays a protective role against oxidative damage. In this work we present evidences that frataxin-deficient Arabidopsis plants accumulate iron in their mitochondria. We suggest that an excess of free iron could be involved in the production of reactive oxygen species (ROS) and could be responsible for the oxidative damage to Fe-S clusters as a consequence these plants have increased sensitivity to oxidative stress. We discuss if the higher NO content observed has an effect protective or deleterious in frataxin-deficient plants. mitochondria. We suggest that an excess of free iron could be involved in the production of reactive oxygen species (ROS) and could be responsible for the oxidative damage to Fe-S clusters as a consequence these plants have increased sensitivity to oxidative stress. We discuss if the higher NO content observed has an effect protective or deleterious in frataxin-deficient plants. Arabidopsis plants accumulate iron in their mitochondria. We suggest that an excess of free iron could be involved in the production of reactive oxygen species (ROS) and could be responsible for the oxidative damage to Fe-S clusters as a consequence these plants have increased sensitivity to oxidative stress. We discuss if the higher NO content observed has an effect protective or deleterious in frataxin-deficient plants.