Characterization of frataxin homologs in plants

TUROWSKI, V.; CARRILLO, M; LEADEN, L; BUSI, M. V.; DIEGO FABIAN GOMEZ CASATI

Puerto Madryn

Congreso; XLVI Reunion SAIB; 2010

SAIB

Frataxin is a highly conserved protein from bacteria to mammals that has been proposed to participate in iron-sulfur cluster assembly, mitochondrial iron homeostasis and defense against oxidative stress. In eukaryotes, frataxin is encoded in the nucleus but has mitochondrial localization. Recently, we reported the presence of a single gene that codify this protein in Arabidopsis thaliana (AtFH); while three different genes has been predicted to codify frataxin isoforms in maize (ZmFH  EU968030, BT040175 y BT055005). We cloned and characterized two of these isoforms (EU968030 and BT055005). Our results indicate that these isoforms are functional and suggest that both have a similar role in maize. We also found that frataxin homologs interact with the mitochondrial cysteine desulfurase AtNfs1 using a pull-down assay. In addition, frataxin increases the catalytic efficiency of AtNfs1, suggesting a direct role of frataxin in the modulation of sulfide transfer into the scaffold proteins Isu and HscB.