Identification and characterization of maize frataxin isoforms.

BUCHENSKY, C.; CARRILLO, M; BUSI, M. V.; DIEGO FABIAN GOMEZ CASATI

Mendoza

Congreso; XLVIII Reunion SAIB; 2012

SAIB

Mitochondria and chloroplasts perform several processes essential for cell life. In many of these, that involve for example electron transfer, gene expression regulation and environmental sensing, participates different Fe-S proteins. In addition, both organelles contain several components that are homologous to the bacterial or yeast Fe–S cluster assembly machinery, suggesting the presence of two biosynthetic pathways. Frataxin (FH) is a highly conserved nuclear encoded protein that has been proposed to participate as iron donor in Fe-S cluster assembly. Besides, this protein is involved in iron homeostasis, heme metabolism, ROS and REDOX control and protection against oxidative damage. However, its precise function remains unclear. This protein has been characterized in bacteria, yeast, humans and in Arabidopsis thaliana plants (AtFH). In eukaryotes, it was reported a a mitochondrial localization for FH. In maize, we identified two coding sequences homologous to AtFH (ZmFH: GRMZM2G062342 and GRMZM2G083755). QPCR experiments showed that ZmFHxx is esxpressed mainly in XXXXX. Furthermore, we cloned, purified and characterized both isoforms,. Results show that at least one of the isoforms is a functional protein because it attenuates Fenton reaction as previously observed with AtFH. Finally, confocal microscopy studies on protoplasts transformed with GFP-ZmFH suggest a mitochondrial localitation for both proteins.