Frataxin oligomerization and metal binding properties in plants

SANCHÉZ M; ATRIAN S; GOMEZ CASAT DF; BUCHENSKY CELESTE; DOMINGUEZ VERA J; BUSI MV; CAPDEVILLA M; PAGANI MA

Córdoba

Congreso; 52th Annual Meeting Argentine Society for Biochemistry and Molecular Biology; 2016

Frataxin is a highly conserved protein involved in FeSclusterbiosynthesis, iron homeostasis, heme metabolism andprotection against oxidative damage. In humans, defects infrataxin levels lead to Friedreich´s ataxia, a progressiveneurodegenerative disease. Previous studies in E. coli, S. cerevisiae and human frataxin indicate that these proteinspresent different oligomerization behavior and different metalsbinding properties, which are specific to each species. Also, ithas been reported that the N-terminaltransit sequence thatdirects its transport to the mitochondria participates in theseprocesses. In plants, frataxin is found in both chloroplast andmitochondria. In the present work, we characterized A. thaliana (AtFH) andZea mays (ZmFH1 and ZmFH2) frataxin proteins. Recombinantproteins in full length, in an intermediate form and in matureform without transit peptide were synthesized, and then theywere studied by ESI-MSspectroscopy. Results indicate thatfrataxins from both plants present common oligomerization andmetals binding properties. In addition, we determined that the N-terminalregion is important in these processes, and our findings suggest the existence of self-cleavage to reach the mature form.