CHARACTERIZATION OF THE FRATAXIN HOMOLOG FTX1 FROM THE GREEN UNICELLULAR ALGAE CHLAMYDOMONAS REINHARDTII

TERENZI, A.; BUSI, M.V.; GOMEZ-CASATI, D.F

Salta

Congreso; LV Reunión Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB) y XIV PABMB Congress; 2019

SAIB, Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

Frataxin plays a key role in cellular iron homeostasis of different organisms. It has been implicated in iron storage, detoxification, and delivery for iron sulfur-cluster assembly and heme biosynthesis. However, its role in iron metabolism remains unclear, especially in photosynthetic organisms. In recent years, the green unicellular alga Chlamydomonas reinhardtii has been used as an excellent experimental system for understanding iron metabolism. In this work, we explore the functions of the frataxin homolog (FTX1) from C. reinhardtii. To perform in vitro studies, FTX1 was cloned, expressed, and purified. The molecular mass and the oligomerization state were determined using native gel electrophoresis. Results showed that FTX1 forms tetramers in the presence of Fe, Zn, and Cu. Octamers were only produced in the presence of Cu. Furthermore, the addition of FTX1 to a mixture of Fe2+ and H2O2 resulted in significant attenuation of Fenton reaction. In addition to this, bacteria expressing FTX1 grew better in LB medium supplemented with a high concentration of metals (Cu, Cd, Fe, Zn, Ni, As) and also after incubation with 20 mM H2O2. Altogether, our results indicate that FTX1 is an essential protein in C. reinhardtii, involved in Fe homeostasis, protection against metal oxidative damage, and the maintenance of redox cellular state.