IBR   13079
INSTITUTO DE BIOLOGIA MOLECULAR Y CELULAR DE ROSARIO
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
C-terminal protein tags affects the activity of Trypanosoma cruzi heme A biosynthetic enzymes
Autor/es:
BRENDA A. CIRULLI; JERÓNIMO BORRA BELTRÁN; MARCELO L. MERLI; LUCAS PAGURA; JULIA A. CRICCO
Lugar:
Rosario
Reunión:
Otro; Ciclo de Divulgación de Trabajos Científicos 2015 - FCByF - UNR; 2015
Institución organizadora:
Facultad de Cs. Bioquímicas y Farmacéuticas- UNR
Resumen:
Trypanosoma cruzi, the etiological agent of Chagas disease, cannot synthesize heme. This parasite must acquire it from different hosts and distribute it to several hemeproteins. We have identified the enzymes responsible for the conversion of heme into heme A in T. cruzi: TcCox10 (heme O synthase) and TcCox15 (heme A synthase) enzymes. We verified their function in the yeast S. cerevisiae and demonstrated that these enzymes are essential in T. cruzi epimastigote. Heme A is only present in cytochrome c oxidase complex (CcO).In the present work, we designed and constructed the GFP fusion of these genes and expressed them in T. cruzi and S. cerevisiae. We demonstrated that the mentioned proteins localized in T. cruzi mitochondrion and we observed an altered activity in yeast compared to the untagged versions: TcCox15-GFP was weakly functional in yeast cox15∆ cells whereas TcCox10-GFP was more functional in yeast cox10∆ cells. The heme O synthase and heme A synthase genes of another parasites -Leishmania mexicana and Plasmodium falciparum- were also expressed in yeast but the results were not conclusive as were with T. cruzi genes.These results indicate that despite the conservation of the proteins along the species, not all of them complemented the function in yeast and the C-terminal tags affected their interaction or stability affecting in their enzymatic activity.