IBR   13079
INSTITUTO DE BIOLOGIA MOLECULAR Y CELULAR DE ROSARIO
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Studies on heme transport and metabolism by Trypanosoma cruzi
Autor/es:
JULIA A CRICCO; SIMÓN M. MENENDEZ BRAVO
Lugar:
Puerto Madryn, Chubut República Argentina
Reunión:
Congreso; XLVI Reunión Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2010
Institución organizadora:
Sociedad Argentina de Investigación en Bioquímica y Biología Molecular
Resumen:
Studies on heme transport and metabolism by Trypanosoma cruzi Julia A. Cricco and Simón Menendez Bravo Instituto de Biología Molecular y Celular de Rosario (IBR) CONICET – UNR Área Biofísica, FCByF UNR Suipacha 531 (2000) Rosario, Santa Fe e-mail: cricco@ibr.gov.ar Trypanosoma cruzi, the etiologic agent for Chagas´ disease, has requirements for several cofactors, one of which is heme. Because this organism is unable to synthesize heme, which serves as a prosthetic group for several heme-proteins, it must be acquired from the environment. After that, heme is transported and inserted into target proteins, which are available throughout different subcellular compartments (included the respiratory chain complexes in the parasite mitochondrion). We are interested into elucidate as to how heme is imported and distributed in T. cruzi, specially focused in its traffic to the mitochondrion. As a first approach to understand heme uptake processes, we designed and optimized conditions to study the biochemical properties of heme transport using a heme fluorescent analog. We observed that heme import is mediated by a membrane active transporter, depending on ATP and sensitive to cation gradients. Once in the mitochondrion, this cofactor has to be inserted into different heme-proteins. We identified and characterized the codifying sequences that encode the T. cruzi enzymes involved in heme A biosynthesis, the essential cofactor of cytochrome c oxidase. We analyzed the mRNA level of these cds (TcCOX10 and TcCOX15) and postulated that the observed changes could be a form of regulation reflecting differences in respiratory requirements at different life stages.