INGEBI   02650
INSTITUTO DE INVESTIGACIONES EN INGENIERIA GENETICA Y BIOLOGIA MOLECULAR "DR. HECTOR N TORRES"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Identification and characterization of AMP-activated protein kinase in Trypanosoma cruzi
Autor/es:
TAMARA STERNLIEB; GUILLERMO D. ALONSO; ALEJANDRA C. SCHOIJET; PATRICIO GENTA
Lugar:
Santa Fe
Reunión:
Congreso; XXVIII Reunión Anual de la Sociedad Argentina de Protozoología y Enfermedades Parasitarias.; 2016
Institución organizadora:
Sociedad Argentina de Protozoología y CURSO - SIMPOSIO Internacional de Biología Celular y Molecular de la Enfermedad de Chagas
Resumen:
The AMP-activated protein kinase (AMPK) is a heterotrimeric enzyme involved in maintaining energy homeostasis in response to nutrient stress in many organisms. Sequence and structure of its subunits may change between organisms, but they maintain the same function. The α subunit contains a kinase catalytic domain as well as a regulatory domain that inhibits the enzyme in the absence of AMP. The β subunit acts as a scaffold for the other components and intervenes in the localization and activity regulation of the complex. While the γ subunit is thought to be involved in AMP binding. During the transition from the mammal host to the insect vector, Trypanosoma cruzi suffers nutritional stress from the absence of glucose in the insect?s midgut. The ability to respond to this stress, allows the parasite to differentiate and survive. Recently, AMPK β and γ subunits have been identified in Trypanosoma brucei, and it was shown that they are involved in surface protein expression changes in response to nutritional stress. Nevertheless, the α subunit couldn?t be found. Using the sequences from T. brucei and bioinformatics tools, we have identified three candidate genes for the AMPK subunits of T. cruzi, TcAMPKβ and TcAMPKγ appear to be highly conserved, while TcAMPKα is only partially conserved, mostly in its catalytic domain. We performed functional studies of these subunits by complementation of S. cerevisiae strains lacking one of the SNF1 complex subunits (kindly provided by Dr. Schmidt, Pittsburgh, USA), proving their ability to revert the ?glucose dependent? phenotype. Until now, we observed that TcAMPKγ effectively restores the ability of yeast lacking Snf4 to grow on plates containing Raffinose as the only carbon source. Also, we overexpressed the β and γ subunits with a hemagglutinin (HA) Tag in CL Brener epimastigotes and evaluated their expression, localization and possible post-translational modifications. So far, these studies suggest that TcAMPKγ co-localizes with glycosomes and suffers from post-translational modifications that shift its expected molecular weight. In the future, we will continue to evaluate the TcAMPK functional role in the parasite and its biochemicalproperties.