NUCLEOCYTOPLASMIC TRANSPORT IN TRYPANOSOMATIDS

MEYER CG; FLAWIÁ, MM; ALONSO GD

Potrero de los Funes, San Luis.

Congreso; XLVII Reunión Anual de SAIB; 2011

SAIB

The exchange of macromolecules between the cytoplasm and the cell nucleus is a vital process in eukaryotic cells. All nuclear proteins synthesized in the cytoplasm must be imported through the nuclear pore complexes generally with the aid of an active, carrier-mediated process. The import of proteins containing nuclear localization signals is facilitated by karyopherin proteins, also known as importins. Trypanosomatids are protozoan parasites with a complex life cycle that alternate between hosts and differentiation stages. They are causative agents of diseases such as Sleeping Sickness, Chagas Disease and leishmaniasis. We show here that nucleocytoplasmic transport seems to be conserved among trypanosomatids as many of the genes involved in it are found in their genomes. Although different importin variants have been discovered in higher eukaryotes, up to date only the canonical importin alpha and importin beta were found in these parasites. Homology modeling of these importins showed high conservation of three-dimensional structure albeit their sequence conservation is rather low. We found out using knock-down experiments that both importins are essential in procyclic forms of Trypanosoma brucei. In order to study their cellular localization, we tagged these proteins to YFP and we finally used yeast knock-out strains for complementation assays to confirm their foreseen function.