CHARACTERIZATION OF EGAT1: A GLUTAMATE TRANSPORTER IN ECHINOCOCCUS GRANULOSUS

CAMICIA, F.; PRADA, L.; CÁNEPA, G.; PEREIRA, C.A.; ROSENZVIT, M.C.

Colonia del Sacramento, Uruguay

Congreso; XXIII CONGRESO MUNDIAL DE HIDATIDOSIS; 2009

Asociación Internacional de Hidatidosis

The cestode Echinococcus granulosus is the causative agent of cystic hydatid disease (CHD), a major zoonosis that affects many areas around the world. Several coding sequences for putative amino acid transporters have been detected by screening of an E. granulosus protoscolex signal sequence trap cDNA library and by bioinformatic analysis of the E. multilocularis genome and the E. granulosus trascriptome. One of them is a 1627 bp long cDNA termed egat1, which contains an ORF of 489 amino acids and amino acid identity of 30% with neutral and excitatory amino acid transporters members of the Dicarboxylate/Amino Acid Na+ and/or H+ Cation Symporter family (DAACS). Additional analysis, showed 9 to 10 transmembrane domains, sequences for N-glycosylation and highly similar hydropathy profile with members of the DAACS family. The localization of EgAT1 was analyzed by in situ hybridization and immunofluorescence in protoscoleces and associated germinal layer. egat1 mRNA was shown throughout the tegument. EgAT1 protein, which showed in Western blots a molecular mass of ~60 kD, was localized in the subtegumental region of the metacestode, particularly around suckers and rostellum of protoscoleces and germinal layer. COS-7 cells transfected with an expression plasmid coding for EgAT1 showed specific glutamate uptake. In the present work we have characterized a new amino acid transporter at the molecular level in cestodes. This work paves the way for the evaluation of EgAT1 as a new drug target against CHD. Supported by YPF Foundation, CONICET and FONCYT.