Sequencing, bioinformatic characterization and expression pattern of a putative amino acid transporter from the parasitic cestode Echinococcus granulosus

CAMICIA, F.; PAREDES, R; CHALAR, C.; GALANTI, N.; KAMENETZKY, L.; GUTIERREZ, A.; ROSENZVIT, M. C.

GENE

Elsevier/North-Holland

Lugar: Netherlands; Año: 2008 vol. 411 p. 1 - 9

0378-1119

We have sequenced and partially characterized an Echinococcus granulosus cDNA, termed egat1, from a protoscolex signal sequence trap (SST)cDNA library. The isolated 1627 bp long cDNA contains an ORF of 489 amino acids and shows an amino acid identity of 30% with neutral andexcitatory amino acid transporters members of the Dicarboxylate/Amino Acid Na+ and/or H+ Cation Symporter family (DAACS) (TC 2.A.23).Additional bioinformatics analysis of EgAT1, confirmed the results obtained by similarity searches and showed the presence of 9 to 10transmembrane domains, consensus sequences for N-glycosylation between the third and fourth transmembrane domain, a highly similar hydropathyprofile with ASCT1 (a known member of DAACS family), high score with SDF (Sodium Dicarboxilate Family) and similar motifs withEDTRANSPORT, a fingerprint of excitatory amino acid transporters. The localization of the putative amino acid transporter was analyzed by in situhybridization and immunofluorescence in protoscoleces and associated germinal layer. The in situ hybridization labelling indicates the distribution ofegat1mRNA throughout the tegument. EgAT1 protein, which showed inWestern blots a molecular mass of ~60 kD, is localized in the subtegumentalregion of the metacestode, particularly around suckers and rostellum of protoscoleces and layers from brood capsules. The sequence and expressionanalyses of EgAT1 pave the way for functional analysis of amino acids transporters of E. granulosus and its evaluation as new drug targets againstcystic echinococcosis.