title: Sequencing, bioinformatic characterization and expression pattern of a putative amino acid transporter from the parasitic cestode Echinococcus granulosus.
abstract: 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 and excitatory 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 10 transmembrane domains, consensus sequences for N-glycosylation between the third and fourth transmembrane domain, a highly similar hydropathy profile with ASCT1 (a known member of DAACS family), high score with SDF (Sodium Dicarboxilate Family) and similar motifs with EDTRANSPORT, a fingerprint of excitatory amino acid transporters. The localization of the putative amino acid transporter was analyzed by in situ hybridization and immunofluorescence in protoscoleces and associated germinal layer. The in situ hybridization labelling indicates the distribution of egat1 mRNA throughout the tegument. EgAT1 protein, which showed in Western blots a molecular mass of approximately 60 kD, is localized in the subtegumental region of the metacestode, particularly around suckers and rostellum of protoscoleces and layers from brood capsules. The sequence and expression analyses of EgAT1 pave the way for functional analysis of amino acids transporters of E. granulosus and its evaluation as new drug targets against cystic echinococcosis.
authors.affiliation: Departamento de Parasitología, Instituto Nacional de Enfermedades Infecciosas, Administración Nacional de Laboratorios e Institutos de Salud Dr Carlos G. Malbrán Av. Vélez Sarsfield 563, 1281 Buenos Aires, Argentina.
authors.forename: Federico
authors.initials: F
authors.lastname: Camicia
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Paredes
authors.forename: Cora
authors.initials: C
authors.lastname: Chalar
authors.forename: Norbel
authors.initials: N
authors.lastname: Galanti
authors.forename: Laura
authors.initials: L
authors.lastname: Kamenetzky
authors.forename: Ariana
authors.initials: A
authors.lastname: Gutierrez
authors.forename: Mara C
authors.initials: MC
authors.lastname: Rosenzvit
mesh_terms: D000595:Amino Acid Sequence; D026905:Amino Acid Transport Systems / Q000235:genetics*; D000818:Animals; D019295:Computational Biology; D048209:Echinococcus granulosus / Q000235:genetics*; D015870:Gene Expression; D007150:Immunohistochemistry; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA
chemical_list: D026905:Amino Acid Transport Systems