Trypanosoma cruzi: Molecular identification and characterization of new members of the Tc13 family. Description of the interaction between the Tc13 antigen from Tulahuén strain and the second extracellular loop of the b1-adrenergic receptor

GARCIA, GA; JOENSEN, LG; BUA, J; AINCIART, N; PERRY, SJ; RUIZ, AM

EXPERIMENTAL PARASITOLOGY

Año: 2003 vol. 103 p. 112 - 119

0014-4894

Trypanosoma cruzi Tc13 antigens belong to the trans-sialidase superfamily. Their sequences have been described only partially and, up to now, their physiological activity has not been elucidated. Here we present two new members of this family from the Tulahuén strain (Tc13Tul) and the CL Brener clone (Tc13CL), being the latter the first Tc13 sequence fully described. Alignment of all Tc13 sequences allowed us to define two sub-families that differ in the number of repeats and the presence or absence of the GPI addition site. Chromoblots demonstrate that Tc13 antigens are mainly located in chromosome III and its homologous. Pull down assays suggest that recombinant MBP-Tc13Tul interacts with the second extracellular loop of the b1-adrenergic receptor. This is the first evidence that a Tc13 antigen acts as a ligand interacting with a neurotransmitter receptor. These observations might add some light to the development of chagasic pathology.