CONICET | Buscador de Institutos y Recursos Humanos

TcBDF1-5 are bromodomain containing factors (BDF) codified in Trypanosoma cruzi genome. Bromodomain is a highly conserved domain in eukaryotes that binds acetyl-lysines. All BDFs reported up to now in other species, show nuclear localization and are associated to other domains or enzymatic activities taking part of multisubunit complexes. TcBDF-1 and -3 expression in T. cruzi was analyzed by western blot (WB) and immunofluorescence (IFI) using purified antibodies. TcBDF1 expression was observed in epimastigotes by WB in the cytoplasmatic fraction. A spotted pattern was seen in the posterior part of epimastigotes and along all the parasite body in trypomastigotes by IFI. TcBDF2 is a nuclear protein in all life cycle stages and it interacts with acetylated histones.TcBDF3 expression was observed in all life cycle stages by WB. It was seen in epimastigotes and amastigotes cytoplasm and at flagella in trypomastigotes and metacyclic trypomastigotes. Surprisingly both TcBDF1 and 3 are not nuclear proteins. We are analyzing their relationship with acetylated proteins in cytoplasm and flagella.TcBDF5 has two tandemly arranged bromodomains. It is bigger in size than the other BDFs. We cloned, expressed and purified its bromodomain region as histidine fusion and used it to obtain antibodies to analyze its cellular localization. It has been proposed that protein acetylation could act as a regulatory modification and that bromodomains may act recognizing acetyl-lysine and transducing the signal, like phosphorilation and SH2 domains do. The broad TcBDFs pattern expression presented here suggests that this regulatory mechanism could be present in T. cruzi.