Bromodomain Factor 3 is essential for Trypanosoma cruzi growth and differentiation

ALONSO VL; RITAGLIATI C; MOTTA CM; CRIBB P; SERRA EC

Rosario

Congreso; L Reunión Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2014

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

Bromodomains (BrDs) are conserved protein modules capable of binding acetylated lysines (Kac) and are found in proteins associated with chromatin and in nearly every nuclear histone acetyltransferase. Trypanosoma cruzi Bromodomain Factor 3 (TcBDF3) is the first exclusively non-nuclear bromodomain-containing protein reported so far. TcBDF3 is expressed in all life cycle stages and interacts with acetylated α-tubulin, the major component of the flagellar and subpellicular microtubules. This ability to interact with acetylated α-tubulin was impaired when we mutated essential aminoacids of the bromodomain binding-pocket. Do to the impossibility to perform RNA interference in this organism we over-expressed the mutated protein in an inducible manner, which acted as a dominant negative mutant. When the mutated protein is over-expressed in Trypanosoma cruzi epimatigotes (non-infective stage) the parasites do not grow normally and the metacyclogenesis (differentiation to the infective stage) rates are diminished. Also, we quantified the infection rates of the parasites over-expressing the wild type and the mutated protein in Vero cells and the localization of the exogenous proteins was determined in all life cycle stages by fluorescence microscopy. These results allowed as concluding that TcBDF3 is essential for Trypanosoma cruzi growth and differentiation.