HISTONE ACETYLATION IN Trypanosoma cruzi.

MEYER, CRISTIAN G.; TORRES, HECTOR N.; FLAWIÁ, MIRTHA M.; ALONSO, GUILLERMO D.

Pinamar, Argentina.

Congreso; X Congress of the Pan-American Association for Biochemistry and Molecular Biology (PABMB), XLI Annual Meeting of the Argentine Society for Biochemistry and Molecular Biology (SAIB) and the XX Annual Meeting of the Argentine Society for Neurochemistry (SAN; 2005

Sociedad Argentina de Investigación Bioquímica y Biología Molecular (SAIB)

Genetic expression in higher eukaryotes is controlled at the beginning of transcription and is greatly influenced by chromatin structure. Lysine acetylation is one of the major modifications on histones tails and has been shown to upregulate transcription. We analyzed In vivo acetylation of T. cruzi histones by Western blot using specific antibodies against acetylated histones H3 or H4. In both cases positive signal was obtained suggesting the presence of this regulatory mechanism in T. cruzi. Searching in T. cruzi genome database (TIGR) we found two sequences corresponding to histone acetyltransferases  belonging to the MYST family (TcHAT1 and TcHAT2) and two histone deacetylases (TcSir2 and TcHDAC). In addition an acetyltransferase involved in transcription elongation (ELP3) was found. All sequences were amplified by PCR, subcloned in pET22b+ vector and expressed in bacteria. After purification, fusion proteins were evaluated for activity. Acetyltransferases from the MYST family show activity only when associated in a major complex but recombinant ELP3 was active as a monomer. Here we present the first evidence for epigenetic control in Trypanosoma cruzi.