Produção Nacional
Revisado por pares
Post-translational modifications of Trypanosoma cruzi histone H4
2006; Elsevier BV; Volume: 150; Issue: 2 Linguagem: Inglês
10.1016/j.molbiopara.2006.08.012
ISSN1872-9428
AutoresJúlia Pinheiro Chagas da Cunha, Ernesto Nakayasu, Igor C. Almeida, Sérgio Schenkman,
Tópico(s)Biochemical and Molecular Research
ResumoHistone tails provide sites for a variety of post-translational modifications implicated in the control of gene expression and chromatin assembly. As both histones and control of gene expression in trypanosomes are highly divergent compared to most eukaryotes, post-translational modifications of Trypanosoma cruzi histones were investigated. After in vivo incubation of live parasites with radiolabeled precursors, histone H4 mainly incorporates [3H]-acetyl, and to a lesser extent [3H]-methyl residues. In contrast, histone H3 preferentially incorporates [3H]-methyl residues. The modifications of histone H4 were further characterized by mass spectrometry. MALDI-TOF–TOF-MS analysis revealed that peptides from histone H4 amino-terminus, obtained by either endoproteinase Glu-C or endoproteinase Arg-C digestion, contain isoforms with 14 and 42 Da additions, suggesting the presence of simultaneous acetylations and/or methylations. Tandem mass spectrometry analysis demonstrated that the N-terminal alanine is methylated, and lysine residues at positions 4, 10, 14 and 57 are acetylated; lysine at position 18 is mono-methylated, while arginine at position 53 is dimethylated. Immunoblotting analyses using specific antibodies raised against synthetic and acetylated peptides of T. cruzi histone H4 indicate that lysine 4 is acetylated in the majority of histone H4, while other acetylations at the N-terminus portion of histone H4 are less abundant.
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