Post-translational modifications of Trypanosoma cruzi histone H4

Mol Biochem Parasitol. 2006 Dec;150(2):268-77. doi: 10.1016/j.molbiopara.2006.08.012. Epub 2006 Sep 18.


Histone 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 [(3)H]-acetyl, and to a lesser extent [(3)H]-methyl residues. In contrast, histone H3 preferentially incorporates [(3)H]-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 42Da 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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylation
  • Amino Acid Sequence
  • Animals
  • Histones / chemistry*
  • Histones / genetics*
  • Histones / isolation & purification
  • Methylation
  • Molecular Sequence Data
  • Peptides
  • Protein Processing, Post-Translational*
  • Protozoan Proteins / chemistry
  • Protozoan Proteins / genetics
  • Protozoan Proteins / isolation & purification
  • Spectrometry, Mass, Electrospray Ionization
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
  • Tandem Mass Spectrometry
  • Trypanosoma cruzi / chemistry
  • Trypanosoma cruzi / genetics*


  • Histones
  • Peptides
  • Protozoan Proteins