Label-free semi-quantitative differential three-dimensional liquid chromatography coupled to mass spectrometry (3D-LC-MS/MS) was used to compare the glycosomal and mitochondrial proteomes of the bloodstream- and insect-form of Trypanosoma brucei. The abundance of glycosomal marker proteins identified in the two life-cycle stages corresponded well with the relative importance of biochemical pathways present in the glycosomes of the two stages and the peptide spectral count ratios of selected enzymes were in good agreement with published data about their enzymatic specific activities. This approach proved extremely useful for the generation of large scale proteomics data for the comparison of different life-cycle stages. Several proteins involved in oxidative stress protection, sugar-nucleotide synthesis, purine salvage, nucleotide-monophosphate formation and purine-nucleotide cycle were identified as glycosomal proteins.

The direct route: a simplified pathway for protein import into the mitochondrion of trypanosomes.Trends Cell Biol. 2008 Jan;18(1):12-8.

Trypanosoma brucei is a unicellular eukaryote that causes the deadly human African trypanosomiasis ('sleeping sickness') in humans. The parasite has a complicated lifestyle, it developmentally changes aspects of its mitochondrial function as it alternates from forms in the tsetse fly to forms adapted for life in the human bloodstream. The single mitochondrion found in each trypanosome has to be duplicated precisely in each round of the cell cycle in order for parasites to replicate, and this depends on the import of proteins from the cytosol. Here we review what is known about the mitochondrial protein import pathway in T. brucei, how it compares with the process in humans, and how the distinguishing features seen in T. brucei and humans promise new understanding of the mitochondrial protein import process in all eukaryotes.