title: Subcellular proteomics of Trypanosoma cruzi reservosomes.
abstract: Reservosomes are the endpoint of the endocytic pathway in Trypanosoma cruzi epimastigotes. These organelles have the particular ability to concentrate proteins and lipids obtained from medium together with the main proteolytic enzymes originated from the secretory pathway, being at the same time a storage organelle and the main site of protein degradation. Subcellular proteomics have been extensively used for profiling organelles in different cell types. Here, we combine cell fractionation and LC-MS/MS analysis to identify reservosome-resident proteins. Starting from a purified reservosome fraction, we established a protocol to isolate reservosome membranes. Transmission electron microscopy was applied to confirm the purity of the fractions. To achieve a better coverage of identified proteins we analyzed the fractions separately and combined the results. LC-MS/MS analysis identified in total 709 T. cruzi-specific proteins; of these, 456 had predicted function and 253 were classified as hypothetical proteins. We could confirm the presence of most of the proteins validated by previous work and identify new proteins from different classes such as enzymes, proton pumps, transport proteins, and others. The definition of the reservosome protein profile is a good tool to assess their molecular signature, identify molecular markers, and understand their relationship with different organelles.
authors.affiliation: Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Brazil.
authors.forename: Celso
authors.initials: C
authors.lastname: Sant'Anna
authors.forename: Ernesto S
authors.initials: ES
authors.lastname: Nakayasu
authors.forename: Miria G
authors.initials: MG
authors.lastname: Pereira
authors.forename: Daniela
authors.initials: D
authors.lastname: Lourenço
authors.forename: Wanderley
authors.initials: W
authors.lastname: de Souza
authors.forename: Igor C
authors.initials: IC
authors.lastname: Almeida
authors.forename: Narcisa L
authors.initials: NL
authors.lastname: Cunha-E-Silva
mesh_terms: D000818:Animals; D002458:Cell Fractionation; D002853:Chromatography, Liquid; D022162:Cytoplasmic Vesicles / Q000737:chemistry* / Q000648:ultrastructure; D050356:Lipid Metabolism; D013058:Mass Spectrometry; D046529:Microscopy, Electron, Transmission; D040901:Proteomics / Q000379:methods; D015800:Protozoan Proteins / Q000032:analysis*; D013347:Subcellular Fractions / Q000737:chemistry* / Q000648:ultrastructure; D014349:Trypanosoma cruzi / Q000737:chemistry* / Q000648:ultrastructure
chemical_list: D015800:Protozoan Proteins