title: Insight into the Exoproteome of the Tissue-Derived Trypomastigote form ofTrypanosoma cruzi.
abstract: The protozoan parasiteTrypanosoma cruzicauses Chagas disease, one of the major neglected infectious diseases. It has the potential to infect any nucleated mammalian cell. The secreted/excreted protein repertoire released byT. cruzitrypomastigotes is crucial in host-pathogen interactions. In this study, mammalian tissue culture-derived trypomastigotes (Y strain) were used to characterize the exoproteome of the infective bloodstream life form. Proteins released into the serum-free culture medium after 3 h of incubation were harvested and digested with trypsin. NanoLC-MS/MS analysis resulted in the identification of 540 proteins, the largest set of released proteins identified to date inTrypanosomaspp. Bioinformatic analysis predicted most identified proteins as secreted, predominantly by non-classical pathways, and involved in host-cell infection. Some proteins possess predicted GPI-anchor signals, these being mostly trans-sialidases, mucin associated surface proteins and surface glycoproteins. Moreover, we enriched phosphopeptides and glycopeptides from tryptic digests. The majority of identified glycoproteins are trans-sialidases and surface glycoproteins involved in host-parasite interaction. Conversely, most identified phosphoproteins have no Gene Ontology classification. The existence of various proteins related to similar functions in the exoproteome likely reflects this parasite's enhanced mechanisms for adhesion, invasion, and internalization of different host-cell types, and escape from immune defenses.
authors.affiliation: Laboratory of Biochemistry and Protein Chemistry, Department of Cell Biology, University of Brasilia, Brasilia, Brazil; Department of Biochemistry and Molecular Biology, University of Southern DenmarkOdense, Denmark.
authors.forename: Rayner M L
authors.initials: RM
authors.lastname: Queiroz
authors.affiliation: Laboratory of Biochemistry and Protein Chemistry, Department of Cell Biology, University of Brasilia , Brasilia, Brazil.
authors.forename: Carlos A O
authors.initials: CA
authors.lastname: Ricart
authors.affiliation: Laboratory of Biochemistry and Protein Chemistry, Department of Cell Biology, University of Brasilia , Brasilia, Brazil.
authors.forename: Mara O
authors.initials: MO
authors.lastname: Machado
authors.affiliation: Laboratory of Host-Pathogen Interaction, Department of Cell Biology, University of Brasilia Brasilia, Brazil.
authors.forename: Izabela M D
authors.initials: IM
authors.lastname: Bastos
authors.affiliation: Laboratory of Host-Pathogen Interaction, Department of Cell Biology, University of Brasilia Brasilia, Brazil.
authors.forename: Jaime M
authors.initials: JM
authors.lastname: de Santana
authors.affiliation: Laboratory of Host-Pathogen Interaction, Department of Cell Biology, University of Brasilia Brasilia, Brazil.
authors.forename: Marcelo V
authors.initials: MV
authors.lastname: de Sousa
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Southern Denmark Odense, Denmark.
authors.forename: Peter
authors.initials: P
authors.lastname: Roepstorff
authors.affiliation: Laboratory of Biochemistry and Protein Chemistry, Department of Cell Biology, University of Brasilia , Brasilia, Brazil.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Charneau
keywords: Chagas disease; bloodstream trypomastigote; glycoprotein; phosphoprotein; secretome; trypanosome