Molecular Characterization and Interactome Analysis of Trypanosoma cruzi Tryparedoxin II

ARIAS, DG; PIÑEYRO, D; IGLESIAS, AA; GUERRERO, SA; ROBELLO, C

JOURNAL OF PROTEOMICS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2015 vol. 120 p. 95 - 104

1874-3919

Trypanosoma cruzi, the causative agent of Chagas disease, possesses two tryparedoxins(TcTXNI and TcTXNII), belonging to the thioredoxin superfamily. TXNs are oxidoreductases which mediate electron transfer between trypanothione and peroxiredoxins. This constitutes a difference with the host cells, in which these activities aremediated by thioredoxins. These differences make TXNs an attractive target for drug development. In a previous work we characterized TcTXNI, including the redox interactome. In this work we extend the study to TcTXNII.Wedemonstrate that TcTXNII is a transmembrane protein anchored to the surface of the mitochondria and endoplasmic reticulum, with a cytoplasmatic orientation of the redox domain. Itwould be expressed during the metacyclogenesis process. In order to continue with the characterization of the redox interactome of T. cruzi, we designed an active site mutant TcTXNII lacking the resolving cysteine, and through the expression of thismutant protein and incubation with T. cruzi proteins, heterodisulfide complexes were isolated by affinity chromatography and identified by mass spectrometry. This allowed us to identify sixteen TcTXNII interacting proteins, which are involved in a wide range of cellular processes, indicating the relevance of TcTXNII, and contributing to our understanding of the redox interactome of T. cruzi.Biological significanceT. cruzi, the causative agent of Chagas disease, constitutes a major sanitary problem in LatinAmerica. The number of estimated infected persons is ca. 8 million, 28 million people are atrisk of infection and ~20,000 deaths occur per year in endemic regions. No vaccines areavailable at present, and most drugs currently in use were developed decades ago and showvariable efficacy with undesirable side effects. The parasite is able to live and prolipherateinside macrophage phagosomes, where it is exposed to cytotoxic reactive oxygen andnitrogen species, derived from macrophage activation. Therefore, T. cruzi antioxidantmechanisms constitute an active field of investigation, since they could provide the basisfor a rational drug development.