title: Redox metabolism in Trypanosoma cruzi: functional characterization of tryparedoxins revisited.
abstract: Tryparedoxins (TXNs) are multipurpose oxidoreductases from trypanosomatids that transfer reducing equivalents from trypanothione to various thiol proteins. In Trypanosoma cruzi, two genes coding for TXN-like proteins have been identified: TXNI, previously characterized as a cytoplasmic protein, and TXNII, a putative tail-anchored membrane protein. In this work, we performed a comparative functional characterization of T. cruzi TXNs. Particularly, we cloned the gene region coding for the soluble version of TXNII for its heterologous expression. The truncated recombinant protein (without its 22 C-terminal transmembrane amino acids) showed TXN activity. It was also able to transfer reducing equivalents from trypanothione, glutathione, or dihydrolipoamide to various acceptors, including methionine sulfoxide reductases and peroxiredoxins. The results support the occurrence and functionality of a second tryparedoxin, which appears as a new component in the redox scenario for T. cruzi.
authors.affiliation: Instituto de Agrobiotecnología del Litoral, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral-CONICET, 3000 Santa Fe, Argentina.
authors.forename: Diego G
authors.initials: DG
authors.lastname: Arias
authors.forename: Vanina E
authors.initials: VE
authors.lastname: Marquez
authors.forename: María L
authors.initials: ML
authors.lastname: Chiribao
authors.forename: Fernanda R
authors.initials: FR
authors.lastname: Gadelha
authors.forename: Carlos
authors.initials: C
authors.lastname: Robello
authors.forename: Alberto A
authors.initials: AA
authors.lastname: Iglesias
authors.forename: Sergio A
authors.initials: SA
authors.lastname: Guerrero
mesh_terms: D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D015870:Gene Expression; D005978:Glutathione / Q000031:analogs & derivatives / Q000378:metabolism*; D010084:Oxidation-Reduction; D011490:Protein Disulfide Reductase (Glutathione); D017382:Reactive Oxygen Species / Q000378:metabolism; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D013095:Spermidine / Q000031:analogs & derivatives / Q000378:metabolism; D013879:Thioredoxins / Q000235:genetics* / Q000378:metabolism; D014349:Trypanosoma cruzi / Q000378:metabolism*
chemical_list: D017382:Reactive Oxygen Species; D011994:Recombinant Proteins; C114110:tryparedoxin; D013879:Thioredoxins; C044809:trypanothione; D011490:Protein Disulfide Reductase (Glutathione); D005978:Glutathione; D013095:Spermidine
keywords: 2-Cys-peroxiredoxin-type tryparedoxin peroxidase; APx; CySSyC; DTT; Free radicals; GPxI; GR; GSH; GSSG; Grx; GspSH; HEDS; L-Met(S)SO; MSRA; Reactive oxygen species; T(SH)(2); TR; TRX; TS(2); TXN; TXNPx; Trypanosoma; Trypanothione; Tryparedoxin; ascorbate peroxidase.; cystine; dithiothreitol; glutaredoxin; glutathione disulfide; glutathione peroxidase-type tryparedoxin peroxidase I; glutathione reductase; hydroxyethyl disulfide; l-methionine-S-sulfoxide; methionine sulfoxide reductase A; reduced glutathione; reduced glutathionylspermidine; t-bOOH; tert-butylhydroperoxide; thioredoxin; trypanothione; trypanothione disulfide; trypanothione reductase; tryparedoxin; β-mercaptoethanol; βME