On the functionality of a methionine sulfoxide reductase B from Trypanosoma cruzi.
Methionine sulfoxide reductase
Redox metabolism
Trypanosoma cruzi
Trypanothione
Tryparedoxin
Journal
Free radical biology & medicine
ISSN: 1873-4596
Titre abrégé: Free Radic Biol Med
Pays: United States
ID NLM: 8709159
Informations de publication
Date de publication:
10 2020
10 2020
Historique:
received:
10
01
2020
revised:
20
06
2020
accepted:
26
06
2020
pubmed:
19
7
2020
medline:
22
6
2021
entrez:
19
7
2020
Statut:
ppublish
Résumé
Methionine is an amino acid susceptible to be oxidized to give a racemic mixture of R and S forms of methionine sulfoxide (MetSO). This posttranslational modification has been reported to occur in vivo under either normal or stress conditions. The reduction of MetSO to methionine is catalyzed by methionine sulfoxide reductases (MSRs), thiol-dependent enzymes present in almost all organisms. These enzymes can reduce specifically one or another of the isomers of MetSO (free and protein-bound). This redox modification could change the structure and function of many proteins, either concerned in redox or other metabolic pathways. The study of antioxidant systems in Trypanosoma cruzi has been mainly focused on the involvement of trypanothione, a specific redox component for these organisms. Though, little information is available concerning mechanisms for repairing oxidized methionine residues in proteins, which would be relevant for the survival of these pathogens in the different stages of their life cycle. We report an in vitro functional and in vivo cellular characterization of methionine sulfoxide reductase B (MSRB, specific for protein-bound MetSO R-enantiomer) from T. cruzi strain Dm28c. MSRB exhibited both cytosolic and mitochondrial localization in epimastigote cells. From assays involving parasites overexpressing MSRB, we observed the contribution of this protein to increase the general resistance against oxidative damage, the infectivity of trypomastigote cells, and intracellular replication of the amastigote stage. Also, we report that epimastigotes overexpressing MSRB exhibit inhibition of the metacyclogenesis process; this suggesting the involvement of the proteins as negative modulators in this cellular differentiation. This report contributes to novel insights concerning redox metabolism in T. cruzi. Results herein presented support the importance of enzymatic steps involved in the metabolism of L-Met and in repairing oxidized macromolecules in this parasite.
Sections du résumé
BACKGROUND
Methionine is an amino acid susceptible to be oxidized to give a racemic mixture of R and S forms of methionine sulfoxide (MetSO). This posttranslational modification has been reported to occur in vivo under either normal or stress conditions. The reduction of MetSO to methionine is catalyzed by methionine sulfoxide reductases (MSRs), thiol-dependent enzymes present in almost all organisms. These enzymes can reduce specifically one or another of the isomers of MetSO (free and protein-bound). This redox modification could change the structure and function of many proteins, either concerned in redox or other metabolic pathways. The study of antioxidant systems in Trypanosoma cruzi has been mainly focused on the involvement of trypanothione, a specific redox component for these organisms. Though, little information is available concerning mechanisms for repairing oxidized methionine residues in proteins, which would be relevant for the survival of these pathogens in the different stages of their life cycle.
METHODS
We report an in vitro functional and in vivo cellular characterization of methionine sulfoxide reductase B (MSRB, specific for protein-bound MetSO R-enantiomer) from T. cruzi strain Dm28c.
RESULTS
MSRB exhibited both cytosolic and mitochondrial localization in epimastigote cells. From assays involving parasites overexpressing MSRB, we observed the contribution of this protein to increase the general resistance against oxidative damage, the infectivity of trypomastigote cells, and intracellular replication of the amastigote stage. Also, we report that epimastigotes overexpressing MSRB exhibit inhibition of the metacyclogenesis process; this suggesting the involvement of the proteins as negative modulators in this cellular differentiation.
CONCLUSIONS AND GENERAL SIGNIFICANCE
This report contributes to novel insights concerning redox metabolism in T. cruzi. Results herein presented support the importance of enzymatic steps involved in the metabolism of L-Met and in repairing oxidized macromolecules in this parasite.
Identifiants
pubmed: 32682073
pii: S0891-5849(20)31132-1
doi: 10.1016/j.freeradbiomed.2020.06.035
pii:
doi:
Substances chimiques
Methionine
AE28F7PNPL
Methionine Sulfoxide Reductases
EC 1.8.4.-
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
96-114Informations de copyright
Copyright © 2020 Elsevier Inc. All rights reserved.