The antioxidant systems in Toxoplasma gondii and the role of cytosolic catalase in defence against oxidative injury
Open Access
- 11 November 2003
- journal article
- research article
- Published by Wiley in Molecular Microbiology
- Vol. 51 (1), 47-61
- https://doi.org/10.1046/j.1365-2958.2003.03823.x
Abstract
Superoxide dismutase, catalase, glutathione peroxidase and peroxiredoxins form an antioxidant network protecting cells against reactive oxygen species (ROS). Catalase is a potent H2O2-detoxifying enzyme, which is unexpectedly absent in some members of the Kinetoplastida and Apicomplexa, but present in Toxoplasma gondii. In T. gondii, catalase appears to be cytosolic. In addition, T. gondii also possesses genes coding for other types of peroxidases, including glutathione/thioredoxin-like peroxidases and peroxiredoxins. This study presents a detailed analysis of the role of catalase in the parasite and reports the existence of antioxidant enzymes localized in the cytosol and the mitochondrion of T. gondii. The catalase gene was disrupted and, in addition, T. gondii cell lines overexpressing either catalase or a cytosolic 1-cys peroxiredoxin, TgPrx2, under the control of a strong promoter were created. Analysis of these mutants confirmed that the catalase activity is cytosolic and is encoded by a unique gene in T. gondii. Furthermore, the catalase confers protection against H2O2 exposure and contributes to virulence in mice. The overexpression of Prx2 also increases protection against H2O2 treatment, suggesting that catalase and other peroxidases function as a defence mechanism against endogenously produced reactive oxygen intermediates and the oxidative stress imposed by the host.Keywords
This publication has 56 references indexed in Scilit:
- Retraction Note to: A cytosolic catalase is needed to extend adult lifespan in C. elegans daf-C and clk-1 mutantsNature, 2003
- Bimodal Targeting of Microsomal CYP2E1 to Mitochondria through Activation of an N-terminal Chimeric Signal by cAMP-mediated PhosphorylationPublished by Elsevier BV ,2002
- Thioredoxin Reductase Is Essential for the Survival ofPlasmodium falciparum Erythrocytic StagesOnline Journal of Public Health Informatics, 2002
- PeroxiredoxinsBiological Chemistry, 2002
- Molecular cloning and characterization of peroxiredoxin from Toxoplasma gondiiThe Korean Journal of Parasitology, 2001
- Import of Peroxisomal Matrix and Membrane ProteinsAnnual Review of Biochemistry, 2000
- Status of Plasmodium falciparum towards catalaseBritish Journal of Haematology, 1998
- Insertional Tagging, Cloning, and Expression of the Hypoxanthine-Xanthine-Guanine Phosphoribosyltransferase GenePublished by Elsevier BV ,1996
- Activity of Human Blood Leukocytes against Toxoplasma gondiiThe Journal of Infectious Diseases, 1979
- Toxoplasma gondii: Isolation and preliminary characterization of temperature-sensitive mutantsExperimental Parasitology, 1976