title: Glutathione reductase-null malaria parasites have normal blood stage growth but arrest during development in the mosquito.
abstract: Malaria parasites contain a complete glutathione (GSH) redox system, and several enzymes of this system are considered potential targets for antimalarial drugs. Through generation of a gamma-glutamylcysteine synthetase (gamma-GCS)-null mutant of the rodent parasite Plasmodium berghei, we previously showed that de novo GSH synthesis is not critical for blood stage multiplication but is essential for oocyst development. In this study, phenotype analyses of mutant parasites lacking expression of glutathione reductase (GR) confirmed that GSH metabolism is critical for the mosquito oocyst stage. Similar to what was found for gamma-GCS, GR is not essential for blood stage growth. GR-null parasites showed the same sensitivity to methylene blue and eosin B as wild type parasites, demonstrating that these compounds target molecules other than GR in Plasmodium. Attempts to generate parasites lacking both GR and gamma-GCS by simultaneous disruption of gr and gamma-gcs were unsuccessful. This demonstrates that the maintenance of total GSH levels required for blood stage survival is dependent on either de novo GSH synthesis or glutathione disulfide (GSSG) reduction by Plasmodium GR. Our studies provide new insights into the role of the GSH system in malaria parasites with implications for the development of drugs targeting GSH metabolism.
authors.affiliation: Department of Microbiology, University of Puerto Rico School of Medicine, San Juan, Puerto Rico 00936-5067.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Pastrana-Mena
authors.affiliation: Department of Molecular Microbiology and Immunology, The Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland 21205.
authors.forename: Rhoel R
authors.initials: RR
authors.lastname: Dinglasan
authors.affiliation: Leiden Malaria Research Group, Department of Parasitology, Center of Infectious Diseases, Leiden University Medical Center, L4-Q, Albinusdreef 2, 2333 ZA Leiden, The Netherlands.
authors.forename: Blandine
authors.initials: B
authors.lastname: Franke-Fayard
authors.affiliation: Department of Microbiology, University of Puerto Rico School of Medicine, San Juan, Puerto Rico 00936-5067.
authors.forename: Joel
authors.initials: J
authors.lastname: Vega-Rodríguez
authors.affiliation: Department of Microbiology, University of Puerto Rico School of Medicine, San Juan, Puerto Rico 00936-5067.
authors.forename: Mariela
authors.initials: M
authors.lastname: Fuentes-Caraballo
authors.affiliation: Department of Biochemistry, University of Puerto Rico School of Medicine, San Juan, Puerto Rico 00936-5067.
authors.forename: Abel
authors.initials: A
authors.lastname: Baerga-Ortiz
authors.affiliation: Department of Molecular Microbiology and Immunology, The Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland 21205.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Coppens
authors.affiliation: Department of Molecular Microbiology and Immunology, The Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland 21205.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Jacobs-Lorena
authors.affiliation: Leiden Malaria Research Group, Department of Parasitology, Center of Infectious Diseases, Leiden University Medical Center, L4-Q, Albinusdreef 2, 2333 ZA Leiden, The Netherlands.
authors.forename: Chris J
authors.initials: CJ
authors.lastname: Janse
authors.affiliation: Department of Microbiology, University of Puerto Rico School of Medicine, San Juan, Puerto Rico 00936-5067. Electronic address: adelfa.serrano@upr.edu.
authors.forename: Adelfa E
authors.initials: AE
authors.lastname: Serrano
mesh_terms: D000818:Animals; D015195:Drug Design; D004791:Enzyme Inhibitors / Q000494:pharmacology; D010697:Eosine I Bluish; D005260:Female; D005452:Fluoresceins / Q000494:pharmacology; D005721:Glutamate-Cysteine Ligase / Q000235:genetics / Q000378:metabolism; D019803:Glutathione Disulfide / Q000235:genetics / Q000378:metabolism; D005980:Glutathione Reductase / Q000235:genetics / Q000378:metabolism*; D008288:Malaria / Q000188:drug therapy / Q000201:enzymology / Q000235:genetics; D008751:Methylene Blue / Q000494:pharmacology; D051379:Mice; D033661:Oocysts / Q000201:enzymology*; D010962:Plasmodium berghei / Q000201:enzymology* / Q000235:genetics; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D004791:Enzyme Inhibitors; D005452:Fluoresceins; D015800:Protozoan Proteins; D005980:Glutathione Reductase; D005721:Glutamate-Cysteine Ligase; D010697:Eosine I Bluish; D008751:Methylene Blue; D019803:Glutathione Disulfide