title: Genetic ablation of plasmoDJ1, a multi-activity enzyme, attenuates parasite virulence and reduces oocyst production.
abstract: Malaria parasites must respond to stresses and environmental signals to perpetuate efficiently during their multistage development in diverse environments. To gain insights into the parasite's stress response mechanisms, we investigated a conserved Plasmodium protein, which we have named plasmoDJ1 on the basis of the presence of a putative cysteine protease motif of the DJ-1/PfpI superfamily, for its activities, potential to respond to stresses and role in parasite development. PlasmoDJ1 is expressed in all intraerythrocytic stages and ookinetes. Its expression was increased 7-9-fold upon heat shock and oxidative stress due to H2O2 and artemisinin; its expression in a stress-sensitive Escherichia coli mutant conferred tolerance against oxidative stress, indicating that plasmoDJ1 has the potential to sense and/or protect from stresses. Recombinant plasmoDJ1 efficiently neutralized H2O2, facilitated renaturation of denatured citrate synthase and showed protease activity, indicating that plasmoDJ1 is a multi-activity protein. Mutation of the catalytic cysteine residue, but not other residues, reduced H2O2-neutralization activity by ~90% and significantly decreased chaperone and protease activities, indicating that these activities are intrinsic to plasmoDJ1. The plasmoDJ1 gene knockout in Plasmodium berghei ANKA attenuated virulence and reduced oocyst production, suggesting a major role for plasmoDJ1 in parasite development, which probably depends on its multiple activities.
authors.forename: Neha
authors.initials: N
authors.lastname: Singhal
authors.lastname: Atul
authors.forename: Babu S
authors.initials: BS
authors.lastname: Mastan
authors.forename: Kota Arun
authors.initials: KA
authors.lastname: Kumar
authors.forename: Puran Singh
authors.initials: PS
authors.lastname: Sijwali
mesh_terms: D000222:Adaptation, Physiological; D000595:Amino Acid Sequence; D000818:Animals; D000962:Antimalarials / Q000494:pharmacology; D037621:Artemisinins / Q000494:pharmacology; D004912:Erythrocytes / Q000187:drug effects / Q000469:parasitology; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005260:Female; D017353:Gene Deletion; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D033661:Oocysts / Q000254:growth & development / Q000378:metabolism*; D018384:Oxidative Stress; D010962:Plasmodium berghei / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000472:pathogenicity*; D010963:Plasmodium falciparum / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000472:pathogenicity*; D015800:Protozoan Proteins / Q000235:genetics* / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D016415:Sequence Alignment; D014774:Virulence
chemical_list: D000962:Antimalarials; D037621:Artemisinins; D015800:Protozoan Proteins; D017382:Reactive Oxygen Species; C031327:artemisinin; D006861:Hydrogen Peroxide