title: PFB0595w is a Plasmodium falciparum J protein that co-localizes with PfHsp70-1 and can stimulate its in vitro ATP hydrolysis activity.
abstract: Heat shock proteins, many of which function as molecular chaperones, play important roles in the lifecycle and pathogenesis of the malaria parasite, Plasmodium falciparum. The P. falciparum heat shock protein 70 (PfHsp70) family of chaperones is potentially regulated by a large complement of J proteins that localize to various intracellular compartments including the infected erythrocyte cytosol. While PfHsp70-1 has been shown to be an abundant cytosolic chaperone, its regulation by J proteins is poorly understood. In this study, we characterized the J protein PFB0595w, a homologue of the well-studied yeast cytosolic J protein, Sis1. PFB0595w, similarly to PfHsp70-1, was localized to the parasite cytosol and its expression was upregulated by heat shock. Additionally, recombinant PFB0595w was shown to be dimeric and to stimulate the in vitro ATPase activity of PfHsp70-1. Overall, the expression, localization and biochemical data for PFB0595w suggest that it may function as a cochaperone of PfHsp70-1, and advances current knowledge on the chaperone machinery of the parasite.
authors.affiliation: Biomedical Biotechnology Research Unit, Department of Biochemistry and Microbiology, Rhodes, Rhodes University, Grahamstown 6140, South Africa.
authors.forename: James M
authors.initials: JM
authors.lastname: Njunge
authors.affiliation: Parasitology, Philipps University Marburg, 35043 Marburg, Germany.
authors.forename: Pradipta
authors.initials: P
authors.lastname: Mandal
authors.affiliation: Parasitology, Philipps University Marburg, 35043 Marburg, Germany.
authors.forename: Jude M
authors.initials: JM
authors.lastname: Przyborski
authors.affiliation: Biomedical Biotechnology Research Unit, Department of Biochemistry and Microbiology, Rhodes, Rhodes University, Grahamstown 6140, South Africa.
authors.forename: Aileen
authors.initials: A
authors.lastname: Boshoff
authors.affiliation: College of Health and Biomedicine, Victoria University, Melbourne 8001, VIC, Australia.
authors.forename: Eva-Rachele
authors.initials: ER
authors.lastname: Pesce
authors.affiliation: Biomedical Biotechnology Research Unit, Department of Biochemistry and Microbiology, Rhodes, Rhodes University, Grahamstown 6140, South Africa; College of Health and Biomedicine, Victoria University, Melbourne 8001, VIC, Australia. Electronic address: gregory.blatch@vu.edu.au.
authors.forename: Gregory L
authors.initials: GL
authors.lastname: Blatch
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism; D004912:Erythrocytes / Q000469:parasitology; D050884:HSP72 Heat-Shock Proteins / Q000378:metabolism*; D006801:Humans; D006868:Hydrolysis; D066298:In Vitro Techniques; D018832:Molecular Chaperones / Q000378:metabolism*; D010963:Plasmodium falciparum / Q000166:cytology / Q000378:metabolism*; D011485:Protein Binding; D055503:Protein Multimerization; D015800:Protozoan Proteins / Q000378:metabolism*; D014018:Tissue Distribution
chemical_list: D050884:HSP72 Heat-Shock Proteins; D018832:Molecular Chaperones; D015800:Protozoan Proteins; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases
keywords: Chaperone; DnaJ; Hsp40; Hsp70; Malaria