title: Proteomic analysis of exported chaperone/co-chaperone complexes of P. falciparum reveals an array of complex protein-protein interactions.
abstract: Malaria parasites modify their human host cell, the mature erythrocyte. This modification is mediated by a large number of parasite proteins that are exported to the host cell, and is also the underlying cause for the pathology caused by malaria infection. Amongst these proteins are many Hsp40 co-chaperones, and a single Hsp70. These proteins have been implicated in several processes in the host cell, including a potential role in protein transport, however the further molecular players in this process remain obscure. To address this, we have utilized chemical cross-linking followed by mass spectrometry and immunoblotting to isolate and characterize proteins complexes containing an exported Hsp40 (PFE55), and the only known exported Hsp70 (PfHsp70x). Our data reveal that both of these proteins are contained in high molecular weight protein complexes. These complexes are found both in the infected erythrocyte, and within the parasite-derived compartment referred to as the parasitophorous vacuole. Surprisingly, our data also reveal an association of PfHsp70x with components of PTEX, a putative protein translocon within the membrane of the parasitophorous vacuole. Our results suggest that the P. falciparum- infected human erythrocyte contains numerous high molecular weight protein complexes, which may potentially be involved in host cell modification.
authors.affiliation: Department of Parasitology, Philipps University Marburg, Marburg, Germany.
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Center for Diagnostics &Therapeutics, Department of Chemistry, Georgia State University, Atlanta, Georgia, USA.
authors.forename: Cheng
authors.initials: C
authors.lastname: Ma
authors.affiliation: Swiss TPH Socinstrasse 57, CH 4002, Basel, Switzerland.|University of Basel, Petersplatz 1, CH 4001 Basel, Switzerland.
authors.forename: Alexander
authors.initials: A
authors.lastname: Oberli
authors.affiliation: Department of Parasitology, Philipps University Marburg, Marburg, Germany.
authors.forename: Astrid
authors.initials: A
authors.lastname: Zinz
authors.affiliation: Department of Parasitology, Philipps University Marburg, Marburg, Germany.
authors.forename: Sonja
authors.initials: S
authors.lastname: Engels
authors.affiliation: Department of Parasitology, Philipps University Marburg, Marburg, Germany.
authors.forename: Jude M
authors.initials: JM
authors.lastname: Przyborski
mesh_terms: D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D002478:Cells, Cultured; D004912:Erythrocytes / Q000378:metabolism / Q000469:parasitology*; D005786:Gene Expression Regulation; D050956:HSP40 Heat-Shock Proteins / Q000235:genetics* / Q000378:metabolism; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics* / Q000378:metabolism; D006790:Host-Parasite Interactions; D006801:Humans; D008970:Molecular Weight; D010963:Plasmodium falciparum / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D011485:Protein Binding; D025941:Protein Interaction Mapping; D021381:Protein Transport; D040901:Proteomics / Q000379:methods; D015800:Protozoan Proteins / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction; D014617:Vacuoles / Q000378:metabolism / Q000469:parasitology
chemical_list: D002352:Carrier Proteins; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D015800:Protozoan Proteins