title: J-dot targeting of an exported HSP40 in Plasmodium falciparum-infected erythrocytes.
abstract: Plasmodium falciparum exports a large number of proteins to its host cell, the mature human erythrocyte, where they are involved in host cell modification. Amongst the proteins trafficked to the host cell, many are heat shock protein (HSP)40 homologues. We previously demonstrated that at least two exported PfHSP40s (referred to as PFE55 and PFA660) localise to mobile structures in the P. falciparum-infected erythrocyte (Kulzer et al., 2010), termed J-dots. The complete molecular content of these structures has not yet been completely resolved, however it is known that they also contain an exported HSP70, PfHSP70x, and are potentially involved in transport of the major cytoadherance ligand, PfEMP1, through the host cell. To understand more about the nature of the association of exported HSP40s with J-dots, here we have studied the signal requirements for recruitment of the proteins to these structures. By expressing various exported GFP chimeras, we can demonstrate that the predicted substrate binding domain is necessary and sufficient for J-dot targeting. This targeting only occurs in human erythrocytes infected with P. falciparum, as it is not conserved when expressing a P. falciparum HSP40 in Plasmodium berghei-infected murine red blood cells, suggesting that J-dots are P. falciparum-specific. This data reveals a new mechanism for targeting of exported proteins to intracellular structures in the P. falciparum-infected erythrocyte.
authors.affiliation: Parasitology, Philipps University Marburg, Karl von Frisch Strasse 8, 35043 Marburg, Germany; Parasitology, Max Planck Institute for Infection Biology, Charitéplatz 1, 10117 Berlin, Germany; Molecular Parasitology, Humboldt University, Philippstrasse 13, 10115 Berlin, Germany.
authors.forename: Wiebke
authors.initials: W
authors.lastname: Petersen
authors.affiliation: Parasitology, Philipps University Marburg, Karl von Frisch Strasse 8, 35043 Marburg, Germany; Research School of Biology, 134 Linnaeus Way, The Australian National University, Canberra, ACT 2601, Australia.
authors.forename: Simone
authors.initials: S
authors.lastname: Külzer
authors.affiliation: Parasitology, Philipps University Marburg, Karl von Frisch Strasse 8, 35043 Marburg, Germany.
authors.forename: Sonja
authors.initials: S
authors.lastname: Engels
authors.affiliation: Parasitology, Philipps University Marburg, Karl von Frisch Strasse 8, 35043 Marburg, Germany.
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Parasitology, Max Planck Institute for Infection Biology, Charitéplatz 1, 10117 Berlin, Germany; Molecular Parasitology, Humboldt University, Philippstrasse 13, 10115 Berlin, Germany.
authors.forename: Alyssa
authors.initials: A
authors.lastname: Ingmundson
authors.affiliation: Centre for Advanced Microscopy, 131 Garran Road, The Australian National University, Canberra, ACT 2601, Australia.
authors.forename: Melanie
authors.initials: M
authors.lastname: Rug
authors.affiliation: Research School of Biology, 134 Linnaeus Way, The Australian National University, Canberra, ACT 2601, Australia.
authors.forename: Alexander G
authors.initials: AG
authors.lastname: Maier
authors.affiliation: Parasitology, Philipps University Marburg, Karl von Frisch Strasse 8, 35043 Marburg, Germany. Electronic address: Przybors@biologie.uni-marburg.de.
authors.forename: Jude M
authors.initials: JM
authors.lastname: Przyborski
mesh_terms: D004912:Erythrocytes / Q000378:metabolism / Q000469:parasitology*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D050956:HSP40 Heat-Shock Proteins / Q000378:metabolism*; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D018832:Molecular Chaperones / Q000378:metabolism; D010963:Plasmodium falciparum / Q000502:physiology*; D014162:Transfection
chemical_list: D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D018832:Molecular Chaperones; D049452:Green Fluorescent Proteins
keywords: Chaperone; Erythrocyte; HSP40; HSP70; J-dot; Malaria; Plasmodium falciparum; Protein targeting