Characterization of the pathway for transport of the cytoadherence‐mediating protein, PfEMP1, to the host cell surface in malaria parasite‐infected erythrocytes

The Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family of antigenically diverse proteins is expressed on the surface of human erythrocytes infected with the malaria parasite P. falciparum, and mediates cytoadherence to the host vascular endothelium. In this report, we show that export of PfEMP1 is slow and inefficient as it takes several hours to traffic newly synthesized proteins to the erythrocyte membrane. Upon removal by trypsin treatment, the surface‐exposed population of PfEMP1 is not replenished during subsequent culture indicating that there is no cycling of PfEMP1 between the erythrocyte surface and an intracellular compartment. The role of Maurer's clefts as an intermediate sorting compartment in trafficking of PfEMP1 was investigated using immunoelectron microscopy and proteolytic digestion of streptolysin O‐permeabilized parasitized erythrocytes. We show that PfEMP1 is inserted into the Maurer's cleft membrane with the C‐terminal domain exposed to the erythrocyte cytoplasm, whereas the N‐terminal domain is buried inside the cleft. Transfer of PfEMP1 to the erythrocyte surface appears to involve electron‐lucent extensions of the Maurer's clefts. Thus, we have delineated some important aspects of the unusual trafficking mechanism for delivery of this critical parasite virulence factor to the erythrocyte surface.

[1]  M. Aikawa.  Parasitological review. Plasmodium: the fine structure of malarial parasites. , 1971, Experimental parasitology.

[2]  A. Pain,et al.  Plasmodium falciparum-infected erythrocytes modulate the maturation of dendritic cells , 1999, Nature.

[3]  S. Bhakdi,et al.  A guide to the use of pore-forming toxins for controlled permeabilization of cell membranes , 1993, Medical Microbiology and Immunology.

[4]  M. Wahlgren,et al.  Molecular Aspects of Severe Malaria , 1996, Clinical Microbiology Reviews.

[5]  A. Craig,et al.  Molecules on the surface of the Plasmodium falciparum infected erythrocyte and their role in malaria pathogenesis and immune evasion. , 2001, Molecular and biochemical parasitology.

[6]  A. Cowman,et al.  clag9: A cytoadherence gene in Plasmodium falciparum essential for binding of parasitized erythrocytes to CD36. , 2000, Proceedings of the National Academy of Sciences of the United States of America.

[7]  A. Craig,et al.  Analysis of adhesive domains from the A4VAR Plasmodium falciparum erythrocyte membrane protein-1 identifies a CD36 binding domain. , 1998, Molecular and biochemical parasitology.

[8]  Kevin Marsh,et al.  Parasite antigens on the infected red cell surface are targets for naturally acquired immunity to malaria , 1998, Nature Medicine.

[9]  P. Preiser,et al.  Small Variant STEVOR Antigen Is Uniquely Located within Maurer's Clefts in Plasmodium falciparum-Infected Red Blood Cells , 2002, Eukaryotic Cell.

[10]  D. Mattei,et al.  Pfsbp1, a Maurer's cleft Plasmodium falciparum protein, is associated with the erythrocyte skeleton. , 2000, Molecular and biochemical parasitology.

[11]  Joseph D. Smith,et al.  Correction for Smith et al., Identification of a Plasmodium falciparum intercellular adhesion molecule-1 binding domain: A parasite adhesion trait implicated in cerebral malaria , 2000, Proceedings of the National Academy of Sciences.

[12]  M. Foley,et al.  A homologue of Sar1p localises to a novel trafficking pathway in malaria-infected erythrocytes. , 1999, European journal of cell biology.

[13]  D. Roos,et al.  Traffic jams: protein transport in Plasmodium falciparum. , 2000, Parasitology today.

[14]  Joseph D. Smith,et al.  Switches in expression of plasmodium falciparum var genes correlate with changes in antigenic and cytoadherent phenotypes of infected erythrocytes , 1995, Cell.

[15]  E. Mccleskey,et al.  A nutrient-permeable channel on the intraerythrocytic malaria parasite , 1993, Nature.

[16]  Kevin Marsh,et al.  Antibody Recognition of Plasmodium falciparum Erythrocyte Surface Antigens in Kenya: Evidence for Rare and Prevalent Variants , 1999, Infection and Immunity.

[17]  Theodore F. Taraschi,et al.  Cloning the P. falciparum gene encoding PfEMP1, a malarial variant antigen and adherence receptor on the surface of parasitized human erythrocytes , 1995, Cell.

[18]  C. Lambros,et al.  Synchronization of Plasmodium falciparum erythrocytic stages in culture. , 1979, The Journal of parasitology.

[19]  J. Barnwell,et al.  Identification of a strain-specific malarial antigen exposed on the surface of Plasmodium falciparum-infected erythrocytes , 1984, The Journal of experimental medicine.

[20]  R. Coppel,et al.  A putative Plasmodium falciparum exported serine/threonine protein kinase. , 1997, Molecular and biochemical parasitology.

[21]  M. Foley,et al.  Evidence for a role for a Plasmodium falciparum homologue of Sec31p in the export of proteins to the surface of malaria parasite-infected erythrocytes. , 2001, Journal of cell science.

[22]  H. Bayley,et al.  Staphylococcal alpha-toxin, streptolysin-O, and Escherichia coli hemolysin: prototypes of pore-forming bacterial cytolysins , 1996, Archives of Microbiology.

[23]  T. Taraschi,et al.  Vesicle-mediated trafficking of parasite proteins to the host cell cytosol and erythrocyte surface membrane in Plasmodium falciparum infected erythrocytes. , 2001, International Journal of Parasitology.

[24]  S. Bhakdi,et al.  Selective permeabilization of infected host cells with pore-forming proteins provides a novel tool to study protein synthesis and viability of the intracellular apicomplexan parasites Plasmodium falciparum and Toxoplasma gondii. , 2001, Molecular and biochemical parasitology.

[25]  Kevin Marsh,et al.  Rapid switching to multiple antigenic and adhesive phenotypes in malaria , 1992, Nature.

[26]  C. Newbold,et al.  Plasmodium falciparum: the human agglutinating antibody response to the infected red cell surface is predominantly variant specific. , 1992, Experimental parasitology.

[27]  M. Aikawa.  Plasmodium: The fine structure of malarial parasites , 1971 .

[28]  S. Bhakdi,et al.  Protein sorting in Plasmodium falciparum-infected red blood cells permeabilized with the pore-forming protein streptolysin O. , 1996, The Biochemical journal.

[29]  A. Holder,et al.  Light microscope morphology of Plasmodium falciparum during a synchronized growth cycle in vitro. , 1983, Annals of tropical medicine and parasitology.

[30]  S. Bhakdi,et al.  Mechanism of membrane damage by streptolysin-O , 1985, Infection and immunity.

[31]  R. Wilson,et al.  Separation of viable schizont-infected red cells of Plasmodium falciparum from human blood. , 1978, Annals of tropical medicine and parasitology.

[32]  J C Reeder,et al.  Targeted mutagenesis of Plasmodium falciparum erythrocyte membrane protein 3 (PfEMP3) disrupts cytoadherence of malaria‐infected red blood cells , 2000, The EMBO journal.

[33]  S. Kyes,et al.  A simple RNA analysis method shows var and rif multigene family expression patterns in Plasmodium falciparum. , 2000, Molecular and biochemical parasitology.

[34]  Hye-Sook Kim,et al.  A Homologue ofN-Ethylmaleimide-sensitive Factor in the Malaria ParasitePlasmodium falciparum Is Exported and Localized in Vesicular Structures in the Cytoplasm of Infected Erythrocytes in the Brefeldin A-sensitive Pathway* , 2001, The Journal of Biological Chemistry.

[35]  R. Coppel,et al.  Mapping the Binding Domains Involved in the Interaction between the Plasmodium falciparum Knob-associated Histidine-rich Protein (KAHRP) and the Cytoadherence Ligand P. falciparumErythrocyte Membrane Protein 1 (PfEMP1)* , 1999, The Journal of Biological Chemistry.

[36]  Mark E. Wickham,et al.  Targeted Gene Disruption Shows That Knobs Enable Malaria-Infected Red Cells to Cytoadhere under Physiological Shear Stress , 1997, Cell.

[37]  J. Reeder,et al.  Evidence for vesicle-mediated trafficking of parasite proteins to the host cell cytosol and erythrocyte surface membrane in Plasmodium falciparum infected erythrocytes. , 2000, Molecular and biochemical parasitology.

[38]  X. Su,et al.  The large diverse gene family var encodes proteins involved in cytoadherence and antigenic variation of plasmodium falciparum-infected erythrocytes , 1995, Cell.

[39]  L. Bannister,et al.  Characterization of membrane proteins exported from Plasmodium falciparum into the host erythrocyte , 1994, Parasitology.

[40]  K. Nakamura,et al.  Plasmodium falciparum-infected erythrocyte receptor(s) for CD36 and thrombospondin are restricted to knobs on the erythrocyte surface. , 1992, The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society.

[41]  D. Ferguson,et al.  Parasite-regulated membrane transport processes and metabolic control in malaria-infected erythrocytes. , 1995, The Biochemical journal.

[42]  K. Haldar.  Intracellular trafficking in Plasmodium-infected erythrocytes. , 1998, Current opinion in microbiology.

[43]  C. Newbold,et al.  Variant antigens and endothelial receptor adhesion in Plasmodium falciparum. , 1996, Proceedings of the National Academy of Sciences of the United States of America.

[44]  K. Mendis,et al.  Rosetting: a new cytoadherence property of malaria-infected erythrocytes. , 1988, The American journal of tropical medicine and hygiene.

[45]  A. Kilejian.  Characterization of a protein correlated with the production of knob-like protrusions on membranes of erythrocytes infected with Plasmodium falciparum. , 1979, Proceedings of the National Academy of Sciences of the United States of America.

[46]  S. Kyes,et al.  Antigenic variation at the infected red cell surface in malaria. , 2001, Annual review of microbiology.

[47]  Leann Tilley,et al.  Trafficking and assembly of the cytoadherence complex in Plasmodium falciparum‐infected human erythrocytes , 2001, The EMBO journal.

[48]  B. Gamain,et al.  Decoding the language of var genes and Plasmodium falciparum sequestration. , 2001, Trends in parasitology.

[49]  M. Foley,et al.  Export of parasite proteins to the erythrocyte cytoplasm: secretory machinery and traffic signals. , 1999, Novartis Foundation symposium.

[50]  B. Knapp,et al.  Plasmodium falciparum aldolase: gene structure and localization. , 1990, Molecular and biochemical parasitology.