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. 1987 May 1;104(5):1269–1280. doi: 10.1083/jcb.104.5.1269

Transport of an Mr approximately 300,000 Plasmodium falciparum protein (Pf EMP 2) from the intraerythrocytic asexual parasite to the cytoplasmic face of the host cell membrane

PMCID: PMC2114467  PMID: 2437128

Abstract

The profound changes in the morphology, antigenicity, and functional properties of the host erythrocyte membrane induced by intraerythrocytic parasites of the human malaria Plasmodium falciparum are poorly understood at the molecular level. We have used mouse mAbs to identify a very large malarial protein (Mr approximately 300,000) that is exported from the parasite and deposited on the cytoplasmic face of the erythrocyte membrane. This protein is denoted P. falciparum erythrocyte membrane protein 2 (Pf EMP 2). The mAbs did not react with the surface of intact infected erythrocytes, nor was Pf EMP 2 accessible to exogenous proteases or lactoperoxidase-catalyzed radioiodination of intact cells. The mAbs also had no effect on in vitro cytoadherence of infected cells to the C32 amelanotic melanoma cell line. These properties distinguish Pf EMP 2 from Pf EMP 1, the cell surface malarial protein of similar size that is associated with the cytoadherent property of P. falciparum-infected erythrocytes. The mAbs did not react with Pf EMP 1. In one strain of parasite there was a significant difference in relative mobility of the 125I-surface-labeled Pf EMP 1 and the biosynthetically labeled Pf EMP 2, further distinguishing these proteins. By cryo-thin-section immunoelectron microscopy we identified organelles involved in the transit of Pf EMP through the erythrocyte cytoplasm to the internal face of the erythrocyte membrane where the protein is associated with electron- dense material under knobs. These results show that the intraerythrocytic malaria parasite has evolved a novel system for transporting malarial proteins beyond its own plasma membrane, through a vacuolar membrane and the host erythrocyte cytoplasm to the erythrocyte membrane, where they become membrane bound and presumably alter the properties of this membrane to the parasite's advantage.

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Selected References

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  1. Aikawa M., Uni Y., Andrutis A. T., Howard R. J. Membrane-associated electron-dense material of the asexual stages of Plasmodium falciparum: evidence for movement from the intracellular parasite to the erythrocyte membrane. Am J Trop Med Hyg. 1986 Jan;35(1):30–36. doi: 10.4269/ajtmh.1986.35.30. [DOI] [PubMed] [Google Scholar]
  2. Aley S. B., Sherwood J. A., Howard R. J. Knob-positive and knob-negative Plasmodium falciparum differ in expression of a strain-specific malarial antigen on the surface of infected erythrocytes. J Exp Med. 1984 Nov 1;160(5):1585–1590. doi: 10.1084/jem.160.5.1585. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Bonner W. M., Laskey R. A. A film detection method for tritium-labelled proteins and nucleic acids in polyacrylamide gels. Eur J Biochem. 1974 Jul 1;46(1):83–88. doi: 10.1111/j.1432-1033.1974.tb03599.x. [DOI] [PubMed] [Google Scholar]
  4. Collins W. E., Warren M., Skinner J. C., Chin W., Richardson B. B. Studies on the Santa Lucia (El Salvador) strain of Plasmodium falciparum in Aotus trivirgatus monkeys. J Parasitol. 1977 Feb;63(1):52–56. [PubMed] [Google Scholar]
  5. Coppel R. L., Cowman A. F., Lingelbach K. R., Brown G. V., Saint R. B., Kemp D. J., Anders R. F. Isolate-specific S-antigen of Plasmodium falciparum contains a repeated sequence of eleven amino acids. Nature. 1983 Dec 22;306(5945):751–756. doi: 10.1038/306751a0. [DOI] [PubMed] [Google Scholar]
  6. Coppel R. L., Culvenor J. G., Bianco A. E., Crewther P. E., Stahl H. D., Brown G. V., Anders R. F., Kemp D. J. Variable antigen associated with the surface of erythrocytes infected with mature stages of Plasmodium falciparum. Mol Biochem Parasitol. 1986 Sep;20(3):265–277. doi: 10.1016/0166-6851(86)90107-6. [DOI] [PubMed] [Google Scholar]
  7. Howard R. J. Alterations in the surface membrane of red blood cells during malaria. Immunol Rev. 1982;61:67–107. doi: 10.1111/j.1600-065x.1982.tb00374.x. [DOI] [PubMed] [Google Scholar]
  8. Howard R. J., Barnwell J. W., Kao V. Antigenic variation of Plasmodium knowlesi malaria: identification of the variant antigen on infected erythrocytes. Proc Natl Acad Sci U S A. 1983 Jul;80(13):4129–4133. doi: 10.1073/pnas.80.13.4129. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Howard R. J., Barnwell J. W., Kao V., Daniel W. A., Aley S. B. Radioiodination of new protein antigens on the surface of Plasmodium knowlesi schizont-infected erythrocytes. Mol Biochem Parasitol. 1982 Dec;6(6):343–367. doi: 10.1016/0166-6851(82)90024-x. [DOI] [PubMed] [Google Scholar]
  10. Howard R. J., Barnwell J. W. Roles of surface antigens on malaria-infected red blood cells in evasion of immunity. Contemp Top Immunobiol. 1984;12:127–200. doi: 10.1007/978-1-4684-4571-8_5. [DOI] [PubMed] [Google Scholar]
  11. Howard R. J., Barnwell J. W. The detergent solubility properties of a malarial (Plasmodium knowlesi) variant antigen expressed on the surface of infected erythrocytes. J Cell Biochem. 1984;24(3):297–306. doi: 10.1002/jcb.240240310. [DOI] [PubMed] [Google Scholar]
  12. Howard R. J., Kao V., Barnwell J. W. Protein antigens of Plasmodium knowlesi clones of different variant antigen phenotype. Parasitology. 1984 Apr;88(Pt 2):221–237. [PubMed] [Google Scholar]
  13. Howard R. J., Uni S., Aikawa M., Aley S. B., Leech J. H., Lew A. M., Wellems T. E., Rener J., Taylor D. W. Secretion of a malarial histidine-rich protein (Pf HRP II) from Plasmodium falciparum-infected erythrocytes. J Cell Biol. 1986 Oct;103(4):1269–1277. doi: 10.1083/jcb.103.4.1269. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Kearney J. F., Radbruch A., Liesegang B., Rajewsky K. A new mouse myeloma cell line that has lost immunoglobulin expression but permits the construction of antibody-secreting hybrid cell lines. J Immunol. 1979 Oct;123(4):1548–1550. [PubMed] [Google Scholar]
  15. Kennett R. H., Denis K. A., Tung A. S., Klinman N. R. Hybrid plasmacytoma production: fusions with adult spleen cells, monoclonal spleen fragments, neonatal spleen cells and human spleen cells. Curr Top Microbiol Immunol. 1978;81:77–91. doi: 10.1007/978-3-642-67448-8_13. [DOI] [PubMed] [Google Scholar]
  16. Kilejian A. Characterization of a protein correlated with the production of knob-like protrusions on membranes of erythrocytes infected with Plasmodium falciparum. Proc Natl Acad Sci U S A. 1979 Sep;76(9):4650–4653. doi: 10.1073/pnas.76.9.4650. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Klotz F. W., Gathings W. E., Cooper M. D. Development and distribution of B lineage cells in the domestic cat: analysis with monoclonal antibodies to cat mu-, gamma-, kappa-, and lambda-chains and heterologous anti-alpha antibodies. J Immunol. 1985 Jan;134(1):95–100. [PubMed] [Google Scholar]
  18. Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
  19. Leech J. H., Barnwell J. W., Aikawa M., Miller L. H., Howard R. J. Plasmodium falciparum malaria: association of knobs on the surface of infected erythrocytes with a histidine-rich protein and the erythrocyte skeleton. J Cell Biol. 1984 Apr;98(4):1256–1264. doi: 10.1083/jcb.98.4.1256. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Leech J. H., Barnwell J. W., Miller L. H., Howard R. J. Identification of a strain-specific malarial antigen exposed on the surface of Plasmodium falciparum-infected erythrocytes. J Exp Med. 1984 Jun 1;159(6):1567–1575. doi: 10.1084/jem.159.6.1567. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Luse S. A., Miller L. H. Plasmodium falciparum malaria. Ultrastructure of parasitized erythrocytes in cardiac vessels. Am J Trop Med Hyg. 1971 Sep;20(5):655–660. [PubMed] [Google Scholar]
  22. Lyon J. A., Haynes J. D., Diggs C. L., Chulay J. D., Haidaris C. G., Pratt-Rossiter J. Monoclonal antibody characterization of the 195-kilodalton major surface glycoprotein of Plasmodium falciparum malaria schizonts and merozoites: identification of additional processed products and a serotype-restricted repetitive epitope. J Immunol. 1987 Feb 1;138(3):895–901. [PubMed] [Google Scholar]
  23. Lyon J. A., Haynes J. D., Diggs C. L., Chulay J. D., Pratt-Rossiter J. M. Plasmodium falciparum antigens synthesized by schizonts and stabilized at the merozoite surface by antibodies when schizonts mature in the presence of growth inhibitory immune serum. J Immunol. 1986 Mar 15;136(6):2252–2258. [PubMed] [Google Scholar]
  24. Lyon J. A., Haynes J. D. Plasmodium falciparum antigens synthesized by schizonts and stabilized at the merozoite surface when schizonts mature in the presence of protease inhibitors. J Immunol. 1986 Mar 15;136(6):2245–2251. [PubMed] [Google Scholar]
  25. Roberts D. D., Sherwood J. A., Spitalnik S. L., Panton L. J., Howard R. J., Dixit V. M., Frazier W. A., Miller L. H., Ginsburg V. Thrombospondin binds falciparum malaria parasitized erythrocytes and may mediate cytoadherence. Nature. 1985 Nov 7;318(6041):64–66. doi: 10.1038/318064a0. [DOI] [PubMed] [Google Scholar]
  26. Sherman I. W. Membrane structure and function of malaria parasites and the infected erythrocyte. Parasitology. 1985 Dec;91(Pt 3):609–645. doi: 10.1017/s0031182000062843. [DOI] [PubMed] [Google Scholar]
  27. Swanstrom R., Shank P. R. X-Ray Intensifying Screens Greatly Enhance the Detection by Autoradiography of the Radioactive Isotopes 32P and 125I. Anal Biochem. 1978 May;86(1):184–192. doi: 10.1016/0003-2697(78)90333-0. [DOI] [PubMed] [Google Scholar]
  28. Tokuyasu K. T. A technique for ultracryotomy of cell suspensions and tissues. J Cell Biol. 1973 May;57(2):551–565. doi: 10.1083/jcb.57.2.551. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Udeinya I. J., Leech J., Aikawa M., Miller L. H. An in vitro assay for sequestration: binding of Plasmodium falciparum-infected erythrocytes to formalin-fixed endothelial cells and amelanotic melanoma cells. J Protozool. 1985 Feb;32(1):88–90. doi: 10.1111/j.1550-7408.1985.tb03019.x. [DOI] [PubMed] [Google Scholar]
  30. Udeinya I. J., Miller L. H., McGregor I. A., Jensen J. B. Plasmodium falciparum strain-specific antibody blocks binding of infected erythrocytes to amelanotic melanoma cells. Nature. 1983 Jun 2;303(5916):429–431. doi: 10.1038/303429a0. [DOI] [PubMed] [Google Scholar]
  31. Udeinya I. J., Schmidt J. A., Aikawa M., Miller L. H., Green I. Falciparum malaria-infected erythrocytes specifically bind to cultured human endothelial cells. Science. 1981 Jul 31;213(4507):555–557. doi: 10.1126/science.7017935. [DOI] [PubMed] [Google Scholar]

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