This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Manger, I. D.
Right arrow Articles by Boothroyd, J. C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Manger, I. D.
Right arrow Articles by Boothroyd, J. C.

 Previous Article  |  Next Article 

Infect Immun, May 1998, p. 2237-2244, Vol. 66, No. 5
0019-9567/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.

The Surface of Toxoplasma Tachyzoites Is Dominated by a Family of Glycosylphosphatidylinositol-Anchored Antigens Related to SAG1

Ian D. Manger, Adrian B. Hehl, and John C. Boothroyd*

Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California 94305

Received 5 November 1997/Returned for modification 17 December 1997/Accepted 2 March 1998

Toxoplasma gondii is an Apicomplexan parasite with a complex life cycle that includes a rapidly dividing asexual stage known as the tachyzoite. The tachyzoite surface has been reported to comprise five major antigens, the most abundant of which is designated SAG1 (for surface antigen 1). At least one of the other four (SAG3) and another recently described minor antigen (SRS1 [for SAG1-related sequence 1]) have previously been shown to be structurally related to SAG1. To determine if further SAG1 homologs exist, we searched a Toxoplasma expressed sequence tag (EST) database and found numerous ESTs corresponding to at least three new genes related to SAG1. Like SAG1, these new SRS genes encode apparently glycosylphosphatidylinositol-anchored proteins that share several motifs and a set of conserved cysteine residues. This family appears to have arisen by divergence from a common ancestor under selection for the conservation of overall topology. The products of two of these new genes (SRS2 and SRS3) are shown to be expressed on the surface of Toxoplasma tachyzoites by immunofluorescence. We also identified strain-specific differences in relative expression levels. A total of 10 members of the SAG1 gene family have now been identified, which apparently include three of the five major surface antigens previously described and one antigen expressed only in bradyzoites. The function of this family may be to provide a redundant system of receptors for interaction with host cells and/or to direct the immune responses that limit acute T. gondii infections.


* Corresponding author. Mailing address: Department of Microbiology and Immunology, Fairchild Science Building, D305, Stanford University School of Medicine, Stanford, CA 94305-5124. Phone: (650) 723-7984. Fax: (650) 723-6853. E-mail: john.boothroyd{at}stanford.edu.


Infect Immun, May 1998, p. 2237-2244, Vol. 66, No. 5
0019-9567/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.



This article has been cited by other articles:

  • Saeij, J. P. J., Arrizabalaga, G., Boothroyd, J. C. (2008). A Cluster of Four Surface Antigen Genes Specifically Expressed in Bradyzoites, SAG2CDXY, Plays an Important Role in Toxoplasma gondii Persistence. Infect. Immun. 76: 2402-2410 [Abstract] [Full Text]  
  • Gilk, S. D., Raviv, Y., Hu, K., Murray, J. M., Beckers, C. J. M., Ward, G. E. (2006). Identification of PhIL1, a Novel Cytoskeletal Protein of the Toxoplasma gondii Pellicle, through Photosensitized Labeling with 5-[125I]Iodonaphthalene-1-Azide.. Eukaryot Cell 5: 1622-1634 [Abstract] [Full Text]  
  • Saksouk, N., Bhatti, M. M., Kieffer, S., Smith, A. T., Musset, K., Garin, J., Sullivan, W. J. Jr., Cesbron-Delauw, M.-F., Hakimi, M.-A. (2005). Histone-Modifying Complexes Regulate Gene Expression Pertinent to the Differentiation of the Protozoan Parasite Toxoplasma gondii. Mol. Cell. Biol. 25: 10301-10314 [Abstract] [Full Text]  
  • Zhou, X. W., Kafsack, B. F. C., Cole, R. N., Beckett, P., Shen, R. F., Carruthers, V. B. (2005). The Opportunistic Pathogen Toxoplasma gondii Deploys a Diverse Legion of Invasion and Survival Proteins. J. Biol. Chem. 280: 34233-34244 [Abstract] [Full Text]  
  • Rachinel, N., Buzoni-Gatel, D., Dutta, C., Mennechet, F. J. D., Luangsay, S., Minns, L. A., Grigg, M. E., Tomavo, S., Boothroyd, J. C., Kasper, L. H. (2004). The Induction of Acute Ileitis by a Single Microbial Antigen of Toxoplasma gondii. J. Immunol. 173: 2725-2735 [Abstract] [Full Text]  
  • Li, L., Brunk, B. P., Kissinger, J. C., Pape, D., Tang, K., Cole, R. H., Martin, J., Wylie, T., Dante, M., Fogarty, S. J., Howe, D. K., Liberator, P., Diaz, C., Anderson, J., White, M., Jerome, M. E., Johnson, E. A., Radke, J. A., Stoeckert, C. J. Jr., Waterston, R. H., Clifton, S. W., Roos, D. S., Sibley, L. D. (2003). Gene Discovery in the Apicomplexa as Revealed by EST Sequencing and Assembly of a Comparative Gene Database. Genome Res 13: 443-454 [Abstract] [Full Text]  
  • Meek, B., Back, J. W., Klaren, V. N. A., Speijer, D., Peek, R. (2002). Conserved regions of protein disulfide isomerase are targeted by natural IgA antibodies in humans. Int Immunol 14: 1291-1301 [Abstract] [Full Text]  
  • Wichroski, M. J., Melton, J. A., Donahue, C. G., Tweten, R. K., Ward, G. E. (2002). Clostridium septicum Alpha-Toxin Is Active against the Parasitic Protozoan Toxoplasma gondii and Targets Members of the SAG Family of Glycosylphosphatidylinositol-Anchored Surface Proteins. Infect. Immun. 70: 4353-4361 [Abstract] [Full Text]  
  • Johnson, J. J., Roberts, C. W., Pope, C., Roberts, F., Kirisits, M. J., Estes, R., Mui, E., Krieger, T., Brown, C. R., Forman, J., McLeod, R. (2002). In Vitro Correlates of Ld-Restricted Resistance to Toxoplasmic Encephalitis and Their Critical Dependence on Parasite Strain. J. Immunol. 169: 966-973 [Abstract] [Full Text]  
  • Dutta, C., Grimwood, J., Kasper, L. H. (2000). Attachment of Toxoplasma gondii to a Specific Membrane Fraction of CHO Cells. Infect. Immun. 68: 7198-7201 [Abstract] [Full Text]  
  • Black, M. W., Boothroyd, J. C. (2000). Lytic Cycle of Toxoplasma gondii. Microbiol. Mol. Biol. Rev. 64: 607-623 [Abstract] [Full Text]  
  • Cevallos, A. M., Zhang, X., Waldor, M. K., Jaison, S., Zhou, X., Tzipori, S., Neutra, M. R., Ward, H. D. (2000). Molecular Cloning and Expression of a Gene Encoding Cryptosporidium parvum Glycoproteins gp40 and gp15. Infect. Immun. 68: 4108-4116 [Abstract] [Full Text]  
  • Channon, J. Y., Suh, E. I., Seguin, R. M., Kasper, L. H. (1999). Attachment Ligands of Viable Toxoplasma gondii Induce Soluble Immunosuppressive Factors in Human Monocytes. Infect. Immun. 67: 2547-2551 [Abstract] [Full Text]  
  • Ferguson, M. (1999). The structure, biosynthesis and functions of glycosylphosphatidylinositol anchors, and the contributions of trypanosome research. J. Cell Sci. 112: 2799-2809 [Abstract]  
  • Howe, D. K., Crawford, A. C., Lindsay, D., Sibley, L. D. (1998). The p29 and p35 Immunodominant Antigens of Neospora caninum Tachyzoites Are Homologous to the Family of Surface Antigens of Toxoplasma gondii. Infect. Immun. 66: 5322-5328 [Abstract] [Full Text]