| Structural highlights
Function
[MIC1_TOXGO] Adhesin. Required for attachment of the parasite to the host cell prior to invasion. Ensures correct folding of MIC6 and transport of the MIC6-MIC1-MIC4 complex into the micronemes.[1] [2] [3] [4] [5] [MIC6_TOXGO] Escorter protein required for import of MIC1 and MIC4 adhesins into the microneme.[6] [7] [8]
Publication Abstract from PubMed
The obligate intracellular parasite Toxoplasma gondii, a member of the phylum Apicomplexa that includes Plasmodium spp., is one of the most widespread parasites and the causative agent of toxoplasmosis. Adhesive complexes composed of microneme proteins (MICs) are secreted onto the parasite surface from intracellular stores and fulfil crucial roles in host-cell recognition, attachment and penetration. Here, we report the high-resolution solution structure of a complex between two crucial MICs, TgMIC6 and TgMIC1. Furthermore, we identify two analogous interaction sites within separate epidermal growth factor-like (EGF) domains of TgMIC6-EGF2 and EGF3-and confirm that both interactions are functional for the recognition of host cell receptor in the parasite, using immunofluorescence and invasion assays. The nature of this new mode of recognition of the EGF domain and its abundance in apicomplexan surface proteins suggest a more generalized means of constructing functional assemblies by using EGF domains with highly specific receptor-binding properties.
Structural insights into microneme protein assembly reveal a new mode of EGF domain recognition.,Sawmynaden K, Saouros S, Friedrich N, Marchant J, Simpson P, Bleijlevens B, Blackman MJ, Soldati-Favre D, Matthews S EMBO Rep. 2008 Nov;9(11):1149-55. Epub 2008 Sep 26. PMID:18818666[9]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Lourenco EV, Pereira SR, Faca VM, Coelho-Castelo AA, Mineo JR, Roque-Barreira MC, Greene LJ, Panunto-Castelo A. Toxoplasma gondii micronemal protein MIC1 is a lactose-binding lectin. Glycobiology. 2001 Jul;11(7):541-7. PMID:11447133
- ↑ Reiss M, Viebig N, Brecht S, Fourmaux MN, Soete M, Di Cristina M, Dubremetz JF, Soldati D. Identification and characterization of an escorter for two secretory adhesins in Toxoplasma gondii. J Cell Biol. 2001 Feb 5;152(3):563-78. PMID:11157983
- ↑ Saouros S, Edwards-Jones B, Reiss M, Sawmynaden K, Cota E, Simpson P, Dowse TJ, Jakle U, Ramboarina S, Shivarattan T, Matthews S, Soldati-Favre D. A novel galectin-like domain from Toxoplasma gondii micronemal protein 1 assists the folding, assembly, and transport of a cell adhesion complex. J Biol Chem. 2005 Nov 18;280(46):38583-91. Epub 2005 Sep 15. PMID:16166092 doi:C500365200
- ↑ Blumenschein TM, Friedrich N, Childs RA, Saouros S, Carpenter EP, Campanero-Rhodes MA, Simpson P, Chai W, Koutroukides T, Blackman MJ, Feizi T, Soldati-Favre D, Matthews S. Atomic resolution insight into host cell recognition by Toxoplasma gondii. EMBO J. 2007 Jun 6;26(11):2808-20. Epub 2007 May 10. PMID:17491595
- ↑ Fourmaux MN, Achbarou A, Mercereau-Puijalon O, Biderre C, Briche I, Loyens A, Odberg-Ferragut C, Camus D, Dubremetz JF. The MIC1 microneme protein of Toxoplasma gondii contains a duplicated receptor-like domain and binds to host cell surface. Mol Biochem Parasitol. 1996 Dec 20;83(2):201-10. PMID:9027753
- ↑ Reiss M, Viebig N, Brecht S, Fourmaux MN, Soete M, Di Cristina M, Dubremetz JF, Soldati D. Identification and characterization of an escorter for two secretory adhesins in Toxoplasma gondii. J Cell Biol. 2001 Feb 5;152(3):563-78. PMID:11157983
- ↑ Saouros S, Edwards-Jones B, Reiss M, Sawmynaden K, Cota E, Simpson P, Dowse TJ, Jakle U, Ramboarina S, Shivarattan T, Matthews S, Soldati-Favre D. A novel galectin-like domain from Toxoplasma gondii micronemal protein 1 assists the folding, assembly, and transport of a cell adhesion complex. J Biol Chem. 2005 Nov 18;280(46):38583-91. Epub 2005 Sep 15. PMID:16166092 doi:C500365200
- ↑ Sawmynaden K, Saouros S, Friedrich N, Marchant J, Simpson P, Bleijlevens B, Blackman MJ, Soldati-Favre D, Matthews S. Structural insights into microneme protein assembly reveal a new mode of EGF domain recognition. EMBO Rep. 2008 Nov;9(11):1149-55. Epub 2008 Sep 26. PMID:18818666 doi:10.1038/embor.2008.179
- ↑ Sawmynaden K, Saouros S, Friedrich N, Marchant J, Simpson P, Bleijlevens B, Blackman MJ, Soldati-Favre D, Matthews S. Structural insights into microneme protein assembly reveal a new mode of EGF domain recognition. EMBO Rep. 2008 Nov;9(11):1149-55. Epub 2008 Sep 26. PMID:18818666 doi:10.1038/embor.2008.179
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