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The ROP2 family of Toxoplasma gondii rhoptry proteins: Proteomic and genomic characterization and molecular modeling
Author(s) -
El Hajj Hiba,
Demey Emmanuelle,
Poncet Joël,
Lebrun Maryse,
Wu Bo,
Galéotti Nathalie,
Fourmaux Marie Noëlle,
MercereauPuijalon Odile,
Vial Henri,
Labesse Gilles,
Dubremetz Jean François
Publication year - 2006
Publication title -
proteomics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.26
H-Index - 167
eISSN - 1615-9861
pISSN - 1615-9853
DOI - 10.1002/pmic.200600187
Subject(s) - rhoptry , biology , protein kinase domain , transmembrane protein , toxoplasma gondii , transmembrane domain , protein family , protein kinase a , gene , genetics , computational biology , kinase , microbiology and biotechnology , antibody , apicomplexa , receptor , malaria , mutant , immunology , plasmodium falciparum
Four rhoptry proteins (ROP) of Toxoplasma gondii previously identified with mAb have been affinity purified and analyzed by MS; the data obtained allowed the genomic sequences to be assigned to these proteins. As previously suggested for some of them by antibody crossreactivity, these proteins were shown to belong to a family, the prototype of which being ROP2. We describe here the proteins ROP2, 4, 5, and 7. These four proteins correspond to the most abundant products of a gene family that comprises several members which we have identified in genomic and EST libraries. Eight additional sequences were found and we have cloned four of them. All members of the ROP2 family contain a protein‐kinase‐like domain, but only some of them possess a bona fide kinase catalytic site. Molecular modeling of the kinase domain demonstrates the conservation of residues critical for the stabilization of the protein‐kinase fold, especially within a hydrophobic segment described so far as transmembrane and which appears as an helix buried inside the protein. The concomitant synthesis of these ROPs by T. gondii tachyzoites suggests a specific role for each of these proteins, especially in the early interaction with the host cell upon invasion.