The ROP2 family of Toxoplasma gondii rhoptry proteins: proteomic and genomic characterization and molecular modeling.
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.
El Hajj
Hiba
H
UMR 5539 CNRS, Université de Montpellier 2, Place E. Bataillon, Montpellier, France.
Demey
Emmanuelle
E
Poncet
Joël
J
Lebrun
Maryse
M
Wu
Bo
B
Galéotti
Nathalie
N
Fourmaux
Marie Noëlle
MN
Mercereau-Puijalon
Odile
O
Vial
Henri
H
Labesse
Gilles
G
Dubremetz
Jean François
JF
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D020134:Catalytic Domain; D002478:Cells, Cultured; D003001:Cloning, Molecular; D020224:Expressed Sequence Tags; D005347:Fibroblasts / Q000469:parasitology; D018503:Genome, Protozoan; D015698:Genomic Library; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008297:Male; D013058:Mass Spectrometry; D008565:Membrane Proteins / Q000032:analysis* / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification; D008958:Models, Molecular; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010449:Peptide Mapping; D010802:Phylogeny; D011485:Protein Binding; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D020543:Proteome / Q000032:analysis*; D015800:Protozoan Proteins / Q000032:analysis* / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012867:Skin / Q000166:cytology; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014122:Toxoplasma / Q000737:chemistry*
D008565:Membrane Proteins; D020543:Proteome; D015800:Protozoan Proteins; C090555:ROP 2 protein, Toxoplasma gondii