Toxoplasma gondii MOB1 interactome

MOB1 is a conserved protein that regulates cellular proliferation versus apoptosis, centrosome duplication and cellular differentiation in multicellular eukaryotes and also cytokinesis and division axis orientation in unicellular and multicellular eukaryotes. Toxoplasma gondii, an obligate intracellular parasite of veterinary and medical importance, presents one MOB1 protein. T. gondii interconverts between several cellular stages during its life cycle, namely between fast replicating tachyzoite and slow replicating bradyzoite stages during its asexual cycle, a key ability for its success as a parasite. Bradyzoites produce tissue cysts, establishing a chronic infection that enables recrudescence. Conversion is dependent on cell cycle regulation and involves cell differentiation and regulation of replication. This led us to select MOB1 as a strong candidate to be involved in the Toxoplasma replication process. To elucidate how MOB1 acts in T. gondii, we employed a proximity biotinylation method and identified the MOB1 interactome. Toxoplasma gondii RH tachyzoites were transfected with BirA containing plasmid vectors for random integration and two strains were isolated. The control strain expresses a FLAG-BirA recombinant protein while the test strain expresses a FLAG-BirA-MOB1 recombinant protein. Biotinylated proteins were purified using streptavidin-agarose beads. The purified proteins were trypsinized and analyzed by nanoLC-MS/MS.