Toxoplasma invasion delayed by Tg ERK7 eradication

Toxoplasma gondii causes serious clinical toxoplasmosis in humans mostly due to its asexual life cycles, which can be artificially divided into five tightly coterminous stages. Any radical or delay for the stage will result in tremendous changes immediately behind. We previously demonstrated that Tg ERK7 is associated with the intracellular proliferation of T. gondii , but during the process, other stages before were not meanwhile determined. To further clarify the function of ERK7 gene in T. gondii , the complemental strain of Δ Tg ERK7 tachyzoites created previously was engineered via electric transfection with the recombinant pUC/ Tgerk7 plasmid, named pUC/ Tg ERK7 strain in this study, and was used together with Δ Tg ERK7 and wild-type GT1 strains to retrospect the phenotypic changes including invasion and attachment. The results showed that Tg ERK7 protein can be re-expressed in the Δ Tg ERK7 tachyzoites and eradication of this protein leads to significantly lower invasion of T. gondii at 1 h and 2 h post-infection ( P < 0.05), which is the key factor causing the following slow intracellular proliferation, in comparison with wild-type GT1 and pUC/ Tg ERK7 parasites; noteworthily, at other early time points including 15 min for attachment assay was no statistical difference ( P > 0.05). The data suggested that ERK7 protein in T. gondii is an important virulence factor that participates in the invasion of this parasite.