Evaluation Of Toxoplasma Gondii Apicoplast Protein TgMAP1c As A Drug Target

Toxoplasma gondii is an intracellular parasitic protozoan,belonging to the Apicomplexa,and an important pathogen causing toxoplasmosis in zoonotic animals.Toxoplasmosis is a parasitic disease with a high infection rate in humans and mammals.At present,the clinical treatment of toxoplasmosis is very limited,and there is an urgent need to find new drug targets to develop new drugs for the treatment of toxoplasmosis.Apicoplast is extremely important for the survival of Toxoplasma gondii,such as the nutrients necessary for the growth of Toxoplasma gondii,such as the synthesis of fatty acids,heme and isoprenoids.Impaired apicoplast function can lead to death.Therefore,apicoplast has always been regarded as ideal drug targets for the treatment of toxoplasmosis.Methionine aminopeptidase can cleave the methionine starting at the N-terminus of the nascent peptide chain and plays an important role in the metabolism of methionine,post-translational modification of protein N-terminus,and protein maturation.Methionine aminopeptidase has been extensively studied as an important drug target in many human diseases.However,whether Toxoplasma methionine aminopeptidase can be used as a drug target for the treatment of toxoplasmosis is still unknown.This study first identified the toxoplasma methionine aminopeptidase by bioinformatics analysis.Overexpression of Toxoplasma gondii methionine aminopeptidase in the worms.The localization of the methionine aminopeptidase(TgMAP1a/b,TgMAP2)encoded by Toxoplasma gondii was observed by laser scanning confocal microscopy.It is located in the cytoplasm of the parasite,and TgMAP1 c is located in the apicoplast.To further explore the function of TgMAP1 c on the apicoplast of Toxoplasma gondii,the TgMAP1c-3HA strain was successfully constructed using the method of endogenous insertion of the worm.Based on this strain,using the method of endogenous insertion of the worm and the Tet-off expression regulation system successfully constructed a TgMAP1 c conditionally deleted strain(iTgMAP1c strain).The effect of TgMAP1 c conditional deletion on Toxoplasma gondii was analyzed by plaque experiment,replication experiment,invasion experiment,fluorescence quantitative PCR experiment,and animal experiment.Experimental results show that the conditional deletion of TgMAP1 c leads to inhibition of the growth and replication level of Toxoplasma gondii,loss of apicoplast,and weakened virulence.Further analysis revealed that the transcription level of the apicoplast genome of TgMAP1 c deficient insect strains was suppressed.In summary,TgMAP1 c plays a key role in the maintenance and biogenesis of Toxoplasma gondii.Therefore,TgMAP1 c may be a potential drug target for the treatment of toxoplasmosis.