A transmembrane domain containing pellicle protein of Toxoplasma gondii enhances virulence and invasion after extracellular stress

► TgTPP1 contains six predicted transmembrane domains. ► TgTPP1 localizes to the pellicle of Toxoplasma gondii. ► Insertion in TgTPP1 reduces virulence during acute infection. ► Insertion in TgTPP1 does not affect growth in standard cell culture. ► Insertion in TgTPP1 decreases invasion after extracellular stress.