Figure 6: A model for arginine transport into T. gondii parasites.
Cationic amino acids such as arginine and lysine enter host cells through cationic amino acid transporters (CAT; grey cylinder). Arginine in the host cell cytosol crosses the parasitophorous vacuole membrane (dashed line) through non-selective pores57, and is taken up by the parasite through two pathways. TgNPT1 (red cylinder) is a selective arginine transporter, and serves as a major route for arginine uptake in vivo. A general cationic amino acid transport system (blue cylinder) facilitates the TgNPT1-independent uptake of both arginine and lysine.
