The Plasmodium falciparum translationally controlled tumor protein: subcellular localization and calcium binding.

Artemisinin derivatives are endoperoxide antimalarials widely used to treat falciparum malaria in areas where drug resistance is common. In Plasmodium falciparum-infected erythrocytes, radiolabeled artemisinin derivatives have been shown to react with malarial proteins, one of which is the Translationally Controlled Tumor Protein (TCTP). The P. falciparum TCTP was found by immunofluorescence to be located in both the cytoplasm and food vacuoles. Immunoelectron microscopy shows that it is present in the parasite cytoplasm as well as in its food vacuolar and limiting membranes. Like other TCTPs, the P. falciparum protein binds to calcium. Further studies on the physiological role of TCTP may aid in understanding the mechanism of action of endoperoxide antimalarials.