The Plasmodium falciparum translationally controlled tumor protein: subcellular localisation 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 hav e been shown to react with malarial proteins, one of which is the Translati onally 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 cytoplas m as well as in its food vacuolar and limiting membranes. Like other TCTPs, the P. falciparum protein binds to calcium. Further studies on the physiol ogical role of TCTP may aid in understanding the mechanism of action of end operoxide antimalarials.