A lactate and formate transporter in the intraerythrocytic malaria parasite, Plasmodium falciparum

The intraerythrocytic malaria parasite relies primarily on glycolysis to fuel its rapid growth and reproduction. The major byproduct of this metabolism, lactic acid, is extruded into the external medium. In this study, we show that the human malaria parasite Plasmodium falciparum expresses at its surface a member of the microbial formate–nitrite transporter family (PfFNT), which, when expressed in Xenopus laevis oocytes, transports both formate and lactate. The transport characteristics of PfFNT in oocytes (pH-dependence, inhibitor-sensitivity and kinetics) are similar to those of the transport of lactate and formate across the plasma membrane of mature asexual-stage P. falciparum trophozoites, consistent with PfFNT playing a major role in the efflux of lactate and hence in the energy metabolism of the intraerythrocytic parasite. Malaria parasites generate metabolic energy through anaerobic glycolysis, yielding lactate that is then secreted out of the parasite cell by an unknown transporter. Here, Marchetti et al. identify and characterize a transporter that may be carrying out such a function in Plasmodium.