Abundant proton pumping in Plasmodium, but why?

Intraerythrocytic Plasmodium parasites depend on glycolysis for energy production. The stoichiometric amounts of lactate and protons produced are efficiently removed by a lactate:H⁺ symporter. However, inhibition of recently identified plasma-membrane proton pumps result in acidification, suggesting additional mechanism(s) for proton generation. This article attempts to integrate the knowledge on the metabolic generation of protons and their disposal in the regulation of parasite cytosolic pH, and suggests additional roles for the various proton pumps that act in the parasite membrane.