Calcium homeostasis and signaling in the blood-stage malaria parasite

The nature of the mechanisms underlying Ca2+ homeostasis in malaria parasites has puzzled investigators for almost two decades. This review summarizes the current knowledge about Ca2+ homeostasis in Plasmodium spp and highlights some key aspects of this process that are specific to this parasite. Plasmodium spp are exposed, during their intracellular stage, not to the usual millimolar concentrations of Ca2+ found in body fluids but rather to the very low Ca2+ environment of the host cell cytoplasm. Two crucial questions then nl ise: (1) how is Ca2+ homeostasis achieved by these protozoa; and (2) no they use Ca2+-based signaling pathways.' By critically reviewing the recent literature in the field, Celia Garcia here provides at least some partial answers to these questions.