Abstract
Calcium ion (Ca(2+)) signaling is one of the most frequently employed mechanisms of signal transduction by eukaryotic cells, and starts with either Ca(2+) release from intracellular stores or Ca(2+) entry through the plasma membrane. In intracellular protist parasites Ca(2+) signaling initiates a sequence of events that may facilitate their invasion of host cells, respond to environmental changes within the host, or regulate the function of their intracellular organelles. In this review we examine recent findings in Ca(2+) signaling in two groups of intracellular protist parasites that have been studied in more detail, the apicomplexan and the trypanosomatid parasites.