Apicomplexan parasites have challenged researchers for nearly a century. A major challenge to developing efficient treatments and vaccines is the parasite's ability to change its cellular and molecular makeup to develop intracellular and extracellular niches in its hosts. Ca2+ signaling is an important messenger for the egress of the malaria parasite from the infected erythrocyte, gametogenesis, ookinete motility in the mosquito, and sporozoite invasion of mammalian hepatocytes. Calcium-dependent protein kinases (CDPKs) have crucial functions in calcium signaling at various stages of the parasite's life cycle; this therefore makes them attractive drug targets against malaria. Here, we summarize the functions of the various CDPK isoforms in relation to the malaria life cycle by emphasizing the molecular mechanism of developmental progression within host tissues. We also discuss the current development of anti-malarial drugs, such as how specific bumped kinase inhibitors (BKIs) for parasite CDPKs have been shown to reduce infection in Toxoplasma gondii, Cryptosporidium parvum, and Plasmodium falciparum. Our suggested combinations of BKIs, artemisinin derivatives with peroxide bridge, and inhibitors on the Ca(2+)-ATPase PfATP6 as a potential target should be inspected further as a treatment against malaria.
Keywords: CDPK; anti-malarial drug; merozoite; oocyst; sporozoite.