title: Calcium signal regulates temperature-dependent transformation of sporozoites in malaria parasite development.
abstract: The infection by the malaria parasite of its mammalian host is initiated by the asexual reproduction of the parasite within the host hepatocyte. Before the reproduction, the elongated sporozoites undergo a depolarizing morphogenesis to the spherical exo-erythrocytic form (EEF). This change can be induced in vitro by shifting the environmental conditions, in the absence of host hepatocytes. Using rodent malaria parasites expressing a FRET-based calcium sensor, YC3.60, we observed that the intracellular calcium increased at the center of the bulbous structure during sporozoite transformation. Modulators of intracellular calcium signaling (A23187 and W-7) accelerated the sporozoite-rounding process. These data suggest that calcium signaling regulates the morphological development of the malaria parasite sporozoite to the EEF, and support a fundamental role for calcium as a universal transducer of external stimuli in the parasitic life cycle.
authors.affiliation: National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Doi
authors.forename: Naoaki
authors.initials: N
authors.lastname: Shinzawa
authors.forename: Shinya
authors.initials: S
authors.lastname: Fukumoto
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Okano
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Kanuka
mesh_terms: D000818:Animals; D000852:Anopheles; D000001:Calcimycin / Q000494:pharmacology; D020013:Calcium Signaling / Q000502:physiology*; D002147:Calmodulin / Q000037:antagonists & inhibitors; D005260:Female; D007476:Ionophores / Q000494:pharmacology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008856:Microscopy, Fluorescence / Q000379:methods; D010962:Plasmodium berghei / Q000187:drug effects / Q000254:growth & development*; D034101:Sporozoites / Q000187:drug effects / Q000254:growth & development; D013449:Sulfonamides / Q000494:pharmacology; D013696:Temperature
chemical_list: D002147:Calmodulin; D007476:Ionophores; D013449:Sulfonamides; D000001:Calcimycin; C017967:W 7