Ca2+ monitoring in Plasmodium falciparum using the yellow cameleon-Nano biosensor

Abstract

Calcium (Ca2+)-mediated signaling is a conserved mechanism in eukaryotes, including the human malaria parasite, Plasmodium falciparum. Due to its small size (300?nM). We determined that the mammalian SERCA inhibitor thapsigargin and antimalarial dihydroartemisinin did not perturb SERCA activity. The change of the cytosolic Ca2+ level in P. falciparum was additionally detectable by flow cytometry. Thus, we propose that the developed YC-Nano-based system is useful to study Ca2+ signaling in P. falciparum and is applicable for drug screening.We are grateful to Japanese Red Cross Blood Society for providing human RBC and plasma. We also thank Tanaka R, Ogoshi (Sakura) M and Matsumoto N for technical assistance and Templeton TJ for critical reading. This study was conducted at the Joint Usage / Research Center on Tropical Disease, Institute of Tropical Medicine, Nagasaki University, Japan. KP was a Tokyo Biochemical Research Foundation (TBRF, http://www.tokyobrf.or.jp) post-doctoral fellow and PEF was a Japanese Society of Promotion Sciences (JSPS) post-doctoral fellow. This work was supported in part by the TBRF (K.P.), JSPS (P.E.F.), Takeda Science Foundation (K.Y.), Grants-in-Aids for Scientific Research 24590509 (K.Y.), 22390079 (O.K.), and for Scientific Research on Innovative Areas 23117008 (O.K.), MEXT, Japan. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript