The genetically encoded calcium indicator GCaMP3 reveals spontaneous calcium oscillations at asexual stages of the human malaria parasite Plasmodium falciparum

Author(s)

dos Santos, Benedito M. ; Pecenin, Mateus F. ; Borges-Pereira, Lucas ; Springer, Eric ; Przyborski, Jude M. ; Martins-Jr, David C. ; Hashimoto, Ronaldo F. ; Garcia, Celia R. S.

• Document type: Journal article
• Source: Molecular and Biochemical Parasitology; v. 260, p. 10-pg., 2024-08-24.

Abstract

Most protocols used to study the dynamics of calcium (Ca2+) in the malaria parasite are based on dyes, which are invasive and do not allow discrimination between the signal from the host cell and the parasite. To avoid this pitfall, we have generated a parasite line expressing the genetically encoded calcium sensor GCaMP3. The PfGCaMP3 parasite line is an innovative tool for studying spontaneous intracellular Ca2+ oscillations without external markers. Using this parasite line, we demonstrate the occurrence of spontaneous Ca2+ oscillations in the ring, trophozoite, and schizont stages in Plasmodium falciparum. Using the Fourier transform to fluorescence intensity data extracted from different experiments, we observe cytosolic Ca2+ fluctuations. These spontaneous cytosolic Ca2+ oscillations occur in the three intraerythrocytic stages of the parasite, with most oscillations occurring in the ring and trophozoite stages. A control parasite line expressing only a GFP control did not reveal such fluctuations, demonstrating the specificity of the observations. Our results clearly show dynamic, spontaneous Ca2+ oscillations during the asexual stage in P. falciparum, independent from external stimuli. (AU)

• FAPESP's process: 20/08988-9 - Evaluation of compounds with antimalarial potential and study of the signal transduction mechanism of GPCR (G-Protein Coupled Receptor) like PfSR25 in Plasmodium falciparum
• Grantee: Benedito Matheus dos Santos
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 17/08684-7 - Decoding Plasmodium signaling at molecular level as a new tool to the development of new antimalarials
• Grantee: Célia Regina da Silva Garcia
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 18/07177-7 - EMU concedido no processo 2011/51295-5: image system
• Grantee: Célia Regina da Silva Garcia
• Support Opportunities: Multi-user Equipment Program
• FAPESP's process: 15/22308-2 - Intermediate representations in Computational Science for knowledge discovery
• Grantee: Roberto Marcondes Cesar Junior
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 18/21934-5 - Network statistics: theory, methods, and applications
• Grantee: André Fujita
• Support Opportunities: Research Projects - Thematic Grants