Quantitative calcium measurements in subcellular compartments of Plasmodium falciparum-infected erythrocytes
Rohrbach P, Friedrich O, Hentschel J, Plattner H, Fink R, Lanzer M (2005)
Publication Type: Journal article, Original article
Publication year: 2005
Journal
Original Authors: Rohrbach P., Friedrich O., Hentschel J., Plattner H., Fink R.H.A., Lanzer M.
Publisher: American Society for Biochemistry and Molecular Biology
Book Volume: 280
Pages Range: 27960-27969
Journal Issue: 30
Abstract
The acidic food vacuole exerts several important functions during intraerythrocytic development of the human malarial parasite Plasmodium falciparum. Hemoglobin taken up from the host erythrocyte is degraded in the food vacuole, and the heme liberated during this process is crystallized to inert hemozoin. Several antimalarial drugs target food vacuolar pathways, such as hemoglobin degradation and heme crystallization. Resistance and sensitization to some antimalarials is associated with mutations in food vacuolar membrane proteins. Other studies suggest a role of the food vacuole in ion homeostasis, and release of Ca from the food vacuole may mediate adopted physiological responses. To investigate whether the food vacuole is an intracellular Ca store, which in turn may affect other physiological functions in which this organelle partakes, we have investigated total and exchangeable Ca within the parasite's food vacuole using x-ray microanalysis and quantitative confocal live cell Ca imaging. Apparent free Ca concentrations of ∼90, ∼350, and ∼400 nM were found in the host erythrocyte cytosol, the parasite cytoplasm, and the food vacuole, respectively. In our efforts to determine free intracellular Ca concentrations, we evaluated several Ca-sensitive fluorochromes in a live cell confocal setting. We found that the ratiometric Ca indicator Fura-Red provides reliable determinations, whereas measurements using the frequently used Fluo-4 are compromised due to problems arising from phototoxicity, photobleaching, and the strong pH dependence of the dye. Our data suggest that the food vacuole contains only moderate amounts of Ca, disfavoring a role as a major intracellular Ca store. © 2005 by The American Society for Biochemistry and Molecular Biology, Inc.
Authors with CRIS profile
Oliver Friedrich
Lehrstuhl für Medizinische Biotechnologie
Rainer Fink
Professur für Physikalische Chemie
Involved external institutions
Germany (DE)How to cite
APA:
Rohrbach, P., Friedrich, O., Hentschel, J., Plattner, H., Fink, R., & Lanzer, M. (2005). Quantitative calcium measurements in subcellular compartments of Plasmodium falciparum-infected erythrocytes. Journal of Biological Chemistry, 280(30), 27960-27969. https://doi.org/10.1074/jbc.M500777200
MLA:
Rohrbach, Petra, et al. "Quantitative calcium measurements in subcellular compartments of Plasmodium falciparum-infected erythrocytes." Journal of Biological Chemistry 280.30 (2005): 27960-27969.
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