Quantitative calcium measurements in subcellular compartments of Plasmodium falciparum-infected erythrocytes

Rohrbach, Petra, Friedrich, Oliver, Hentschel, Joachim, Plattner, Helmut, Fink, Rainer H. A. and Lanzer, Michael (2005) Quantitative calcium measurements in subcellular compartments of Plasmodium falciparum-infected erythrocytes. The Journal of Biological Chemistry, 280 30: 27960-27969. doi:10.1074/jbc.M500777200

Attached Files (Some files may be inaccessible until you login with your UQ eSpace credentials)
Name Description MIMEType Size Downloads
UQ201877_OA.pdf Full text (open access) application/pdf 648.03KB 0

Author Rohrbach, Petra
Friedrich, Oliver
Hentschel, Joachim
Plattner, Helmut
Fink, Rainer H. A.
Lanzer, Michael
Title Quantitative calcium measurements in subcellular compartments of Plasmodium falciparum-infected erythrocytes
Formatted title
Quantitative calcium measurements in subcellular compartments of Plasmodium falciparum-infected erythrocytes
Journal name The Journal of Biological Chemistry   Check publisher's open access policy
ISSN 0021-9258
1083-351X
Publication date 2005-07-29
Sub-type Article (original research)
DOI 10.1074/jbc.M500777200
Open Access Status File (Publisher version)
Volume 280
Issue 30
Start page 27960
End page 27969
Total pages 10
Editor Herbert Tabor
Place of publication Bethesda, MD, U.S.A.
Publisher American Society for Biochemistry and Molecular Biology
Language eng
Subject 0601 Biochemistry and Cell Biology
0904 Chemical Engineering
Formatted 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 Ca2+ from the food vacuole may mediate adopted physiological responses. To investigate whether the food vacuole is an intracellular Ca2+ store, which in turn may affect other physiological functions in which this organelle partakes, we have investigated total and exchangeable Ca2+ within the parasite's food vacuole using x-ray microanalysis and quantitative confocal live cell Ca2+ imaging. Apparent free Ca2+ 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 Ca2+ concentrations, we evaluated several Ca2+-sensitive fluorochromes in a live cell confocal setting. We found that the ratiometric Ca2+ 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 Ca2+, disfavoring a role as a major intracellular Ca2+ store.
© 2005 by The American Society for Biochemistry and Molecular Biology, Inc.
Keyword Food vacuole
Malarial parasites
Subcellular compartments
X-ray microanalysis
Q-Index Code C1

Document type: Journal Article
Sub-type: Article (original research)
Collections: Excellence in Research Australia (ERA) - Collection
School of Biomedical Sciences Publications
 
Versions
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 45 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 46 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Wed, 07 Apr 2010, 10:22:09 EST by June Temby on behalf of Faculty of Science