PfCHA is a mitochondrial divalent cation/H+ antiporter in Plasmodium falciparum
The human malaria parasite Plasmodium falciparum is capable of adapting to vastly different extracellular Ca2+ environments while maintaining tight control of its intracellular Ca2+ concentration. The mechanisms underpinning Ca2+ homeostasis in this important pathogen are only partly understood. Her...
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| Main Authors: | , , , , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
14 May 2010
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| In: |
Molecular microbiology
Year: 2010, Volume: 76, Issue: 6, Pages: 1591-1606 |
| ISSN: | 1365-2958 |
| DOI: | 10.1111/j.1365-2958.2010.07187.x |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1111/j.1365-2958.2010.07187.x Verlag, lizenzpflichtig, Volltext: https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2958.2010.07187.x 
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| Author Notes: | Alexander Rotmann, Cecilia Sanchez, Armand Guiguemde, Petra Rohrbach, Anurag Dave, Naziha Bakouh, Gabrielle Planelles and Michael Lanzer |
| Summary: | The human malaria parasite Plasmodium falciparum is capable of adapting to vastly different extracellular Ca2+ environments while maintaining tight control of its intracellular Ca2+ concentration. The mechanisms underpinning Ca2+ homeostasis in this important pathogen are only partly understood. Here we have functionally expressed the putative Ca2+/H+ antiporter PfCHA in Xenopus laevis oocytes. Our data suggest that PfCHA mediates H+-coupled Ca2+ and Mn2+ exchange. The apparent dissociation constant KM for Ca2+ of 2.2 ± 0.7 mM and the maximal velocity Vmax of 0.6 ± 0.1 nmol per oocyte per hour are consistent with PfCHA being a low-affinity high-capacity Ca2+ carrier. In the parasite, PfCHA was found to localize to the mitochondrion. Physiological studies conducted with live parasitized erythrocytes, and using Fluo-4 and Rhod-2 to monitor cytoplasmic and mitochondrial Ca2+ dynamics, suggest that the mitochondrion serves as a dynamic Ca2+ store and that PfCHA functions as a Ca2+ efflux system expelling excess Ca2+ from the mitochondrion. PfCHA lacks appreciable homologies to the human mitochondrial Ca2+/H+ exchanger and might represent an evolutionary divergent class of mitochondrial cation antiporter, which, in turn, might provide novel opportunities for intervention. |
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| Item Description: | Gesehen am 21.06.2023 |
| Physical Description: | Online Resource |
| ISSN: | 1365-2958 |
| DOI: | 10.1111/j.1365-2958.2010.07187.x |