Phosphoenolpyruvate carboxylase identified as a key enzyme in erythrocytic Plasmodium falciparum carbon metabolism.
Phospoenolpyruvate carboxylase (PEPC) is absent from humans but encoded in the Plasmodium falciparum genome, suggesting that PEPC has a parasite-specific function. To investigate its importance in P. falciparum, we generated a pepc null mutant (D10(Δpepc) ), which was only achievable when malate, a...
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| Language: | English |
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Public Library of Science (PLoS)
2014-01-01
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| Series: | PLoS Pathogens |
| Online Access: | https://doi.org/10.1371/journal.ppat.1003876 |
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| author | Janet Storm Sonal Sethia Gavin J Blackburn Achuthanunni Chokkathukalam David G Watson Rainer Breitling Graham H Coombs Sylke Müller |
| author_facet | Janet Storm Sonal Sethia Gavin J Blackburn Achuthanunni Chokkathukalam David G Watson Rainer Breitling Graham H Coombs Sylke Müller |
| author_sort | Janet Storm |
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| description | Phospoenolpyruvate carboxylase (PEPC) is absent from humans but encoded in the Plasmodium falciparum genome, suggesting that PEPC has a parasite-specific function. To investigate its importance in P. falciparum, we generated a pepc null mutant (D10(Δpepc) ), which was only achievable when malate, a reduction product of oxaloacetate, was added to the growth medium. D10(Δpepc) had a severe growth defect in vitro, which was partially reversed by addition of malate or fumarate, suggesting that pepc may be essential in vivo. Targeted metabolomics using (13)C-U-D-glucose and (13)C-bicarbonate showed that the conversion of glycolytically-derived PEP into malate, fumarate, aspartate and citrate was abolished in D10(Δpepc) and that pentose phosphate pathway metabolites and glycerol 3-phosphate were present at increased levels. In contrast, metabolism of the carbon skeleton of (13)C,(15)N-U-glutamine was similar in both parasite lines, although the flux was lower in D10(Δpepc); it also confirmed the operation of a complete forward TCA cycle in the wild type parasite. Overall, these data confirm the CO2 fixing activity of PEPC and suggest that it provides metabolites essential for TCA cycle anaplerosis and the maintenance of cytosolic and mitochondrial redox balance. Moreover, these findings imply that PEPC may be an exploitable target for future drug discovery. |
| format | Article |
| id | doaj-art-d2a64c2bb86a48999a10a5353d42d4ef |
| institution | Kabale University |
| issn | 1553-7366 1553-7374 |
| language | English |
| publishDate | 2014-01-01 |
| publisher | Public Library of Science (PLoS) |
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| series | PLoS Pathogens |
| spelling | doaj-art-d2a64c2bb86a48999a10a5353d42d4ef2025-08-20T03:46:43ZengPublic Library of Science (PLoS)PLoS Pathogens1553-73661553-73742014-01-01101e100387610.1371/journal.ppat.1003876Phosphoenolpyruvate carboxylase identified as a key enzyme in erythrocytic Plasmodium falciparum carbon metabolism.Janet StormSonal SethiaGavin J BlackburnAchuthanunni ChokkathukalamDavid G WatsonRainer BreitlingGraham H CoombsSylke MüllerPhospoenolpyruvate carboxylase (PEPC) is absent from humans but encoded in the Plasmodium falciparum genome, suggesting that PEPC has a parasite-specific function. To investigate its importance in P. falciparum, we generated a pepc null mutant (D10(Δpepc) ), which was only achievable when malate, a reduction product of oxaloacetate, was added to the growth medium. D10(Δpepc) had a severe growth defect in vitro, which was partially reversed by addition of malate or fumarate, suggesting that pepc may be essential in vivo. Targeted metabolomics using (13)C-U-D-glucose and (13)C-bicarbonate showed that the conversion of glycolytically-derived PEP into malate, fumarate, aspartate and citrate was abolished in D10(Δpepc) and that pentose phosphate pathway metabolites and glycerol 3-phosphate were present at increased levels. In contrast, metabolism of the carbon skeleton of (13)C,(15)N-U-glutamine was similar in both parasite lines, although the flux was lower in D10(Δpepc); it also confirmed the operation of a complete forward TCA cycle in the wild type parasite. Overall, these data confirm the CO2 fixing activity of PEPC and suggest that it provides metabolites essential for TCA cycle anaplerosis and the maintenance of cytosolic and mitochondrial redox balance. Moreover, these findings imply that PEPC may be an exploitable target for future drug discovery.https://doi.org/10.1371/journal.ppat.1003876 |
| spellingShingle | Janet Storm Sonal Sethia Gavin J Blackburn Achuthanunni Chokkathukalam David G Watson Rainer Breitling Graham H Coombs Sylke Müller Phosphoenolpyruvate carboxylase identified as a key enzyme in erythrocytic Plasmodium falciparum carbon metabolism. PLoS Pathogens |
| title | Phosphoenolpyruvate carboxylase identified as a key enzyme in erythrocytic Plasmodium falciparum carbon metabolism. |
| title_full | Phosphoenolpyruvate carboxylase identified as a key enzyme in erythrocytic Plasmodium falciparum carbon metabolism. |
| title_fullStr | Phosphoenolpyruvate carboxylase identified as a key enzyme in erythrocytic Plasmodium falciparum carbon metabolism. |
| title_full_unstemmed | Phosphoenolpyruvate carboxylase identified as a key enzyme in erythrocytic Plasmodium falciparum carbon metabolism. |
| title_short | Phosphoenolpyruvate carboxylase identified as a key enzyme in erythrocytic Plasmodium falciparum carbon metabolism. |
| title_sort | phosphoenolpyruvate carboxylase identified as a key enzyme in erythrocytic plasmodium falciparum carbon metabolism |
| url | https://doi.org/10.1371/journal.ppat.1003876 |
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