Plasmodium falciparum glutamate dehydrogenase a is dispensable and not a drug target during erythrocytic development
Abstract Background Plasmodium falciparum contains three genes encoding potential glutamate dehydrogenases. The protein encoded by gdha has previously been biochemically and structurally characterized. It was suggested that it is important for the supply of reducing equivalents during intra-erythroc...
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ftdoajarticles:oai:doaj.org/article:f2b1264f31a446bf92e1e9d07df55dcb 2023-05-15T15:16:32+02:00 Plasmodium falciparum glutamate dehydrogenase a is dispensable and not a drug target during erythrocytic development Engel Paul C Llinas Manuel Olszewski Kellen Patzewitz Eva-Maria Aparicio Isabela Perner Jan Storm Janet Müller Sylke 2011-07-01T00:00:00Z https://doi.org/10.1186/1475-2875-10-193 https://doaj.org/article/f2b1264f31a446bf92e1e9d07df55dcb EN eng BMC http://www.malariajournal.com/content/10/1/193 https://doaj.org/toc/1475-2875 doi:10.1186/1475-2875-10-193 1475-2875 https://doaj.org/article/f2b1264f31a446bf92e1e9d07df55dcb Malaria Journal, Vol 10, Iss 1, p 193 (2011) Arctic medicine. Tropical medicine RC955-962 Infectious and parasitic diseases RC109-216 article 2011 ftdoajarticles https://doi.org/10.1186/1475-2875-10-193 2022-12-31T11:46:23Z Abstract Background Plasmodium falciparum contains three genes encoding potential glutamate dehydrogenases. The protein encoded by gdha has previously been biochemically and structurally characterized. It was suggested that it is important for the supply of reducing equivalents during intra-erythrocytic development of Plasmodium and, therefore, a suitable drug target. Methods The gene encoding the NADP(H)-dependent GDHa has been disrupted by reverse genetics in P. falciparum and the effect on the antioxidant and metabolic capacities of the resulting mutant parasites was investigated. Results No growth defect under low and elevated oxygen tension, no up- or down-regulation of a number of antioxidant and NADP(H)-generating proteins or mRNAs and no increased levels of GSH were detected in the D10 Δ gdha parasite lines. Further, the fate of the carbon skeleton of [ 13 C] labelled glutamine was assessed by metabolomic studies, revealing no differences in the labelling of α-ketoglutarate and other TCA pathway intermediates between wild type and mutant parasites. Conclusions First, the data support the conclusion that D10 Δ gdha parasites are not experiencing enhanced oxidative stress and that GDHa function may not be the provision of NADP(H) for reductive reactions. Second, the results imply that the cytosolic, NADP(H)-dependent GDHa protein is not involved in the oxidative deamination of glutamate but that the protein may play a role in ammonia assimilation as has been described for other NADP(H)-dependent GDH from plants and fungi. The lack of an obvious phenotype in the absence of GDHa may point to a regulatory role of the protein providing glutamate (as nitrogen storage molecule) in situations where the parasites experience a limiting supply of carbon sources and, therefore, under in vitro conditions the enzyme is unlikely to be of significant importance. The data imply that the protein is not a suitable target for future drug development against intra-erythrocytic parasite development. Article in Journal/Newspaper Arctic Directory of Open Access Journals: DOAJ Articles Arctic Malaria Journal 10 1 193 |
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Directory of Open Access Journals: DOAJ Articles |
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English |
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Arctic medicine. Tropical medicine RC955-962 Infectious and parasitic diseases RC109-216 |
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Arctic medicine. Tropical medicine RC955-962 Infectious and parasitic diseases RC109-216 Engel Paul C Llinas Manuel Olszewski Kellen Patzewitz Eva-Maria Aparicio Isabela Perner Jan Storm Janet Müller Sylke Plasmodium falciparum glutamate dehydrogenase a is dispensable and not a drug target during erythrocytic development |
topic_facet |
Arctic medicine. Tropical medicine RC955-962 Infectious and parasitic diseases RC109-216 |
description |
Abstract Background Plasmodium falciparum contains three genes encoding potential glutamate dehydrogenases. The protein encoded by gdha has previously been biochemically and structurally characterized. It was suggested that it is important for the supply of reducing equivalents during intra-erythrocytic development of Plasmodium and, therefore, a suitable drug target. Methods The gene encoding the NADP(H)-dependent GDHa has been disrupted by reverse genetics in P. falciparum and the effect on the antioxidant and metabolic capacities of the resulting mutant parasites was investigated. Results No growth defect under low and elevated oxygen tension, no up- or down-regulation of a number of antioxidant and NADP(H)-generating proteins or mRNAs and no increased levels of GSH were detected in the D10 Δ gdha parasite lines. Further, the fate of the carbon skeleton of [ 13 C] labelled glutamine was assessed by metabolomic studies, revealing no differences in the labelling of α-ketoglutarate and other TCA pathway intermediates between wild type and mutant parasites. Conclusions First, the data support the conclusion that D10 Δ gdha parasites are not experiencing enhanced oxidative stress and that GDHa function may not be the provision of NADP(H) for reductive reactions. Second, the results imply that the cytosolic, NADP(H)-dependent GDHa protein is not involved in the oxidative deamination of glutamate but that the protein may play a role in ammonia assimilation as has been described for other NADP(H)-dependent GDH from plants and fungi. The lack of an obvious phenotype in the absence of GDHa may point to a regulatory role of the protein providing glutamate (as nitrogen storage molecule) in situations where the parasites experience a limiting supply of carbon sources and, therefore, under in vitro conditions the enzyme is unlikely to be of significant importance. The data imply that the protein is not a suitable target for future drug development against intra-erythrocytic parasite development. |
format |
Article in Journal/Newspaper |
author |
Engel Paul C Llinas Manuel Olszewski Kellen Patzewitz Eva-Maria Aparicio Isabela Perner Jan Storm Janet Müller Sylke |
author_facet |
Engel Paul C Llinas Manuel Olszewski Kellen Patzewitz Eva-Maria Aparicio Isabela Perner Jan Storm Janet Müller Sylke |
author_sort |
Engel Paul C |
title |
Plasmodium falciparum glutamate dehydrogenase a is dispensable and not a drug target during erythrocytic development |
title_short |
Plasmodium falciparum glutamate dehydrogenase a is dispensable and not a drug target during erythrocytic development |
title_full |
Plasmodium falciparum glutamate dehydrogenase a is dispensable and not a drug target during erythrocytic development |
title_fullStr |
Plasmodium falciparum glutamate dehydrogenase a is dispensable and not a drug target during erythrocytic development |
title_full_unstemmed |
Plasmodium falciparum glutamate dehydrogenase a is dispensable and not a drug target during erythrocytic development |
title_sort |
plasmodium falciparum glutamate dehydrogenase a is dispensable and not a drug target during erythrocytic development |
publisher |
BMC |
publishDate |
2011 |
url |
https://doi.org/10.1186/1475-2875-10-193 https://doaj.org/article/f2b1264f31a446bf92e1e9d07df55dcb |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
Malaria Journal, Vol 10, Iss 1, p 193 (2011) |
op_relation |
http://www.malariajournal.com/content/10/1/193 https://doaj.org/toc/1475-2875 doi:10.1186/1475-2875-10-193 1475-2875 https://doaj.org/article/f2b1264f31a446bf92e1e9d07df55dcb |
op_doi |
https://doi.org/10.1186/1475-2875-10-193 |
container_title |
Malaria Journal |
container_volume |
10 |
container_issue |
1 |
container_start_page |
193 |
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1766346837643493376 |