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Physiological Regulation of Isocitrate Dehydrogenase and the Role of 2-Oxoglutarate in Prochlorococcus sp. Strain PCC 9511

The enzyme isocitrate dehydrogenase (ICDH; EC 1.1.1.42) catalyzes the oxidative decarboxylation of isocitrate, to produce 2-oxoglutarate. The incompleteness of the tricarboxylic acids cycle in marine cyanobacteria confers a special importance to isocitrate dehydrogenase in the C/N balance, since 2-o...

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Autores principales: Domínguez-Martín, María Agustina, López-Lozano, Antonio, Diez, Jesús, Gómez-Baena, Guadalupe, Rangel-Zúñiga, Oriol Alberto, García-Fernández, José Manuel
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4111581/
https://www.ncbi.nlm.nih.gov/pubmed/25061751
http://dx.doi.org/10.1371/journal.pone.0103380
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author Domínguez-Martín, María Agustina
López-Lozano, Antonio
Diez, Jesús
Gómez-Baena, Guadalupe
Rangel-Zúñiga, Oriol Alberto
García-Fernández, José Manuel
author_facet Domínguez-Martín, María Agustina
López-Lozano, Antonio
Diez, Jesús
Gómez-Baena, Guadalupe
Rangel-Zúñiga, Oriol Alberto
García-Fernández, José Manuel
author_sort Domínguez-Martín, María Agustina
collection PubMed
description The enzyme isocitrate dehydrogenase (ICDH; EC 1.1.1.42) catalyzes the oxidative decarboxylation of isocitrate, to produce 2-oxoglutarate. The incompleteness of the tricarboxylic acids cycle in marine cyanobacteria confers a special importance to isocitrate dehydrogenase in the C/N balance, since 2-oxoglutarate can only be metabolized through the glutamine synthetase/glutamate synthase pathway. The physiological regulation of isocitrate dehydrogenase was studied in cultures of Prochlorococcus sp. strain PCC 9511, by measuring enzyme activity and concentration using the NADPH production assay and Western blotting, respectively. The enzyme activity showed little changes under nitrogen or phosphorus starvation, or upon addition of the inhibitors DCMU, DBMIB and MSX. Azaserine, an inhibitor of glutamate synthase, induced clear increases in the isocitrate dehydrogenase activity and icd gene expression after 24 h, and also in the 2-oxoglutarate concentration. Iron starvation had the most significant effect, inducing a complete loss of isocitrate dehydrogenase activity, possibly mediated by a process of oxidative inactivation, while its concentration was unaffected. Our results suggest that isocitrate dehydrogenase responds to changes in the intracellular concentration of 2-oxoglutarate and to the redox status of the cells in Prochlorococcus.
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spelling pubmed-41115812014-07-29 Physiological Regulation of Isocitrate Dehydrogenase and the Role of 2-Oxoglutarate in Prochlorococcus sp. Strain PCC 9511 Domínguez-Martín, María Agustina López-Lozano, Antonio Diez, Jesús Gómez-Baena, Guadalupe Rangel-Zúñiga, Oriol Alberto García-Fernández, José Manuel PLoS One Research Article The enzyme isocitrate dehydrogenase (ICDH; EC 1.1.1.42) catalyzes the oxidative decarboxylation of isocitrate, to produce 2-oxoglutarate. The incompleteness of the tricarboxylic acids cycle in marine cyanobacteria confers a special importance to isocitrate dehydrogenase in the C/N balance, since 2-oxoglutarate can only be metabolized through the glutamine synthetase/glutamate synthase pathway. The physiological regulation of isocitrate dehydrogenase was studied in cultures of Prochlorococcus sp. strain PCC 9511, by measuring enzyme activity and concentration using the NADPH production assay and Western blotting, respectively. The enzyme activity showed little changes under nitrogen or phosphorus starvation, or upon addition of the inhibitors DCMU, DBMIB and MSX. Azaserine, an inhibitor of glutamate synthase, induced clear increases in the isocitrate dehydrogenase activity and icd gene expression after 24 h, and also in the 2-oxoglutarate concentration. Iron starvation had the most significant effect, inducing a complete loss of isocitrate dehydrogenase activity, possibly mediated by a process of oxidative inactivation, while its concentration was unaffected. Our results suggest that isocitrate dehydrogenase responds to changes in the intracellular concentration of 2-oxoglutarate and to the redox status of the cells in Prochlorococcus. Public Library of Science 2014-07-25 /pmc/articles/PMC4111581/ /pubmed/25061751 http://dx.doi.org/10.1371/journal.pone.0103380 Text en © 2014 Domínguez-Martín et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Domínguez-Martín, María Agustina
López-Lozano, Antonio
Diez, Jesús
Gómez-Baena, Guadalupe
Rangel-Zúñiga, Oriol Alberto
García-Fernández, José Manuel
Physiological Regulation of Isocitrate Dehydrogenase and the Role of 2-Oxoglutarate in Prochlorococcus sp. Strain PCC 9511
title Physiological Regulation of Isocitrate Dehydrogenase and the Role of 2-Oxoglutarate in Prochlorococcus sp. Strain PCC 9511
title_full Physiological Regulation of Isocitrate Dehydrogenase and the Role of 2-Oxoglutarate in Prochlorococcus sp. Strain PCC 9511
title_fullStr Physiological Regulation of Isocitrate Dehydrogenase and the Role of 2-Oxoglutarate in Prochlorococcus sp. Strain PCC 9511
title_full_unstemmed Physiological Regulation of Isocitrate Dehydrogenase and the Role of 2-Oxoglutarate in Prochlorococcus sp. Strain PCC 9511
title_short Physiological Regulation of Isocitrate Dehydrogenase and the Role of 2-Oxoglutarate in Prochlorococcus sp. Strain PCC 9511
title_sort physiological regulation of isocitrate dehydrogenase and the role of 2-oxoglutarate in prochlorococcus sp. strain pcc 9511
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4111581/
https://www.ncbi.nlm.nih.gov/pubmed/25061751
http://dx.doi.org/10.1371/journal.pone.0103380
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