The complex allosteric and redox regulation of the fumarate hydratase and malate dehydratase reactions of Arabidopsis thaliana Fumarase 1 and 2 gives clues for understanding the massive accumulation of fumarate
Arabidopsis thaliana possesses two fumarase genes (FUM), AtFUM1 (At2g47510) encoding for the mitochondrial Krebs cycle-associated enzyme and AtFUM2 (At5g50950) for the cytosolic isoform required for fumarate massive accumulation. Here, the comprehensive biochemical studies of AtFUM1 and AtFUM2 shows...
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2018
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_1742464X_v285_n12_p2205_Zubimendi http://hdl.handle.net/20.500.12110/paper_1742464X_v285_n12_p2205_Zubimendi |
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paper:paper_1742464X_v285_n12_p2205_Zubimendi2023-06-08T16:27:05Z The complex allosteric and redox regulation of the fumarate hydratase and malate dehydratase reactions of Arabidopsis thaliana Fumarase 1 and 2 gives clues for understanding the massive accumulation of fumarate allosteric and redox regulation Arabidopsis enzyme kinetics fumarase paralogous genes asparagine fumarate hydratase glutamine hydrolyase malic acid derivative oxaloacetic acid protein aggregate allosterism Arabidopsis thaliana bioaccumulation controlled study Editorial enzyme activity enzyme analysis enzyme kinetics mass spectrometry nonhuman oxidation reduction reaction pH phylogeny phytochemistry plant cell priority journal protein function Arabidopsis thaliana possesses two fumarase genes (FUM), AtFUM1 (At2g47510) encoding for the mitochondrial Krebs cycle-associated enzyme and AtFUM2 (At5g50950) for the cytosolic isoform required for fumarate massive accumulation. Here, the comprehensive biochemical studies of AtFUM1 and AtFUM2 shows that they are active enzymes with similar kinetic parameters but differential regulation. For both enzymes, fumarate hydratase (FH) activity is favored over the malate dehydratase (MD) activity; however, MD is the most regulated activity with several allosteric activators. Oxalacetate, glutamine, and/or asparagine are modulators causing the MD reaction to become preferred over the FH reaction. Activity profiles as a function of pH suggest a suboptimal FUM activity in Arabidopsis cells; moreover, the direction of the FUM reaction is sensitive to pH changes. Under mild oxidation conditions, AtFUMs form high mass molecular aggregates, which present both FUM activities decreased to a different extent. The biochemical properties of oxidized AtFUMs (oxAtFUMs) were completely reversed by NADPH-supplied Arabidopsis leaf extracts, suggesting that the AtFUMs redox regulation can be accomplished in vivo. Mass spectrometry analyses indicate the presence of an active site-associated intermolecular disulfide bridge in oxAtFUMs. Finally, a phylogenetic approach points out that other plant species may also possess cytosolic FUM2 enzymes mainly encoded by paralogous genes, indicating that the evolutionary history of this trait has been drawn through a process of parallel evolution. Overall, according to our results, a multilevel regulatory pattern of FUM activities emerges, supporting the role of this enzyme as a carbon flow monitoring point through the organic acid metabolism in plants. © 2018 Federation of European Biochemical Societies 2018 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_1742464X_v285_n12_p2205_Zubimendi http://hdl.handle.net/20.500.12110/paper_1742464X_v285_n12_p2205_Zubimendi |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
allosteric and redox regulation Arabidopsis enzyme kinetics fumarase paralogous genes asparagine fumarate hydratase glutamine hydrolyase malic acid derivative oxaloacetic acid protein aggregate allosterism Arabidopsis thaliana bioaccumulation controlled study Editorial enzyme activity enzyme analysis enzyme kinetics mass spectrometry nonhuman oxidation reduction reaction pH phylogeny phytochemistry plant cell priority journal protein function |
| spellingShingle |
allosteric and redox regulation Arabidopsis enzyme kinetics fumarase paralogous genes asparagine fumarate hydratase glutamine hydrolyase malic acid derivative oxaloacetic acid protein aggregate allosterism Arabidopsis thaliana bioaccumulation controlled study Editorial enzyme activity enzyme analysis enzyme kinetics mass spectrometry nonhuman oxidation reduction reaction pH phylogeny phytochemistry plant cell priority journal protein function The complex allosteric and redox regulation of the fumarate hydratase and malate dehydratase reactions of Arabidopsis thaliana Fumarase 1 and 2 gives clues for understanding the massive accumulation of fumarate |
| topic_facet |
allosteric and redox regulation Arabidopsis enzyme kinetics fumarase paralogous genes asparagine fumarate hydratase glutamine hydrolyase malic acid derivative oxaloacetic acid protein aggregate allosterism Arabidopsis thaliana bioaccumulation controlled study Editorial enzyme activity enzyme analysis enzyme kinetics mass spectrometry nonhuman oxidation reduction reaction pH phylogeny phytochemistry plant cell priority journal protein function |
| description |
Arabidopsis thaliana possesses two fumarase genes (FUM), AtFUM1 (At2g47510) encoding for the mitochondrial Krebs cycle-associated enzyme and AtFUM2 (At5g50950) for the cytosolic isoform required for fumarate massive accumulation. Here, the comprehensive biochemical studies of AtFUM1 and AtFUM2 shows that they are active enzymes with similar kinetic parameters but differential regulation. For both enzymes, fumarate hydratase (FH) activity is favored over the malate dehydratase (MD) activity; however, MD is the most regulated activity with several allosteric activators. Oxalacetate, glutamine, and/or asparagine are modulators causing the MD reaction to become preferred over the FH reaction. Activity profiles as a function of pH suggest a suboptimal FUM activity in Arabidopsis cells; moreover, the direction of the FUM reaction is sensitive to pH changes. Under mild oxidation conditions, AtFUMs form high mass molecular aggregates, which present both FUM activities decreased to a different extent. The biochemical properties of oxidized AtFUMs (oxAtFUMs) were completely reversed by NADPH-supplied Arabidopsis leaf extracts, suggesting that the AtFUMs redox regulation can be accomplished in vivo. Mass spectrometry analyses indicate the presence of an active site-associated intermolecular disulfide bridge in oxAtFUMs. Finally, a phylogenetic approach points out that other plant species may also possess cytosolic FUM2 enzymes mainly encoded by paralogous genes, indicating that the evolutionary history of this trait has been drawn through a process of parallel evolution. Overall, according to our results, a multilevel regulatory pattern of FUM activities emerges, supporting the role of this enzyme as a carbon flow monitoring point through the organic acid metabolism in plants. © 2018 Federation of European Biochemical Societies |
| title |
The complex allosteric and redox regulation of the fumarate hydratase and malate dehydratase reactions of Arabidopsis thaliana Fumarase 1 and 2 gives clues for understanding the massive accumulation of fumarate |
| title_short |
The complex allosteric and redox regulation of the fumarate hydratase and malate dehydratase reactions of Arabidopsis thaliana Fumarase 1 and 2 gives clues for understanding the massive accumulation of fumarate |
| title_full |
The complex allosteric and redox regulation of the fumarate hydratase and malate dehydratase reactions of Arabidopsis thaliana Fumarase 1 and 2 gives clues for understanding the massive accumulation of fumarate |
| title_fullStr |
The complex allosteric and redox regulation of the fumarate hydratase and malate dehydratase reactions of Arabidopsis thaliana Fumarase 1 and 2 gives clues for understanding the massive accumulation of fumarate |
| title_full_unstemmed |
The complex allosteric and redox regulation of the fumarate hydratase and malate dehydratase reactions of Arabidopsis thaliana Fumarase 1 and 2 gives clues for understanding the massive accumulation of fumarate |
| title_sort |
complex allosteric and redox regulation of the fumarate hydratase and malate dehydratase reactions of arabidopsis thaliana fumarase 1 and 2 gives clues for understanding the massive accumulation of fumarate |
| publishDate |
2018 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_1742464X_v285_n12_p2205_Zubimendi http://hdl.handle.net/20.500.12110/paper_1742464X_v285_n12_p2205_Zubimendi |
| _version_ |
1768542664493367296 |