Physiological functions of pyruvate:NADP+ oxidoreductase and 2-oxoglutarate decarboxylase in Euglena gracilis under aerobic and anaerobic conditions
| Autor: | Ryuta Hayashi, Mitsuhiro Ueda, Shigeo Takenaka, Yoshihisa Nakano, Tatsuji Sakamoto, Hiroshi Inui, Takahiro Ishikawa, Kazutaka Miyatake, Masami Nakazawa |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Pyruvate decarboxylation Pyruvate dehydrogenase kinase Organic Chemistry General Medicine Pyruvate dehydrogenase phosphatase Biology Pyruvate dehydrogenase complex Applied Microbiology and Biotechnology Biochemistry Analytical Chemistry Pyruvate carboxylase Citric acid cycle 03 medical and health sciences 030104 developmental biology Dihydrolipoyl transacetylase Oxoglutarate dehydrogenase complex Molecular Biology Biotechnology |
| Zdroj: | Bioscience, Biotechnology, and Biochemistry. 81:1386-1393 |
| ISSN: | 1347-6947 0916-8451 |
| Popis: | In Euglena gracilis, pyruvate:NADP+ oxidoreductase, in addition to the pyruvate dehydrogenase complex, functions for the oxidative decarboxylation of pyruvate in the mitochondria. Furthermore, the 2-oxoglutarate dehydrogenase complex is absent, and instead 2-oxoglutarate decarboxylase is found in the mitochondria. To elucidate the central carbon and energy metabolisms in Euglena under aerobic and anaerobic conditions, physiological significances of these enzymes involved in 2-oxoacid metabolism were examined by gene silencing experiments. The pyruvate dehydrogenase complex was indispensable for aerobic cell growth in a glucose medium, although its activity was less than 1% of that of pyruvate:NADP+ oxidoreductase. In contrast, pyruvate:NADP+ oxidoreductase was only involved in the anaerobic energy metabolism (wax ester fermentation). Aerobic cell growth was almost completely suppressed when the 2-oxoglutarate decarboxylase gene was silenced, suggesting that the tricarboxylic acid cycle is modified in Euglena and 2-oxoglutarate decarboxylase takes the place of the 2-oxoglutarate dehydrogenase complex in the aerobic respiratory metabolism. |
| Databáze: | OpenAIRE |
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