Ιδρυματικό Αποθετήριο
Πολυτεχνείο Κρήτης
Πολυτεχνείο Κρήτης
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| URI | http://purl.tuc.gr/dl/dias/1F7862E7-6408-4140-923D-A7BF35A23260 | - |
| Αναγνωριστικό | https://doi.org/10.1104/pp.107.107813 | - |
| Γλώσσα | en | - |
| Τίτλος | The isoenzyme seven of tobacco NAD(H)- dependent glutamate dehydrogenase exhibits high deaminating and low aminating activities in vivo | en |
| Δημιουργός | Paranychianakis Nikolaos | en |
| Δημιουργός | Παρανυχιανακης Νικολαος | el |
| Δημιουργός | Damianos S. Skopelitis | en |
| Δημιουργός | Antonios Kouvarakis | en |
| Δημιουργός | Apostolis Spyros | en |
| Δημιουργός | Kalliopi A. Roubelakis-Angelakis | en |
| Δημιουργός | Euripides G. Stephanou | en |
| Εκδότης | American Society of Plant Biologists | en |
| Περίληψη | Following the discovery of glutamine synthetase/glutamate (Glu) synthase, the physiological roles of Glu dehydrogenase (GDH) in nitrogen metabolism in plants remain obscure and is the subject of considerable controversy. Recently, transgenics were used to overexpress the gene encoding for the β-subunit polypeptide of GDH, resulting in the GDH-isoenzyme 1 deaminating in vivo Glu. In this work, we present transgenic tobacco (Nicotiana tabacum) plants overexpressing the plant gdh gene encoding for the α-subunit polypeptide of GDH. The levels of transcript correlated well with the levels of total GDH protein, the α-subunit polypeptide, and the abundance of GDH-anionic isoenzymes. Assays of transgenic plant extracts revealed high in vitro aminating and low deaminating activities. However, gas chromatography/mass spectrometry analysis of the metabolic fate of 15NH4 or [15N]Glu revealed that GDH-isoenzyme 7 mostly deaminates Glu and also exhibits low ammonium assimilating activity. These and previous results firmly establish the direction of the reactions catalyzed by the anionic and cationic isoenzymes of GDH in vivo under normal growth conditions and reveal a paradox between the in vitro and in vivo enzyme activities. | el |
| Τύπος | Peer-Reviewed Journal Publication | en |
| Τύπος | Δημοσίευση σε Περιοδικό με Κριτές | el |
| Άδεια Χρήσης | http://creativecommons.org/licenses/by/4.0/ | en |
| Ημερομηνία | 2015-10-23 | - |
| Ημερομηνία Δημοσίευσης | 2015 | - |
| Βιβλιογραφική Αναφορά | . Skopelitis, D.S., Paranychianakis, N.V., Spyros, A., Kouvarakis, A., Stephanou, E., Roubelakis-Angelakis, K.A., "The isoenzyme seven of tobacco NAD(H)- dependent glutamate dehydrogenase exhibits high deaminating and low aminating activities in vivo", Plant Physiology, Vol. 145, no. 4, pp. 1726-1734, Dec. 2007, doi: 10.1104/pp.107.107813 | en |
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