Identification of ADP-ribosylation site in human glutamate dehydrogenase isozymes.

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Citation

Choi MM, Huh JW, Yang SJ, Cho EH, Choi SY, Cho SW

Identification of ADP-ribosylation site in human glutamate dehydrogenase isozymes.

FEBS Lett. 2005 Aug 1;579(19):4125-30.

PubMed ID
16023112 [ View in PubMed
]
Abstract

When the influence of ADP-ribosylation on the activities of the purified human glutamate dehydrogenase isozymes (hGDH1 and hGDH2) was measured in the presence of 100 microM NAD+ for 60 min, hGDH isozymes were inhibited by up to 75%. If incubations were performed for longer time periods up to 3 h, the inhibition of hGDH isozymes did not increased further. This phenomenon may be related to the reversibility of ADP-ribosylation in mitochondria. ADP-ribosylated hDGH isozymes were reactivated by Mg2+-dependent mitochondrial ADP-ribosylcysteine hydrolase. The stoichiometry between incorporated ADP-ribose and GDH subunits shows a modification of one subunit per catalytically active homohexamer. Since ADP and GTP had no effects on the extent of modification, it would appear that the ADP-ribosylation is unlikely to occur in allosteric sites. It has been proposed that Cys residue may be involved in the ADP-ribosylation of GDH, although identification of the reactive Cys residue has not been reported. To identify the reactive Cys residue involved in the ADP-ribosylation, we performed cassette mutagenesis at three different positions (Cys59, Cys119, and Cys274) using synthetic genes of hGDH isozymes. Among the Cys residues tested, only Cys119 mutants showed a significant reduction in the ADP-ribosylation. These results suggest a possibility that the Cys119 residue has an important role in the regulation of hGDH isozymes by ADP-ribosylation.

DrugBank Data that Cites this Article

Polypeptides
NameUniProt ID
Glutamate dehydrogenase 1, mitochondrialP00367Details
Glutamate dehydrogenase 2, mitochondrialP49448Details