Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.4.1.2 (glutamate dehydrogenase)
 4,380 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In Saccharomyces cerevisiae, the transcription factors Gln3p and Nil1p of the GATA family play a determinant role in expression of genes that are subject to nitrogen catabolite repression. Here we report the isolation of a new yeast mutant, gan1-1, exhibiting dramatically decreased NAD-linked glutamate dehydrogenase (NAD-GDH) and glutamine synthetase (GS) activities. The GAN1 gene was cloned and found to encode a 488-amino-acid polypeptide bearing no typical DNA binding domain. Gan1p is required for full expression of GLN1, GDH2 and also other nitrogen utilization genes, including GAP1, PUT4, MEP2 and GDH1. The extent to which Gan1p is required, however, varies according to the gene and to the nitrogen source available. We show that Gan1p is in fact involved in Gln3p- and Nil1p-dependent transcription. In the case of Gln3p-dependent transcription, the degree to which Gan1p is required appears to be gene specific. The contribution of Gan1p to gene expression is also influenced by the nitrogen status of the cell. We found that GAN1 is identical to ADA1, which encodes a component of the ADA/GCN5 co-activator complex. Ada1/Gan1p thus represents the first reported case of an accessory protein (a co-activator) linking the GATA-binding proteins Gln3p and Nil1p, mediating nitrogen-regulated transcription, to the basal transcription machinery.
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PMID:A co-activator of nitrogen-regulated transcription in Saccharomyces cerevisiae. 1004 20

In the yeast Saccharomyces cerevisiae, two NADP(+)-dependent glutamate dehydrogenase isoenzymes encoded by GDH1 and GDH3 catalyze the synthesis of glutamate from ammonium and alpha-ketoglutarate. In this work we analyzed GDH1 transcriptional regulation, in order to deepen the studies in regard to its physiological role. Our results indicate that: (i) GDH1 expression is strictly controlled in ethanol-grown cultures, constituting a fine-tuning mechanism that modulates the abundance of Gdh1p monomers under this condition, (ii) GDH1 expression is controlled by transcriptional activators that have been considered as exclusive of either nitrogen (Gln3p and Gcn4p) or carbon metabolism (HAP complex), and (iii) chromatin remodeling complexes play a role in GDH1 expression; ADA2 and ADA3 up-regulated GDH1 expression on ethanol, while that on glucose was ADA3-dependent. SPT3 and SNF2 activated GDH1 expression on either carbon source whereas GCN5 played no role in any condition tested. The above described combinatorial control results in a refined mechanism that coordinates carbon and nitrogen utilization.
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PMID:GDH1 expression is regulated by GLN3, GCN4, and HAP4 under respiratory growth. 1205 66