Glutamate biosynthesis superpathway (WP191)

Saccharomyces cerevisiae

Yeast cells contain 3 pathways for the synthesis of glutamate. Two pathways are mediated by two isoforms of glutamate dehydrogenase, encoded by GDH1 and GDH3 (CITS: [2989290])(CITS: [9287019]). The third pathway is driven by the combined activities of glutamine synthetase and glutamate synthase, encoded by GLN1 and GLT1, respectively (CITS: [2570348])(CITS: [8923741]). Studies of GDH1 and GDH3 regulation indicate that the cell uses these isoforms under different growth conditions (CITS: [11562373]). Expression of GDH3 is induced by ethanol and repressed by glucose, whereas GDH1 expression is high in either carbon source. Gdh1p uses alpha-ketoglutarate at a higher rate than Gdh3p. Thus, under fermentative growth conditions, Gdh1p drives glutamate biosynthesis, whereas in nonfermentable or limiting carbon sources, Gdh3p is the key isoform involved in balancing distribution of alpha-ketoglutarate to glutamate biosynthesis and energy metabolism. SOURCE: SGD pathways,


Meredith Braymer , Daniela Digles , Egon Willighagen , Martina Summer-Kutmon , and Eric Weitz


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Saccharomyces cerevisiae



Pathway Ontology

glutamic acid/glutamate biosynthetic pathway


Label Type Compact URI Comment
ATP Metabolite cas:1927-31-7
NADPH Metabolite cas:53-57-6
2 L-glutamate Metabolite cas:56-86-0
phosphate Metabolite cas:14265-44-2
NADH Metabolite cas:53-84-9
ADP Metabolite cas:58-64-0
NADPH Metabolite cas:53-57-6
L-glutamine Metabolite cas:56-85-9
L-glutamate Metabolite cas:56-86-0
IDP3 GeneProduct sgd:S000004954
IDP2 GeneProduct sgd:S000004164
GDH3 GeneProduct sgd:S000000058
GLT1 GeneProduct sgd:S000002330
GLN1 GeneProduct sgd:S000006239
IDP1 GeneProduct sgd:S000002224
GDH1 GeneProduct sgd:S000005902


  1. Expression and gene disruption analysis of the isocitrate dehydrogenase family in yeast. Zhao WN, McAlister-Henn L. Biochemistry. 1996 Jun 18;35(24):7873–8. PubMed Europe PMC Scholia