Glutamate dehydrogenase

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glutamate dehydrogenase 1
Identifiers
Symbol	GLUD1 GLUD
HUGO	4335
Entrez	2746
OMIM	138130
RefSeq	NM_005271
UniProt	P00367
Other data
EC number	1.4.1.3
Locus	Chr. 10 q21.1-24.3

glutamate dehydrogenase 2
Identifiers
Symbol	GLUD2 GLUDP1
HUGO	4336
Entrez	2747
OMIM	300144
RefSeq	NM_012084
UniProt	P49448
Other data
Locus	Chr. X q25

Glutamate dehydrogenase is an enzyme, present in mitochondria of eukaryotes, as are some of the other enzymes required for urea synthesis, that converts glutamate to α-Ketoglutarate, and vice versa. Its cofactor for the glutamate to α-Ketoglutarate reaction, which produces ammonium as a bi-product, is NAD⁺. Its cofactor for the reverse reaction, α-Ketoglutarate to glutamate, is NADP⁺. This reverse reaction uses ammonium to incorporate nitrogen and α-Ketoglutarate into glutamate.

The enzyme represents a key link between catabolic and biosynthetic pathways, and is therefore ubiquitous in both higher and lower organisms.

Ammonia incorporation in animals occurs through the actions of glutamate dehydrogenase and glutamine synthetase. Glutamate plays the central role in mammalian nitrogen flow, serving as both a nitrogen donor and nitrogen acceptor.

In Humans the activity of glutamate dehydrogenase is controlled through ADP-ribosilation, a covalent modification carried out by the gene sirt4. This regulation is relaxed in response to caloric restriction and low blood glucose. Under these curcumstances glutamate dehydrogenase activity is raised to increase the amount of α-Ketoglutarate that is produced. The product α-Ketoglutarate can be used to provide energy by being used in the citric acid cycle.