Glutamate decarboxylase

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Glutamic acid decarboxylase 1
Identifiers
Symbol	GAD1 GLUTAMATE DECARBOXYLASE, BRAIN, 67-KD; GAD67
HUGO	4092
Entrez	2571
OMIM	605363
UniProt	Q99259
Other data
EC number	4.1.1.15
Locus	Chr. 2 q31

glutamic acid decarboxylase 2
Identifiers
Symbol	GAD2
HUGO	11284
Entrez	2572
OMIM	4093
UniProt	Q05329
PDB	1ES0
Other data
EC number	4.1.1.15
Locus	Chr. 10 p11.23

Glutamate decarboxylase (GAD) is an enzyme that catalyzes the decarboxylation of glutamate to GABA and CO₂. GAD uses PLP as a cofactor. The reaction goes as follows:

HOOC-CH₂-CH₂-CH(NH₂)-COOH → CO₂ + HOOC-CH₂-CH₂-CH₂NH₂

In mammals, GAD exists in two isoforms encoded by two different genes - Gad1 and Gad2. These isoforms are GAD₆₇ and GAD₆₅ with molecular weights of 67 and 65 kDa, respectively.^[1] GAD1 and GAD2 are expressed in the brain where GABA is used as a neurotransmitter, GAD2 is also expressed in the pancreas.

1 Role in pathology
- 1.1 Diabetes
- 1.2 Schizophrenia and Bipolar disorder
2 References

[edit] Role in pathology

[edit] Diabetes

Both GAD₆₇ and GAD₆₅ are targets of autoantibodies in people who later develop insulin-dependent diabetes mellitus ^[2] ^{FT, FT}.

[edit] Schizophrenia and Bipolar disorder

Substantial dysregulation of GAD mRNA expression is observed in schizophrenia and bipolar disorder.^[3]

[edit] References

^ Erlander MG, Tillakaratne NJK, Feldblum S, Patel N, Tobin AJ (1991) Two genes encode distinct glutamate decarboxylases. Neuron 7:91-100. PMID 2069816
^ Baekkeskov S, Aanstoot HJ, Christgau S, Reetz A, Solimena M, Cascalho M, Folli F, Richter-Olesen H, De Camilli P. (1990) Identification of the 64K autoantigen in insulin-dependent diabetes as the GABA-synthesizing enzyme glutamic acid decarboxylase. Nature. 347(6289):151-6. PMID 1697648
^ Woo TU, Walsh JP, Benes FM. (2004) Arch Gen Psychiatry. 61(7):649-57. Density of glutamic acid decarboxylase 67 messenger RNA-containing neurons that express the N-methyl-D-aspartate receptor subunit NR2A in the anterior cingulate cortex in schizophrenia and bipolar disorder. PMID 15237077