4-aminobutyrate aminotransferase, mitochondrial (ABAT (also GABA-T, GABA transaminase/GABA-AT, GABAT))

4-aminobutyrate aminotransferase, mitochondrial (ABAT), is a pyridoxal 5'-phosphate-dependent enzyme located in the mitochondrial matrix. It catalyzes the conversion of gamma-aminobutyric acid (GABA)—the chief inhibitory neurotransmitter in the central nervous system—into succinic semialdehyde, thereby playing a pivotal role in GABA catabolism and regulation of neuronal excitability. The enzyme is a homodimer and is essential for terminating GABAergic neurotransmission. Deficiency of ABAT leads to severe neurological impairment, while pharmacological inhibition (e.g., by vigabatrin) is a therapeutic strategy for epilepsy and occasionally other neurological conditions. This enzyme is also implicated in the pathogenesis of rare inborn errors of metabolism and may contribute to gastrointestinal disorders such as GERD via altered GABA signaling

Other names

GABA transaminaseGABA-TGABA-ATGABATGamma-amino-N-butyrate transaminase(S)-3-amino-2-methylpropionate transaminaseL-AIBAT

Irreversible inhibition of GABA transaminase (by vigabatrin), leading to increased brain GABA levels and enhanced inhibitory neurotransmission