protein
4-aminobutyrate aminotransferase, mitochondrial
Gene
ABAT
Organism
Homo sapiens(9606)
Length
500 aa
Mass
56,439 Da
ABAT (4-aminobutyrate aminotransferase, mitochondrial) is a mitochondrial enzyme that catalyzes the conversion of gamma-aminobutyrate and L-beta-aminoisobutyrate to their respective semialdehyde products, including succinate semialdehyde. This transamination reaction is central to GABA catabolism and the conversion of non-protein amino acids (UniProt: P80404).
Loss-of-function mutations in ABAT cause GABA-transaminase deficiency (GABATD, MIM 613163), a rare autosomal recessive disorder characterized by psychomotor retardation, hypotonia, seizures, and EEG abnormalities. The enzyme's role in GABA metabolism positions it at the intersection of neurotransmitter homeostasis and energy metabolism (UniProt: P80404).
ABAT is upregulated in Alzheimer's disease brain tissue. Analysis of post-mortem AD brain relative to age-matched controls by TMT-labeled proteomics across four subcellular fractions showed ABAT elevation with a mean log2 fold-change of +0.32 (Chaparral AD proteomics). This upregulation suggests altered GABAergic signaling or metabolic compensation in the AD brain, though the functional consequence remains to be determined.
Generated from the curated entity record below. May contain errors — verify against source links.
Proteomics Evidence · AD
↑ Up in ADP3
not detected
P2
not detected
S2
not detected
S3
+0.322
Mean log₂FC across detected fractions: +0.3219 (1 of 4 fractions detected)
Human post-mortem AD brain vs age-matched controls, TMT-labeled, 4 subcellular fractions (P2, P3, S2, S3), DDA proteomics.
Related Publications
Browse all →Tau molecular diversity contributes to clinical heterogeneity in Alzheimer's disease.
Dujardin Simon et al.Nature medicine2020PMID 32572268Deep Multilayer Brain Proteomics Identifies Molecular Networks in Alzheimer's Disease Progression.
Bai Bing et al.Neuron2020PMID 31926610A Multi-network Approach Identifies Protein-Specific Co-expression in Asymptomatic and Symptomatic Alzheimer's Disease.
Seyfried Nicholas T et al.Cell systems2017PMID 27989508Large-scale deep multi-layer analysis of Alzheimer's disease brain reveals strong proteomic disease-related changes not observed at the RNA level.
Johnson Erik C B et al.Nature neuroscience2022PMID 35115731Organization and regulation of gene transcription.
Cramer PatrickNature2019PMID 31462772
Function
Catalyzes the conversion of gamma-aminobutyrate and L-beta-aminoisobutyrate to succinate semialdehyde and methylmalonate semialdehyde, respectively (PubMed:10407778, PubMed:15528998). Can also convert delta-aminovalerate and beta-alanine (By similarity)
Disease associations
GABA-transaminase deficiencyGABATD
An enzymatic deficiency resulting in psychomotor retardation, hypotonia, hyperreflexia, lethargy, refractory seizures, and EEG abnormalities. GABATD inheritance is autosomal recessive.
Sources
Last updated 5/8/2026, 6:39:48 AM