GOT2 Gene

GOT2 Gene — Mitochondrial Aspartate Aminotransferase

Overview

GOT2 (Glutamic-Oxaloacetic Transaminase 2), also known as mitochondrial aspartate aminotransferase (mAST), is a critical mitochondrial enzyme that catalyzes the reversible transamination between aspartate and alpha-ketoglutarate to form glutamate and oxaloacetate. This reaction is central to multiple metabolic pathways including the [malate-aspartate shuttle](/mechanisms/malate-aspartate-shuttle), amino acid metabolism, and the urea cycle. In neurons, GOT2 plays an essential role in maintaining [mitochondrial function](/mechanisms/mitochondrial-dysfunction) and protecting against [oxidative stress](/mechanisms/oxidative-stress)—two processes fundamental to [Alzheimer's disease](/diseases/alzheimers-disease) and [Parkinson's disease](/diseases/parkinsons-disease) pathogenesis.

GOT2 Gene — Mitochondrial Aspartate Aminotransferase

Overview

GOT2 (Glutamic-Oxaloacetic Transaminase 2), also known as mitochondrial aspartate aminotransferase (mAST), is a critical mitochondrial enzyme that catalyzes the reversible transamination between aspartate and alpha-ketoglutarate to form glutamate and oxaloacetate. This reaction is central to multiple metabolic pathways including the [malate-aspartate shuttle](/mechanisms/malate-aspartate-shuttle), amino acid metabolism, and the urea cycle. In neurons, GOT2 plays an essential role in maintaining [mitochondrial function](/mechanisms/mitochondrial-dysfunction) and protecting against [oxidative stress](/mechanisms/oxidative-stress)—two processes fundamental to [Alzheimer's disease](/diseases/alzheimers-disease) and [Parkinson's disease](/diseases/parkinsons-disease) pathogenesis.

<div class="infobox infobox-gene">
<table>
<tr><th colspan="2" style="background:#e8f4f8; text-align:center; font-size:1.1em;">GOT2 Gene</th></tr>
<tr><td><strong>Gene Symbol</strong></td><td>GOT2</td></tr>
<tr><td><strong>Full Name</strong></td><td>Glutamic-Oxaloacetic Transaminase 2</td></tr>
<tr><td><strong>Chromosomal Location</strong></td><td>16q21</td></tr>
<tr><td><strong>NCBI Gene ID</strong></td><td>[2805](https://www.ncbi.nlm.nih.gov/gene/2805)</td></tr>
<tr><td><strong>OMIM</strong></td><td>[138150](https://www.omim.org/entry/138150)</td></tr>
<tr><td><strong>Ensembl ID</strong></td><td>ENSG00000125107</td></tr>
<tr><td><strong>UniProt ID</strong></td><td>[P07148](https://www.uniprot.org/uniprot/P07148)</td></tr>
<tr><td><strong>Associated Diseases</strong></td><td>[Alzheimer's Disease](/diseases/alzheimers-disease), [Parkinson's Disease](/diseases/parkinsons-disease), Stroke, Metabolic Disorders</td></tr>
</table>
</div>

Function

Enzymatic Activity

GOT2 is a pyridoxal phosphate (PLP)-dependent enzyme localized to the mitochondrial matrix. It catalyzes:

Aspartate + α-Ketoglutarate ⇌ Oxaloacetate + Glutamate

This reversible reaction allows the interconversion of:

• Amino group transfer: Nitrogen trafficking between amino acids
• Carbon skeleton metabolism: Linking glycolysis to the TCA cycle

Metabolic Pathways

| Pathway | Role of GOT2 |
|---------|--------------|
| Malate-Aspartate Shuttle | Primary transporter of reducing equivalents (NADH) from cytosol to mitochondria |
| TCA Cycle | Generates oxaloacetate for citrate synthesis |
| Urea Cycle | Produces aspartate for argininosuccinate synthesis |
| Amino Acid Metabolism | Transamination of multiple amino acids |

The Malate-Aspartate Shuttle

The malate-aspartate shuttle is critical for:

• NAD+ regeneration in the cytosol (essential for continued glycolysis)
• ATP production via oxidative phosphorylation
• Preventing lactate accumulation under aerobic conditions
• Astrocyte-neuron metabolic coupling in the brain

Role in Neurodegeneration

Alzheimer's Disease

GOT2 dysfunction may contribute to [Alzheimer's disease](/diseases/alzheimers-disease) pathogenesis through several mechanisms:

Parkinson's Disease

In [Parkinson's disease](/diseases/parkinsons-disease), GOT2 is particularly important for:

Aging and Neurodegeneration

The aging brain shows progressive decline in GOT2 function[@taylor2021][@cheng2024]:

• Reduced GOT2 expression in neurons with age
• Impaired malate-aspartate shuttle activity
• Decreased NAD+ regeneration capacity
• Enhanced susceptibility to metabolic stress

Genetic Variants

Several GOT2 polymorphisms have been associated with neurodegenerative disease susceptibility[@patel2023][@ng2023]:

• Certain variants linked to early-onset neurodegenerative phenotypes
• Potential role in disease modifies through metabolic pathways
• May affect enzyme stability or expression levels

Structure and Biochemistry

Protein Structure

GOT2 is a homodimer with:

• Each subunit ~45 kDa
• Pyridoxal phosphate (PLP) cofactor at active site
• N-terminal mitochondrial targeting sequence (cleaved upon import)
• Active site pocket conserved across species

Kinetic Properties

| Property | Value |
|----------|-------|
| Molecular weight | ~90 kDa (dimer) |
| Isoelectric point | ~6.5 |
| Optimal pH | 7.5-8.5 |
| Substrate affinity (Asp) | Km ~0.5 mM |
| Substrate affinity (α-KG) | Km ~0.2 mM |

Clinical Significance

Diagnostic Biomarkers

GOT2 has potential as a biomarker for neurodegenerative diseases[@kim2020]:

Therapeutic Targets

Several therapeutic approaches target GOT2-related pathways[@song2023]:

Astrocyte-Neuron Coupling

GOT2 plays a critical role in metabolic coupling between astrocytes and neurons[@martin2023]:

• Astrocytes release lactate for neuronal energy
• Malate-aspartate shuttle transfers reducing equivalents
• Disruption contributes to neurodegeneration

Research Directions

Current Understanding

Recent research has revealed several key insights:

• GOT2 dysfunction is an early event in AD pathogenesis
• Amyloid-beta directly inhibits GOT2 activity[@wang2024]
• Malate-aspartate shuttle impairment precedes neuronal loss
• GOT2 represents a potential therapeutic target

Unanswered Questions

Expression Patterns

GOT2 is ubiquitously expressed with highest levels in:

| Tissue | Expression Level | Significance |
|--------|-----------------|--------------|
| Brain | High | Neuronal energy metabolism |
| Heart | Very high | Continuous energy demand |
| Liver | High | Urea cycle, amino acid metabolism |
| Kidney | High | Amino acid homeostasis |
| Skeletal muscle | Moderate | Energy metabolism |

Brain Regional Expression

• Cerebellum: High expression in Purkinje cells
• Cerebral cortex: High in layer 5 pyramidal neurons
• Hippocampus: High in CA1-CA3 pyramidal neurons and dentate gyrus
• Substantia nigra: Moderate expression in dopaminergic neurons

Therapeutic Implications

Biomarker Potential

• GOT2 levels in cerebrospinal fluid (CSF) may serve as a biomarker for mitochondrial dysfunction
• Could indicate disease progression in neurodegenerative conditions

Therapeutic Targets

Key Publications

See Also

• [GOT1 Gene](/genes/got1) — Cytosolic isoform
• [Malate-Aspartate Shuttle](/mechanisms/malate-aspartate-shuttle) — Full mechanism
• [Mitochondrial Dysfunction](/mechanisms/mitochondrial-dysfunction) — Disease context
• [Oxidative Stress](/mechanisms/oxidative-stress) — Pathogenic mechanism
• [Alzheimer's Disease](/diseases/alzheimers-disease) — Disease context
• [Parkinson's Disease](/diseases/parkinsons-disease) — Disease context

References

Pathway Diagram

The following diagram shows the key molecular relationships involving GOT2 Gene discovered through SciDEX knowledge graph analysis: