DLAT Gene

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gene1686 wordssynced 2026-04-02

title: DLAT - Dihydrolipoamide S-Acetyltransferase
category: gene

DLAT — Dihydrolipoamide S-Acetyltransferase

Introduction

DLAT (Dihydrolipoamide S-Acetyltransferase) encodes the E2 component of the pyruvate dehydrogenase complex (PDC), a critical metabolic enzyme linking glycolysis to the TCA cycle. This gene has garnered significant attention in neurodegenerative disease research due to the central role of glucose metabolism in neuronal function and the well-documented cerebral hypometabolism in Alzheimer's disease[@gibson2010][@blass2010].

<div class="infobox infobox-gene">
<table>
<tr><th colspan="2" style="background:#e8f4f8; text-align:center; font-size:1.1em;">Dihydrolipoamide S-Acetyltransferase</th></tr>
<tr><td><strong>Gene Symbol</strong></td><td>DLAT</td></tr>
<tr><td><strong>Full Name</strong></td><td>Dihydrolipoamide S-Acetyltransferase</td></tr>
<tr><td><strong>Chromosome</strong></td><td>11q23.1</td></tr>
<tr><td><strong>NCBI Gene ID</strong></td><td>[1737](https://www.ncbi.nlm.nih.gov/gene/1737)</td></tr>
<tr><td><strong>OMIM</strong></td><td>608770</td></tr>
<tr><td><strong>Ensembl ID</strong></td><td>ENSG00000150768</td></tr>
<tr><td><strong>UniProt ID</strong></td><td>[P10515](https://www.uniprot.org/uniprot/P10515)</td></tr>
<tr><td><strong>Protein Class</strong></td><td>Metabolic Enzyme (E2 Component)</td></tr>
<tr><td><strong>Associated Diseases</strong></td><td>[Alzheimer's Disease](/diseases/alzheimers-disease), Pyruvate Dehydrogenase Deficiency, Diabetes</td></tr>
</table>
</div>

...

title: DLAT - Dihydrolipoamide S-Acetyltransferase
category: gene

DLAT — Dihydrolipoamide S-Acetyltransferase

Introduction

Overview

Mermaid diagram (expand to render)

DLAT is the central structural and catalytic component of the pyruvate dehydrogenase complex, forming a 24-mer cubic core that organizes the entire complex["@patel2014"]. The complex consists of three main enzymatic components: E1 (pyruvate dehydrogenase, encoded by PDHA1 and PDHB), E2 (DLAT), and E3 (dihydrolipoamide dehydrogenase, encoded by DLD), along with regulatory enzymes E3BP and PDK. This multi-enzyme complex is embedded in the mitochondrial matrix and is essential for cellular energy production through aerobic respiration.

The pyruvate dehydrogenase complex catalyzes the oxidative decarboxylation of pyruvate to acetyl-CoA, the rate-limiting step that links glycolysis to the TCA cycle and oxidative phosphorylation. This reaction is fundamental to aerobic energy metabolism, and its dysfunction has profound consequences for cellular energetics, particularly in high-energy-demand tissues like the brain.

Gene Structure and Expression

Protein Architecture

The DLAT protein serves dual roles as both the structural scaffold and catalytic engine of the PDC. Each DLAT monomer consists of three distinct domains:

| Domain | Position | Function |
|--------|----------|----------|
| N-terminal lipoyl domain | 1-90 | Contains lipoyllysine for cofactor attachment |
| Peripheral subunit-binding domain | 91-200 | Binds E1 and E3 components |
| C-terminal catalytic domain | 201-647 | Catalyzes acetyl transfer to CoA |

The DLAT protein forms a 24-mer cubic core through dimerization of 12 identical subunits, creating a remarkable architectural feat that positions the catalytic sites optimally for substrate channeling between E1, E2, and E3 components[@patel2014].

Catalytic Mechanism

The acetyltransfer reaction proceeds through a series of intermediate steps:

E1-mediated oxidative decarboxylation: Pyruvate is decarboxylated and the resulting acyl group is transferred to the lipoyllysine arm of DLAT

Intramolecular transfer: The acetyl group moves to the active site of the catalytic domain

CoA transfer: The acetyl group is transferred to CoA, forming acetyl-CoA

This mechanism ensures efficient substrate channeling without release of intermediate products, maximizing metabolic efficiency.

Lipoylation: A Critical Post-Translational Modification

The lipoylation of DLAT is essential for its function. The lipoic acid cofactor, covalently attached to a lysine residue in the lipoyl domain, serves as a swinging arm that carries acetyl groups between the active sites of E1, E2, and E3. This process requires:

Lipoic acid synthesis: De novo creation of the dithiolane ring
Enzyme-mediated attachment: Lipoate-protein ligases (LPL) catalyze attachment
Regeneration: Lipoate dehydrogenase regenerates oxidized lipoate

Defects in lipoylation lead to PDC dysfunction and severe metabolic disease[@stacpoole2012][@yang2011].

Role in Neuronal Energy Metabolism

Neurons are highly energy-dependent cells requiring continuous ATP production for:

Maintenance of membrane potentials and ion gradients
Neurotransmitter synthesis and release
Cytoskeletal dynamics and axonal transport
Synaptic plasticity processes
Action potential propagation

DLAT-mediated PDC activity is the rate-limiting step linking glycolysis to oxidative phosphorylation. In neurons, this process is particularly critical because[@capitano2020][@moreira2013]:

High basal metabolic rate: The brain represents only 2% of body weight but consumes ~20% of resting metabolic oxygen and glucose

Limited anaerobic capacity: Neurons have limited capacity for anaerobic metabolism compared to other cell types

Mitochondrial dependence: Unlike other tissues, neurons rely almost exclusively on oxidative phosphorylation

Activity-dependent demand: Synaptic activity dramatically increases energy requirements

The vulnerability of neuronal glucose metabolism to dysfunction makes PDC a critical node in understanding neurodegenerative processes.

Disease Associations

DLAT variants and expression changes are associated with several conditions:

Pyruvate Dehydrogenase Complex Deficiency

PDC deficiency is one of the most common inherited metabolic disorders of energy metabolism[@stacpoole2012]:

Inheritance: Autosomal recessive
Clinical Features: Lactic acidosis, metabolic encephalopathy, developmental delay, hypotonia, ataxia
Mechanism: Loss-of-function mutations in DLAT reduce PDC activity below critical thresholds
Treatment: Ketogenic diet as alternative energy source (bypasses PDC)
Prognosis: Varies from severe neonatal onset to milder adult-onset forms

Alzheimer's Disease

DLAT shows significant downregulation in AD brains and is implicated in disease pathogenesis through multiple mechanisms[@gibson2010][@blass2010][@ding2013][@perez2019]:

Cerebral Hypometabolism:

Reduced DLAT expression contributes to decreased glucose metabolism in AD
FDG-PET studies consistently show reduced cerebral glucose uptake in AD
The temporal pattern of hypometabolism correlates with regional vulnerability
DLAT reduction is part of broader mitochondrial dysfunction

Amyloid-β Effects:

Amyloid-beta oligomers may impair PDC function through direct interaction
Mitochondrial Aβ accumulation correlates with reduced enzymatic activity
Aβ-induced oxidative stress damages DLAT and other mitochondrial proteins

Tau Pathology:

Hyperphosphorylated tau correlates with reduced PDC activity
Tau-mediated sequestration of mitochondrial proteins contributes to dysfunction
The combination of Aβ and tau creates a synergistic metabolic deficit

Therapeutic Implications:

PDC activation is being explored as a therapeutic strategy
Lipoic acid supplementation has shown cognitive benefits[@hauptmann2009]
Ketogenic approaches may bypass metabolic deficits[@karim2020]

Diabetes and Metabolic Syndrome

Altered PDC activity affects glucose homeostasis
Insulin resistance associated with reduced PDC function
Metabolic inflexibility in skeletal muscle and brain

Expression Patterns

Brain Distribution

DLAT is expressed throughout the brain with highest levels in regions with high metabolic demand:

| Brain Region | Expression Level | Significance |
|--------------|------------------|---------------|
| Cerebral Cortex | High | High synaptic density, elevated energy demand |
| Hippocampus | High | Memory formation, CA1 especially vulnerable in AD |
| Basal Ganglia | Moderate-High | Motor control, dopaminergic neuron maintenance |
| Cerebellum | High | Motor coordination, Purkinje cells |
| Brainstem | Moderate | Vital functions, cranial nerve nuclei |
| White Matter | Lower | Myelinated axons, lower metabolic activity |

Cellular Distribution

Neurons: High expression in pyramidal neurons and interneurons
Astrocytes: Moderate expression, support neuronal metabolism
Oligodendrocytes: Lower expression, lipid synthesis support
Microglia: Low baseline expression, increases in neuroinflammation

Regulation by Metabolic State

DLAT expression is regulated by:

PGC-1α: Master regulator of mitochondrial biogenesis
Thyroid hormone: Responsive to metabolic demands
AMPK: Activated during energy stress
Sirtuins: NAD+-dependent deacetylases affect activity

Interaction Network

DLAT interacts with multiple proteins within the mitochondrial metabolic network:

| Protein | Role | Interaction Type |
|---------|------|------------------|
| PDHA1 | E1α (pyruvate dehydrogenase) | Catalytic substrate binding |
| PDHB | E1β | Forms heterotetramer with PDHA1 |
| DLAT | Self | Forms 24-mer core through dimerization |
| DLD | E3 (dihydrolipoamide dehydrogenase) | Electron transfer |
| PDHX | E3BP | Alternative E3 binding protein |
| PDP1/PDP2 | Phosphatases | Regulatory dephosphorylation |
| PDK1/PDK2/PDK3 | Kinases | Regulatory phosphorylation |

These interactions coordinate the metabolic flux through the PDC, with kinase/phosphatase regulation providing rapid control of PDC activity in response to cellular energy demands[@perez2019][@sorrentino2017].

Regulation

DLAT activity is regulated at multiple levels:

Transcriptional Regulation

PGC-1α: Coactivation drives mitochondrial biogenesis including DLAT
Thyroid hormone: Responsive to metabolic demands
AMPK: Activated during energy stress, increases expression
Sirtuins: NAD+-dependent regulation of mitochondrial function

Post-Translational Regulation

| Modification | Effect | Enzyme |
|--------------|--------|--------|
| Phosphorylation | Inhibits PDC activity | PDK1/2/3 |
| Dephosphorylation | Activates PDC | PDP1/2 |
| Lipoylation | Essential for catalytic function | LPL family |
| Acetylation | Metabolic regulation | Acetyltransferases |

Allosteric Regulation

Product inhibition: Acetyl-CoA inhibits DLAT activity
Energy sensing: NADH/NAD+ ratio signals metabolic status
Feedback: ATP/ADP ratio provides energy state feedback

Therapeutic Implications

Given the central role of DLAT in cellular metabolism, several therapeutic strategies are being explored[@hauptmann2009][@yang2011][@karim2020]:

Metabolic Modulation

PDC Activators: Compounds that enhance PDC activity directly

Lipoic Acid Supplementation: Supports lipoylation status and mitochondrial function

CoQ10 and B-vitamins: Support mitochondrial electron transport chain

Ketogenic Approaches

The ketogenic diet bypasses PDC by providing alternative fuel:

ketone bodies are converted to acetyl-CoA independent of PDC
Has shown benefits in some AD patients
Particularly relevant for patients with PDC dysfunction

Gene Therapy and Protein Replacement

Viral vector delivery of functional DLAT
Enzyme replacement therapy (in development)
Small molecule correctors of lipoylation defects

Mitochondrial Biogenesis

PGC-1α activators increase DLAT expression
AMPK agonists promote mitochondrial health
Sirtuin activators enhance metabolic function

Key Publications

[Patel et al., Pyruvate dehydrogenase complex: structure and function. J Mol Biol. 2014](https://pubmed.ncbi.nlm.nih.gov/24484368/)

[Gibson et al., DLAT and brain metabolism in AD. J Neurosci. 2010](https://pubmed.ncbi.nlm.nih.gov/20471853/)

[Stacpoole et al., Pyruvate dehydrogenase deficiency. Mitochondrion. 2012](https://pubmed.ncbi.nlm.nih.gov/22767438/)

[Yang et al., Lipoic acid supplementation effects on mitochondrial function. J Nutr Biochem. 2011](https://pubmed.ncbi.nlm.nih.gov/21945435/)

[Ding et al., Early decline in glucose transport and metabolism in AD mouse brain. J Alzheimers Dis. 2013](https://pubmed.ncbi.nlm.nih.gov/24244584/)

[Blass et al., Cerebral metabolic deficiencies in Alzheimer's disease. J Alzheimers Dis. 2010](https://pubmed.ncbi.nlm.nih.gov/20061642/)

[Hauptmann et al., Lipoic acid improves cerebral blood flow and cognitive function. Pharmacopsychiatry. 2009](https://pubmed.ncbi.nlm.nih.gov/19205924/)

[Capitano et al., Metabolic dysfunction in Alzheimer's disease. Cell Death Dis. 2020](https://pubmed.ncbi.nlm.nih.gov/33298890/)

[Perez et al., Pyruvate dehydrogenase complex activity in Alzheimer's disease. Ann Neurol. 2019](https://pubmed.ncbi.nlm.nih.gov/31016796/)

[Karim et al., Targeting mitochondrial dysfunction in Alzheimer's disease. Adv Exp Med Biol. 2020](https://pubmed.ncbi.nlm.nih.gov/32072470/)

[Sheng et al., Mitochondrial dysfunction in Alzheimer's disease. Neurochem Int. 2012](https://pubmed.ncbi.nlm.nih.gov/22842627/)

[Mani et al., Pyruvate dehydrogenase complex in brain aging and neurodegeneration. Ageing Res Rev. 2023](https://pubmed.ncbi.nlm.nih.gov/37244106/)

[Kumar et al., Mitochondrial bioenergetics and metabolic dysfunction in Alzheimer's disease. Free Radic Biol Med. 2021](https://pubmed.ncbi.nlm.nih.gov/34044012/)

[Korotchkina et al., Regulation of the pyruvate dehydrogenase complex. Biochim Biophys Acta. 2005](https://pubmed.ncbi.nlm.nih.gov/15857603/)

[Hume et al., Neuronal metabolism and neurodegenerative disease. J Neurochem. 2021](https://pubmed.ncbi.nlm.nih.gov/34256789/)

External Links

[GeneCards - DLAT](https://www.genecards.org/cgi-bin/carddisp.pl?gene=DLAT)
[UniProt - DLAT](https://www.uniprot.org/uniprot/P10515)
[NCBI Gene - DLAT](https://www.ncbi.nlm.nih.gov/gene/1737)
[OMIM - DLAT](https://www.omim.org/entry/608770)
[Ensembl - DLAT](https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000150768)

Pathway Diagram

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

Mermaid diagram (expand to render)

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DLAT Gene

DLAT — Dihydrolipoamide S-Acetyltransferase

Introduction

DLAT — Dihydrolipoamide S-Acetyltransferase

Introduction

Overview

Gene Structure and Expression

Protein Architecture

Catalytic Mechanism

Lipoylation: A Critical Post-Translational Modification

Role in Neuronal Energy Metabolism

Disease Associations

Pyruvate Dehydrogenase Complex Deficiency

Alzheimer's Disease

Diabetes and Metabolic Syndrome

Expression Patterns

Brain Distribution

Cellular Distribution

Regulation by Metabolic State

Interaction Network

Regulation

Transcriptional Regulation

Post-Translational Regulation

Allosteric Regulation

Therapeutic Implications

Metabolic Modulation

Ketogenic Approaches

Gene Therapy and Protein Replacement

Mitochondrial Biogenesis

Key Publications

See Also

External Links

Pathway Diagram