COMT Gene

COMT Gene

Introduction

<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">COMT Gene</th>
</tr>
<tr>
<td class="label">Gene Symbol</td>
<td>COMT</td>
</tr>
<tr>
<td class="label">Full Name</td>
<td>Catechol-O-Methyltransferase</td>
</tr>
<tr>
<td class="label">Chromosome</td>
<td>22</td>
</tr>
<tr>
<td class="label">Genomic Location</td>
<td>22q11.21</td>
</tr>
<tr>
<td class="label">OMIM</td>
<td>116790</td>
</tr>
<tr>
<td class="label">Ensembl ID</td>
<td>ENSG00000093072</td>
</tr>
<tr>
<td class="label">UniProt ID</td>
<td>P21964</td>
</tr>
<tr>
<td class="label">Drug</td>
<td>Type</td>
</tr>
<tr>
<td class="label">Entacapone</td>
<td>Selective, peripheral</td>
</tr>
<tr>
<td class="label">Tolcapone</td>
<td>Non-selective, central</td>
</tr>
<tr>
<td class="label">Opicapone</td>
<td>Selective, peripheral</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">ALS</a>, <a href="/wiki/alzheimer" style="color:#ef9a9a">ALZHEIMER</a>, <a href="/wiki/alzheimer's" style="color:#ef9a9a">ALZHEIMER'S</a>, <a href="/wiki/alzheimer's-disease" style="color:#ef9a9a">ALZHEIMER'S DISEASE</a>, <a href="/wiki/als" style="color:#ef9a9a">Als</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">185 edges</a></td>
</tr>
</table>

Pathway Diagram

COMT Gene

Introduction

<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">COMT Gene</th>
</tr>
<tr>
<td class="label">Gene Symbol</td>
<td>COMT</td>
</tr>
<tr>
<td class="label">Full Name</td>
<td>Catechol-O-Methyltransferase</td>
</tr>
<tr>
<td class="label">Chromosome</td>
<td>22</td>
</tr>
<tr>
<td class="label">Genomic Location</td>
<td>22q11.21</td>
</tr>
<tr>
<td class="label">OMIM</td>
<td>116790</td>
</tr>
<tr>
<td class="label">Ensembl ID</td>
<td>ENSG00000093072</td>
</tr>
<tr>
<td class="label">UniProt ID</td>
<td>P21964</td>
</tr>
<tr>
<td class="label">Drug</td>
<td>Type</td>
</tr>
<tr>
<td class="label">Entacapone</td>
<td>Selective, peripheral</td>
</tr>
<tr>
<td class="label">Tolcapone</td>
<td>Non-selective, central</td>
</tr>
<tr>
<td class="label">Opicapone</td>
<td>Selective, peripheral</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">ALS</a>, <a href="/wiki/alzheimer" style="color:#ef9a9a">ALZHEIMER</a>, <a href="/wiki/alzheimer's" style="color:#ef9a9a">ALZHEIMER'S</a>, <a href="/wiki/alzheimer's-disease" style="color:#ef9a9a">ALZHEIMER'S DISEASE</a>, <a href="/wiki/als" style="color:#ef9a9a">Als</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">185 edges</a></td>
</tr>
</table>

Pathway Diagram

Comt Gene is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

Overview

The COMT (Catechol-O-Methyltransferase) gene encodes an enzyme that degrades catecholamines including dopamine, epinephrine, and norepinephrine. COMT activity in the prefrontal cortex regulates dopamine levels and cognitive function. A common functional polymorphism (Val158Met) affects enzyme activity and is associated with psychiatric disorders. [@pmid2006a]

This gene is involved in: [@pmid2007]

• Dopamine metabolism: Degrades dopamine in the synapse
• Cognition: Modulates prefrontal cortical function
• Stress response: Regulates catecholamine levels
• Disease associations: [Parkinson's disease](/diseases/parkinsons-disease), schizophrenia, impulsivity, pain

Gene Overview

Normal Function

The COMT gene encodes catechol-O-methyltransferase, an enzyme that catalyzes the methylation of catecholamines using S-adenosylmethionine (SAM) as a methyl donor. COMT is essential for dopamine catabolism in the prefrontal [cortex](/brain-regions/cortex).

Enzyme Variants

Soluble COMT (S-COMT)

• Cytosolic enzyme
• Predominantly expressed in peripheral tissues
• Lower activity compared to MB-COMT

Membrane-Bound COMT (MB-COMT)

• N-terminally anchored to the cell membrane
• Higher substrate affinity
• Predominantly expressed in brain tissue

Biochemical Properties

• Requires Mg²⁺ as a cofactor
• S-adenosylmethionine (SAM) as methyl donor
• Products: HVA (from dopamine), MHPG (from norepinephrine)
• Inactivated by catecholamine metabolites

Disease Associations

Parkinson's Disease

COMT is central to Parkinson's disease treatment:

• Levodopa metabolism: COMT inhibitors (entacapone, tolcapone, opicapone) prolong levodopa half-life
• Endogenous dopamine: COMT regulates extracellular dopamine levels in the striatum
• Polymorphisms: Val158Met variant affects COMT activity and PD risk
• Motor fluctuations: COMT activity contributes to wearing-off phenomenon

Alzheimer's Disease

• COMT polymorphisms associated with AD risk and age of onset
• Interaction with [APOE](/proteins/apoe-protein) ε4 modifies AD risk
• Prefrontal cortex dopamine deficits contribute to cognitive impairment
• COMT inhibitors under investigation for cognitive enhancement

Schizophrenia

• Val158Met polymorphism affects prefrontal cortex function
• Met allele associated with poorer executive function
• Met allele associated with increased risk for schizophrenia
• Dopamine dysregulation hypothesis

Other Conditions

• Attention deficit hyperactivity disorder (ADHD): COMT variants
• Bipolar disorder: Dopamine metabolism alterations
• Pain disorders: COMT polymorphisms in pain sensitivity

Expression Patterns

Brain Regional Distribution

• Highest expression in prefrontal cortex
• High expression in [hippocampus](/brain-regions/hippocampus) and amygdala
• Moderate expression in basal ganglia
• Lower expression in brainstem

Cell-Type Specific Expression

• [Neurons](/entities/neurons): Primary expression in dopaminergic and noradrenergic neurons
• [Astrocytes](/entities/astrocytes): Contribute to catecholamine metabolism
• [Microglia](/entities/microglia): Low expression under normal conditions

Developmental Expression

• Present throughout development
• Expression increases in adolescence
• Peak expression in adulthood
• Age-related changes in activity

Molecular Mechanisms

Dopamine Metabolism

Epinephrine and Norepinephrine Metabolism

Interaction with Other Enzymes

• Monoamine oxidase (MAO): Complementary dopamine catabolism pathway
• Dopa decarboxylase (DDC): Converts L-DOPA to dopamine
• Dopamine transporter (DAT): Reuptake of extracellular dopamine

Genetic Variants

Val158Met Polymorphism

• Val allele: High activity COMT enzyme
• Met allele: Thermolabile enzyme with 40% lower activity
• Met/Met: Lower prefrontal cortex dopamine, better working memory
• Val/Val: Higher dopamine catabolism, efficient prefrontal function

Other Polymorphisms

• -287A>G promoter variant
• 472A>G (His62His) variant
• 413C>T (Ser136Ser) variant

Therapeutic Targeting

COMT Inhibitors in Clinical Use

Drug Development

• Novel brain-penetrant COMT inhibitors
• Selective S-COMT inhibitors
• Combined DDC/COMT inhibitors
• Gene therapy approaches

Research Directions

• Biomarkers for COMT inhibitor response
• Personalized medicine based on genotype
• Novel formulations with improved CNS penetration

Animal Models

COMT Knockout Mice

• Increased dopamine levels in prefrontal cortex
• Enhanced working memory
• Increased stress response
• Changed pain sensitivity

Transgenic Models

• Human COMT transgenic mice
• Humanized Val158Met knock-in mice
• Region-specific COMT overexpression

Research Directions

• Understanding Val158Met effects on brain function
• Developing brain-penetrant COMT inhibitors
• Biomarker development for patient selection
• Gene therapy approaches

Key Publications

Background

The study of Comt Gene has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.

Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.

External Links

• [NCBI Gene](https://www.ncbi.nlm.nih.gov/gene/1312)
• [Ensembl](https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000093072)
• [UniProt](https://www.uniprot.org/uniprot/P21964)
• [OMIM](https://www.omim.org/entry/116790)

References

PMID: 16684957(https://pubmed.ncbi.nlm.nih.gov/16684957/) PMID: 16380913(https://pubmed.ncbi.nlm.nih.gov/16380913/) PMID: 17412775(https://pubmed.ncbi.nlm.nih.gov/17412775/) PMID: 12629556(https://pubmed.ncbi.nlm.nih.gov/12629556/) PMID: 19141701(https://pubmed.ncbi.nlm.nih.gov/19141701/) PMID: 21207076(https://pubmed.ncbi.nlm.nih.gov/21207076/)

Pathway Diagram

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