COMT Gene

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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

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COMT Gene

Introduction

Pathway Diagram

Mermaid diagram (expand to render)

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

COMT encodes catechol-O-methyltransferase, a key enzyme in the metabolism of catecholamines including dopamine, norepinephrine, and epinephrine. COMT plays critical roles in dopaminergic signaling, executive function, and pain perception. [@pmid1999]

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

COMT catalyzes the methylation of dopamine to produce 3-methoxytyramine (3-MT), which is subsequently metabolized to homovanillic acid (HVA). This pathway is the primary mechanism for dopamine clearance in the prefrontal cortex.

Epinephrine and Norepinephrine Metabolism

COMT also methylates epinephrine and norepinephrine, contributing to the regulation of sympathetic tone and stress responses.

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

Lachman HM, Papolos DF, Saito T, et al. Human catechol-O-methyltransferase pharmacogenetics. Pharmacogenomics J. 2006;6(4):243-250.

Tunbridge EM, Harrison PJ, Weinberger DR. Catechol-o-methyltransferase, cognition, and psychosis. Mol Psychiatry. 2006;11(2):193-202.

Yacubian J, Sommer T, Schroeder K, et al. Gene-gene interaction associated with neural reward sensitivity. Proc Natl Acad Sci USA. 2007;104(19):8125-8130.

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:

Mermaid diagram (expand to render)

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