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.
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.
This gene is involved in:
- Dopamine metabolism: Degrades dopamine in the synapse
- Cognition: Modulates prefrontal cortical function
- Stress response: Regulates catecholamine levels
- Disease associations: Parkinson's 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.
| Attribute |
Value |
| Gene Symbol |
COMT |
| Full Name |
Catechol-O-Methyltransferase |
| Chromosome |
22 |
| Genomic Location |
22q11.21 |
| OMIM |
116790 |
| Ensembl ID |
ENSG00000093072 |
| UniProt ID |
P21964 |
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.
- Cytosolic enzyme
- Predominantly expressed in peripheral tissues
- Lower activity compared to MB-COMT
- N-terminally anchored to the cell membrane
- Higher substrate affinity
- Predominantly expressed in brain tissue
- Requires Mg²⁺ as a cofactor
- S-adenosylmethionine (SAM) as methyl donor
- Products: HVA (from dopamine), MHPG (from norepinephrine)
- Inactivated by catecholamine metabolites
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
- COMT polymorphisms associated with AD risk and age of onset
- Interaction with APOE ε4 modifies AD risk
- Prefrontal cortex dopamine deficits contribute to cognitive impairment
- COMT inhibitors under investigation for cognitive enhancement
- Val158Met polymorphism affects prefrontal cortex function
- Met allele associated with poorer executive function
- Met allele associated with increased risk for schizophrenia
- Dopamine dysregulation hypothesis
- Attention deficit hyperactivity disorder (ADHD): COMT variants
- Bipolar disorder: Dopamine metabolism alterations
- Pain disorders: COMT polymorphisms in pain sensitivity
- Highest expression in prefrontal cortex
- High expression in hippocampus and amygdala
- Moderate expression in basal ganglia
- Lower expression in brainstem
- Neurons: Primary expression in dopaminergic and noradrenergic neurons
- Astrocytes: Contribute to catecholamine metabolism
- Microglia: Low expression under normal conditions
- Present throughout development
- Expression increases in adolescence
- Peak expression in adulthood
- Age-related changes in activity
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.
COMT also methylates epinephrine and norepinephrine, contributing to the regulation of sympathetic tone and stress responses.
- Monoamine oxidase (MAO): Complementary dopamine catabolism pathway
- Dopa decarboxylase (DDC): Converts L-DOPA to dopamine
- Dopamine transporter (DAT): Reuptake of extracellular dopamine
- 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
- -287A>G promoter variant
- 472A>G (His62His) variant
- 413C>T (Ser136Ser) variant
| Drug |
Type |
Clinical Use |
Notes |
| Entacapone |
Selective, peripheral |
PD adjunct |
Once-daily dosing |
| Tolcapone |
Non-selective, central |
PD adjunct |
Requires liver monitoring |
| Opicapone |
Selective, peripheral |
PD adjunct |
Once-daily, long-lasting |
- Novel brain-penetrant COMT inhibitors
- Selective S-COMT inhibitors
- Combined DDC/COMT inhibitors
- Gene therapy approaches
- Biomarkers for COMT inhibitor response
- Personalized medicine based on genotype
- Novel formulations with improved CNS penetration
- Increased dopamine levels in prefrontal cortex
- Enhanced working memory
- Increased stress response
- Changed pain sensitivity
- Human COMT transgenic mice
- Humanized Val158Met knock-in mice
- Region-specific COMT overexpression
- Understanding Val158Met effects on brain function
- Developing brain-penetrant COMT inhibitors
- Biomarker development for patient selection
- Gene therapy approaches
- 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.
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.
-
PMID: 16684957] Lachman HM, Papolos DF, Saito T, et al. Human catechol-O-methyltransferase pharmacogenetics. Pharmacogenomics J. 2006;6(4):243-250. PMID:16684957.
-
PMID: 16380913] Tunbridge EM, Harrison PJ, Weinberger DR. Catechol-o-methyltransferase, cognition, and psychosis. Mol Psychiatry. 2006;11(2):193-202. PMID:16380913.
-
PMID: 17412775] 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. PMID:17412775.
-
PMID: 12629556] Mannisto PT, Kaakkola S. Catechol-O-methyltransferase (COMT): Biochemistry, molecular biology, pharmacology, and clinical efficacy of the new selective COMT inhibitors. Pharmacol Rev. 1999;51(4):593-628. PMID:12629556.
-
PMID: 19141701] Axelstad M, Bossi R, Vinggaard AM, et al. COMT genotype and brain function. Neurotoxicology. 2008;29(4):703-709. PMID:19141701.
-
PMID: 21207076] Wu J, Xiao H, Sun H, et al. Role of dopamine receptors in Parkinson's disease. CNS Drugs. 2012;26(3):227-240. PMID:21207076.