MAOB Gene

MAOB Gene

Introduction

Maob 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

MAOB (Monoamine Oxidase B) is a mitochondrial enzyme encoded by the MAOB gene on chromosome Xp11.23[@mandel2020]. It primarily metabolizes phenylethylamine and benzylamine, and plays a critical role in dopamine catabolism in the brain["@bortolato2021"]. MAOB is predominantly expressed in platelets and in the mitochondrial outer membrane of serotonergic and dopaminergic [neurons](/entities/neurons).

MAOB Gene

Introduction

Maob 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

MAOB (Monoamine Oxidase B) is a mitochondrial enzyme encoded by the MAOB gene on chromosome Xp11.23[@mandel2020]. It primarily metabolizes phenylethylamine and benzylamine, and plays a critical role in dopamine catabolism in the brain["@bortolato2021"]. MAOB is predominantly expressed in platelets and in the mitochondrial outer membrane of serotonergic and dopaminergic [neurons](/entities/neurons).

<div class="infobox infobox-gene">
<table>
<tr><th colspan="2" style="background:#f0f0f0;">MAOB - Monoamine Oxidase B</th></tr>
<tr><td><strong>Gene Symbol</strong></td><td>MAOB</td></tr>
<tr><td><strong>Full Name</strong></td><td>Monoamine Oxidase B</td></tr>
<tr><td><strong>Chromosomal Location</strong></td><td>Xp11.23</td></tr>
<tr><td><strong>NCBI Gene ID</strong></td><td>4129</td></tr>
<tr><td><strong>OMIM ID</strong></td><td>309860</td></tr>
<tr><td><strong>Ensembl ID</strong></td><td>ENSG00000105707</td></tr>
<tr><td><strong>UniProt ID</strong></td><td>[P50395](https://www.uniprot.org/uniprot/P50395)</td></tr>
<tr><td><strong>Protein Family</strong></td><td>Monoamine oxidase family</td></tr>
<tr><td><strong>Subcellular Location</strong></td><td>Mitochondrial outer membrane</td></tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/alzheimer's-disease" style="color:#ef9a9a">ALZHEIMER'S DISEASE</a>, <a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/alzheimer" style="color:#ef9a9a">Alzheimer</a>, <a href="/wiki/anxiety" style="color:#ef9a9a">Anxiety</a>, <a href="/wiki/cardiovascular" style="color:#ef9a9a">Cardiovascular</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">113 edges</a></td>
</tr>
</table>
</div>

Function

Catalytic Activity

MAOB has distinct substrate specificity:

• Phenylethylamine: Primary substrate (preferentially metabolized)
• Benzylamine: Secondary substrate
• Dopamine: Minor substrate (mostly by MAOB in human brain)
• 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP): Activated by MAOB to toxic MPP+

Brain Neurochemistry

• Dopamine catabolism: Major pathway in human brain
• Phenylethylamine turnover: Regulates neuromodulator levels
• Trace amine metabolism: Processes trace neurotransmitters
• Neuroprotection: Produces H₂O₂ (can be neurotoxic)

Peripheral Distribution

• Platelets: Primary peripheral location
• Liver: Xenobiotic metabolism
• Intestine: Dietary amine metabolism

Disease Associations

Parkinson's Disease

• MAOB inhibitors: Selegiline, rasagiline used in treatment
• Dopamine protection: Prevents oxidative deamination
• Disease modification: May slow progression
• Combination therapy: With levodopa[@mandel2020]

Alzheimer's Disease

• MAOB activity increased in AD
• Associated with disease progression
• May affect amyloid pathology
• Therapeutic target

Attention Deficit Hyperactivity Disorder (ADHD)

• MAOB polymorphisms associated with ADHD
• May affect dopamine signaling
• Therapeutic implications

Molecular Mechanisms

Enzyme Properties

• FAD cofactor: Covalently bound flavin
• Substrate binding: Pocket determines specificity
• Kinetics: Lower Km for phenylethylamine than MAOA
• Inhibition: Selective inhibitors available

MAOB in Neurodegeneration

Therapeutic Approaches

MAO-B Inhibitors

| Drug | Type | Status | Indication |
|------|------|--------|------------|
| Selegiline | Irreversible | Approved (FDA) | Parkinson's disease (adjunct) |
| Rasagiline | Irreversible | Approved (FDA) | Parkinson's disease |
| Safinamide | Reversible | Approved | Parkinson's disease |
| Ladostigil | Irreversible | Research | AD/PD |

Neuroprotective Strategies

• Reduce oxidative stress: Antioxidant co-therapy
• Iron chelation: MAOB produces reactive oxygen
• Combination approaches: With dopamine agonists

See Also

• [MAOB Protein](/proteins/maob-protein)
• [MAOA Gene](/proteins/maoa-protein)
• [Selegiline](/therapeutics/selegiline)
• [Dopamine Metabolism](/mechanisms/dopamine-metabolism)
• [Parkinson's Disease](/diseases/parkinsons-disease)
• [Alzheimer's Disease](/diseases/alzheimers-disease)

External Links

• [UniProt: P50395](https://www.uniprot.org/uniprot/P50395)
• [GeneCards: MAOB](https://www.genecards.org/cgi-bin/carddisp.pl?gene=MAOB)
• [OMIM: MAOB](https://www.omim.org/entry/309860)
• [PubMed: MAOB Parkinson's](https://pubmed.ncbi.nlm.nih.gov/?term=MAOB+Parkinson+treatment)

Background

The study of Maob 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.

Brain Atlas Resources

• [Allen Human Brain Atlas - MAOB Expression](https://human.brain-map.org/microarray/search/show?search_term=MAOB)
• [Allen Cell Type Atlas](https://celltypes.brain-map.org/)
• [BrainSpan Atlas of the Developing Human Brain](https://brainspan.org/)

Allen Brain Atlas Data

Single-cell RNA sequencing data from the Allen Brain Atlas shows MAOB expression:

• Substantia nigra pars compacta: High expression in dopaminergic neurons
• Basal ganglia: High expression in striatum (caudate and putamen)
• Hippocampus: Moderate expression in pyramidal neurons of CA regions
• Cerebral cortex: Low to moderate expression across cortical layers
• Locus coeruleus: Expression in noradrenergic neurons

• MAOB is predominantly expressed in glial cells (astrocytes and microglia) rather than neurons
• Elevated MAOB expression in Parkinson's disease may reflect increased astrocyte activation
• The enzyme is localized to the outer mitochondrial membrane
• MAOB expression increases with age in the human brain

• [Allen Brain Atlas - MAOB Expression](https://portal.brain-map.org/)
• [Allen Cell Type Atlas - MAOB in Neurons and Glia](https://celltypes.brain-map.org/)

References

Pathway Diagram

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