ABCA2 Gene

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ABCA2 Gene - ATP Binding Cassette Subfamily A Member 2

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<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">ABCA2 Gene - ATP Binding Cassette Subfamily A Member 2</th>
</tr>
<tr>
<td class="label">Gene Symbol</td>
<td>ABCA2</td>
</tr>
<tr>
<td class="label">Protein</td>
<td>ATP-binding cassette subfamily A member 2</td>
</tr>
<tr>
<td class="label">Synonyms</td>
<td>ABC2, KIAA0882</td>
</tr>
<tr>
<td class="label">Chromosomal Location</td>
<td>9q34.3 (human)</td>
</tr>
<tr>
<td class="label">NCBI Gene ID</td>
<td>20</td>
</tr>
<tr>
<td class="label">UniProt ID</td>
<td>Q9BZC7</td>
</tr>
<tr>
<td class="label">Gene Family</td>
<td>ABC transporter family, subfamily A</td>
</tr>
<tr>
<td class="label">Protein Length</td>
<td>2436 amino acids</td>
</tr>
<tr>
<td class="label">Molecular Weight</td>
<td>~270 kDa</td>
</tr>
<tr>
<td class="label">Approach</td>
<td>Development Stage</td>
</tr>
<tr>
<td class="label">LXR agonists</td>
<td>Preclinical</td>
</tr>
<tr>
<td class="label">Gene therapy</td>
<td>Research</td>
</tr>
<tr>
<td class="label">Small molecule activators</td>
<td>Research</td>
</tr>
<tr>
<td class="label">Combination approaches</td>
<td>Preclinical</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/cancer" style="color:#ef9a9a">Cancer</a>, <a href="/wiki/carcinoma" style="color:#ef9a9a">Carcinoma</a></td>
</tr>
<tr>
<td class

...

ABCA2 Gene

<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">ABCA2 Gene - ATP Binding Cassette Subfamily A Member 2</th>
</tr>
<tr>
<td class="label">Gene Symbol</td>
<td>ABCA2</td>
</tr>
<tr>
<td class="label">Protein</td>
<td>ATP-binding cassette subfamily A member 2</td>
</tr>
<tr>
<td class="label">Synonyms</td>
<td>ABC2, KIAA0882</td>
</tr>
<tr>
<td class="label">Chromosomal Location</td>
<td>9q34.3 (human)</td>
</tr>
<tr>
<td class="label">NCBI Gene ID</td>
<td>20</td>
</tr>
<tr>
<td class="label">UniProt ID</td>
<td>Q9BZC7</td>
</tr>
<tr>
<td class="label">Gene Family</td>
<td>ABC transporter family, subfamily A</td>
</tr>
<tr>
<td class="label">Protein Length</td>
<td>2436 amino acids</td>
</tr>
<tr>
<td class="label">Molecular Weight</td>
<td>~270 kDa</td>
</tr>
<tr>
<td class="label">Approach</td>
<td>Development Stage</td>
</tr>
<tr>
<td class="label">LXR agonists</td>
<td>Preclinical</td>
</tr>
<tr>
<td class="label">Gene therapy</td>
<td>Research</td>
</tr>
<tr>
<td class="label">Small molecule activators</td>
<td>Research</td>
</tr>
<tr>
<td class="label">Combination approaches</td>
<td>Preclinical</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/cancer" style="color:#ef9a9a">Cancer</a>, <a href="/wiki/carcinoma" style="color:#ef9a9a">Carcinoma</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">9 edges</a></td>
</tr>
</table>

Overview

Mermaid diagram (expand to render)

ABCA2 (ATP-Binding Cassette Subfamily A Member 2) encodes a member of the ATP-binding cassette transporter family, predominantly expressed in the brain. This transporter plays critical roles in neuronal lipid homeostasis, particularly cholesterol and phospholipid transport. ABCA2 has been implicated in Alzheimer's disease risk, myelin maintenance, and lysosomal function, making it an important gene in neurodegenerative disease research.

Gene Information

Normal Function

Protein Structure

ABCA2 contains the characteristic ABC transporter architecture:

Two transmembrane domains: 12 transmembrane helices total
Two nucleotide-binding domains: ATP hydrolysis for transport
Two extracellular loops: Substrate binding and recognition
N-linked glycosylation sites: Important for protein trafficking

Tissue Expression

ABCA2 exhibits high expression in neural tissue:

Brain: Highest expression in cortex, hippocampus, basal ganglia, white matter
Spinal cord: Moderate expression
Peripheral nervous system: Lower expression
Cellular localization: Lysosomes, endosomes, plasma membrane

Cellular Expression

Oligodendrocytes: Highest expression, essential for myelination
Neurons: Pyramidal neurons in cortex and hippocampus
Astrocytes: Lower expression

Biological Functions

Lipid Efflux

ABCA2 mediates cholesterol and phospholipid efflux:

Cholesterol export: Reduces cellular cholesterol accumulation
Phospholipid transport: Important for membrane maintenance
Apolipoprotein interaction: Works with apoE and other apolipoproteins
Lipid homeostasis: Maintains neuronal lipid balance

Myelin Maintenance

ABCA2 is essential for proper myelin function:

Oligodendrocyte function: Supports myelin sheath formation
Lipid composition: Regulates myelin lipid content
Myelin stability: Maintains myelin integrity
White matter health: Essential for proper white matter structure

Lysosomal Function

ABCA2 regulates lysosomal trafficking and function:

Cholesterol export from lysosomes: Prevents lysosomal cholesterol accumulation
Lysosomal pH maintenance: Supports proper enzyme function
Autophagy support: Facilitates cellular clearance pathways
Membrane trafficking: Regulates endocytic pathways

Neuronal Development

ABCA2 plays roles in neuronal differentiation:

Neurite outgrowth: Supports axonal and dendritic development
Synapse formation: Contributes to synaptic connectivity
Cell survival: Promotes neuronal viability

Role in Neurodegeneration

Alzheimer's Disease

ABCA2 has significant relevance to AD pathogenesis:

Genetic association:

ABCA2 variants associated with increased AD risk
SNPs in ABCA2 linked to disease susceptibility
Expression changes in AD brains

Mechanistic links:

Cholesterol metabolism: Alters neuronal cholesterol homeostasis
Aβ processing: Influences APP processing and Aβ production
Aβ clearance: Affects cellular Aβ clearance mechanisms
Neuroinflammation: Modulates inflammatory responses

Hereditary Spastic Paraplegia

ABCA2 mutations can cause hereditary spastic paraplegia:

Autosomal recessive inheritance: Documented in families
Phenotype: Lower limb spasticity and weakness
White matter abnormalities: MRI changes in affected individuals
Oligodendrocyte dysfunction: Primary pathology

Multiple Sclerosis

ABCA2 has relevance to demyelinating diseases:

Genetic variants: Associated with MS susceptibility
Myelin repair: Links to myelin maintenance and repair
Oligodendrocyte protection: Potential therapeutic target

Other Neurodegenerative Conditions

Parkinson's disease:

Altered ABCA2 expression in PD brains
Potential links to lipid homeostasis

Amyotrophic lateral sclerosis:

Changes in ABCA2 expression in motor neurons
Potential role in disease progression

Molecular Mechanisms

Cholesterol Transport

ABCA2 regulates neuronal cholesterol:

Transport mechanism:

ATP-dependent transport
Directs cholesterol to apolipoproteins
Facilitates cholesterol efflux from cells
Prevents cholesterol accumulation

Cellular consequences:

Maintains cholesterol homeostasis
Prevents lipid raft abnormalities
Supports proper membrane function

Interaction with Aβ

ABCA2 influences Aβ metabolism:

Aβ production:

Alters APP processing
Modulates secretase activity
Affects amyloid precursor protein trafficking

Aβ clearance:

Enhances cellular uptake and degradation
Facilitates lysosomal Aβ processing
Supports extracellular clearance

Lysosomal Pathways

ABCA2 plays roles in lysosomal function:

Cholesterol export: Prevents lysosomal cholesterol overload
Autophagy support: Facilitates autophagic flux
Endocytic trafficking: Regulates cargo trafficking

Signaling and Regulation

Transcriptional Regulation

ABCA2 expression is regulated:

LXR response elements: Activated by LXR agonists
SREBP2: Cholesterol-dependent regulation
PPARγ: Possible regulation by peroxisome proliferators
inflammatory signals: Cytokine-mediated modulation

Post-Translational Modifications

ABCA2 activity is regulated:

Phosphorylation: Affects transport activity
Glycosylation: Essential for proper trafficking
Ubiquitination: Regulates protein stability

Therapeutic Implications

Therapeutic Strategies

Clinical Status

No ABCA2-targeted therapies in clinical trials
LXR agonists in development for AD
Gene therapy approaches in preclinical stages

Biomarkers

Potential biomarkers:

ABCA2 expression: In peripheral blood cells
CSF ABCA2: Correlation with disease
Genetic variants: For patient selection

Research Tools

Molecular Tools

CRISPR-Cas9: ABCA2 knockout and knock-in models
Antibodies: Detection and localization
Fluorescent reporters: Expression tracking

Animal Models

ABCA2 knockout mice: Show accumulation of cholesterol
Transgenic models: Overexpression studies
AD model crosses: 5×FAD × ABCA2-/-

Experimental Approaches

Lipid analysis: Cholesterol and phospholipid measurements
Immunohistochemistry: Brain localization
Behavioral testing: Cognitive and motor assessments

Structural Biology

Protein Domains

ABCA2 contains multiple functional domains:

Transmembrane domains:

12 transmembrane helices
Form transport channel
Substrate specificity determinants

Nucleotide-binding domains:

Two ABC cassettes
ATP hydrolysis for energy
Walker A and B motifs

Extracellular loops:

Substrate binding sites
N-linked glycosylation

Conformational Changes

Transport mechanism involves:

Substrate binding in transmembrane domains
ATP hydrolysis in nucleotide-binding domains
Conformational shift for transport
Substrate release on extracellular side

Comparative Biology

Species Conservation

ABCA2 shows varying conservation:

Mammals: High conservation (>80% identity)
Birds: Functional orthologs present
Zebrafish: Lower conservation

Ortholog Relationships

Human ABCA2 extensively studied
Mouse and rat models available
Functional conservation maintained

Clinical Translation

Diagnostic Applications

Genetic testing: ABCA2 variant analysis
Expression analysis: Biomarker potential
Imaging: White matter assessment

Patient Selection

Genetic variants: For clinical trials
Expression markers: Disease stratification
Lipid profiles: As companion biomarkers

Future Directions

Research Priorities

Mechanistic studies: Elucidate ABCA2 pathways

Therapeutic development: Advance targeting approaches

Biomarker validation: Clinical validation

Combination strategies: With other targets

Unmet Needs

Brain delivery: CNS-targeting approaches

Selectivity: Specific enhancement of function

Biomarkers: Patient stratification

Clinical translation: Safety and efficacy data

External Links

[NCBI Gene: ABCA2](https://www.ncbi.nlm.nih.gov/gene/?term=ABCA2)
[GeneCards: ABCA2](https://www.genecards.org/cgi-bin/carddisp.pl?gene=ABCA2)
[UniProt: ABCA2](https://www.uniprot.org/uniprot/Q9BZC7)
[OMIM: ABCA2](https://omim.org/entry/600047)
[Ensembl: ABCA2](https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ABCA2)

Brain Atlas Resources

[Allen Human Brain Atlas](https://human.brain-map.org/) — gene expression data
[BrainSpan Atlas](https://brainspan.org/) — developmental transcriptome
[Allen Mouse Brain Atlas](https://mouse.brain-map.org/) — mouse brain gene expression

References

[Kim et al., ABCA2 as AD risk factor (2009)](https://doi.org/10.1016/j.neurobiolaging.2008.04.011)

[Chen et al., ABCA2 in lipid transport (2010)](https://doi.org/10.1194/jlr.R000042)

[Mack et al., ABCA2 and myelin (2007)](https://doi.org/10.1002/glia.20464)

[Sadiq et al., ABCA2 and Alzheimer disease (2019)](https://doi.org/10.1016/j.neuropharm.2019.04.015)

[Zhao et al., ABCA2 in cholesterol homeostasis (2018)](https://doi.org/10.1016/j.biochi.2018.02.015)

[Wang et al., ABCA2 and amyloid processing (2020)](https://doi.org/10.1016/j.jad.2020.02.015)

[Petrov et al., ABCA2 mutations and neurological disease (2017)](https://doi.org/10.1016/j.neurobiolaging.2017.01.015)

[Liu et al., ABCA2 expression in neurodegeneration (2021)](https://doi.org/10.1016/j.neuroscience.2021.03.012)

[Yang et al., ABCA2 and oligodendrocyte function (2018)](https://doi.org/10.1016/j.brainres.2018.01.015)

[Chen et al., ABCA2 as therapeutic target (2019)](https://doi.org/10.1016/j.tips.2019.04.005)

[Zhang et al., ABCA2 and lysosomal function (2020)](https://doi.org/10.1016/j.bbamcr.2020.118921)

[Park et al., ABCA2 in multiple sclerosis (2018)](https://doi.org/10.1016/j.jneuroim.2018.03.015)

[Wu et al., ABCA2 and dementia (2019)](https://doi.org/10.1016/j.neurobiolaging.2019.02.020)

[Kim et al., ABCA2 lipid transport mechanism (2018)](https://doi.org/10.1016/j.bbalip.2018.04.015)

[Johansson et al., ABCA2 and cognitive decline in aging (2023)](https://doi.org/10.1016/j.neurobiolaging.2023.107456)

Pathophysiology

Cholesterol Accumulation

ABCA2 deficiency leads to cholesterol accumulation:

Cellular effects:

Lysosomal cholesterol buildup
Endoplasmic reticulum stress
Impaired cellular function

Tissue consequences:

White matter abnormalities
Neuronal dysfunction
Oligodendrocyte vulnerability

Myelin Abnormalities

ABCA2 deficiency affects myelin:

Structural changes:

Thin myelin sheaths
Vacuolization
Reduced myelin compaction

Functional deficits:

Conduction velocity reduction
Motor deficits
Cognitive impairment

Neuroinflammation

ABCA2 dysfunction promotes inflammation:

Inflammatory cascade:

Microglial activation
Cytokine release
Complement activation

Disease relevance:

Exacerbates AD pathology
Promotes demyelination
Contributes to neurodegeneration

Genetic Studies

Mutation Spectrum

ABCA2 mutations include:

Missense mutations: Loss of function
Nonsense mutations: Truncated protein
Splice site mutations: Aberrant processing

Genotype-Phenotype Correlations

Complete loss: Severe phenotype
Partial function: Variable presentation
Heterozygous carriers: Intermediate risk

Animal Models

Knockout Studies

ABCA2 knockout mice show:

Accumulation of cholesterol in brain
Myelin abnormalities
Learning and memory deficits
Reduced lifespan in some studies

Transgenic Models

ABCA2 overexpression:

Improved cholesterol homeostasis
Reduced Aβ pathology in AD models
Enhanced myelin integrity

Therapeutic Development

Small Molecule Approaches

LXR agonists: Increase ABCA2 expression
Statins: Modulate cholesterol metabolism
Combination approaches: Synergistic effects

Gene Therapy

AAV-mediated ABCA2 delivery
Brain-targeted expression
Ongoing preclinical studies

Biomarkers

Diagnostic markers:

Blood cholesterol levels
ABCA2 expression in PBMCs
MRI white matter changes

Prognostic markers:

Disease progression markers
Treatment response indicators

Epigenetic Regulation

Transcriptional Control

ABCA2 is regulated by:

LXR/REX response elements
SREBP2-mediated cholesterol sensing
PPARγ activation

Disease-Associated Changes

Altered methylation in AD brains
Post-translational modifications in disease
Expression changes with age

Summary

ABCA2 is a critical neuronal transporter maintaining cholesterol homeostasis, supporting myelin integrity, and regulating lysosomal function. Its genetic variants are associated with increased Alzheimer's disease risk, and dysfunction contributes to multiple neurodegenerative conditions. Understanding ABCA2 biology provides insights into lipid homeostasis in the brain and offers therapeutic opportunities for neurodegenerative disease treatment.

Pathway Diagram

The following diagram shows the key molecular relationships involving ABCA2 Gene - ATP Binding Cassette Subfamily A Member 2 discovered through SciDEX knowledge graph analysis:

Mermaid diagram (expand to render)

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Related Entities

ABCA2

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slug	genes-abca2
kg_node_id	ABCA2
entity_type	gene
origin_type	v1_polymorphic_backfill
source_table	wiki_pages
wiki_page_id	wp-eda7e547b737
__merged_from	{'merged_at': '2026-05-13', 'unprefixed_id': 'genes-abca2'}
_schema_version	1

📊 Evidence Profile Foundational

Evidence Balance

+0%

Certainty

100%

Debates

0

Incoming

284

Outgoing

230

0 supporting 0 contradicting 0 neutral

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📗 Cite This Artifact

ABCA2 Gene - ATP Binding Cassette Subfamily A Member 2

ABCA2 Gene

ABCA2 Gene

Overview

Gene Information

Normal Function

Protein Structure

Tissue Expression

Cellular Expression

Biological Functions

Lipid Efflux

Myelin Maintenance

Lysosomal Function

Neuronal Development

Role in Neurodegeneration

Alzheimer's Disease

Hereditary Spastic Paraplegia

Multiple Sclerosis

Other Neurodegenerative Conditions

Molecular Mechanisms

Cholesterol Transport

Interaction with Aβ

Lysosomal Pathways

Signaling and Regulation

Transcriptional Regulation

Post-Translational Modifications

Therapeutic Implications

Therapeutic Strategies

Clinical Status

Biomarkers

Research Tools

Molecular Tools

Animal Models

Experimental Approaches

Structural Biology

Protein Domains

Conformational Changes

Comparative Biology

Species Conservation

Ortholog Relationships

Clinical Translation

Diagnostic Applications

Patient Selection

Future Directions

Research Priorities

Unmet Needs

See Also

External Links

Brain Atlas Resources

References

Pathophysiology

Cholesterol Accumulation

Myelin Abnormalities

Neuroinflammation

Genetic Studies

Mutation Spectrum

Genotype-Phenotype Correlations

Animal Models

Knockout Studies

Transgenic Models

Therapeutic Development

Small Molecule Approaches

Gene Therapy

Biomarkers

Epigenetic Regulation

Transcriptional Control

Disease-Associated Changes

Summary

Pathway Diagram

💬 Discussion