ACVR2A Gene

ACVR2A — Activin A Receptor Type 2A

<div class="infobox infobox-gene">
<table>
<tr><th colspan="2" style="background:#e8f4ea; text-align:center; font-size:1.1em;">Activin A Receptor Type 2A</th></tr>
<tr><td><strong>Gene Symbol</strong></td><td>ACVR2A</td></tr>
<tr><td><strong>Full Name</strong></td><td>Activin A Receptor Type 2A</td></tr>
<tr><td><strong>Chromosome</strong></td><td>2q22.3</td></tr>
<tr><td><strong>NCBI Gene ID</strong></td><td>[92](https://www.ncbi.nlm.nih.gov/gene/92)</td></tr>
<tr><td><strong>OMIM</strong></td><td>[102581](https://www.omim.org/entry/102581)</td></tr>
<tr><td><strong>Ensembl ID</strong></td><td>ENSG00000198893</td></tr>
<tr><td><strong>UniProt ID</strong></td><td>[P27037](https://www.uniprot.org/uniprot/P27037)</td></tr>
<tr><td><strong>Protein Length</strong></td><td>513 amino acids</td></tr>
<tr><td><strong>Associated Diseases</strong></td><td>Alzheimer's Disease, Parkinson's Disease, Amyotrophic Lateral Sclerosis, Cancer</td></tr>
</table>
</div>

Overview

ACVR2A (Activin A Receptor Type 2A) is a member of the TGF-beta superfamily of serine/threonine kinase receptors. It functions as a type II receptor that binds activin A, activin B, and other TGF-beta superfamily ligands, forming receptor complexes with type I receptors (ALK4/ACVR1B) to transduce signals via SMAD2/3 phosphorylation [@activin2019].

ACVR2A — Activin A Receptor Type 2A

<div class="infobox infobox-gene">
<table>
<tr><th colspan="2" style="background:#e8f4ea; text-align:center; font-size:1.1em;">Activin A Receptor Type 2A</th></tr>
<tr><td><strong>Gene Symbol</strong></td><td>ACVR2A</td></tr>
<tr><td><strong>Full Name</strong></td><td>Activin A Receptor Type 2A</td></tr>
<tr><td><strong>Chromosome</strong></td><td>2q22.3</td></tr>
<tr><td><strong>NCBI Gene ID</strong></td><td>[92](https://www.ncbi.nlm.nih.gov/gene/92)</td></tr>
<tr><td><strong>OMIM</strong></td><td>[102581](https://www.omim.org/entry/102581)</td></tr>
<tr><td><strong>Ensembl ID</strong></td><td>ENSG00000198893</td></tr>
<tr><td><strong>UniProt ID</strong></td><td>[P27037](https://www.uniprot.org/uniprot/P27037)</td></tr>
<tr><td><strong>Protein Length</strong></td><td>513 amino acids</td></tr>
<tr><td><strong>Associated Diseases</strong></td><td>Alzheimer's Disease, Parkinson's Disease, Amyotrophic Lateral Sclerosis, Cancer</td></tr>
</table>
</div>

Overview

ACVR2A (Activin A Receptor Type 2A) is a member of the TGF-beta superfamily of serine/threonine kinase receptors. It functions as a type II receptor that binds activin A, activin B, and other TGF-beta superfamily ligands, forming receptor complexes with type I receptors (ALK4/ACVR1B) to transduce signals via SMAD2/3 phosphorylation [@activin2019].

ACVR2A plays critical roles in neural development, synaptic plasticity, neurogenesis, and neuronal survival. The protein is expressed throughout the brain in both neurons and glia, with particularly high expression in the [hippocampus](/brain-regions/hippocampus), [cerebral cortex](/brain-regions/cortex), and [substantia nigra](/brain-regions/substantia-nigra). Dysregulation of ACVR2A signaling has been implicated in [Alzheimer's disease](/diseases/alzheimers-disease), [Parkinson's disease](/diseases/parkinsons-disease), and other neurodegenerative conditions [@tgfbeta2021].

Structure and Biochemistry

Protein Domain Architecture

ACVR2A possesses the canonical structure of a type II TGF-beta receptor:

The kinase domain contains the conserved activation segment and regulatory sites that mediate downstream signaling through SMAD proteins.

Ligand Binding and Receptor Activation

ACVR2A binds multiple TGF-beta superfamily ligands:

• Activin A (INHBA homodimer): Primary ligand in the nervous system
• Activin B (INHBB homodimer): Alternative ligand with overlapping functions
• Inhibins: Can form complexes with ACVR2A to modulate signaling
• BMPs: Bone morphogenetic proteins can also activate ACVR2A at higher concentrations

Post-Translational Modifications

ACVR2A undergoes several post-translational modifications:

• Phosphorylation: Multiple serine/threonine residues in the kinase domain are phosphorylated during activation
• Glycosylation: N-linked glycosylation in the extracellular domain affects ligand binding
• Ubiquitination: Regulates receptor turnover and degradation
• Sumoylation: Modulates receptor stability and signaling

Normal Physiological Function

Neural Development

During development, ACVR2A signaling regulates multiple aspects of neurodevelopment [@kuo2019]:

• Neural tube patterning: Controls dorsal-ventral axis specification
• Neurogenesis: Regulates neural progenitor cell proliferation and differentiation
• Neuronal migration: Guides post-mitotic neurons to their final positions
• Axon guidance: Provides repulsive cues for growing axons
• Synaptogenesis: Controls the formation and refinement of synaptic connections

Synaptic Plasticity

In the adult brain, ACVR2A continues to play important roles in synaptic function [@activin2017]:

Long-Term Potentiation (LTP)

• Activin A enhances LTP in hippocampal neurons
• ACVR2A is required for the consolidation phase of LTP
• SMAD2/3 signaling participates in transcription-dependent LTP maintenance

Long-Term Depression (LTD)

• Activin modulates LTD induction in certain paradigms
• ACVR2A regulates AMPA receptor internalization
• Participates in synaptic scaling and homeostatic plasticity

Dendritic Spines

• Controls dendritic spine morphology
• Regulates spine density and stability
• Modulates synaptic strength through structural plasticity

Neurogenesis

ACVR2A signaling regulates adult neurogenesis in the [hippocampus](/brain-regions/hippocampus) [@yuan2020]:

• Promotes neural progenitor cell (NPC) proliferation in the subventricular zone and dentate gyrus
• Controls differentiation toward neuronal fate
• Supports survival of newly generated neurons
• Facilitates integration into existing circuits

Neuroprotection

ACVR2A activation provides neuroprotective effects through multiple mechanisms [@activin2019a]:

• Anti-apoptotic signaling: Promotes neuronal survival through PI3K/AKT pathway activation
• Anti-excitotoxic effects: Protects against glutamate-induced excitotoxicity
• Anti-inflammatory actions: Modulates microglial activation and cytokine production
• Oxidative stress reduction: Enhances antioxidant defenses

Expression Pattern

Brain Regional Distribution

ACVR2A exhibits widespread expression throughout the central nervous system:

• Hippocampus: High expression in CA1, CA3, and dentate gyrus neurons [@mueller2022]
• Cerebral cortex: Enriched in layers II-VI pyramidal neurons
• Substantia nigra: Expressed in dopaminergic neurons of the pars compacta
• Cerebellum: Purkinje cells show high expression
• Hypothalamus: Present in various nuclei including the arcuate nucleus
• Amygdala: Moderate expression in central and basal nuclei

Cellular and Subcellular Localization

Within the brain, ACVR2A is expressed in:

• Neurons: Both excitatory pyramidal neurons and inhibitory interneurons
• Astrocytes: GFAP-positive astrocytes throughout the brain
• Microglia: Resting and activated microglial cells
• Oligodendrocytes: Pre-myelinating and mature oligodendrocytes

• Plasma membrane: Primary receptor location
• Endosomes: Signaling compartments for receptor internalization
• Nucleus: Some SMAD-dependent nuclear localization

Role in Neurodegenerative Diseases

Alzheimer's Disease

ACVR2A dysfunction contributes to [Alzheimer's disease](/diseases/alzheimers-disease) pathogenesis through multiple mechanisms [@liu2021]:

Amyloid-Beta Effects

• Activin A levels are altered in AD brains and may modulate amyloid pathology
• ACVR2A signaling can influence APP processing
• Impaired SMAD signaling affects neuronal vulnerability to Aβ toxicity

Tau Pathology

• SMAD2/3 signaling dysregulated in tauopathy [@wang2021]
• ACVR2A signaling intersects with tau phosphorylation pathways
• Altered activin signaling may contribute to tau spreading

Synaptic Dysfunction

• Loss of activin/ACVR2A signaling contributes to synaptic failure
• Impaired LTP and memory consolidation
• Reduced dendritic spine density in AD models

Neuroinflammation

• Activin signaling modulates microglial activation
• ACVR2A dysfunction may exacerbate neuroinflammation
• Altered cytokine regulation in AD brains

Parkinson's Disease

ACVR2A has significant implications for [Parkinson's disease](/diseases/parkinsons-disease) [@acvra2018][@kim2023]:

Dopaminergic Neuron Survival

• Activin A promotes survival of dopaminergic neurons
• ACVR2A variants may modify PD risk
• Protective effects against 6-OHDA and MPTP toxicity

Alpha-Synuclein Pathology

• TGF-beta signaling interacts with [alpha-synuclein](/proteins/alpha-synuclein) aggregation
• ACVR2A may influence alpha-synuclein toxicity
• Protective effects against dopaminergic degeneration

Neuroinflammation

• Activin modulates microglial activation states
• May reduce pro-inflammatory cytokine production
• Potential therapeutic target for neuroinflammation

Amyotrophic Lateral Sclerosis

ACVR2A is relevant to ALS through [@taylor2019]:

• Motor neuron survival promotion
• Glial cell interactions
• Neuroinflammatory modulation
• Connection with BMP signaling pathways

Aging

Age-related changes in ACVR2A signaling contribute to neuronal vulnerability [@mueller2022]:

• Reduced ACVR2A expression in aging brain
• Impaired SMAD signaling with age
• Decreased neurogenic capacity
• Increased neuroinflammation

Molecular Pathways

ACVR2A Signaling Cascade

Cross-Talk with Other Pathways

ACVR2A signaling intersects with multiple other pathways [@chen2020]:

| Pathway | Interaction |
|---------|-------------|
| BMP signaling | Shared SMAD4, competitive and cooperative |
| PI3K/AKT | Downstream survival signaling |
| MAPK/ERK | Non-SMAD pathway activation |
| Wnt signaling | Cross-inhibition at transcriptional level |

Therapeutic Implications

Activin-Based Therapies

ACVR2A represents a promising therapeutic target for neurodegenerative diseases [@johnson2022]:

• Recombinant activin A: Protein-based delivery for neuroprotection
• Small molecule agonists: Brain-penetrant activin mimetics
• Gene therapy: Viral vector-mediated ACVR2B expression

Receptor Modulation Strategies

• ACVR2A overexpression: Increase receptor levels for enhanced signaling
• Receptor stabilization: Prevent degradation and enhance signaling
• Decoy receptors: Soluble ACVR2A-Fc fusion proteins

SMAD Pathway Enhancement

• SMAD2/3 pathway activators: Target downstream of receptor
• Inhibitory SMAD7 blockade: Reduce negative feedback
• SMAD4 enhancement: Improve nuclear translocation

Challenges and Considerations

• Delivery: Getting therapeutics across the blood-brain barrier
• Specificity: Avoiding off-target effects on related receptors
• Timing: Optimal intervention window in disease progression
• Dose optimization: Balancing efficacy with potential side effects

Research Directions

Current Knowledge Gaps

Emerging Research Areas

• Single-cell analysis: ACVR2A expression in specific neuronal subtypes
• Structural studies: ACVR2A-ligand and ACVR2A-ACVR1B complex structures
• Biomarkers: ACVR2A as disease biomarker or therapeutic response indicator
• Combination therapies: ACVR2A targeting with other disease-modifying approaches

Cross-Links

• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Parkinson's Disease](/diseases/parkinsons-disease)
• [Amyotrophic Lateral Sclerosis](/diseases/als)
• [TGF-beta Signaling Pathway](/mechanisms/tgf-beta-signaling)
• [Synaptic Plasticity](/mechanisms/synaptic-plasticity-ltp)
• [Adult Neurogenesis](/mechanisms/adult-neurogenesis)
• [Neuroinflammation](/mechanisms/neuroinflammation)
• [SMAD2/3 Signaling](/mechanisms/smad-signaling-pathway)
• [Hippocampus](/brain-regions/hippocampus)
• [Cerebral Cortex](/brain-regions/cortex)
• [Substantia Nigra](/brain-regions/substantia-nigra)
• [ACVR2B](/genes/acvr2b)
• [ACVR1](/genes/acvr1)

Key Publications

External Links

• [NCBI Gene: ACVR2A](https://www.ncbi.nlm.nih.gov/gene/92)
• [UniProt: P27037](https://www.uniprot.org/uniprot/P27037)
• [Ensembl: ENSG00000198893](https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000198893)
• [OMIM: 102581](https://www.omim.org/entry/102581)
• [GeneCards: ACVR2A](https://www.genecards.org/cgi-bin/carddisp.pl?gene=ACVR2A)

Pathway Diagram

The following diagram shows the key molecular relationships involving ACVR2A Gene discovered through SciDEX knowledge graph analysis: