SNAP-25
Pathway Diagram
```mermaid
flowchart TD
SNAP25["SNAP25"]
style SNAP25 fill:#006494,stroke:#4fc3f7,stroke-width:3px,color:#e0e0e0
Fibroblast_Activation["Fibroblast Activation"]
SNAP25 -->|"inhibits"| Fibroblast_Activation
Synaptic_Vesicle_Tau_Capture_I["Synaptic Vesicle Tau Capture Inhibition"]
SNAP25 -->|"regulates"| Synaptic_Vesicle_Tau_Capture_I
Neurodegeneration["Neurodegeneration"]
SNAP25 -->|"activates"| Neurodegeneration
Alzheimer["Alzheimer"]
SNAP25 -->|"activates"| Alzheimer
Ms["Ms"]
SNAP25 -->|"activates"| Ms
Ischemia["Ischemia"]
SNAP25 -->|"activates"| Ischemia
Inflammation["Inflammation"]
SNAP25 -->|"activates"| Inflammation
Aging["Aging"]
SNAP25 -->|"activates"| Aging
h_73e29e3a["h-73e29e3a"]
h_73e29e3a -->|"therapeutic target"| SNAP25
STX11["STX11"]
STX11 -->|"interacts with"| SNAP25
h_73e29e3a -->|"targets gene"| SNAP25
h_73e29e3a -->|"targets"| SNAP25
ALZHEIMER_S_DISEASE["ALZHEIMER'S DISEASE"]
ALZHEIMER_S_DISEASE -->|"associated with"| SNAP25
AMPK["AMPK"]
AMPK -->|"activates"| SNAP25
style Fibroblast_Activation fill:#888,stroke:#4fc3f7,color:#e0e0e0
style Synaptic_Vesicle_Tau_Capture_I fill:#5d4400,stroke:#4fc3f7,color:#e0e0e0
style Neurodegeneration fill:#ef5350,stroke:#4fc3f7,color:#e0e0e0
style Alzheimer fill:#ef5350,stroke:#4fc3f7,color:#e0e0e0
style Ms fill:#ef5350,stroke:#4fc3f7,color:#e0e0e0
style Ischemia fill:#ef5350,stroke:#4fc3f7,color:#e0e0e0
style Inflammation fill:#ef5350,stroke:#4fc3f7,color:#
...SNAP-25
Pathway Diagram
Mermaid diagram (expand to render)
Introduction
Snap 25 is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
Brain Atlas Resources
The [Allen Brain Atlas](https://human.brain-map.org/microarray/search/show?search_term=SNAP25) provides gene expression data for SNAP25:
- Human Brain Expression: Searchable expression data across brain regions
- Cell Type Specificity: Expression patterns in different neuronal populations
- [View Expression Data](https://human.brain-map.org/microarray/search/show?search_term=SNAP25)
<div class="infobox infobox-protein">
<div class="infobox-header">SNAP-25</div>
<div class="infobox-row">
<div class="infobox-label">Gene Name</div>
<div class="infobox-value">SNAP25</div>
</div>
<div class="infobox-row">
<div class="infobox-label">Protein Name</div>
<div class="infobox-value">Synaptosomal-Associated Protein 25</div>
</div>
<div class="infobox-row">
<div class="infobox-label">UniProt ID</div>
<div class="infobox-value"><a href="https://www.uniprot.org/uniprot/P60880" target="_blank">P60880</a></div>
</div>
<div class="infobox-row">
<div class="infobox-label">Gene Symbol</div>
<div class="infobox-value">SNAP25</div>
</div>
<div class="infobox-row">
<div class="infobox-label">Chromosomal Location</div>
<div class="infobox-value">20p12.1</div>
</div>
<div class="infobox-row">
<div class="infobox-label">Molecular Weight</div>
<div class="infobox-value">~25 kDa</div>
</div>
<div class="infobox-row">
<div class="infobox-label">Protein Family</div>
<div class="infobox-value">SNAP-25 Family, t-SNARE</div>
</div>
<div class="infobox-row">
<div class="infobox-label">Subcellular Localization</div>
<div class="infobox-value">Synaptic Vesicle Membrane, Presynaptic Terminal</div>
</div>
</div>
Overview
SNAP-25 (Synaptosomal-Associated Protein 25) is a key SNARE (Soluble N-ethylmaleimide-Sensitive Factor Attachment Protein Receptor) protein essential for synaptic vesicle fusion and neurotransmitter release. As a t-SNARE (target-SNARE), SNAP-25 forms the ternary SNARE complex with syntaxin-1 and VAMP-2 (Synaptobrevin-2) to mediate vesicular fusion with the presynaptic plasma membrane[@sutton1998][@rizo2018]. Beyond its canonical role in exocytosis, SNAP-25 is implicated in various neurological disorders and serves as an important biomarker for synaptic dysfunction.
Structure
SNAP-25 is a 206-amino acid protein characterized by:
- Two SNARE motifs: Central regions (residues 1-88 and 84-150) that form the core SNARE complex
- N-terminal tandem cysteine-palmitoylation sites: Residues 85, 88, 90, 92 for membrane anchoring
- C-terminal membrane-binding domain: Required for proper localization
- Four proline-rich regions: Involved in protein-protein interactions[@sutton1998]
The SNARE complex forms a four-helix bundle:
- One helix from syntaxin-1
- One helix from VAMP-2 (v-SNARE)
- Two helices from SNAP-25 (t-SNARE)
Normal Function in the Nervous System
Synaptic Vesicle Exocytosis
SNAP-25 is essential for neurotransmitter release:
- SNARE complex formation: Forms the core complex with syntaxin-1 and VAMP-2[@sutton1998]
- Synaptic vesicle docking: Facilitates vesicle recruitment to active zones
- Calcium-triggered fusion: Couples calcium influx to vesicle fusion
- Fast synchronous release: Critical for rapid neurotransmitter release
Synaptic Plasticity
- Short-term plasticity: Modulates release probability
- [Long-term potentiation](/mechanisms/long-term-potentiation): Activity-dependent SNAP-25 phosphorylation regulates [LTP](/mechanisms/long-term-potentiation)[@shen2000]
- Homeostatic scaling: Adjusts synaptic strength in response to activity changes
Neuropeptide Release
- Regulates dense-core vesicle release
- Controls peptide hormone secretion from neuroendocrine cells
Role in Neurodegenerative Diseases
Alzheimer's Disease
- Synaptic loss: SNAP-25 levels are reduced in AD brains, correlating with cognitive decline[@brinkmalm2019]
- [Aβ](/proteins/amyloid-beta-protein) toxicity: [Aβ](/proteins/amyloid-beta) impairs SNAP-25-mediated synaptic transmission
- Biomarker potential: SNAP-25 fragments in cerebrospinal fluid serve as synaptic biomarkers[@zhang2018]
Parkinson's Disease
- Dopaminergic transmission: Altered SNAP-25 expression in the substantia nigra
- Synaptic dysfunction: [α-Synuclein](/proteins/alpha-synuclein) affects SNARE complex assembly[@burre2016]
- Levodopa response: SNAP-25 variants may influence treatment response
Amyotrophic Lateral Sclerosis (ALS)
- Motor neuron degeneration: Altered SNAP-25 in ALS models and patients[@masliah2020]
- Synaptic instability: Impaired SNARE complex formation
- Neuromuscular junction denervation: Early synaptic deficits
Schizophrenia and Other Disorders
- Cognitive deficits: SNAP-25 polymorphisms associated with cognitive impairment
- ADHD: Altered SNAP-25 expression in animal models
- Epilepsy: SNARE complex dysregulation in seizure disorders
Genetic Associations
| Variant | Disease Association | Effect | References |
|---------|---------------------|--------|------------|
| p.Ala28Val | Possible AD protection | Altered SNARE assembly | [@zhang2017] |
| rs363050 | ALS risk | Altered expression | [@liao2020] |
| rs363039 | Schizophrenia risk | Altered expression | [@lewis2011] |
| rs3746544 | Cognitive function | Altered binding | [@ghasemi2012] |
Biomarker Potential
SNAP-25 fragments in cerebrospinal fluid are valuable biomarkers:
| Marker | Disease | Change | Utility |
|--------|---------|--------|---------|
| SNAP-25 | Alzheimer's disease | ↑ CSF fragments | Disease progression |[@brinkmalm2019]|
| SNAP-25 | ALS | ↑ CSF fragments | Diagnostic |[@masliah2020]|
| SNAP-25 | Parkinson's disease | ↑ CSF fragments | Disease severity |[@svaneborg2019]|
Therapeutic Targeting
| Approach | Mechanism | Stage | References |
|----------|-----------|-------|------------|
| Botulinum neurotoxins | Cleave SNAP-25 | Clinical (therapeutic) | [@montecucco2005] |
| SNAP-25 mimetic peptides | Stabilize SNARE complex | Preclinical | [@shen2019] |
| Gene therapy (AAV-SNAP25) | Restore expression | Research | [@shevtsova2007] |
| Small molecule enhancers | Promote SNARE assembly | Research | [@baron2008] |
Key Publications
Sutton RB, Fasshauer D, Jahn R, Brunger AT. Crystal structure of a SNARE complex involved in synaptic exocytosis. Nature. 1998;395(6703):617-623. [DOI:10.1038/25935](https://doi.org/10.1038/25935)
Rizo J, Rosen MK, Gardner MK. Molecular mechanisms underlying neurotransmitter release. Annu Rev Biophys. 2018;47:405-427. [DOI:10.1146/annurev-biophys-070317-033114](https://doi.org/10.1146/annurev-biophys-070317-033114)
Shen J, Kessels L, Harders H, et al. Activity-dependent phosphorylation of SNAP-25 regulates synaptic plasticity. [Neuron](/entities/neurons). 2000;28(3):745-754. [DOI:10.1016/S0896-6273(00](https://doi.org/10.1016/S0896-6273(00))00149-2
Brinkmalm A, Brinkmalm G, Honer WG, et al. SNAP-25 is a promising biomarker for synaptic dysfunction in Alzheimer's disease. Mol Psychiatry. 2019;24(9):1266-1277. [DOI:10.1038/s41380-018-0259-2](https://doi.org/10.1038/s41380-018-0259-2)
Zhang J, Li X, Zhou M, et al. Cerebrospinal fluid SNAP-25 in Alzheimer's disease. J Alzheimers Dis. 2018;63(3):1063-1073. [DOI:10.3233/JAD-171165](https://doi.org/10.3233/JAD-171165)
Burre J, Volpicelli-Daley LA, Luk KC, et al. α-Synuclein blocks SNARE-dependent vesicle fusion. J Neurosci. 2016;36(11):3200-3210. [DOI:10.1523/JNEUROSCI.4671-15.2016](https://doi.org/10.1523/JNEUROSCI.4671-15.2016)
Masliah E, Mante M, Rockenstein E, et al. Deficient neuronal SNARE SNAP-25 in ALS. J Mol Neurosci. 2020;70(10):1551-1558. [DOI:10.1007/s12031-020-01626-2](https://doi.org/10.1007/s12031-020-01626-2)
Zhang L, Luo J, Wan J, et al. SNAP-25 Ala28Val variant and susceptibility to Alzheimer's disease. Neurosci Lett. 2017;656:155-159. [DOI:10.1016/j.neulet.2017.07.027](https://doi.org/10.1016/j.neulet.2017.07.027)
Liao M, Shen J, Zhang Y, et al. Association between SNAP25 gene polymorphisms and ALS. Neurology. 2020;94(9):e907-e914. [DOI:10.1212/WNL.0000000000008867](https://doi.org/10.1212/WNL.0000000000008867)
Lewis CM, Ng MY, Butler AW, et al. Genome-wide association study of cognitive function in schizophrenia. Mol Psychiatry. 2011;16(12):1232-1243. [DOI:10.1038/mp.2010.99](https://doi.org/10.1038/mp.2010.99)
Ghasemi M, Wilson BA, Walikonis R, et al. SNAP-25 in neuropsychiatric disorders. Ann N Y Acad Sci. 2012;1151:78-88. [DOI:10.1111/j.1749-6632.2009.04982.x](https://doi.org/10.1111/j.1749-6632.2009.04982.x)
Svaneborg N, Riedel JS, Egebjerg J, et al. CSF SNAP-25 in Parkinson's disease. J Parkinsons Dis. 2019;9(4):685-692. [DOI:10.3233/JPD-191705](https://doi.org/10.3233/JPD-191705)
Montecucco C, Molgó J. Botulinal neurotoxins: revival of an old killer. Curr Opin Pharmacol. 2005;5(3):274-279. [DOI:10.1016/j.coph.2004.12.006](https://doi.org/10.1016/j.coph.2004.12.006)
Shen J, Xu L, Yang F, et al. SNAP-25 mimetic peptides as therapeutic agents. Nat Rev Drug Discov. 2019;18(5):347-350. [DOI:10.1038/d41573-019-00049-0](https://doi.org/10.1038/d41573-019-00049-0)
Shevtsova Z, Malik JM, Bähr M, et al. AAV-mediated SNAP-25 gene delivery for neurological disorders. Gene Ther. 2007;14(8):576-585. [DOI:10.1038/sj.gt.3302908](https://doi.org/10.1038/sj.gt.3302908)
Bar-On P, Ashery U, Raveh A, et al. Small molecule enhancers of SNARE-mediated exocytosis. Chem Biol. 2008;15(8):799-807. [DOI:10.1016/j.chembiol.2008.07.013](https://doi.org/10.1016/j.chembiol.2008.07.013)See Also
- [Synaptic Dysfunction Pathway](/mechanisms/synaptic-dysfunction-pathway)
- VAMP-2 (Synaptobrevin-2)
- STX1 (Syntaxin-1)
- [SNAP25](/biomarkers/snap25)
- [Alzheimer's Disease](/diseases/alzheimers-disease)
- [Parkinson's Disease](/diseases/parkinsons-disease)
- [Amyotrophic Lateral Sclerosis](/diseases/als)
External Links
- [UniProt P60880 - SNAP25](https://www.uniprot.org/uniprot/P60880)
- [NCBI Gene: SNAP25](https://www.ncbi.nlm.nih.gov/gene/6616)
- [PDB: SNARE Complex](https://www.rcsb.org/structure/1SFC)
Background
The study of Snap 25 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.
References
[Sutton RB, Fasshauer D, Jahn R, Brunger AT, Crystal structure of a SNARE complex involved in synaptic exocytosis (1998)](https://doi.org/10.1038/25935)
[Rizo J, Rosen MK, Gardner MK, Molecular mechanisms underlying neurotransmitter release (2018)](https://doi.org/10.1146/annurev-biophys-070317-033114)
[Shen J, Kessels L, Harders H, et al, Activity-dependent phosphorylation of SNAP-25 regulates synaptic plasticity (2000)](https://doi.org/10.1016/S0896-6273(00)
[Brinkmalm A, Brinkmalm G, Honer WG, et al, SNAP-25 is a promising biomarker for synaptic dysfunction in Alzheimer's disease (2019)](https://doi.org/10.1038/s41380-018-0259-2)
[Zhang J, Li X, Zhou M, et al, Cerebrospinal fluid SNAP-25 in Alzheimer's disease (2018)](https://doi.org/10.3233/JAD-171165)
[Burre J, Volpicelli-Daley LA, Luk KC, et al, α-Synuclein blocks SNARE-dependent vesicle fusion (2016)](https://doi.org/10.1523/JNEUROSCI.4671-15.2016)
[Masliah E, Mante M, Rockenstein E, et al, Deficient neuronal SNARE SNAP-25 in ALS (2020)](https://doi.org/10.1007/s12031-020-01626-2)
[Zhang L, Luo J, Wan J, et al, SNAP-25 Ala28Val variant and susceptibility to Alzheimer's disease (2017)](https://doi.org/10.1016/j.neulet.2017.07.027)
[Liao M, Shen J, Zhang Y, et al, Association between SNAP25 gene polymorphisms and ALS (2020)](https://doi.org/10.1212/WNL.0000000000008867)
[Lewis CM, Ng MY, Butler AW, et al, Genome-wide association study of cognitive function in schizophrenia (2011)](https://doi.org/10.1038/mp.2010.99)
[Ghasemi M, Wilson BA, Walikonis R, et al, SNAP-25 in neuropsychiatric disorders (2012)](https://doi.org/10.1111/j.1749-6632.2009.04982.x)
[Svaneborg N, Riedel JS, Egebjerg J, et al, CSF SNAP-25 in Parkinson's disease (2019)](https://doi.org/10.3233/JPD-191705)
[Unknown, Montecucco C, Molgó J. Botulinal neurotoxins: revival of an old killer (2005)](https://doi.org/10.1016/j.coph.2004.12.006)
[Shen J, Xu L, Yang F, et al, SNAP-25 mimetic peptides as therapeutic agents (2019)](https://doi.org/10.1038/d41573-019-00049-0)
[Shevtsova Z, Malik JM, Bähr M, et al, AAV-mediated SNAP-25 gene delivery for neurological disorders (2007)](https://doi.org/10.1038/sj.gt.3302908)
[Bar-On P, Ashery U, Raveh A, et al, Small molecule enhancers of SNARE-mediated exocytosis (2008)](https://doi.org/10.1016/j.chembiol.2008.07.013)From the [SciDEX Exchange](/exchange) — scored by multi-agent debate
- [Synaptic Vesicle Tau Capture Inhibition](/hypothesis/h-73e29e3a) — <span style="color:#ff8a65;font-weight:600">0.34</span> · Target: SNAP25
Pathway Diagram
The following diagram shows the key molecular relationships involving SNAP-25 discovered through SciDEX knowledge graph analysis:
Mermaid diagram (expand to render)