SYN2 Gene

SYN2 — Synapsin II

Introduction

Syn2 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.

<div class="infobox infobox-gene"> [@gitler2008]
<table>
<tr><th colspan="2" style="background:#e8f4f8; text-align:center; font-size:1.1em;">Synapsin II</th></tr>
<tr><td><strong>Gene Symbol</strong></td><td>SYN2</td></tr>
<tr><td><strong>Full Name</strong></td><td>Synapsin II</td></tr>
<tr><td><strong>Chromosome</strong></td><td>3p25.2</td></tr>
<tr><td><strong>NCBI Gene ID</strong></td><td>[6854](https://www.ncbi.nlm.nih.gov/gene/6854)</td></tr>
<tr><td><strong>OMIM</strong></td><td>185600</td></tr>
<tr><td><strong>Ensembl ID</strong></td><td>ENSG00000153147</td></tr>
<tr><td><strong>UniProt ID</strong></td><td>[Q9UQ88](https://www.uniprot.org/uniprot/Q9UQ88)</td></tr>
<tr><td><strong>Associated Diseases</strong></td><td>Alzheimer's Disease, Parkinson's Disease, Epilepsy, Schizophrenia, Autism</td></tr>
</table>
</div>

Overview

...

SYN2 — Synapsin II

Introduction

Syn2 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.

<div class="infobox infobox-gene"> [@gitler2008]
<table>
<tr><th colspan="2" style="background:#e8f4f8; text-align:center; font-size:1.1em;">Synapsin II</th></tr>
<tr><td><strong>Gene Symbol</strong></td><td>SYN2</td></tr>
<tr><td><strong>Full Name</strong></td><td>Synapsin II</td></tr>
<tr><td><strong>Chromosome</strong></td><td>3p25.2</td></tr>
<tr><td><strong>NCBI Gene ID</strong></td><td>[6854](https://www.ncbi.nlm.nih.gov/gene/6854)</td></tr>
<tr><td><strong>OMIM</strong></td><td>185600</td></tr>
<tr><td><strong>Ensembl ID</strong></td><td>ENSG00000153147</td></tr>
<tr><td><strong>UniProt ID</strong></td><td>[Q9UQ88](https://www.uniprot.org/uniprot/Q9UQ88)</td></tr>
<tr><td><strong>Associated Diseases</strong></td><td>Alzheimer's Disease, Parkinson's Disease, Epilepsy, Schizophrenia, Autism</td></tr>
</table>
</div>

Overview

SYN2 (Synapsin II) is a neuronal phosphoprotein that plays essential roles in synaptic vesicle dynamics, neurotransmitter release, and synaptic plasticity. It is a member of the synapsin family (SYN1, SYN2, SYN3) and is primarily expressed in presynaptic terminals of [neurons](/entities/neurons) throughout the brain["@masliah2000"]. Synapsin II, along with other synapsins, is critical for maintaining synaptic vesicle pools and regulating the kinetics of neurotransmitter release, making it fundamental to normal brain function and vulnerable in neurodegenerative diseases["@gitler2008"].

Gene Structure

• Chromosomal location: 3p25.2
• Gene family: Synapsin family
• Alternative splicing: Multiple isoforms (SYN2A, SYN2B)

Protein Structure

Isoforms

• SYN2A: Longer isoform, 706 amino acids
• SYN2B: Shorter isoform, 513 amino acids

Domain Organization

• N-terminal domain: Membrane binding
• Central region: Phosphorylation sites
• C-terminal domain: Protein-protein interactions

Post-Translational Modifications

• Phosphorylation: Multiple serine sites (PKA, CaMKII)
• Alternative splicing: Generates functional variants

Molecular Function

Synaptic Vesicle Dynamics

Synapsin II orchestrates the synaptic vesicle lifecycle:

Vesicle clustering: Maintains reserve pool at terminals

Vesicle tethering: Links vesicles to cytoskeleton

Release modulation: Regulates release probability

Recycling: Facilitates vesicle reformation

Phosphorylation Regulation

| Kinase | Site | Effect |
|--------|------|--------|
| PKA | Ser9, Ser443 | Dissociates from vesicles |
| CaMKII | Multiple sites | Activity-dependent release |
| MAPK | Ser428 | Long-term plasticity |

Protein Interactions

• Synapsin I/III: Functional redundancy
• Synaptophysin: Vesicle organization
• CSPα: Chaperone function

Expression Pattern

Brain Distribution

| Region | Expression | Notes |
|--------|-----------|-------|
| [Hippocampus](/brain-regions/hippocampus) | Very High | CA1-CA3, dentate gyrus |
| Cerebral [Cortex](/brain-regions/cortex) | Very High | All layers |
| Cerebellum | High | Granule cells |
| Basal Ganglia | Moderate | Striatum |
| Brainstem | Moderate | Motor nuclei |

Cellular Localization

• Presynaptic terminals
• Synaptic vesicles
• Cytoskeleton-associated

Role in Disease

Alzheimer's Disease

• Downregulation: Significant reduction in AD brain
• Synaptic loss: Correlates with cognitive decline
• Mechanisms: Transcriptional dysregulation
• Biomarker potential: CSF synapsin II

Parkinson's Disease

• Reduced expression: In substantia nigra
• [α-Synuclein](/proteins/alpha-synuclein) interactions: Pathological links
• Dopaminergic terminals: Vulnerability

Epilepsy

• Mutations: Associated with seizure disorders
• Altered dynamics: Affects release probability
• Therapeutic target: Modulators in development

Neuropsychiatric Disorders

• Schizophrenia: Altered expression
• Autism: Rare variants identified
• Bipolar disorder: Genetic associations

Therapeutic Approaches

Drug Development

• Synapsin modulators: Small molecule approaches
• Gene therapy: AAV-mediated expression
• Neuroprotective strategies: Preserve synaptic function

Biomarker Applications

• CSF synapsin II measurement
• Disease progression monitoring

Research Directions

Structural studies: Domain function

Therapeutic development: Targeted approaches

Genetics: Variant analysis

Biomarkers: Clinical utility

Animal models: Knockout studies

Animal Models

• SYN2 knockout: Viable with subtle deficits
• Double knockouts: Synapsin redundancy
• Transgenic: Disease models

Disease Associations

Top DisGeNET gene-disease associations for this gene are listed below. Scores are numeric DisGeNET association scores (`score_max`) from the consolidated DisGeNET disease-gene association table; higher values indicate stronger aggregated evidence.

| Disease | DisGeNET score | Evidence sources | Supporting PMID count |
|---|---:|---|---:|
| autistic disorder | 0.100 | BeFree/MGD | 1 |
| epilepsy syndrome | 0.003 | BeFree/GAD | 3 |
| type 2 diabetes mellitus | 0.002 | GAD | 1 |
| bipolar disorder | 0.001 | BeFree | 3 |
| Alzheimer's disease | 0.000 | BeFree | 1 |

Source: DisGeNET-derived consolidated disease-gene associations (`dhimmel/disgenet`, gene symbol `SYN2`).

See Also

• [Synapsin II Protein](/proteins/synapsin-2)
• [SYN1 Gene](/proteins/syn1-protein)
• [SYN3 Gene](/proteins/syn3-protein)
• [Synaptophysin Protein](/proteins/synaptophysin-protein)
• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Parkinson's Disease](/diseases/parkinsons-disease)
• [Epilepsy](/diseases/epilepsy)
• [Synaptic Dysfunction Pathway](/mechanisms/synaptic-dysfunction-pathway)

External Links

• [NCBI Gene: SYN2](https://www.ncbi.nlm.nih.gov/gene/6854)
• [UniProt: Q9UQ88](https://www.uniprot.org/uniprot/Q9UQ88)
• [Ensembl: ENSG00000153147](https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000153147)
• [Allen Brain Atlas: SYN2](https://human.brain-map.org/microarray/search/show?search_term=SYN2)

Background

The study of Syn2 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.

References

Masliah E, et al, Synapsins in neurodegenerative disease (2000)

Gitler D, et al, Synapsin and Parkinson's disease (2008)

Pathway Diagram

The following diagram shows the key molecular relationships involving SYN2 Gene discovered through SciDEX knowledge graph analysis: