SV2A — Synaptic Vesicle Protein 2A

SV2A Gene

<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">SV2A — Synaptic Vesicle Protein 2A</th>
</tr>
<tr>
<td class="label">Gene Symbol</td>
<td>SV2A</td>
</tr>
<tr>
<td class="label">Full Name</td>
<td>Synaptic Vesicle Protein 2A</td>
</tr>
<tr>
<td class="label">Chromosomal Location</td>
<td>1p31.1</td>
</tr>
<tr>
<td class="label">NCBI Gene ID</td>
<td>9902</td>
</tr>
<tr>
<td class="label">OMIM ID</td>
<td>158621</td>
</tr>
<tr>
<td class="label">Ensembl ID</td>
<td>ENSG00000159166</td>
</tr>
<tr>
<td class="label">UniProt ID</td>
<td>Q9H0Y5</td>
</tr>
<tr>
<td class="label">Disease</td>
<td>Mechanism</td>
</tr>
<tr>
<td class="label">Alzheimer's Disease</td>
<td>SV2A expression reduced in AD brains; involved in synaptic loss</td>
</tr>
<tr>
<td class="label">Parkinson's Disease</td>
<td>Altered SV2A affects dopaminergic synapse function</td>
</tr>
<tr>
<td class="label">Epilepsy</td>
<td>SV2A is the therapeutic target for levetiracetum; mutations cause epilepsy</td>
</tr>
<tr>
<td class="label">Intellectual Disability</td>
<td>Haploinsufficiency affects synaptic vesicle function</td>
</tr>
<tr>
<td class="label">Target</td>
<td>Approach</td>
</tr>
<tr>
<td class="label">SV2A</td>
<td>Levetiracetam (already approved)</td>
</tr>
<tr>
<td class="label">SV2A modulators</td>
<td>Novel anti-epileptic drugs</td>

...

SV2A Gene

<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">SV2A — Synaptic Vesicle Protein 2A</th>
</tr>
<tr>
<td class="label">Gene Symbol</td>
<td>SV2A</td>
</tr>
<tr>
<td class="label">Full Name</td>
<td>Synaptic Vesicle Protein 2A</td>
</tr>
<tr>
<td class="label">Chromosomal Location</td>
<td>1p31.1</td>
</tr>
<tr>
<td class="label">NCBI Gene ID</td>
<td>9902</td>
</tr>
<tr>
<td class="label">OMIM ID</td>
<td>158621</td>
</tr>
<tr>
<td class="label">Ensembl ID</td>
<td>ENSG00000159166</td>
</tr>
<tr>
<td class="label">UniProt ID</td>
<td>Q9H0Y5</td>
</tr>
<tr>
<td class="label">Disease</td>
<td>Mechanism</td>
</tr>
<tr>
<td class="label">Alzheimer's Disease</td>
<td>SV2A expression reduced in AD brains; involved in synaptic loss</td>
</tr>
<tr>
<td class="label">Parkinson's Disease</td>
<td>Altered SV2A affects dopaminergic synapse function</td>
</tr>
<tr>
<td class="label">Epilepsy</td>
<td>SV2A is the therapeutic target for levetiracetum; mutations cause epilepsy</td>
</tr>
<tr>
<td class="label">Intellectual Disability</td>
<td>Haploinsufficiency affects synaptic vesicle function</td>
</tr>
<tr>
<td class="label">Target</td>
<td>Approach</td>
</tr>
<tr>
<td class="label">SV2A</td>
<td>Levetiracetam (already approved)</td>
</tr>
<tr>
<td class="label">SV2A modulators</td>
<td>Novel anti-epileptic drugs</td>
</tr>
<tr>
<td class="label">SV2A expression restoration</td>
<td>Gene therapy for epilepsy</td>
</tr>
<tr>
<td class="label">Drug</td>
<td>Mechanism</td>
</tr>
<tr>
<td class="label">Levetiracetam</td>
<td>SV2A modulator</td>
</tr>
<tr>
<td class="label">Brivaracetam</td>
<td>Higher SV2A affinity</td>
</tr>
<tr>
<td class="label">Seletracetam</td>
<td>SV2A binding</td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">2 edges</a></td>
</tr>
</table>

Introduction

Sv2A — Synaptic Vesicle Protein 2A 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

SV2A (Synaptic Vesicle Protein 2A) is a gene encoding a major synaptic vesicle protein that functions as a regulator of neurotransmitter release and is the target of the anti-epileptic drug levetiracetam. [@bajjalieh1992]

Gene Information

Function

SV2A is an integral membrane protein localized to synaptic vesicles:

• Neurotransmitter Release: Modulates vesicle fusion and neurotransmitter release kinetics
• Levetiracetam Binding: Primary target for the antiepileptic drug levetiracetam (Keppra)
• Vesicle Cycling: Involved in synaptic vesicle priming and fusion
• Calcium Regulation: May play a role in calcium-dependent release
• Synaptic Plasticity: Important for maintaining normal synaptic function and plasticity

Disease Associations

Expression

SV2A is expressed throughout the central nervous system:

• Cerebral [cortex](/brain-regions/cortex) (pyramidal neurons)
• [Hippocampus](/brain-regions/hippocampus) (CA1-CA3 regions)
• Cerebellum (granule cells, Purkinje cells)
• Basal ganglia
• [Thalamus](/brain-regions/thalamus)
• Brainstem
• Spinal cord

Therapeutic Targeting

Key Publications

SV2A is the synaptic vesicle protein for levetiracetam - Nature (2004) - PMID: 14764983(https://pubmed.ncbi.nlm.nih.gov/14764983/)

SV2A structure and function - J Biol Chem (2008) - PMID: 18586678(https://pubmed.ncbi.nlm.nih.gov/18586678/)

SV2A in Alzheimer's disease - Brain (2012) - PMID: 22166481(https://pubmed.ncbi.nlm.nih.gov/22166481/)

SV2A and synaptic plasticity - Proc Natl Acad Sci (2015) - PMID: 25675510(https://pubmed.ncbi.nlm.nih.gov/25675510/)

See Also

• [Synaptic Vesicle Cycle](/cell-types/synaptic-vesicle-cycle)
• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Parkinson's Disease](/diseases/parkinsons-disease)
• [Levetiracetam](/therapeutics/levetiracetam)

Molecular Mechanisms

Structure and Topology

SV2A is a member of the major facilitator superfamily (MFS) of transporters:

• [12 Transmembrane Domains*: Organized in a typical MFS fold](/genes/ran)
• Cytoplasmic N- and C-termini: Long cytoplasmic loops for protein interactions
• [Large Vesicular Lumen Loop*: External loop between TM1 and TM2](/genes/ar)
• Conserved Motifs: MFS signature sequences in TM 2, 5, 8, and 11

Levetiracetam Binding

The SV2A protein is the direct target of levetiracetam:

• [Binding Site*: Located within transmembrane domains](/genes/ran)
• [Conformational Change*: Drug binding alters SV2A function](/genes/nct)
• [Synaptic Vesicle Release*: Modulates release probability](/genes/rel)
• [Affinities*: SV2A > SV2B > SV2C for levetiracetam binding](/genes/sv2c)

Modulation of Neurotransmitter Release

SV2A regulates synaptic transmission through multiple mechanisms:

• Vesicle Priming: Facilitates preparation of vesicles for release
• Fusion Machinery: Interacts with SNARE complex proteins
• Calcium Sensing: May modulate calcium entry through voltage-gated channels
• Release Probability: Reduces asynchronous release; normalizes synchronous release

SV2 Isoforms and Function

Three SV2 isoforms exist with distinct distributions:

• SV2A: Ubiquitous in all synaptic terminals; essential for viability
• SV2B: Predominantly in retina and some brain regions
• SV2C: Found in basal ganglia and olfactory bulb

Role in Neurodegeneration

Alzheimer's Disease

SV2A dysfunction contributes to synaptic failure in AD:

• Expression Reduction: 30-50% reduction in AD hippocampus
• Synaptic Loss: Correlates with cognitive decline
• [Aβ](/proteins/amyloid-beta) Effects: [Aβ](/proteins/amyloid-beta) oligomers reduce SV2A expression
• Therapeutic Potential: SV2A modulators may protect synapses

Parkinson's Disease

Dopaminergic terminals show specific vulnerabilities:

• Vesicle Cycling: High-frequency release demands efficient SV2A function
• [Alpha-Synuclein](/mechanisms/alpha-synuclein) Interaction: α-syn may affect SV2A trafficking
• Levetiracetam Effects: Being investigated for PD cognitive dysfunction

Epilepsy

SV2A is central to epilepsy treatment:

• Levetiracetam: First-line anti-epileptic drug targeting SV2A
• Mechanism: Reduces seizure frequency by modulating SV2A function
• Drug Resistance: Some patients show reduced SV2A expression
• Novel Therapies: Next-generation SV2A modulators in development

Therapeutic Implications

Anti-Epileptic Drugs

Neurodegeneration

• Synaptic Protection: SV2A modulators may protect against synaptic loss
• Combination Therapies: SV2A targeting with other mechanisms
• Biomarker Potential: SV2A PET ligands for synaptic density

Animal Models

Knockout Studies

• SV2A KO Mice: Viable but reduced seizure threshold
• Conditional KO: Region-specific deletion reveals circuit roles
• SV2B/SV2C Double KO: Compensatory mechanisms between isoforms

Disease Models

• Epilepsy Models: SV2A expression changes during seizures
• AD Models: SV2A reduction in [APP](/entities/app-protein) transgenic mice
• Therapeutic Testing: Levetiracetam efficacy in mouse models

Research Directions

• Structural Studies: Cryo-EM of SV2A-ligand complexes
• PET Ligands: [^11C]UCB-J for synaptic density imaging
• Gene Therapy: AAV-SV2A for epilepsy treatment
• Biomarkers: SV2A as marker of synaptic health

Clinical Significance

SV2A mutations and variations:

• Epilepsy: Rare mutations cause early-onset epilepsy
• Psychiatric Disorders: Association with schizophrenia and depression
• Drug Response: SV2A variants affect levetiracetam response

Background

The study of Sv2A — Synaptic Vesicle Protein 2A 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

External Links

• [NCBI Gene: SV2A](/- [UniProt: SV2A](https://www.uniprot.org/uniprot/Q9H0Y5)
• [GeneCards: SV2A](https://www.genecards.org/cgi-bin/card- [OMIM: SV2A](https://www.omim.org/entry/158621)

Pathway Diagram

The following diagram shows the key molecular relationships involving SV2A — Synaptic Vesicle Protein 2A discovered through SciDEX knowledge graph analysis: