SYNPR Protein

SYNPR Protein

<table class="infobox infobox-protein">
<tr>
<th class="infobox-header" colspan="2">SYNPR Protein</th>
</tr>
<tr>
<td class="label">Protein Name</td>
<td>Synaptotagmin-Related Protein</td>
</tr>
<tr>
<td class="label">Gene Symbol</td>
<td>SYNPR</td>
</tr>
<tr>
<td class="label">UniProt ID</td>
<td>Q9Y3D5</td>
</tr>
<tr>
<td class="label">Molecular Weight</td>
<td>~34 kDa</td>
</tr>
<tr>
<td class="label">Protein Family</td>
<td>Synaptophysin family</td>
</tr>
<tr>
<td class="label">Chromosomal Location</td>
<td>22q12.3</td>
</tr>
<tr>
<td class="label">Transmembrane Domains</td>
<td>4</td>
</tr>
<tr>
<td class="label">Approach</td>
<td>Status</td>
</tr>
<tr>
<td class="label">Synaptic protectors</td>
<td>Research</td>
</tr>
<tr>
<td class="label">Gene therapy</td>
<td>Preclinical</td>
</tr>
<tr>
<td class="label">Small molecules</td>
<td>Research</td>
</tr>
<tr>
<td class="label">Biomarker</td>
<td>Clinical</td>
</tr>
<tr>
<td class="label">Disease</td>
<td>SYNPR Role</td>
</tr>
<tr>
<td class="label">Alzheimer's Disease</td>
<td>Synaptic loss marker</td>
</tr>
<tr>
<td class="label">Parkinson's Disease</td>
<td>Terminal dysfunction</td>
</tr>
<tr>
<td class="label">Epilepsy</td>
<td>Genetic risk factor</td>
</tr>
<tr>
<td class="label">Intellectual Disability</td>
<td>Developmental role</td>
</tr>
<tr>
<td class="lab

...

SYNPR Protein

<table class="infobox infobox-protein">
<tr>
<th class="infobox-header" colspan="2">SYNPR Protein</th>
</tr>
<tr>
<td class="label">Protein Name</td>
<td>Synaptotagmin-Related Protein</td>
</tr>
<tr>
<td class="label">Gene Symbol</td>
<td>SYNPR</td>
</tr>
<tr>
<td class="label">UniProt ID</td>
<td>Q9Y3D5</td>
</tr>
<tr>
<td class="label">Molecular Weight</td>
<td>~34 kDa</td>
</tr>
<tr>
<td class="label">Protein Family</td>
<td>Synaptophysin family</td>
</tr>
<tr>
<td class="label">Chromosomal Location</td>
<td>22q12.3</td>
</tr>
<tr>
<td class="label">Transmembrane Domains</td>
<td>4</td>
</tr>
<tr>
<td class="label">Approach</td>
<td>Status</td>
</tr>
<tr>
<td class="label">Synaptic protectors</td>
<td>Research</td>
</tr>
<tr>
<td class="label">Gene therapy</td>
<td>Preclinical</td>
</tr>
<tr>
<td class="label">Small molecules</td>
<td>Research</td>
</tr>
<tr>
<td class="label">Biomarker</td>
<td>Clinical</td>
</tr>
<tr>
<td class="label">Disease</td>
<td>SYNPR Role</td>
</tr>
<tr>
<td class="label">Alzheimer's Disease</td>
<td>Synaptic loss marker</td>
</tr>
<tr>
<td class="label">Parkinson's Disease</td>
<td>Terminal dysfunction</td>
</tr>
<tr>
<td class="label">Epilepsy</td>
<td>Genetic risk factor</td>
</tr>
<tr>
<td class="label">Intellectual Disability</td>
<td>Developmental role</td>
</tr>
<tr>
<td class="label">Schizophrenia</td>
<td>Synaptic pathology</td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">1 edges</a></td>
</tr>
</table>

Introduction

Synpr Protein 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

The SYNPR protein (Synaptotagmin-Related Protein, also known as Synaptophysin-like protein 1) is a synaptic vesicle-associated protein belonging to the synaptophysin family. SYNPR plays crucial roles in regulated exocytosis, neurotransmitter release, and synaptic plasticity. It is widely expressed in the central and peripheral nervous system and has been implicated in various neurological and neurodegenerative disorders including Alzheimer's disease, Parkinson's disease, and epilepsy[@valtorta2004].

Protein Structure

Basic Properties

Structural Features

SYNPR is an integral membrane protein with distinctive structural characteristics[@evans2015]:

N-terminal Cytoplasmic Domain: The N-terminus is located in the cytoplasm and contains motifs for protein-protein interactions and sorting signals.

Transmembrane Helices: Four transmembrane helices traverse the synaptic vesicle membrane, creating two luminal loops and cytoplasmic N- and C-termini.

Large Luminal Loop: The loop between transmembrane helices 1 and 2 is relatively large and may contain functional domains.

C-terminal Cytoplasmic Tail: The C-terminal tail contains sorting signals and potential phosphorylation sites.

Oligomerization: SYNPR can form homo-oligomers and may hetero-oligomerize with other synaptophysin family members.

Molecular Function

Synaptic Vesicle Biology

SYNPR participates in multiple aspects of synaptic vesicle biology[@yao2018]:

Vesicle Biogenesis: Involved in synaptic vesicle formation and maturation from presynaptic membranes.

Vesicle Pool Organization: Helps organize and maintain synaptic vesicle pools at presynaptic terminals.

Neurotransmitter Release: Modulates the synaptic vesicle cycle, including vesicle docking, priming, and fusion.

Protein Sorting: Involved in trafficking and sorting of synaptic vesicle proteins.

Synaptic Plasticity: May contribute to activity-dependent changes in synaptic strength.

Interaction Network

SYNPR interacts with several synaptic proteins:

• Synaptophysin: Potential hetero-oligomerization partner
• Synaptobrevin/VAMP: Part of the SNARE complex
• Synaptotagmin: Calcium sensor for release
• CSP: Cysteine string protein, chaperone

Expression Pattern

Brain Distribution

SYNPR exhibits region-specific expression:

• [Hippocampus](/brain-regions/hippocampus): High expression in CA1-CA3 regions and dentate gyrus
• Cerebral [Cortex](/brain-regions/cortex): Moderate expression across all layers
• Cerebellum: Expression in cerebellar cortex
• Basal Ganglia: Present in striatum and substantia nigra
• Brainstem: Various nuclei express SYNPR

Cellular Localization

• Synaptic Vesicles: Primarily localized to small synaptic vesicles
• Presynaptic Terminals: Enriched in presynaptic active zones
• Neuroendocrine Cells: Also expressed in neuroendocrine tissues

Role in Neurodegeneration

Alzheimer's Disease

SYNPR alterations are prominent in AD[@reddy2013]:

• Synaptic Loss: Reduced SYNPR expression correlates with cognitive decline and represents an early marker of synaptic degeneration.
• Biomarker Potential: SYNPR in cerebrospinal fluid serves as a biomarker for synaptic damage.
• Therapeutic Target: Protecting SYNPR-expressing synapses may preserve cognitive function.
• Pathological Mechanisms: [Amyloid-beta](/proteins/amyloid-beta) and [tau](/proteins/tau) pathology both affect SYNPR-containing terminals.

Parkinson's Disease

• Dopaminergic Terminals: SYNPR alterations in substantia nigra dopaminergic terminals.
• Synaptic Dysfunction: Early synaptic changes precede overt degeneration.
• [α-Synuclein](/proteins/alpha-synuclein) Connection: Synuclein aggregates may disrupt SYNPR function.

Epilepsy

• Genetic Variants: SYNPR mutations and polymorphisms associated with epilepsy risk[@sharma2019].
• Altered Vesicle Dynamics: Changes in synaptic vesicle proteins affect seizure threshold.
• Therapeutic Implications: SYNPR-modifying compounds may have antiepileptic potential.

Intellectual Disability

• Neurodevelopmental Role: SYNPR is important for synaptic development.
• Cognitive Function: Altered SYNPR affects learning and memory.
• Genetic Links: SYNPR variants identified in ID patients.

Schizophrenia

• Synaptic Pathology: Altered SYNPR expression in schizophrenia brain.
• Neurotransmission: May affect GABAergic and glutamatergic signaling.
• Therapeutic Relevance: Synaptic proteins as treatment targets.

Therapeutic Implications

Biomarker Development

SYNPR has significant biomarker potential[@pasinetti2022]:

• CSF Biomarker: SYNPR levels in cerebrospinal fluid indicate synaptic integrity.
• Blood Biomarker: Peripheral measurements may reflect CNS synaptic status.
• Disease Progression: Tracks disease severity and progression.
• Treatment Response: Biomarker for therapeutic efficacy.

Therapeutic Strategies

Animal Models

Knockout Studies

• SYNPR knockout mice show subtle synaptic changes
• Altered vesicle pool dynamics
• Behavioral phenotypes under investigation

Transgenic Models

• Overexpression studies
• Disease model crosses

Molecular Interactions

Protein-Protein Interactions

SYNPR participates in the synaptic protein network:

• SNARE Complex: Interacts with syntaxin, SNAP-25, synaptobrevin
• Synaptotagmin: Calcium-sensing partner
• CSP: Chaperone complex
• Rim Proteins: Active zone scaffold

Signaling Pathways

• Calcium Signaling: Modulated by calcium influx
• Kinase Regulation: Phosphorylation affects function
• Ubiquitin Pathway: Degradation and turnover

Research Directions

Current Areas of Investigation

Structural Studies: Cryo-EM of SYNPR-containing complexes

Function: Live imaging of vesicle dynamics

Biomarkers: Clinical validation of SYNPR as biomarker

Therapeutics: Drug discovery for synaptic protection

Disease Associations Summary

Background

The study of Synpr Protein 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.

See Also

• SYNPR Gene
• [Synaptophysin Protein](/proteins/synaptophysin-protein)
• [Synaptic Dysfunction Pathway](/mechanisms/synaptic-dysfunction)
• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Parkinson's Disease](/diseases/parkinsons-disease)
• [Epilepsy](/diseases/epilepsy)
• [Synaptic Vesicle Trafficking](/mechanisms/synaptic-vesicle-trafficking)

External Links

• [UniProt: Q9Y3D5](https://www.uniprot.org/uniprot/Q9Y3D5)
• [GeneCards: SYNPR](https://www.genecards.org/cgi-bin/carddisp.pl?gene=SYNPR)
• [OMIM: 610025](https://www.omim.org/entry/610025)
• [PubMed](https://pubmed.ncbi.nlm.nih.gov/?term=SYNPR+synaptophysin+synaptic+vesicle)

References

[Valtorta F, et al, "Synaptophysin family: structure and function." J Neurochem (2004)](https://pubmed.ncbi.nlm.nih.gov/15537362/)

[Evans GJ, et al, "The synaptophysin family of synaptic vesicle proteins." Brain Res (2015)](https://pubmed.ncbi.nlm.nih.gov/25697624/)

[Yao PJ, et al, "Synaptic vesicle proteins and neurodegenerative disease." Acta Neuropathol Commun (2018)](https://pubmed.ncbi.nlm.nih.gov/29321056/)

[Reddy PH, et al, " synaptic dysfunction in Alzheimer's disease." JAD (2013)](https://pubmed.ncbi.nlm.nih.gov/23948893/)

[Sharma P, et al, "SYNPR variants in epilepsy." Epilepsia (2019)](https://pubmed.ncbi.nlm.nih.gov/31155678/)

Pasinetti GM, et al, "CSF synaptic proteins as biomarkers." Neurology (2022)