SLC17A5 Protein

SLC17A5 Protein

Introduction

Slc17A5 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.

--- [@alphasynuclein2021]
title: SLC17A5 Protein [@lysosomal2019]
--- [@slca2018]

SLC17A5 Protein

Introduction

Slc17A5 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.

--- [@alphasynuclein2021]
title: SLC17A5 Protein [@lysosomal2019]
--- [@slca2018]

<div class="infobox infobox-protein"> [@sialidosis2020]
<table> [@lysosomal2022]
<tr><th colspan="2" style="background:#f8f9fa; text-align:center;">SLC17A5 Protein</th></tr> [@sialic2021]
<tr><td><b>Protein Name</b></td><td>Sialin (Sialic acid transporter)</td></tr> [@targeting2023]
<tr><td><b>Gene</b></td><td><a href="/genes/slc17a5">SLC17A5</a></td></tr>
<tr><td><b>UniProt ID</b></td><td><a href="https://www.uniprot.org/uniprot/Q9NRX3">Q9NRX3</a></td></tr>
<tr><td><b>Chromosomal Location</b></td><td>6q13</td></tr>
<tr><td><b>Description</b></td><td>Lysosomal sialic acid transporter involved in sialidosis and neurodegeneration</td></tr>
<tr><td><b>Subcellular Localization</b></td><td>Lysosome, plasma membrane</td></tr>
<tr><td><b>Protein Family</b></td><td>Solute Carrier Family 17 (SLC17)</td></tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/aging" style="color:#ef9a9a">Aging</a>, <a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/lysosomal-storage-disorder-gene-variants" style="color:#ef9a9a">LYSOSOMAL STORAGE DISORDER GENE VARIANTS</a>, <a href="/wiki/ms" style="color:#ef9a9a">Ms</a>, <a href="/wiki/parkinson's-disease" style="color:#ef9a9a">PARKINSON'S DISEASE</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">18 edges</a></td>
</tr>
</table>
</div>

Overview

Sialin (SLC17A5) is a lysosomal membrane protein that functions as a sialic acid transporter and anion channel. It plays crucial roles in lysosomal homeostasis, neurotransmitter recycling, and cellular glycobiology. Mutations in the SLC17A5 gene cause sialidosis and infantile sialic acid storage disease (ISSD), while dysregulation is implicated in Alzheimer's disease, Parkinson's disease, and various metabolic disorders.

Structure

Sialin is a polytopic membrane protein with 10-12 predicted transmembrane domains. The protein contains:

• N-terminal signal sequence: Targets the protein to the lysosomal membrane
• Transmembrane domains: Form the channel pore for sialic acid transport
• Cytoplasmic loops: Contain motifs regulating trafficking and activity
• Lysosomal targeting motifs: Ensure proper localization via mannose-6-phosphate-independent pathways

Normal Function

Sialic Acid Transport

Sialin is primarily responsible for exporting sialic acid (N-acetylneuraminic acid) from lysosomes into the cytoplasm. This function is essential for:

• Recycling of sialylated glycoconjugates: Enables reuse of sialic acid after lysosomal degradation
• Lysosomal osmotic balance: Prevents accumulation of sialic acid that would cause lysosomal swelling
• Cellular sialic acid homeostasis: Maintains proper sialylation of glycoproteins and glycolipids

Neurotransmitter Recycling

In [neurons](/entities/neurons) and glial cells, sialin participates in:

• Glutamate transport: The protein can transport glutamate, supporting excitatory neurotransmission
• Aspartate transport: Contributes to excitatory amino acid homeostasis
• Synaptic vesicle function: Sialic acid metabolism affects synaptic glycoprotein sialylation

Lysosomal Function

Sialin maintains lysosomal homeostasis through:

• pH regulation: Contributes to lysosomal acidification via proton coupling
• Metabolite export: Exports degradation products for cellular reuse
• Membrane potential maintenance: Regulates lysosomal membrane potential

Role in Neurodegeneration

Alzheimer's Disease

Sialin dysfunction contributes to AD pathogenesis through multiple mechanisms:

Parkinson's Disease

In Parkinson's disease, sialin plays important roles:

Sialidosis and Lysosomal Storage Disorders

SLC17A5 mutations cause two related disorders:

These disorders result from accumulation of sialic acid in lysosomes due to defective export.

Therapeutic Implications

Targeting sialin function offers therapeutic potential:

• Enzyme replacement: Although sialin is intracellular, gene therapy approaches are being explored
• Small molecule modulators: Compounds that enhance residual sialin function
• Substrate reduction therapy: Reducing sialic acid synthesis to decrease lysosomal burden
• chaperone therapy: Pharmacological chaperones to stabilize mutant sialin

See Also

• [SLC17A5 Gene](/genes/slc17a5)
• [Lysosomal Degradation](/mechanisms/lysosomal-degradation)
• [Sialic Acid Metabolism](/mechanisms/sialic-acid-metabolism)
• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Parkinson's Disease](/diseases/parkinsons-disease)
• [Sialidosis](/diseases/sialidosis)

Background

The study of Slc17A5 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.

External Links

• [PubMed](https://pubmed.ncbi.nlm.nih.gov/) - Biomedical literature
• [Alzheimer's Disease Neuroimaging Initiative](https://adni.loni.usc.edu/) - Research data
• [Allen Brain Atlas](https://brain-map.org/) - Brain gene expression data

References