TLR7 Protein

TLR7 Protein - Toll-Like Receptor 7

Introduction

Tlr7 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.

<div class="infobox .infobox-protein"> [@bsibsi2002]
<table>
<tr><th colspan="2" style="background:#f0f0f0;">Protein Information</th></tr>
<tr><td><strong>Protein Name</strong></td><td>Toll-Like Receptor 7 (TLR7)</td></tr>
<tr><td><strong>Gene</strong></td><td>TLR7</td></tr>
<tr><td><strong>UniProt ID</strong></td><td>Q9NYK5</td></tr>
<tr><td><strong>PDB Structure</strong></td><td>5GMF, 5ZFM</td></tr>
<tr><td><strong>Molecular Weight</strong></td><td>~120 kDa</td></tr>
<tr><td><strong>Subcellular Localization</strong></td><td>Endoplasmic Reticulum, Endosomes</td></tr>
<tr><td><strong>Protein Family</strong></td><td>Toll-Like Receptor Family</td></tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/autism" style="color:#ef9a9a">Autism</a>, <a href="/wiki/autoimmune" style="color:#ef9a9a">Autoimmune</a>, <a href="/wiki/diabetes" style="color:#ef9a9a">Diabetes</a>, <a href="/wiki/inflammation" style="color:#ef9a9a">Inflammation</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">98 edges</a></td>
</tr>
</table>
</div>

Overview

...

TLR7 Protein - Toll-Like Receptor 7

Introduction

Tlr7 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.

<div class="infobox .infobox-protein"> [@bsibsi2002]
<table>
<tr><th colspan="2" style="background:#f0f0f0;">Protein Information</th></tr>
<tr><td><strong>Protein Name</strong></td><td>Toll-Like Receptor 7 (TLR7)</td></tr>
<tr><td><strong>Gene</strong></td><td>TLR7</td></tr>
<tr><td><strong>UniProt ID</strong></td><td>Q9NYK5</td></tr>
<tr><td><strong>PDB Structure</strong></td><td>5GMF, 5ZFM</td></tr>
<tr><td><strong>Molecular Weight</strong></td><td>~120 kDa</td></tr>
<tr><td><strong>Subcellular Localization</strong></td><td>Endoplasmic Reticulum, Endosomes</td></tr>
<tr><td><strong>Protein Family</strong></td><td>Toll-Like Receptor Family</td></tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/autism" style="color:#ef9a9a">Autism</a>, <a href="/wiki/autoimmune" style="color:#ef9a9a">Autoimmune</a>, <a href="/wiki/diabetes" style="color:#ef9a9a">Diabetes</a>, <a href="/wiki/inflammation" style="color:#ef9a9a">Inflammation</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">98 edges</a></td>
</tr>
</table>
</div>

Overview

TLR7 (Toll-Like Receptor 7) is an endosomal pattern recognition receptor that recognizes single-stranded RNA (ssRNA) from viruses and synthetic compounds like imidazoquinolines. TLR7 is primarily expressed in plasmacytoid dendritic cells (pDCs) and other immune cells, where it plays critical roles in antiviral immunity and has been implicated in autoimmune and neurodegenerative conditions.

Structure

TLR7 is a type I transmembrane protein localized in endosomal compartments:

Domain Architecture

• Signal peptide: N-terminal signal peptide
• Leucine-rich repeats (LRRs): 23 LRR motifs for nucleic acid recognition
• Z-loop: Protease-sensitive region important for ligand access
• Transmembrane domain: Single pass transmembrane helix
• TIR domain: Intracellular signaling domain

Structure-Function

• Recognizes ssRNA in endosomal compartments
• Requires acidified endosomes for activation

Normal Function

TLR7 plays critical roles in antiviral immunity:

Immune Recognition

• ssRNA recognition: Detects viral ssRNA (influenza, HIV, HCV)
• Synthetic ligands: Recognizes imidazoquinolines (R848)
• Endosomal localization: Requires internalization for activation

Signaling Pathways

MyD88-dependent pathway: Activates [NF-kB](/entities/nf-kb) and IRF7

Type I interferon: Strong IFN-alpha production in pDCs

Pro-inflammatory cytokines: IL-6, TNF-alpha, IL-12

Cellular Functions

• Antiviral immunity: Critical for viral RNA detection
• pDC function: Major producer of type I interferons
• Immune cell activation: Activates B cells, monocytes

Role in Disease

Alzheimer Disease

• TLR7 activation may contribute to neuroinflammation
• May recognize viral or endogenous RNA in brain
• TLR7+ [microglia](/cell-types/microglia-neuroinflammation) in AD brain regions

Parkinson Disease

• TLR7 can be activated by extracellular RNA from dying neurons
• Contributes to microglial activation and neuroinflammation

Viral Encephalitis

• Critical for antiviral responses in CNS
• Excessive activation can contribute to immunopathology

Expression

| Cell Type | Expression Level | Notes |
|----------|-----------------|-------|
| Plasmacytoid DCs | Very High | Primary expression site |
| Monocytes | Moderate | Myeloid lineage |
| B Cells | Moderate | Some expression |
| Microglia | Low-Moderate | Brain expression |
| [Neurons](/entities/neurons) | Low | Limited expression |

Therapeutic Targeting

| Approach | Agent | Status | Notes |
|----------|-------|--------|-------|
| TLR7 Antagonists | IRS-661, OTC-654 | Research | Block signaling |
| Anti-viral therapy | Nucleotide analogs | Clinical | Viral diseases |
| Immunomodulation | Hydroxychloroquine | Used in SLE | Clinical |

Protein Interactions

• MyD88: Primary adaptor protein
• IRF7: Transcription factor for IFN production
• UNC93B1: Required for endosomal trafficking
• AP-1: Transcription factor activation

Background

The study of Tlr7 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

• TLR7 Gene
• [TLR8](/genes/tlr8)
• [Toll-Like Receptors](/mechanisms/toll-like-receptor-signaling)
• [Neuroinflammation](/mechanisms/neuroinflammation-pathway)
• [Microglia](/cell-types/microglia)

External Links

• [UniProt: TLR7](https://www.uniprot.org/uniprot/Q9NYK5)
• [PDB: TLR7](https://www.ebi.ac.uk/pdbe/pdbe-search?targetUrl=http://www.ebi.ac.uk/pdbe/entry/pdb/5gmf)
• [NCBI Protein: TLR7](https://www.ncbi.nlm.nih.gov/protein/51284)

References

Diebold SS, Kaisho T, Hemmi H, Akira S, Reis e Sousa C, Innate antiviral responses by means of TLR7-mediated recognition of single-stranded RNA (2004)

Bsibsi M, Ravid R, Gveric D, van Noort JM, Broad expression of Toll-like receptors in the human central nervous system (2002)