GJA1 Protein

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GJA1 Protein

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GJA1 Protein

Overview

<table class="infobox infobox-protein">
<tr>
<th class="infobox-header" colspan="2">GJA1 Protein</th>
</tr>
<tr>
<td class="label">Protein Name</td>
<td>Gap junction protein alpha 1 (Connexin 43)</td>
</tr>
<tr>
<td class="label">Gene</td>
<td>[GJA1](/genes/gja1)</td>
</tr>
<tr>
<td class="label">UniProt ID</td>
<td>[P17302](https://www.uniprot.org/uniprot/P17302)</td>
</tr>
<tr>
<td class="label">PDB IDs</td>
<td>5ERA, 6MHJ, 7LFY</td>
</tr>
<tr>
<td class="label">Molecular Weight</td>
<td>43.0 kDa</td>
</tr>
<tr>
<td class="label">Subcellular Localization</td>
<td>Plasma membrane (gap junctions), astrocyte endfeet</td>
</tr>
<tr>
<td class="label">Protein Family</td>
<td>Connexin family (21 members in humans)</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">ALS</a>, <a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/alzheimer" style="color:#ef9a9a">Alzheimer</a>, <a href="/wiki/alzheimer's-disease" style="color:#ef9a9a">Alzheimer's Disease</a>, <a href="/wiki/arthritis" style="color:#ef9a9a">Arthritis</a></td>
</tr>
<tr>
<td class="label">SciDEX Hypotheses</td>
<td><a href="/hypothesis/h-16ee87a4" style="color:#ce93d8" title="Score: 0.63">Astrocytic Connexin-43 Upregulation Enha...</a><br><a href="/hypothesis/h-3a901ec3" style="color:#ce93d8" title="Score: 0.48">Astroglial Gap Junction Coordination via...</a><br><a href="/hypothesis/h-1

...

GJA1 Protein

Overview

<table class="infobox infobox-protein">
<tr>
<th class="infobox-header" colspan="2">GJA1 Protein</th>
</tr>
<tr>
<td class="label">Protein Name</td>
<td>Gap junction protein alpha 1 (Connexin 43)</td>
</tr>
<tr>
<td class="label">Gene</td>
<td>[GJA1](/genes/gja1)</td>
</tr>
<tr>
<td class="label">UniProt ID</td>
<td>[P17302](https://www.uniprot.org/uniprot/P17302)</td>
</tr>
<tr>
<td class="label">PDB IDs</td>
<td>5ERA, 6MHJ, 7LFY</td>
</tr>
<tr>
<td class="label">Molecular Weight</td>
<td>43.0 kDa</td>
</tr>
<tr>
<td class="label">Subcellular Localization</td>
<td>Plasma membrane (gap junctions), astrocyte endfeet</td>
</tr>
<tr>
<td class="label">Protein Family</td>
<td>Connexin family (21 members in humans)</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">ALS</a>, <a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/alzheimer" style="color:#ef9a9a">Alzheimer</a>, <a href="/wiki/alzheimer's-disease" style="color:#ef9a9a">Alzheimer's Disease</a>, <a href="/wiki/arthritis" style="color:#ef9a9a">Arthritis</a></td>
</tr>
<tr>
<td class="label">SciDEX Hypotheses</td>
<td><a href="/hypothesis/h-16ee87a4" style="color:#ce93d8" title="Score: 0.63">Astrocytic Connexin-43 Upregulation Enha...</a><br><a href="/hypothesis/h-3a901ec3" style="color:#ce93d8" title="Score: 0.48">Astroglial Gap Junction Coordination via...</a><br><a href="/hypothesis/h-13ef5927" style="color:#ce93d8" title="Score: 0.41">CX43 hemichannel engineering enables siz...</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">227 edges</a></td>
</tr>
</table>

Pathway Diagram

Mermaid diagram (expand to render)

Gja1 Protein plays an important role in the study of neurodegenerative diseases. This page provides comprehensive information about this topic, including its mechanisms, significance in disease processes, and therapeutic implications.

Introduction

Gja1 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. [@chen2022]

GJA1 (Connexin-43, Cx43) is the most abundant connexin in the brain. It forms gap junctions allowing direct intercellular communication between [astrocytes](/entities/astrocytes) and [neurons](/entities/neurons). Connexin-43 hemichannels also release signaling molecules like ATP, glutamate, and NAD+. [@giaume2021]

Protein Overview

Structure

GJA1 is a four-pass transmembrane protein with intracellular N- and C-termini. Six GJA1 proteins assemble to form a hemichannel (connexon), and two hemichannels from adjacent cells dock to form a gap junction channel. The C-terminal tail contains phosphorylation sites that regulate channel gating and assembly.

Normal Function

Connexin-43 forms gap junction channels enabling direct cell-to-cell transfer of ions (Ca²+, K+), small metabolites (ATP, glucose, glutamate), and signaling molecules. In the brain:

Astrocyte Networks: Forms extensive gap junction coupling between astrocytes, enabling calcium wave propagation and metabolic cooperation
Neuronal-Glial Communication: Hemichannels release ATP and glutamate for signaling
Neurovascular Coupling: Located in astrocyte endfeet surrounding blood vessels
K+ Buffering: Helps clear extracellular potassium during neuronal activity

Role in Neurodegeneration

Alzheimer's Disease

GJA1 expression is altered in AD brains, particularly around amyloid plaques
Gap junction coupling between astrocytes is disrupted, affecting metabolic support
Hemichannel activity is increased, leading to excessive glutamate release and excitotoxicity
Research shows Cx43 deficiency accelerates amyloid pathology in mouse models
Therapeutic strategies include gap junction modulators and hemichannel blockers

Parkinson's Disease

Altered GJA1 expression in substantia nigra and striatum
Disrupted astrocytic coupling affects dopamine neuron survival
Hemichannel dysfunction contributes to neuroinflammation
Gap junction blockers show protective effects in PD models

Stroke and Traumatic Brain Injury

GJA1 plays dual roles in both protective and damaging responses
Early gap junction closure is protective; reopening contributes to secondary injury
Therapeutic window for modulation is narrow

Epilepsy

GJA1 expression and function are altered in epileptic tissue
Aberrant gap junction coupling contributes to seizure spread
Gap junction blockers (e.g., carbenoxolone) have shown anti-seizure effects

Therapeutic Targeting

Gap Junction Modulators

Carbenoxolone: Broad gap junction blocker, limited by poor [blood-brain barrier](/entities/blood-brain-barrier) penetration
Mefloquine: Potent Cx43 blocker, being investigated for CNS applications
Rotigaptide: Gap junction opener, for enhancing astrocyte coupling

Hemichannel Blockers

Gap19: Selective Cx43 hemichannel blocker
TAT-Gap19: Cell-penetrating version for in vivo applications
Danusertib: Cx43 phosphorylation inhibitor

Gene Therapy Approaches

Viral delivery of GJA1 to enhance astrocyte coupling
CRISPR-based editing of GJA1 regulatory elements

Overview

Gja1 Protein plays an important role in the study of neurodegenerative diseases. This page provides comprehensive information about this topic, including its mechanisms, significance in disease processes, and therapeutic implications.

Background

The study of Gja1 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

[UniProt: P17302](https://www.uniprot.org/uniprot/P17302)
[PDB: 5ERA, 6MHJ](https://www.rcsb.org/)
[HGNC: 4017](https://www.genenames.org/data/hgnc_data.php?appid=2)

References

[De Bock M, et al, Connexin hemichannels as novel therapeutic targets in neuroinflammation (2023)](https://pubmed.ncbi.nlm.nih.gov/36204834/)

[Chen W, et al, Connexin-43 in Alzheimer's disease: Regulation and therapeutic potential (2022)](https://pubmed.ncbi.nlm.nih.gov/35910256/)

[Giaume C, et al, Gap junctional communication in brain cells: Implications for neural stem cells and neurodegenerative diseases (2021)](https://pubmed.ncbi.nlm.nih.gov/34453982/)

[Kimelberg BK, Connexin hemichannels and the failure of neuronal networks in Alzheimer's disease (2020)](https://pubmed.ncbi.nlm.nih.gov/32004589/)

[Nakase T, et al, Gap junction communication and propagation of neuronal injury in Alzheimer's disease (2019)](https://pubmed.ncbi.nlm.nih.gov/31211943/)

[Takeuchi H, et al, Astrocytic gap junction blockade as a therapeutic target for neurodegeneration (2021)](https://pubmed.ncbi.nlm.nih.gov/33895231/)

[Wang N, et al, Connexin 43 and stroke: Dual roles in ischemic injury and repair (2019)](https://pubmed.ncbi.nlm.nih.gov/31735128/)

[Decrock E, et al, Therapeutic modulation of gap junctions in neurological disorders (2022)](https://pubmed.ncbi.nlm.nih.gov/35033581/)

From the [SciDEX Exchange](/exchange) — scored by multi-agent debate

[Astroglial Gap Junction Coordination via Connexin-43 Phosphorylation Modulation](/hypothesis/h-3a901ec3) — <span style="color:#ffd54f;font-weight:600">0.48</span> · Target: GJA1
[CX43 hemichannel engineering enables size-selective mitochondrial transfer](/hypothesis/h-13ef5927) — <span style="color:#ffd54f;font-weight:600">0.41</span> · Target: GJA1

Pathway Diagram

The following diagram shows the key molecular relationships involving GJA1 Protein discovered through SciDEX knowledge graph analysis:

Mermaid diagram (expand to render)

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Related Entities

GJA1

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origin_type	v1_polymorphic_backfill
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📊 Evidence Profile Foundational

Evidence Balance

+0%

Certainty

100%

Debates

0

Incoming

28

Outgoing

80

0 supporting 0 contradicting 0 neutral

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📗 Cite This Artifact

GJA1 Protein

GJA1 Protein

Overview

GJA1 Protein

Overview

Pathway Diagram

Introduction

Protein Overview

Structure

Normal Function

Role in Neurodegeneration

Alzheimer's Disease

Parkinson's Disease

Stroke and Traumatic Brain Injury

Epilepsy

Therapeutic Targeting

Gap Junction Modulators

Hemichannel Blockers

Gene Therapy Approaches

Overview

Background

See Also

External Links

References

Pathway Diagram

💬 Discussion

📗 Cite This Artifact

GJA1 Protein

GJA1 Protein

Overview

GJA1 Protein

Overview

Pathway Diagram

Introduction

Protein Overview

Structure

Normal Function

Role in Neurodegeneration

Alzheimer's Disease

Parkinson's Disease

Stroke and Traumatic Brain Injury

Epilepsy

Therapeutic Targeting

Gap Junction Modulators

Hemichannel Blockers

Gene Therapy Approaches

Overview

Background

See Also

External Links

References

Related Hypotheses

Pathway Diagram

💬 Discussion