HSPA5 — Heat Shock Protein Family A (Hsp70) Member 5

HSPA5 — Heat Shock Protein Family A (Hsp70) Member 5

Introduction

Hspa5 — Heat Shock Protein Family A (Hsp70) Member 5 is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

HSPA5 — Heat Shock Protein Family A (Hsp70) Member 5

Introduction

Hspa5 — Heat Shock Protein Family A (Hsp70) Member 5 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-gene">
<table>
<tr><th colspan="2" style="background:#f0f0f0; text-align:center;">Gene Information</th></tr>
<tr><td><strong>Symbol</strong></td><td>HSPA5</td></tr>
<tr><td><strong>Full Name</strong></td><td>Heat Shock Protein Family A (Hsp70) Member 5</td></tr>
<tr><td><strong>Chromosome</strong></td><td>9</td></tr>
<tr><td><strong>NCBI Gene ID</strong></td><td><a href="https://www.ncbi.nlm.nih.gov/gene/3309" target="_blank">3309</a></td></tr>
<tr><td><strong>OMIM</strong></td><td><a href="https://www.omim.org/entry/138120" target="_blank">138120</a></td></tr>
<tr><td><strong>UniProt ID</strong></td><td><a href="https://www.uniprot.org/uniprot/P11021" target="_blank">P11021</a></td></tr>
<tr><td><strong>Ensembl ID</strong></td><td><a href="https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000156006" target="_blank">ENSG00000156006</a></td></tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">ALS</a>, <a href="/wiki/aging" style="color:#ef9a9a">Aging</a>, <a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/arthritis" style="color:#ef9a9a">Arthritis</a>, <a href="/wiki/atherosclerosis" style="color:#ef9a9a">Atherosclerosis</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">352 edges</a></td>
</tr>
</table>
</div>

Overview

HSPA5, also known as GRP78 (Glucose-Regulated Protein 78), is a major endoplasmic reticulum (ER) chaperone protein. It plays a critical role in protein folding, quality control, and the unfolded protein response (UPR). HSPA5 is essential for maintaining ER homeostasis and has been implicated in neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, and ALS, where ER stress is a key pathological feature.

Normal Function

HSPA5/GRP78 is a BiP (Binding Immunoglobulin Protein) that resides in the ER lumen. It assists in protein folding, assembly of protein complexes, and targeting misfolded proteins for degradation via ER-associated degradation (ERAD). HSPA5 is a key regulator of the [UPR](/entities/unfolded-protein-response), activating ATF6, PERK, and IRE1 signaling pathways in response to ER stress.

Expression Pattern

Highly expressed in brain, particularly in [neurons](/entities/neurons) and glia. Upregulated in response to cellular stress.

Disease Associations

| Disease | Role in Disease |
|---------|-----------------
| [Alzheimer's Disease](/diseases/alzheimers-disease) | ER stress response, [Aβ](/proteins/amyloid-beta) interaction, UPR activation |
| [Parkinson's Disease](/diseases/parkinsons-disease) | [α-Synuclein](/proteins/alpha-synuclein) quality control, ER stress |
| [ALS](/diseases/amyotrophic-lateral-sclerosis) | Protein aggregate clearance, motor neuron survival |
| [Huntington's Disease](/diseases/huntington-disease) | Mutant [huntingtin](/proteins/huntingtin-protein) quality control |

Key Publications

[^1] [^2] [^3] [^4] [^5]

Overview

HSPA5 (Heat Shock Protein Family A Member 5), also known as GRP78 or BiP, is an endoplasmic reticulum (ER) chaperone essential for protein folding and the unfolded protein response (UPR). HSPA5 is critical for ER proteostasis.

Gene Characteristics

• Gene Symbol: HSPA5 / GRP78 / BiP
• Location: Chromosome 9q33.3
• NCBI Gene ID: 3309
• Protein: HSPA5/GRP78/BiP
• Family: Hsp70 family (ER-resident)

Function

HSPA5/GRP78:

• ER chaperone activity
• Protein folding and assembly
• UPR sensor (with PERK, IRE1, ATF6)
• Calcium binding
• Anti-apoptotic function

Role in Neurodegeneration

Alzheimer's Disease

• Elevated in AD brain
• Response to ER stress
• [Aβ](/proteins/amyloid-beta) affects ER function
• Potential therapeutic target

Parkinson's Disease

• Upregulated in PD brain
• Response to α-synuclein toxicity
• ER stress in dopaminergic neurons

ALS

• ER stress in motor neurons
• Mutant protein accumulation
• Therapeutic implications

Therapeutic Approaches

| Approach | Target | Status |
|----------|--------|--------|
| HSPA5/GRP78 inducers | Enhance chaperone activity | Research |
| UPR modulators | Modulate ER stress response | Preclinical |

See Also

• [ER Stress Pathway](/mechanisms/er-stress-pathway)
• [Unfolded Protein Response](/mechanisms/endoplasmic-reticulum-stress)mechanisms/er-stress-unfolded-protein-response)
• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Parkinson's Disease](/diseases/parkinsons-disease)
• [Amyotrophic Lateral Sclerosis](/diseases/amyotrophic-lateral-sclerosis)

External Links

• [UniProt: P11021](https://www.uniprot.org/uniprot/P11021)
• [NCBI Gene: 3309](https://www.ncbi.nlm.nih.gov/gene/3309)

Expression Pattern

HSPA5 is expressed at high levels in the brain, particularly in neurons (especially in somata and dendrites), [astrocytes](/entities/astrocytes), and [microglia](/entities/microglia). The expression is upregulated under conditions of ER stress.

Molecular Mechanisms

ER Chaperone Function

UPR Regulation

Role in Neurodegeneration

Alzheimer's Disease

Parkinson's Disease

ALS

Therapeutic Targeting

Small molecule HSPA5 inducers (e.g., tunicamycin, celecoxib derivatives), gene therapy to increase HSPA5 expression, and peptide-based approaches are being explored.

Background

The study of Hspa5 — Heat Shock Protein Family A (Hsp70) Member 5 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

^[1] De Camilli P, Cameron R, Greengard P. Synapsin I: a synaptic vesicle-associated neuronal phosphoprotein. J Cell Biol. 1983;96(5):1355-1373. PMID: 6682992(https://pubmed.ncbi.nlm.nih.gov/6682992/)

^[2] Hsia AY, Masliah E, McConlogue L, et al. Plaque-independent disruption of neural circuits in Alzheimer's disease. Proc Natl Acad Sci U S A. 1999;96(6):3228-3233. PMID: 10077666(https://pubmed.ncbi.nlm.nih.gov/10077666/)

^[3] Chesselet MF, Richter F, Zhu C, et al. Alpha-synuclein and synaptic function. J Mol Neurosci. 2012;47(3):461-470. PMID: 22328567(https://pubmed.ncbi.nlm.nih.gov/22328567/)

^[4] Fassio A, Patry L, Congia S, et al. De novo mutations of the gene encoding synapsin I (SYN1) in patients with epilepsy. Brain. 2011;134(Pt 10):2864-2878. PMID: 28628578(https://pubmed.ncbi.nlm.nih.gov/28628578/)

[^1]: [Reference missing - citation needed]

[^2]: [Reference missing - citation needed]

[^3]: [Reference missing - citation needed]

[^4]: [Reference missing - citation needed]

[^5]: [Reference missing - citation needed]

Pathway Diagram

Pathway Diagram

The following diagram shows the key molecular relationships involving HSPA5 — Heat Shock Protein Family A (Hsp70) Member 5 discovered through SciDEX knowledge graph analysis: