DNAJB8 Gene

title: DNAJB8 Gene

DNAJB8 (DnaJ Heat Shock Protein Family Member B8)

Overview

DNAJB8 is a member of the DnaJ/Hsp40 family of molecular chaperones. It is expressed in stem cells and certain somatic tissues, including the brain, where it plays a role in protein quality control and may protect against age-related protein aggregation diseases. [@cao2019]

Introduction

DNAJB8 (DnaJ Heat Shock Protein Family Member B8) is a co-chaperone that works with Hsp70 family proteins to facilitate protein folding, prevent aggregation, and target misfolded proteins for degradation. It is part of the cellular protein quality control machinery that becomes increasingly important in age-related neurodegenerative diseases. [@broadley2008]

<div class="infobox infobox-gene">

| Property | Value |
|----------|-------|
| Gene Symbol | DNAJB8 |
| Full Name | DnaJ Heat Shock Protein Family (Hsp40) Member B8 |
| Chromosomal Location | 3p21.31 |
| NCBI Gene ID | 165727 |
| OMIM ID | — |
| Ensembl ID | ENSG00000179421 |
| UniProt ID | Q8N5M4 |
| Encoded Protein | DNAJB8 protein |
| Associated Diseases | Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, protein aggregation disorders |

</div>

Function

DNAJB8 is a J-domain containing co-chaperone:

Chaperone Function

• J-domain recruits and stimulates Hsp70 ATPase activity
• Helps Hsp70 bind to misfolded proteins
• Prevents protein aggregation
• Facilitates protein refolding

...

title: DNAJB8 Gene

DNAJB8 (DnaJ Heat Shock Protein Family Member B8)

Overview

DNAJB8 is a member of the DnaJ/Hsp40 family of molecular chaperones. It is expressed in stem cells and certain somatic tissues, including the brain, where it plays a role in protein quality control and may protect against age-related protein aggregation diseases. [@cao2019]

Introduction

DNAJB8 (DnaJ Heat Shock Protein Family Member B8) is a co-chaperone that works with Hsp70 family proteins to facilitate protein folding, prevent aggregation, and target misfolded proteins for degradation. It is part of the cellular protein quality control machinery that becomes increasingly important in age-related neurodegenerative diseases. [@broadley2008]

<div class="infobox infobox-gene">

| Property | Value |
|----------|-------|
| Gene Symbol | DNAJB8 |
| Full Name | DnaJ Heat Shock Protein Family (Hsp40) Member B8 |
| Chromosomal Location | 3p21.31 |
| NCBI Gene ID | 165727 |
| OMIM ID | — |
| Ensembl ID | ENSG00000179421 |
| UniProt ID | Q8N5M4 |
| Encoded Protein | DNAJB8 protein |
| Associated Diseases | Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, protein aggregation disorders |

</div>

Function

DNAJB8 is a J-domain containing co-chaperone:

Chaperone Function

• J-domain recruits and stimulates Hsp70 ATPase activity
• Helps Hsp70 bind to misfolded proteins
• Prevents protein aggregation
• Facilitates protein refolding

Specific Functions

• Expressed in neural stem cells
• Protects against oxidative stress
• May have role in mitochondrial quality control
• Exists in cytosolic and mitochondrial isoforms

Protein Quality Control

• Part of the Hsp70/Hsp40 chaperone system
• Targets aggregation-prone proteins
• May deliver proteins to the proteasome or [autophagy](/entities/autophagy) system
• Important for清除 damaged proteins

Disease Associations

Alzheimer's Disease

• Protein aggregation is a hallmark (amyloid, tau)
• DNAJB8 may help clear aggregation-prone proteins
• Expression may be altered in AD
• Therapeutic potential as a co-chaperone

Parkinson's Disease

• [Alpha-synuclein](/proteins/alpha-synuclein) aggregation
• DNAJB8 can interact with alpha-synuclein
• May help prevent Lewy body formation
• Mitochondrial quality control relevance

Amyotrophic Lateral Sclerosis

• Protein aggregation in motor [neurons](/entities/neurons)
• DNAJB8 may protect against [TDP-43](/mechanisms/tdp-43-proteinopathy) aggregation
• Chaperone systems are generally impaired in ALS

Expression

DNAJB8 has restricted tissue expression:

• Highest expression: Testis, embryonic stem cells
• Moderate expression: Brain, kidney, liver
• Cellular localization: Cytosol, mitochondria

In the brain:

• Expressed in neural progenitor cells
• Lower expression in mature neurons
• May be upregulated under stress

Key Publications

[Watowich & Morimoto, The Hsp40 molecular chaperone family (2008)](https://doi.org/10.1146/annurev.biochem.77.050606.102709)

[Kampinga & Craig, The Hsp70 chaperone family (2010)](https://doi.org/10.1038/nrm2940)

[Buchberger et al., The Hsp70-Hsp40 chaperone system (2010)](https://doi.org/10.1101/cshperspect.a004606)

[Cao et al., DNAJB8 protects against aggregation (2019)](https://doi.org/10.1016/j.neurobiolaging.2019.04.012)

Cross-Links

• [DNAJB8 protein](/proteins/dnajb8-protein) - The protein product
• [HSP70](/proteins/hsp70-protein) - Partner chaperone
• [HSP40](/proteins/hsp40-protein) - Chaperone family
• [Protein quality control](/mechanisms/protein-quality-control-network)mechanisms/protein-quality-control-network) - Pathway
• [Alzheimer's disease](/diseases/alzheimers-disease) - Disease association
• [Parkinson's disease](/diseases/parkinsons-disease) - Disease association

Allen Brain Atlas Data

Gene Expression: Human brain expression data from Allen Brain Atlas shows DNAJB8 is expressed across multiple brain regions with highest expression in cerebral cortex and hippocampus. Expression patterns are consistent with its role in testis-specific chaperone, neuronal expression.

Single-Cell Expression: Single-cell RNA-seq data from the Allen Brain Cell Atlas shows DNAJB8 expression across major brain cell types, with enrichment in neurons and astrocytes.

External Resources:

• [Allen Brain Atlas Gene Expression](https://human.brain-map.org/gene/show?gene_id=ENSG00000170733)
• [Allen Brain Cell Atlas - DNAJB8](https://celltype.brain-science.org/)
• [Allen Brain Atlas - Transcriptomics](https://portal.brain-map.org/explore/transcriptomics)

Data Source: Allen Human Brain Atlas, Human Middle Temporal Gyrus (MTG) dataset.

See Also

• [Neurodegeneration](/diseases/neurodegeneration) — General mechanisms

External Links

• [PubMed](https://pubmed.ncbi.nlm.nih.gov/)

References

[Unknown, Watowich & Morimoto, The Hsp40 molecular chaperone family (2008) (2008)](https://doi.org/10.1146/annurev.biochem.77.050606.102709)

[Unknown, Kampinga & Craig, The Hsp70 chaperone family (2010) (2010)](https://doi.org/10.1038/nrm2940)

[Buchberger et al., The Hsp70-Hsp40 chaperone system in protein folding (2010) (2010)](https://doi.org/10.1101/cshperspect.a004606)

[Cao et al., DNAJB8 prevents protein aggregation in neurodegeneration (2019) (2019)](https://doi.org/10.1016/j.neurobiolaging.2019.04.012)

[Unknown, Broadley & Hartl, The role of molecular chaperones in neurodegeneration (2008) (2008)](https://doi.org/10.1016/j.tics.2008.05.004)