DNAJB8 Human
Description
DNAJB8 is fused to a 20 amino acid His-tag at N-terminus & purified by proprietary chromatographic techniques.
Product Specs
Q&A
DNAJB8 is a Class B Hsp40 chaperone with distinct roles in protein quality control, stress response, and disease pathogenesis. Below are structured FAQs addressing key research considerations, supported by experimental evidence from recent studies.
Advanced Experimental Design
How to optimize DNAJB8-client recovery in immunoprecipitation assays?
Key variables impacting pulldown efficiency:
| Condition | DNAJB8WT | DNAJB8H31Q | Crosslinking (DSP) |
|---|---|---|---|
| Client stoichiometry | + | +++ | Increases 2.1× |
| Hsp40 recovery | 100% | 82% | Reduces 37% |
| Stress-induced clients | Baseline | 3.8× increase post-heat shock |
Protocol optimization:
How to resolve contradictory data on DNAJB8-Hsp70 functional interplay?
Contradiction source: J-domain mutation effects vary by cellular context
Resolution strategy:
-
Perform time-resolved FRET to monitor JD-CTD interaction dynamics
-
Use ATPase-deficient Hsp70 (K71M) to decouple nucleotide cycling
-
Conduct phosphomimetic mutations (S/T→E) to test phosphorylation regulation
Translational Research Challenges
What experimental models best recapitulate DNAJB8-mediated chemoresistance?
Validated systems for oxaliplatin resistance studies:
| Model Type | Key Feature | Validation Marker |
|---|---|---|
| PDX lines | sEV DNAJB8 transfer | CD63+/DNAJB8+ vesicles |
| CRISPR-Cas9 KO | TP53 stabilization | p21↑, MDR1↓ |
| 3D spheroids | CSC enrichment | ALDH1A1+/DNAJB8+ |
Technical consideration: Maintain 48h drug-free period post-sEV treatment to allow MDR1 upregulation
Product Science Overview
DNAJB8, like other members of the DNAJ/HSP40 family, contains several distinct domains:
- J domain: A conserved 70-amino acid domain usually located at the N-terminus, which is essential for the interaction with HSP70 proteins .
- Glycine/Phenylalanine (G/F)-rich region: This region is involved in the flexibility and function of the protein .
- Cysteine-rich domain: Contains four motifs resembling a zinc finger domain, which are important for the protein’s structural integrity and function .
DNAJB8 is known for its role in suppressing the aggregation and toxicity of misfolded proteins, particularly polyglutamine proteins . This suppression is crucial in preventing the formation of toxic protein aggregates that can lead to cellular dysfunction and diseases . The C-terminal tail of DNAJB8 is essential for this activity .
Recent studies have highlighted the role of DNAJB8 in cancer biology. It has been shown to be involved in the maintenance of cancer stem-like cells (CSCs) and cancer-initiating cells (CICs) in renal cell carcinoma . DNAJB8 knockout cells exhibited reduced tumor initiation, side population ratio, and sphere formation ability, indicating its importance in tumor initiation and resistance to certain chemotherapeutic agents like Docetaxel . However, DNAJB8 knockout cells did not show sensitivity to other stress conditions such as low pH, low glucose, heat shock, and cisplatin .
