DNAJB8 Human

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 .

The DNAJB8 gene is located on chromosome 3q21.3 . It was identified through the search of expressed sequence tag (EST) databases for J domain-containing proteins . The predicted type II transmembrane protein contains 227 amino acids with an N-terminal J domain .