The DNAJB2 Knockout A-549 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population genetically engineered to disrupt the DNAJB2 gene. This product provides a heterogeneous pool of A-549 cells harboring targeted gene disruption, enabling loss-of-function studies of DNAJB2 without clonal selection. The polyclonal format preserves cellular diversity while abrogating DNAJB2 expression, offering a physiologically relevant model for investigating chaperone-mediated protein quality control. As a research-grade reagent, these cells serve as a versatile tool for probing the molecular mechanisms governed by the Hsp40 co-chaperone DNAJB2 in human lung epithelial carcinoma contexts.
The host cell line, A-549, is an established human alveolar basal epithelial adenocarcinoma line derived from a lung adenocarcinoma. This adherent cell line is widely utilized in cancer biology, drug metabolism, and toxicology research. A-549 cells express key components of the cellular stress response and protein homeostasis machinery, making them a suitable background for examining the impact of DNAJB2 loss on proteostasis. Their epithelial origin and malignant phenotype provide a context to study how co-chaperone dysfunction intersects with lung cancer pathophysiology and stress adaptation.
DNAJB2 encodes an Hsp40 (DnaJ) co-chaperone that functions as a critical regulator of the Hsp70 chaperone cycle. Mechanistically, DNAJB2 binds to misfolded proteins and recruits Hsp70 for ATP-dependent substrate processing. It interacts directly with the E3 ubiquitin ligase STUB1/CHIP, facilitating the transfer of ubiquitin to Hsp70-bound clients and targeting them for proteasomal degradation. DNAJB2 is transcriptionally activated by HSF1 in response to cellular stress, such as heat shock and proteotoxic insults. Its activity is modulated by BAG family co-chaperones and the 26S proteasome complex. Through these interactions, DNAJB2 orchestrates a balance between protein refolding and degradation to prevent toxic protein aggregation and maintain cellular proteostasis.
Disruption of DNAJB2 in A-549 cells creates a powerful model for dissecting the Hsp70-STUB1/CHIP ubiquitin-proteasome axis. Loss of this co-chaperone is predicted to impair the clearance of misfolded proteins, leading to accumulation of ubiquitinated aggregates and heightened stress sensitivity. This knockout model is particularly relevant for studying protein quality control mechanisms implicated in distal hereditary motor neuropathy, Charcot-Marie-Tooth disease type 2T, and spinal muscular atrophy with lower extremity predominance. In the A-549 background, it also provides a platform to explore how chaperone dysfunction influences cancer cell survival, stress granule dynamics, and responses to proteasome inhibitors.
Researchers can employ these DNAJB2 knockout cells for a broad spectrum of applications, including neurodegenerative disease modeling, proteinopathy studies, and dissection of the ubiquitin-proteasome system. Typical assays include western blotting and RT-qPCR to validate DNAJB2 ablation and assess downstream protein and transcript levels, immunofluorescence to visualize aggregate formation and stress granule dynamics, and co-immunoprecipitation to examine interactions with Hsp70 and STUB1/CHIP. Functional readouts such as proteasome activity assays and cell viability assays under stress conditions (e.g., heat shock or proteasome inhibition) enable quantitative assessment of proteostatic capacity. These cells are also suitable for drug screening campaigns aimed at identifying modulators of the Hsp70 chaperone network. For additional information or technical support, please contact Ascent Research.
