DNAJC3 Knockout A-549 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal cell population derived from the human A-549 lung adenocarcinoma line, engineered to disrupt the DNAJC3 gene and abolish its protein expression. This heterogeneous knockout pool captures diverse genetic alterations, offering a physiological model for studying DNAJC3-dependent functions without clonal selection bias. The polyclonal format is well-suited for pooled functional screens, drug response profiling, and population-level analyses where averaging across editing events enhances reproducibility of phenotypic observations.
The parental A-549 cell line is an extensively characterized human lung adenocarcinoma epithelial model, originally isolated from a patient. It displays epithelial morphology and is widely used as a model system for respiratory epithelium and non-small cell lung cancer (NSCLC) research. A-549 cells harbor relevant mutations, such as in KRAS and STK11, and are responsive to ER stress-inducing agents like tunicamycin and thapsigargin, making them a pertinent host for dissecting UPR mechanisms in a cancer environment.
DNAJC3 (p58IPK) is a co-chaperone that negatively regulates the unfolded protein response (UPR) by directly binding and inhibiting the ER stress sensors PERK (EIF2AK3) and PKR (EIF2AK2). Under steady-state conditions, DNAJC3 associates with BiP and, upon ER stress, releases to suppress PERK oligomerization and kinase activity, thus dampening eIF2?? phosphorylation and downstream ATF4/CHOP-mediated pro-apoptotic signaling. DNAJC3 also modulates PKR activation, a kinase involved in translational control and antiviral responses. Consequently, DNAJC3 knockout removes this inhibitory brake, leading to hyperactivation of the PERK-eIF2??-ATF4 axis, sustained ER stress, and increased susceptibility to apoptosis, as evidenced by elevated CHOP and caspase activity.
In the A-549 adenocarcinoma context, DNAJC3 loss holds particular significance due to the elevated basal ER stress inherent to cancer cells. Lung cancer cells experience proteostatic challenges from oncogenic signaling and hypoxia; disrupting DNAJC3 exacerbates this imbalance, potentially sensitizing cells to ER stress-inducing chemotherapeutics like proteasome inhibitors or taxanes. This model enables systematic evaluation of UPR-targeted therapies and identification of synthetic lethal interactions with DNAJC3 deficiency, offering a powerful tool for cancer biology and drug discovery.
These polyclonal knockout cells support a wide range of experimental applications, including elucidation of ER stress responses, UPR signaling dynamics, and apoptosis regulation. Representative assays include Western blot detection of phospho-eIF2??, ATF4, and CHOP accumulation, RT-qPCR analysis of UPR target genes (e.g., DDIT3, TRIB3), PERK in vitro kinase activity measurements, and cell viability assays under tunicamycin or thapsigargin treatment. The model is also suitable for drug screening targeting the PERK-eIF2?? pathway and for studies on viral replication where PKR signaling is engaged. For further details, batch validation, or custom gene-editing inquiries, contact Ascent Research.
