The DNAJB11 Knockout NCI-H1299 Polyclonal Cells constitute a CRISPR/Cas9-mediated loss-of-function polyclonal population featuring disruption of the DNAJB11 gene. This knockout model is generated by introducing targeted gene disruptions using non-homologous end joining, resulting in a heterogeneous pool of NCI-H1299 cells lacking functional DNAJB11 protein. This polyclonal format preserves population-level diversity while eliminating target gene expression, providing a versatile tool for studying DNAJB11-dependent cellular processes without the clonal selection biases inherent in monoclonal knockout lines.
The parental NCI-H1299 cell line is a widely utilized human lung adenocarcinoma epithelial model established from a lymph node metastasis of a 43-year-old male patient. These cells are characterized by p53 deficiency, which abolishes canonical DNA damage responses and promotes genomic instability. Derived from a metastatic site, NCI-H1299 cells exhibit aggressive malignant properties and are frequently employed in cancer research to dissect mechanisms of tumor progression, invasion, and metastatic colonization. Their p53-null background renders them particularly suitable for investigating stress response pathways that crosstalk with p53-independent survival signaling.
DNAJB11, also known as ERdj3, functions as an ER-resident co-chaperone that directly collaborates with the major ER chaperone HSPA5/BiP. DNAJB11 recognizes and binds exposed hydrophobic patches on misfolded polypeptides, delivering them to HSPA5/BiP for refolding or, when refolding fails, facilitating their retrotranslocation and degradation via the ER-associated degradation (ERAD) pathway. This process involves interaction with key ERAD components including SEL1L, HRD1, and the VCP/p97 AAA-ATPase. DNAJB11 is transcriptionally regulated by ER stress through the unfolded protein response (UPR) sensors IRE1??, PERK, and ATF6, which activate downstream transcription factors XBP1, ATF4, and cleaved ATF6, respectively. Consequently, DNAJB11 operates within a tightly orchestrated network that maintains ER proteostasis and determines cell fate under proteotoxic stress.
In the context of NCI-H1299 cells, DNAJB11 knockout abolishes a critical node in the ER quality control machinery. Given the absence of functional p53, cells rely heavily on adaptive UPR signaling to survive intrinsic and extrinsic stressors, including those encountered during rapid proliferation and metastasis. Disruption of DNAJB11 is predicted to cause accumulation of misfolded proteins, unresolved ER stress, and potential sensitization to apoptosis, making this model invaluable for exploring how ER stress checkpoint dysfunction influences cancer cell viability and therapeutic vulnerability. The polyclonal nature also allows one to assess heterogeneous adaptive responses that may emerge in a tumor microenvironment.
This knockout cell population is suited for a range of mechanistic and translational studies. Researchers can investigate ERAD pathway dynamics using co-immunoprecipitation of HSPA5/BiP complexes or proteasome activity assays. UPR activation can be profiled via western blotting for BiP, CHOP, and phosphorylated IRE1??, or by RT-qPCR of XBP1 splicing. Functional assays include viability measurements following treatment with ER stress inducers such as tunicamycin or thapsigargin, and flow cytometric quantification of annexin V-positive apoptotic cells. The model also supports drug discovery efforts targeting ER proteostasis in cancer and kidney diseases linked to DNAJB11 mutations. For additional information or custom services, please contact Ascent Research.
