The DNAJB14 Knockout HAP1 Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout cell population designed for targeted disruption of the DNAJB14 gene in the HAP1 human cell line. This product provides a genetically heterogeneous loss-of-function model, enabling researchers to interrogate DNAJB14-dependent functions without clonal isolation. The polyclonal format retains allelic diversity, reflecting a population-level knockout background suitable for pooled screening and robust functional assays. It is particularly valuable for investigating endoplasmic reticulum (ER) stress responses, the unfolded protein response (UPR), and proteostasis regulation in a near-haploid genetic context.
HAP1 cells are a near-haploid human cell line originally derived from KBM-7 chronic myeloid leukemia cells, exhibiting disomy only for chromosome 8 and a portion of chromosome 15. This minimal diploid content facilitates high-efficiency CRISPR/Cas9-mediated gene targeting, as loss-of-function mutations are readily uncovered without the complexity of diploid compensation. The adherent, fibroblastoid morphology and stable karyotype make HAP1 cells a trusted host for functional genomics, receptor signaling studies, and chemical-genetic screens. Their leukemia origin also provides a relevant background for exploring cancer cell biology and drug sensitivity mechanisms.
At the molecular level, DNAJB14 encodes an ER-resident DnaJ (Hsp40) co-chaperone that directly interacts with and stimulates the ATPase activity of BiP (HSPA5), a central chaperone of the ER. DNAJB14 is activated by upstream ER stress sensors including ATF6, IRE1, and PERK, as well as heat shock factor 1 (HSF1). It functions downstream of these regulators to facilitate proper protein folding, assembly, and ER quality control, and it participates in ER-associated degradation (ERAD) through interactions with components such as DNAJC10/ERdj5. Disruption of DNAJB14 impacts downstream targets including BiP client proteins and UPR effectors like CHOP and XBP1, perturbing the adaptive signaling cascade that involves IRE1-mediated XBP1 splicing and PERK-dependent ATF4 translation.
Introduction of DNAJB14 knockout into the haploid HAP1 background yields a simplified genetic tool for dissecting ER proteostasis without interference from a second wild-type allele. This model is particularly well-suited for studying ER stress-associated conditions, proteostasis disorders, and the role of chaperone networks in cancer survival. The near-haploid state enables unambiguous interpretation of UPR pathway perturbations and facilitates large-scale screens for synthetic lethal interactions or chemical suppressors of ER stress. By eliminating DNAJB14 function, researchers can examine how co-chaperone loss reshapes the ER folding environment and sensitizes cells to stress.
Typical applications include Western blot analysis of UPR markers such as BiP and CHOP, RT-qPCR quantification of XBP1 splicing and ATF4 target genes, and ER stress induction using tunicamycin or thapsigargin to probe pathway activation thresholds. Co-immunoprecipitation assays can assess altered BiP?Csubstrate interactions, while immunofluorescence microscopy reveals ER morphology changes. Cell viability assays under chronic ER stress conditions further define the functional consequences of DNAJB14 loss. This polyclonal knockout population is an essential resource for probing chaperone-governed proteostasis and for identifying modulators of the UPR in drug discovery contexts. For further details or technical support, please contact Ascent Research.
