The DNAJB14 Knockout K-562 Polyclonal Cells constitute a CRISPR/Cas9-edited polyclonal knockout cell population in which the DNAJB14 gene has been disrupted. This product provides a mixed population of K-562 cells carrying diverse editing events at the DNAJB14 locus, generating a powerful loss-of-function model for investigating the role of this Hsp40 co-chaperone. The polyclonal format preserves cellular heterogeneity and avoids artifacts of clonal selection, offering a more physiologically relevant system for studying protein homeostasis networks. The targeted disruption of DNAJB14 enables researchers to dissect its contributions to protein quality control, ER-associated degradation (ERAD), and the unfolded protein response (UPR) without the confounding influence of wild-type gene expression.
The host cell line, K-562, is a well-characterized human suspension lymphoblast line derived from a 53-year-old female with chronic myelogenous leukemia (CML) in blast crisis. K-562 cells are BCR-ABL-positive and harbor the Philadelphia chromosome, resulting in constitutive tyrosine kinase activity that drives uncontrolled proliferation and survival. These cells express both erythroid and myeloid markers, serving as a classic model for erythroleukemia and hematopoietic malignancies. Their robust growth in suspension culture and well-documented signaling pathways make them an ideal background for studying the intersection of oncogenic stress and proteostasis mechanisms, particularly how chaperone networks modulate the fitness of transformed cells.
DNAJB14 encodes a member of the DnaJ/Hsp40 family that functions as a co-chaperone for Hsp70 proteins, including HSPA1A and HSPA8. It stimulates the ATPase activity of Hsp70, facilitating the binding and release of substrate proteins during folding and quality control. Mechanistically, DNAJB14 is integral to the ERAD pathway, where it recognizes misfolded proteins and, through interactions with the VCP-UBQLN complex, delivers them to the ubiquitin-proteasome system. DNAJB14 is activated by upstream signals such as heat shock, ER stress, and the accumulation of unfolded proteins, which trigger ER stress sensors ATF6, IRE1, and PERK. Knockout of DNAJB14 disrupts Hsp70-dependent folding and ERAD, potentially leading to proteotoxic stress and altered UPR signaling.
In the K-562 leukemia background, DNAJB14 knockout holds significant translational relevance. CML cells exhibit elevated basal ER stress due to high protein synthesis demands and oncogenic BCR-ABL signaling, making them reliant on robust proteostasis networks. Loss of DNAJB14 may impair the cells’ ability to manage misfolded protein burden, sensitizing them to proteasome inhibitors like bortezomib or other agents that exacerbate ER stress. This model therefore provides a platform to explore how co-chaperone dysfunction influences cancer cell viability, apoptosis, and drug sensitivity, potentially uncovering vulnerabilities in chaperone-addicted tumors.
Researchers can employ these polyclonal knockout cells in a broad array of experiments. Typical applications include western blotting and RT-qPCR to confirm DNAJB14 disruption, analysis of ER stress markers such as BiP, CHOP, and ATF4, and flow cytometric assessment of apoptosis via Annexin V staining. Co-immunoprecipitation assays with HSPA1A or HSPA8 can probe chaperone interactions, while luciferase reporters measure UPR activation. Drug sensitivity profiling with proteasome inhibitors or studies of proteasome activity further elucidate the functional consequences of DNAJB14 loss. This product is a versatile tool for dissecting chaperone-mediated proteostasis in hematologic cancer. For more details, please contact Ascent Research.
