The DNAJB2 Knockout K-562 Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout cell population engineered for constitutive disruption of the DNAJB2 gene in the K-562 lymphoblastoid cell line. This product provides a heterogeneous pool of edited cells carrying diverse loss-of-function alleles at the target locus, enabling robust functional studies without clonal selection artifacts. The polyclonal format is well-suited for pooled loss-of-function screens, bulk biochemical analyses, and experiments requiring representative gene-disruption effects across a mixed population. Researchers can employ this model to dissect DNAJB2-dependent processes without the confounding influence of monoclonal adaptation.
The parental K-562 cell line was established from the pleural effusion of a 53-year-old female with chronic myelogenous leukemia (CML) in blast crisis. K-562 cells are suspension-adapted, immortalized hematopoietic progenitors that harbor the Philadelphia chromosome, resulting in expression of the BCR-ABL1 fusion oncoprotein. This cell line serves as a widely used model for studying CML biology, erythroid differentiation, and innate immune recognition by natural killer cells. The hematopoietic context offers a distinctive platform to examine the interplay between oncogenic signaling, proteotoxic stress, and chaperone networks.
DNAJB2 (HSJ1) encodes a J-domain co-chaperone that recruits Hsp70 ATPases??primarily HSPA1A and HSPA8??to misfolded client proteins. DNAJB2 stimulates Hsp70 ATP hydrolysis, promoting substrate refolding or directing terminally misfolded proteins into degradation pathways via interactions with the STUB1/CHIP ubiquitin ligase and the BAG3 co-chaperone. Under cellular stress conditions, DNAJB2 expression is upregulated by heat shock transcription factor 1 (HSF1), enhancing the capacity for proteostasis through the ubiquitin-proteasome system and chaperone-mediated autophagy. Key downstream substrates include polyglutamine-expanded proteins such as mutant huntingtin, linking DNAJB2 to the clearance of neurotoxic aggregates. Knockout of DNAJB2 thus disrupts a central node in the protein quality control network, impairing disposal of misfolded species and compromising cellular resilience to proteotoxic insults.
In the K-562 background, DNAJB2 disruption provides a unique model to explore how loss of co-chaperone function intersects with the oncogenic stress environment driven by BCR-ABL1. Chronic myelogenous leukemia cells are subject to elevated oxidative stress and protein misfolding due to activated tyrosine kinase signaling, making them reliant on robust chaperone systems. DNAJB2 knockout may sensitize K-562 cells to proteasome inhibitors or autophagy modulators, offering insights into therapeutic vulnerabilities. Additionally, this model permits investigation of how hematopoietic cells manage protein aggregation??a process increasingly implicated in both cancer biology and neurodegenerative disorders.
This knockout cell population is designed for a broad array of experimental applications in molecular cell biology and drug discovery. Researchers can investigate the mechanistic role of DNAJB2 in chaperone-assisted protein degradation using co-immunoprecipitation to assess interactions with HSPA1A, HSPA8, or STUB1, and monitor autophagic flux via LC3-II turnover assays. It serves as a relevant system for modeling distal hereditary motor neuropathy and spinal muscular atrophy by analyzing aggregate-prone substrates such as polyglutamine-expanded proteins. Functional readouts including flow cytometric analysis of apoptosis and cell cycle, combined with proteasome activity measurements, allow screening of small molecules that modulate protein quality control pathways. The K-562 platform further enables studies of the heat shock response and its integration with leukemogenic signaling. For technical inquiries or assistance in designing experiments, please contact Ascent Research.
