This product is a CRISPR/Cas9-edited polyclonal knockout cell population derived from the HAP1 human cell line, targeting HSPA4 gene disruption. HSPA4 encodes a stress-inducible molecular chaperone essential for protein folding and thermotolerance. The polyclonal pool provides a heterogeneous gene-edited population for robust loss-of-function experiments in a near-haploid context, avoiding clonal isolation. This versatile tool enables investigation of proteostasis and stress pathways.
HAP1 is a near-haploid human cell line originating from the KBM-7 chronic myeloid leukemia line, characterized by a haploid karyotype, BCR-ABL negativity, and wild-type p53. This genetic simplicity makes HAP1 ideal for genetic screening and functional genomics, as the single allele simplifies knockout phenotype analysis. The haploid nature reduces genetic buffering, facilitating clear delineation of gene function in studies of drug response and signaling.
HSPA4 functions as a highly conserved molecular chaperone central to the heat shock response and protein quality control. It is transcriptionally upregulated by HSF1 in response to heat shock, oxidative stress, and unfolded proteins. HSPA4 binds misfolded client proteins, promoting their folding or targeting them for ubiquitin-proteasomal degradation. Mechanistically, HSPA4 forms complexes with co-chaperones such as HSPBP1, STUB1/CHIP, DNAJB1 (Hsp40), and BAG family members, thereby modulating substrate triage and apoptosis. Through these interactions, HSPA4 influences MAPK signaling, antigen processing, and the unfolded protein response, integrating stress signals with survival decisions.
In HAP1 cells, HSPA4 disruption provides a robust model to dissect heat shock responsiveness and proteostatic control. The haploid polyclonal knockout permits assessment of HSPA4 loss on cellular fitness under stress, without allelic redundancy. This system is especially relevant for studying cancer cell stress biology, as HSPA4 is often overexpressed in malignancies and linked to drug resistance. Moreover, the wild-type p53 background allows exploration of chaperone-tumor suppressor cross-talk during therapeutic stress responses.
Researchers can employ these cells in diverse applications, including heat shock biology, proteostasis investigation, and cancer stress adaptation studies. Typical assays include viability assays under hyperthermia or oxidative stress, co-immunoprecipitation and western blotting for client protein interactions, and apoptosis profiling via caspase activation. RT-qPCR and immunofluorescence further enable analysis of stress-gene induction and chaperone localization. The polyclonal format supports population-level analyses of drug sensitivity and resistance mechanisms. For detailed information, please contact Ascent Research.
