EIF2AK3 Knockout HAP1 Polyclonal Cells consist of a CRISPR/Cas9-edited polyclonal population derived from human HAP1 cells, with disruption of the EIF2AK3 gene encoding the ER stress kinase PERK. This pooled knockout model offers a loss-of-function system for studying PERK-mediated signaling without clonal selection, capturing heterogeneous cellular responses to ER stress.
The HAP1 host line is a near-haploid adherent cell line from a chronic myeloid leukemia (CML) patient carrying the BCR-ABL1 fusion. Its predominantly haploid karyotype (except a disomic fragment of chromosome 8) simplifies gene targeting and phenotypic analysis, making it a standard platform for functional genomics and CRISPR screens. The CML origin provides a cancer-relevant background for stress signaling research.
PERK, encoded by EIF2AK3, is an ER-resident kinase activated by unfolded protein accumulation. Upon ER stress, PERK dimerizes and autophosphorylates, then phosphorylates EIF2S1 (eIF2??) at Ser51, attenuating global translation while selectively increasing ATF4 translation. ATF4 drives expression of adaptive genes including DDIT3 (CHOP) and PPP1R15A (GADD34). Upstream, GRP78/BiP dissociation regulates PERK, while DNAJC3 (P58IPK) modulates its activity. PERK also engages NFE2L2 (NRF2) antioxidant responses. Chronic stress shifts signaling toward CHOP-dependent apoptosis.
EIF2AK3 disruption in the haploid HAP1 context enables clean interrogation of PERK function without allelic redundancy. This model allows precise analysis of eIF2?? phosphorylation, ATF4/CHOP induction, and crosstalk between the UPR and other pathways. The leukemia-derived background further permits investigation of PERK??s role in cancer cell survival and sensitivity to ER stress-inducing therapies.
Typical applications include Western blotting for phospho-eIF2??, ATF4, and CHOP; RT-qPCR for ATF4 and DDIT3; immunofluorescence of ER stress foci; ATF4-luciferase reporter assays; and drug sensitivity testing with tunicamycin or thapsigargin. The cells are suitable for PERK inhibitor screening and research into cancer therapeutic resistance, diabetes, and neurodegeneration. For further information, contact Ascent Research.
