The EIF2AK2 Knockout HAP1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout population of HAP1 cells in which the EIF2AK2 gene has been disrupted. These polyclonal knockout cells provide a loss-of-function model for studying the protein kinase PKR, a central component of the antiviral innate immune response and the integrated stress response. The mixed clonal population preserves the genetic heterogeneity expected from polyclonal knockout pools, while eliminating functional PKR expression through targeted gene disruption.
HAP1 is a near-haploid human cell line derived from the KBM-7 chronic myeloid leukemia (CML) cell line, which was isolated from a male patient. Its haploid genome simplifies genetic analysis and enables unambiguous genotype-to-phenotype mapping in functional genomics studies. HAP1 cells are widely employed as a screening platform for genome-wide knockout, CRISPR interference, and pathway-focused investigations, making them particularly well-suited for dissecting signaling networks involved in cancer, stress responses, and host?Cpathogen interactions.
EIF2AK2 encodes the serine/threonine kinase PKR, which is activated by double-stranded RNA (dsRNA), interferon-??/??, or PACT (PRKRA). Activated PKR autophosphorylates and subsequently phosphorylates eIF2?? (EIF2S1), inhibiting global cap-dependent translation while selectively enhancing translation of ATF4 mRNA. The ATF4-driven transcriptional program induces CHOP (DDIT3) and other effectors that govern cell fate decisions toward apoptosis or adaptation. Additionally, PKR activates NF-??B by phosphorylating I??B and modulates JNK signaling, often cooperating with MAVS and STAT3. Negative regulators include TRBP (TARBP2) and the inhibitory chaperone P58IPK, ensuring tight control of antiviral and stress responses.
In the haploid HAP1 background, disruption of EIF2AK2 results in complete ablation of PKR protein function without compensatory masking by a second allele, thereby creating a clean genetic system for interrogating PKR-dependent pathways. This model enables precise dissection of eIF2???CATF4?CCHOP signaling and PKR-mediated NF-??B activation in the context of myeloid-derived cells, offering a relevant platform for studies of hematopoietic stress responses and oncogenic signaling. Moreover, the polyclonal nature of the population minimizes clonal bias while preserving uniformity of the knockout, making the cells suitable for experimental protocols that require large cell numbers or high-throughput screening.
These EIF2AK2 polyclonal knockout cells are a versatile tool for a broad spectrum of applications, including the investigation of antiviral innate immunity mechanisms, the study of translational control under cellular stress, functional dissection of the unfolded protein response, and validation of PKR as a therapeutic target in cancer and neurodegenerative diseases. Representative assays include western blotting for phosphorylated eIF2??, RT-qPCR of ATF4 and CHOP target genes, immunofluorescence for PKR subcellular localization, apoptosis analysis, luciferase-based interferon response reporter assays, polysome profiling, and flow cytometry for stress markers. Additionally, the cells are suitable for genome-wide screens aimed at identifying host factors required for viral replication or modulators of the integrated stress response. For further technical details and support, please contact Ascent Research.
