The ATF6 Knockout HAP1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population designed to provide a loss-of-function model for the ATF6 gene. This product offers a heterogeneous pool of HAP1 cells carrying targeted disruptions of ATF6, enabling robust functional genomics studies without clonal selection. As a polyclonal knockout product, it maintains genetic diversity while eliminating ATF6 expression, making it suitable for pooled screening approaches and batch-level phenotypic assays where population-level responses are critical.
The host cell line, HAP1, is a near-haploid human chronic myeloid leukemia cell line derived from the KBM-7 line. This adherent, male-derived cell line possesses a predominantly haploid karyotype that significantly simplifies CRISPR/Cas9-mediated gene disruption by requiring editing of a single allele. HAP1 cells are widely adopted in genetic screening, functional genomics, and signaling pathway dissection due to their stable growth characteristics, ease of transfection, and amenability to high-throughput assays, providing a well-characterized leukemic background for interrogating gene function.
ATF6 encodes a transcription factor that serves as a principal regulator of the unfolded protein response (UPR). Under endoplasmic reticulum (ER) stress, accumulated misfolded proteins cause ATF6 to dissociate from the chaperone BiP/GRP78 and traffic to the Golgi apparatus. There, it undergoes regulated intramembrane proteolysis by the site-1 protease MBTPS1 and site-2 protease MBTPS2, releasing the active N-terminal fragment ATF6(N). This fragment translocates to the nucleus, where it interacts with NF-Y complexes and binds ER stress response elements (ERSE) to transcriptionally activate UPR target genes including HSPA5 (GRP78), HYOU1, DNAJB9, CALR, and ER-associated degradation (ERAD) machinery components. ATF6 thus coordinates adaptive responses to restore ER proteostasis, acting downstream of ER stress sensors and upstream of XBP1-mediated pathways.
In the HAP1 leukemic context, ATF6 knockout provides a potent model to dissect the ATF6 branch of the UPR and its contributions to cancer cell fitness. Chronic myeloid leukemia cells often exploit UPR pathways to tolerate oncogenic stress, making ATF6 disruption a valuable tool for understanding how ER stress signaling supports malignant proliferation and survival. The haploid background ensures efficient knockout, facilitating genetic interaction studies and drug target validation where ATF6-dependent activities may be selectively required under proteotoxic stress conditions relevant to multiple ER stress-related disorders, including diabetes and neurodegenerative diseases.
This knockout cell population supports diverse research applications. Users can quantify UPR target gene induction via qPCR or RNA-seq after chemical ER stressors such as tunicamycin, monitor ATF6 cleavage and BiP levels by Western blot, and assess ATF6 transcriptional activity using ERSE-driven luciferase reporters. Indirect immunofluorescence enables visualization of ATF6(N) nuclear translocation, while cell viability or apoptosis assays under tunicamycin treatment evaluate functional consequences of ATF6 loss. These applications position the product for high-content chemical screens and mechanistic studies in cancer biology and ER stress signaling. For further information or custom model requests, please contact Ascent Research.
