The JAGN1 Knockout HAP1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population with targeted disruption of the JAGN1 gene in the HAP1 human cell line. JAGN1 encodes Jagged1, a transmembrane ligand essential for Notch receptor-mediated cell-cell signaling that controls cell fate, proliferation, differentiation, and apoptosis. This loss-of-function model provides a genetically defined system for interrogating Jagged1-dependent pathway activity, bypassing the need for pharmacologic inhibitors or dominant-negative constructs.
HAP1 is a near-haploid, adherent, fibroblast-like cell line derived from the KBM-7 chronic myeloid leukemia line. Its near-haploid genome simplifies genetic manipulation, enabling efficient knockout generation and facilitating genetic screens by reducing confounding heterozygosity. This makes HAP1 an ideal host for studying the functional consequences of gene disruption in a human context, particularly for signaling pathways involved in hematological malignancies.
Mechanistically, Jagged1 binds NOTCH1?C4 receptors on neighboring cells, initiating ADAM10/ADAM17-mediated shedding and subsequent gamma-secretase cleavage, which releases the Notch intracellular domain (NICD). NICD translocates to the nucleus and complexes with CSL (RBPJ) and MAML to activate transcription of target genes including HES1, HEY1, Cyclin D1, and c-MYC. JAG1 expression is modulated by upstream signals such as TGF-??, HIF-1??, ETS factors, and pro-inflammatory cytokines (TNF-??, IL-1??), and it functionally interacts with NF-??B pathway components. Through these interactions, Jagged1 governs hematopoiesis, angiogenesis, epithelial-mesenchymal transition (EMT), and oncogenic transformation.
In the HAP1 background, JAGN1 knockout eliminates Jagged1-driven Notch activation, offering a potent model for dissecting ligand-specific roles in leukemogenesis and hematopoietic stem cell maintenance. The haploid state amplifies phenotype penetrance, enabling robust detection of changes in Notch target gene expression and cellular behavior. This system is directly relevant to Alagille syndrome??caused by JAG1 haploinsufficiency??as well as congenital heart defects and malignancies such as leukemia and breast cancer, where aberrant Notch signaling is pivotal. The polyclonal nature avoids clonal artifacts and ensures population-level reliability.
These cells support diverse assays: co-culture Notch activation, CSL-luciferase reporter, Western blot for NICD/HES1, immunofluorescence for JAG1/NOTCH1 localization, RT-qPCR profiling of HES1/HEY1, and flow cytometry for surface receptors. Functional assays include migration, invasion, apoptosis, and angiogenesis tube formation. They are ideal for drug screens targeting Notch modulators and for disease modeling of Jagged1-related pathologies. For further information, please contact Ascent Research.
