The EFNA1 Knockout HAP1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population targeting the EFNA1 gene in a human haploid cell background. The polyclonal pool contains a range of loss-of-function edits, providing a robust model for functional screens and pooled assays without single-clone variability. EFNA1 encodes ephrin-A1, a glycosylphosphatidylinositol (GPI)-anchored ligand that initiates bidirectional signaling upon binding EphA receptors. The knockout disrupts both forward and reverse signaling, enabling dissection of its contributions to cell adhesion, repulsion, and migration.
The host cell line HAP1 is a near-haploid, adherent, fibroblast-like line derived from the KBM-7 chronic myeloid leukemia (CML) cells. Its haploid karyotype facilitates efficient gene editing and simplifies genotypic analysis, as a single disruptive mutation can lead to functional knockout. HAP1 cells retain key signaling networks, including those governing cytoskeletal dynamics and cell adhesion, making them a widely adopted platform for functional genomics and drug screening. Their adherent growth and scalable culture conditions are compatible with high-throughput imaging and biochemical assays. Importantly, HAP1 cells express endogenous EphA receptors, providing a physiologically relevant context for investigating ephrin-A1-mediated signaling.
Ephrin-A1 is a GPI-anchored ligand that binds to EphA receptor tyrosine kinases, triggering receptor clustering and bidirectional signaling. Forward signaling, propagated through EphA receptors, activates SRC family kinases, FAK, and Rho GTPases such as RHOA and ROCK, leading to actin cytoskeletal reorganization. Reverse signaling via ephrin-A1 can modulate integrin function and MMPs, influencing cell adhesion and matrix remodeling. EFNA1 transcription is regulated by TP53, HIF1A, and TNF, linking its expression to hypoxic, inflammatory, and DNA damage responses. Downstream targets include the MAPK/ERK and PI3K/AKT pathways, which coordinate cell proliferation, survival, and motility. The gene product is also shed by ADAM10, generating a soluble form that can act at a distance, adding complexity to its functional repertoire.
In HAP1 cells, ephrin-A1 knockout eliminates both forward and reverse signaling, making this model valuable for studying bidirectional communication in a simplified genetic background. The haploid state ensures complete functional ablation with a single allele disruption, eliminating residual partial activity. This is particularly useful for investigating ephrin?A1??s role in contact?dependent repulsion, migration, and invasion??processes critical in angiogenesis and tumor progression. Because HAP1 cells express relevant EphA receptors, the model allows direct examination of ligand?receptor interactions without confounding from diploid compensatory mechanisms, providing a clean platform to interrogate signaling kinetics and feedback loops.
Researchers can use these polyclonal knockout cells in phospho-signaling analyses via western blotting and flow cytometry to assess downstream activation of SRC, ERK1/2, and AKT upon stimulation with soluble ephrin?A1 or EphA?Fc fusion proteins. Functional assays such as transwell migration, adhesion to various matrices, and time?lapse imaging directly probe ephrin?A1??s role in cell motility. Co?culture experiments with endothelial or tumor cell lines enable study of juxtacrine signaling and angiogenic sprouting. This tool supports drug target validation, high?content screening, and mechanistic dissection of Eph?ephrin signaling in oncology and cardiovascular research. For further information, please contact Ascent Research.
