The ARPC1B Knockout HAP1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal population of near-haploid HAP1 cells harboring a targeted disruption of the ARPC1B gene. This loss-of-function model abolishes expression of the Arp2/3 complex subunit ARPC1B, a critical nucleator of branched actin filaments. The polyclonal format provides a heterogeneous pool of edited cells suitable for robust functional studies and genetic screens without clonal selection.
The HAP1 cell line is an adherent, near-haploid human cell line derived from a male chronic myelogenous leukemia patient, exhibiting fibroblast-like morphology. Its nearly haploid karyotype simplifies knockout generation by requiring disruption of only one allele, minimizing functional redundancy. HAP1 cells retain core actin regulatory machinery, facilitating cytoskeletal dynamics studies in a genetically tractable system compatible with high-content imaging and flow cytometry.
ARPC1B encodes a subunit of the Arp2/3 complex, which nucleates branched actin networks essential for lamellipodia and cell motility. The complex is activated by nucleation-promoting factors like WASP and WAVE proteins, which are stimulated by Rho GTPases Rac1 and Cdc42 downstream of receptor tyrosine kinases and chemokine receptors. ARPC1B directly interacts with subunits ARPC2-5, ACTR2/ARP2, ACTR3/ARP3, and actin, stabilizing the complex for Y-branch formation. Active Arp2/3 generates branched filaments driving protrusion, adhesion turnover, phagocytosis, and immune synapse assembly. Disruption of ARPC1B therefore compromises actin reorganization, impairing migration and endocytosis.
In the HAP1 background, ARPC1B knockout provides a simplified model to study Arp2/3 function. HAP1 cells exhibit fundamental actin-dependent processes like lamellipodium formation and migration, and the haploid genome ensures complete loss-of-function without allelic compensation. This system is useful for investigating interactions with WASP/WAVE and Rho GTPases, probing ARPC1A isoform compensation, and modeling actin dysregulation associated with ARPC1B-related immunodeficiency 71.
These polyclonal knockout cells support a variety of assays: Western blotting and immunofluorescence for ARPC1B and actin structures; live-cell imaging for migration and invasion; flow cytometry for phagocytosis and adhesion. They are also suitable for pooled CRISPR screens. This model enables mechanistic studies of cytoskeletal dynamics, immune dysfunction, and cancer cell motility. For further details, please contact Ascent Research.
