The HS1BP3 Knockout HAP1 Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout cell population designed to disrupt the HS1BP3 gene in the HAP1 near-haploid human cell model. This polyclonal knockout pool provides a heterogeneous loss-of-function model for studying HS1BP3-dependent processes without clonal artifacts, offering a robust tool for functional genomics, immune signaling, and actin cytoskeleton research.
HAP1 cells are a near-haploid, suspension-adapted leukemic cell line derived from the KBM-7 chronic myeloid leukemia line. Originating from a male donor, HAP1 cells maintain a largely haploid karyotype with the exception of disomy 8 and a partial disomy of chromosome 15. Their near-haploid genome simplifies genetic analysis and facilitates CRISPR-based knockout screening, while their hematopoietic origin makes them particularly suited for investigating immune cell biology, signal transduction, and hematological malignancy mechanisms.
HS1BP3 encodes a scaffold protein that orchestrates the linkage between HS1 (HCLS1) and the actin cytoskeleton and endocytic machinery in hematopoietic cells. Upon stimulation of immune receptors such as the T cell receptor (TCR), B cell receptor (BCR), or Fc epsilon RI, Src family kinases (Lyn, Fyn) and Syk kinase phosphorylate HS1, which then recruits HS1BP3. HS1BP3 subsequently bridges the signal to actin nucleation via the Arp2/3 and WAVE complexes, promoting actin polymerization, and to endocytic processes by interacting with dynamin and cortactin. This molecular cascade couples receptor activation to cytoskeletal remodeling and receptor internalization, central events in modulating immune cell activation and trafficking.
The HAP1 cell background provides an optimal platform for dissecting HS1BP3 function. As a hematopoietic suspension cell line, HAP1 cells naturally express key signaling components such as ZAP70, LAT, and PLC??1, enabling reconstitution or knock-in studies to complement the knockout. The near-haploid nature minimizes confounding effects from allelic variation, ensuring that the polyclonal disruption yields a clean loss-of-function readout. This model is therefore invaluable for dissecting the molecular determinants of actin dynamics, endocytosis, and immune receptor signaling in a genetically simplified environment, and for linking HS1BP3 to pathologies like hematological malignancies and autoimmune disorders.
Researchers can employ this polyclonal knockout pool in a wide array of functional assays, including western blotting and RT-qPCR to confirm target disruption, immunofluorescence to visualize F-actin reorganization, and flow cytometry to monitor receptor internalization kinetics. Co-immunoprecipitation and proximity-based assays can map HS1BP3 interactomes with dynamin or cortactin, while phospho-signaling analyses following immune stimulation dissect upstream pathway activation. Additional applications include phagocytosis and migration assays to assess cytoskeletal-dependent processes, and large-scale CRISPR screens to identify synthetic lethal partners. This product is an essential resource for advancing studies in immune cell biology and cancer signaling. For further information, please contact Ascent Research.
