The IBTK Knockout HAP1 Polyclonal Cells product comprises a population of CRISPR/Cas9-edited HAP1 cells with targeted disruption of the IBTK gene, providing a pooled knockout model for studying IBTK function. As polyclonal knockout cells, this product enables investigation of gene loss-of-function effects without clonal selection bias, making it suitable for experiments where heterogeneous knockout responses are informative. The CRISPR/Cas9-mediated gene disruption in these polyclonal cells facilitates the study of IBTK-dependent mechanisms in a near-haploid human cell background, offering a robust system for genetic and biochemical analyses.
HAP1 cells are a male human chronic myeloid leukemia-derived adherent cell line that is functionally near-haploid, stemming from the KBM-7 parental line. Their near-haploid karyotype greatly simplifies genetic studies by eliminating the complexity of diploid gene redundancy, enabling unambiguous interpretation of knockout phenotypes. HAP1 cells have become a workhorse model for haploid genetic screens and targeted gene function studies, particularly in the context of cancer biology and signal transduction, due to their ease of culture and compatibility with a wide range of cell-based assays.
IBTK encodes a BTB?CBACK?Ckelch domain-containing protein that serves as a substrate adaptor for the CUL3-RING E3 ubiquitin ligase complex, together with RBX1. Through this interaction, IBTK mediates the ubiquitination and subsequent proteasomal degradation of key targets such as the anti-apoptotic protein MCL-1. In parallel, IBTK directly binds and inhibits Bruton’s tyrosine kinase (BTK), a critical component of B-cell receptor (BCR) signaling. By suppressing BTK kinase activity, IBTK negatively regulates downstream signaling cascades, including phosphorylation of PLCG2 and activation of the NF-??B transcription factor. Thus, IBTK functions at a convergence point between the ubiquitin-proteasome pathway and BCR signal transduction to govern cell survival and proliferation.
In the HAP1 cellular context, IBTK knockout provides a powerful tool to dissect BCR signaling and ubiquitin-dependent regulatory networks without the confounding influence of a full diploid genome. The near-haploid background facilitates straightforward linking of genotype to phenotype in studies of apoptosis, NF-??B activity, and proteasomal degradation. As IBTK is implicated in multiple myeloma and other B-cell malignancies, where MCL-1 and BTK are often dysregulated, this knockout model enables investigation of therapeutic vulnerabilities and resistance mechanisms in a clean genetic system.
This polyclonal knockout cell population is ideal for a broad range of applications, including ubiquitination assays, co-immunoprecipitation of CUL3 and BTK complexes, western blotting for MCL-1 stability, RT-qPCR analysis of NF-??B target genes, and flow cytometry-based apoptosis or viability assays. It can be employed in haploid genetic screens to identify synthetic lethal interactions or modulators of BCR signaling. Additionally, the cells are suited for pharmacological studies with BTK inhibitors or proteasome inhibitors, providing a platform for preclinical drug testing. Researchers are encouraged to contact Ascent Research for further information on product use and customization options.
