The KBTBD6 Knockout HAP1 Polyclonal Cells are a population of CRISPR/Cas9-edited HAP1 cells with targeted disruption of the KBTBD6 gene. This polyclonal knockout pool provides a loss-of-function model for investigating KBTBD6 function in a near-haploid leukemia background. The polyclonal nature ensures representation of diverse editing outcomes while enabling robust pooled analyses typical of functional genomics screens.
HAP1 cells, derived from the male chronic myeloid leukemia cell line KBM-7, are near-haploid except for chromosome 8 and a portion of chromosome 15. They express the BCR-ABL1 fusion oncogene and lack functional p53, rendering them a pertinent model for leukemogenesis and drug response studies. The near-haploid karyotype reduces genetic complexity, facilitating unambiguous genotype-phenotype correlations in CRISPR-based screens and functional assays.
KBTBD6 encodes a substrate adaptor for the Cullin-3?CRING E3 ubiquitin ligase complex, which includes the scaffold protein CUL3 and the RING protein RBX1. Through its Kelch repeat domains, KBTBD6 recruits the transcriptional repressor ZBTB38 for ubiquitination and subsequent proteasomal degradation. Degradation of ZBTB38 relieves repression of target genes such as CDKN1A (p21), thereby influencing cell proliferation and survival. The complex is regulated by NEDD8 conjugation to CUL3 and possibly by upstream cellular signals that remain to be fully defined.
In the HAP1 CML background, disruption of KBTBD6 is expected to stabilize ZBTB38, leading to sustained transcriptional repression of pro-proliferative or anti-apoptotic genes, including CDKN1A. This may alter BCR-ABL1-driven signaling networks and modulate sensitivity to tyrosine kinase inhibitors or other therapeutics. Consequently, these cells are a valuable tool for dissecting ubiquitin-dependent control of transcription in leukemia and for identifying vulnerabilities specific to KBTBD6 loss.
Applications include validation of CRISPR screening hits, ubiquitin-proteasome system analysis, and drug target discovery in hematologic malignancies. Typical assays encompass Western blotting for KBTBD6, ZBTB38, and p21; RT-qPCR for CDKN1A transcript levels; cell viability and clonogenic assays; apoptosis detection by flow cytometry; co-immunoprecipitation to assess CUL3 complex interactions; and ubiquitination assays to monitor ZBTB38 turnover. These cells are also suited for drug sensitivity screens aimed at identifying compounds that selectively target KBTBD6-deficient leukemia cells. For further details or customized solutions, please contact Ascent Research.
