The KLHL9 Knockout HAP1 Polyclonal Cells product provides a CRISPR/Cas9-edited polyclonal population of human near-haploid HAP1 cells harboring disruption of the KLHL9 locus. This loss-of-function model enables investigation of KLHL9-dependent processes in a homogeneous yet genetically varied knockout background, avoiding the clonal biases of isolated cell lines. The polyclonal format preserves population-level complexity while eliminating target gene function, making it suitable for functional genomics, pathway analysis, and phenotypic screening.
HAP1 is a near-haploid cell line derived from the KBM-7 chronic myeloid leukemia (CML) line, characterized by a single copy of most chromosomes except for a disomy of chromosome 8. As a hematopoietic progenitor model, HAP1 retains features of leukemic cells and offers an experimentally tractable system for genetic manipulation. Its near-haploidy simplifies interpretation of knockout phenotypes, as mutations are unmasked by a single allele, enhancing sensitivity in loss-of-function studies. This background is widely used in haploid genetic screens and cell biology research, particularly for studying cell cycle regulation, signaling, and cancer-relevant pathways.
KLHL9 encodes a substrate adaptor for the Cullin3-RING E3 ubiquitin ligase (CRL3), forming a heterodimer with KLHL13 to recruit Aurora B kinase (AURKB) for ubiquitination. During cytokinesis, the KLHL9?CKLHL13 complex binds AURKB at the midbody and catalyzes K48-linked polyubiquitination, targeting it for proteasomal degradation. This step is critical for abscission; its failure results in cytokinetic defects and tetraploidy. The process is regulated by upstream mitotic spindle checkpoint signals and cell cycle-dependent kinases. The CRL3 core consists of CUL3 and RBX1, and the subcomplex includes factors such as KCTD10.
In HAP1 leukemic cells, KLHL9 loss disrupts Aurora B degradation, leading to impaired cytokinesis and polyploidy. This mirrors the chromosomal instability observed in many cancers. The near-haploid background enables straightforward genotype?Cphenotype correlations, making it a powerful model for studying ubiquitin-mediated control of mitosis. Its hematopoietic origin also provides relevance for leukemogenesis research, allowing investigation of defective midbody abscission in blood cancers.
Research applications include dissection of CRL3 ubiquitin ligase mechanisms, live-cell imaging of cytokinesis, and genetic screens for midbody abscission regulators. Compatible assays encompass immunoblotting for AURKB ubiquitination, co-immunoprecipitation of CUL3 complexes, midbody immunofluorescence, flow cytometry for cell cycle/ploidy, and in vitro ubiquitination reactions. For further information, please contact Ascent Research.
