The APTX Knockout HAP1 Polyclonal Cells constitute a CRISPR/Cas9-edited polyclonal knockout cell population designed for the disruption of the APTX gene in the HAP1 human cell line. This product provides a genetically heterogeneous pool of APTX-deficient cells, enabling robust loss-of-function studies without assuming clonal uniformity or specific editing outcomes. The polyclonal format preserves diverse background genotypes while ensuring target-gene ablation through CRISPR/Cas9-mediated genome editing, facilitating the investigation of aprataxin-dependent cellular processes.
HAP1 is a human near-haploid cell line derived from the KBM-7 chronic myeloid leukemia parental line, originating from a male donor. Its near-haploid karyotype makes it an exceptionally tractable model for CRISPR-based functional genomics, as single-copy gene disruption typically yields complete loss-of-function phenotypes. HAP1 cells are widely employed in knockout screening and mechanistic studies, providing a defined, genetically simplified background ideal for dissecting gene-specific contributions to DNA repair pathways.
Aprataxin, encoded by APTX, resolves abortive DNA ligation intermediates via deadenylation of 5??-AMP-DNA adducts, essential for completing single-strand break repair. Recruited by XRCC1, Aptx operates within a complex including DNA ligase III and is regulated by PARP1 activation at damage sites and CK2-mediated phosphorylation. Its deficiency causes accumulation of unsealed DNA breaks and hyperactivation of poly(ADP-ribose) polymerases, leading to genomic instability. This molecular dysfunction underlies ataxia with oculomotor apraxia type 1 (AOA1), a hereditary neurodegenerative disorder.
In the HAP1 background, APTX disruption creates an effective model for studying aprataxin deficiency. The near-haploid genome ensures that Cas9-mediated gene disruption yields a complete loss-of-function phenotype, eliminating confounding wild-type allele expression. This allows direct assessment of Aptx??s role in genome maintenance, DNA repair kinetics, and sensitivity to genotoxic stress, mirroring the cellular pathology observed in AOA1.
Applications of these polyclonal knockout cells include alkaline comet assays for DNA strand breaks, immunofluorescence detection of ??H2AX and 53BP1 repair foci, and colony formation assays following genotoxic challenge. They are well-suited for RT-qPCR profiling of DNA repair gene expression and drug sensitivity screens with PARP inhibitors or alkylating agents. Combined with biochemical analysis of XRCC1 and DNA ligase III complexes, the model facilitates detailed investigation of single-strand break repair and its link to neurodegeneration. For more information, please contact Ascent Research.
