The KCNQ2 Knockout HAP1 Polyclonal Cells are a genetically edited population generated by CRISPR/Cas9-mediated disruption of the KCNQ2 gene in the near-haploid HAP1 cell line. This polyclonal knockout pool provides a loss-of-function model for studying Kv7.2 channel biology without clonal isolation.
HAP1 is a near-haploid human cell line derived from the chronic myeloid leukemia KBM-7 line, originally from a male patient. Its near-haploid karyotype, with most chromosomes present in single copy, facilitates unambiguous genetic manipulation and high-efficiency CRISPR editing, making it a versatile platform for functional genomics. These cells retain key signaling pathways relevant to myeloid biology, yet are amenable to expression of ectopic neuronal channels like KCNQ2/KCNQ3 for electrophysiological studies.
KCNQ2 encodes the Kv7.2 voltage-gated potassium channel subunit, which co-assembles with KCNQ3 to form M-channels that generate the subthreshold M-current, suppressing neuronal excitability. M-channel activity is critically regulated by PIP?, and Gq-coupled receptors such as muscarinic M1 or bradykinin B2 activate PLC?? to deplete PIP?, inhibiting the channel. Downstream, PKC and Ca2?/calmodulin further modulate channel function. The KCNQ2/KCNQ3 complex interacts with calmodulin, AKAP79/150, syntaxin-1A, and KCNE auxiliary subunits, linking it to diverse signaling and trafficking pathways.
While HAP1 is not a neuronal cell, its haploid background simplifies genotype-phenotype correlation, making it ideal for dissecting KCNQ2??s molecular interactions and pharmacological properties. Loss of KCNQ2 in these cells eliminates the obligate partner for KCNQ3, providing a clean background for heterologous expression of wild-type or mutant channels. This enables precise studies of channel assembly, surface trafficking, and regulation in a reductionist system, particularly for investigating GPCR-mediated M-current suppression mechanisms. The model also supports screening of compounds that modulate Kv7.2/7.3 channel activity, such as retigabine or novel candidates.
Researchers can employ this knockout pool in whole-cell patch-clamp recordings (co-expressing KCNQ3) to measure M-current, thallium flux assays, and membrane potential dye-based high-throughput screens to evaluate channel modulators like retigabine. The cells support functional validation of epilepsy-associated KCNQ2 variants via rescue experiments. Additionally, biochemical assays such as Western blotting, RT-qPCR, and co-immunoprecipitation can probe protein expression and interactions. The absence of KCNQ2 protein expression is readily confirmed by Western blotting. For further information or custom inquiries, please contact Ascent Research.
