The JPH1 Knockout HAP1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population designed for targeted disruption of the JPH1 gene in the HAP1 cell line. This product provides a versatile loss-of-function model, generated through CRISPR/Cas9-mediated gene disruption, without selection of individual clones. The resulting polyclonal pool enables robust genetic perturbation studies while minimizing clonal artifacts, offering a reliable platform for investigating JPH1-dependent biological processes including excitation-contraction coupling and calcium signaling.
HAP1 is a near-haploid human cell line derived from the KBM-7 chronic myeloid leukemia line, isolated from a male donor. Its haploid karyotype makes it exceptionally suited for knockout and functional genomic screens, as disruption of a single allele yields complete loss-of-function phenotypes. HAP1 cells retain fundamental mammalian signaling pathways, express a broad complement of ion channels and signaling molecules, and are widely employed in studies of gene function, protein interactions, and drug responses. This host background ensures that JPH1 knockout effects are observed against a clean genetic landscape.
JPH1 encodes junctophilin-1, a junctional membrane complex protein that bridges the plasma membrane and the endoplasmic/sarcoplasmic reticulum (ER/SR) membrane systems. It physically organizes microdomains by linking plasma membrane calcium channels, such as CACNA1S, to ER/SR calcium release channels including RYR1 and ITPR1, thereby facilitating excitation-contraction coupling and calcium-induced calcium release. JPH1 transcription is regulated by muscle-lineage factors like MyoD and MEF2, and by the calcium-responsive factor NFATC1. Downstream, JPH1-mediated calcium signals activate CAMK2A and promote NFATC3 nuclear translocation, driving expression of genes critical for muscle function. JPH1 also interacts with JPH2 and TRDN to stabilize the junctional complex, positioning it as a central node in calcium microdomain control.
Knockout of JPH1 in HAP1 cells disrupts junctional membrane complex formation, leading to altered intracellular calcium dynamics and impaired downstream calcium-dependent signaling. The near-haploid nature of HAP1 ensures that CRISPR-mediated disruption produces a uniform loss-of-function effect across the polyclonal population, providing a clean model for dissecting JPH1-dependent pathways. This system is particularly relevant for studying the molecular underpinnings of congenital myopathy and cardiac arrhythmias, where JPH1 dysfunction is implicated. Additionally, it enables characterization of calcium signaling networks independent of muscle-specific context, as HAP1 cells express key components of the calcium handling machinery.
These JPH1 knockout HAP1 polyclonal cells are suited for diverse experimental applications. They can be utilized in calcium imaging assays to assess changes in intracellular calcium transients, in co-immunoprecipitation and interaction proteomics to map JPH1-dependent protein complexes, and in Western blotting or RT-qPCR to verify knockout status and downstream target expression. RNA-seq analyses can reveal transcriptome-wide changes in JPH1-regulated gene networks. The cells are also ideal for drug screening campaigns targeting calcium-handling proteins or for validating chemical probes that modulate excitation-contraction coupling. Finally, they serve as a valuable reference in functional genomics screens. For further technical details, please contact Ascent Research.
