The DTNB Knockout HAP1 Polyclonal Cells are a CRISPR/Cas9-edited population of HAP1 cells carrying a disruption of the dystrobrevin beta (DTNB) gene. This polyclonal knockout model provides a stable loss-of-function system to study DTNB??s role in the dystrophin-associated glycoprotein complex (DGC) without the limitations of transient gene silencing.
HAP1 is a near-haploid, adherent, fibroblast-like line derived from the KBM-7 chronic myeloid leukemia (CML) cell line. It has a male karyotype and is p53 deficient, facilitating easy genome editing and clonal isolation. The near-haploid genome simplifies functional genomic studies, as a single allele disruption yields a null phenotype.
DTNB encodes dystrobrevin beta, a scaffolding protein that anchors the actin cytoskeleton to the DGC through direct binding with dystrophin and syntrophins (e.g., SNTA1, SNTB1, SNTB2). It also interacts with dystrobrevin alpha (DTNA), sarcoglycans, dystroglycan, ankyrin, and neuronal nitric oxide synthase (nNOS). Upstream regulation is mediated by MEF2 transcription factors and calcium signaling, while downstream targets include nNOS, aquaporin-4, and voltage-gated sodium channels. Consequently, DTNB disruption destabilizes the DGC, impairing syntrophin-mediated signaling, nitric oxide production, and ion channel localization at the membrane.
In the HAP1 near-haploid context, DTNB knockout offers a clean system to investigate DGC-related adhesion and migration outside muscle tissue, given the cell line??s fibroblastoid properties. The p53 deficiency may unmask additional roles for dystrobrevin beta in genome maintenance and cell cycle checkpoints, making this model useful for studying cross-talk between DGC integrity and stress signaling pathways. It also facilitates high-throughput genetic and chemical screens to identify modifiers of DGC function.
Applications include western blotting for DTNB and DGC components, immunocytochemistry to assess membrane localization, cell adhesion and migration assays, nNOS activity measurement, RT-qPCR profiling, co-immunoprecipitation of DGC complexes, and calcium flux analyses. The model is suited for muscular dystrophy disease modeling, drug screening for dystrophinopathies, and investigation of cardiomyopathy and neurological disorders. The near-haploid background also supports synthetic lethality screens and genetic modifier studies. For inquiries, please contact Ascent Research.
