The H1-4 Knockout HAP1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population with targeted disruption of the H1-4 gene, which encodes linker histone H1.4. This loss-of-function model enables investigation of linker histone biology, chromatin organization, and gene expression regulation. The polyclonal nature ensures diverse editing events while maintaining functional knockout across the population, suitable for pooled phenotypic screens and population-level analyses.
The HAP1 host cell line is a near-haploid human fibroblast-like line derived from chronic myeloid leukemia (CML) KBM-7 cells. It features a haploid karyotype and BCR-ABL oncogene expression, providing a robust platform for functional genomic studies. The near-haploid genome simplifies genetic analysis, enabling unambiguous genotype-phenotype correlations and facilitating CRISPR-based screens. This male-derived, adherent line retains fibroblastoid morphology and is widely used for investigating cellular processes in cancer-relevant contexts.
Histone H1.4 binds nucleosome core particles and linker DNA, promoting chromatin compaction and higher-order structure formation. It is regulated by upstream factors including E2F transcription factors, NF-Y, and CDK/cyclin complexes such as cyclin E/CDK2, which phosphorylate H1.4 to modulate chromatin interactions. H1-4 functions downstream of DNA replication signals and interacts with nucleosome components, HMGN proteins, PARP1, and HP1 to control nucleosome spacing, DNA accessibility, and transcriptional programs. Disruption of H1-4 alters chromatin organization, impacting gene expression patterns and DNA damage response pathways.
In the HAP1 context, H1-4 knockout provides a powerful model to dissect chromatin-mediated regulatory mechanisms. The BCR-ABL-positive leukemia background and near-haploid genetics allow studies of oncogenic signaling crosstalk with chromatin remodeling. This model is particularly valuable for investigating how linker histone H1.4 influences cancer cell behavior, including proliferation and genomic stability, given its role in DNA damage responses and transcriptional control. HAP1’s compatibility with high-throughput screening further enhances its utility for drug target validation and epigenetic modifier discovery.
Research applications span functional genomics, chromatin biology, and cancer research. Representative assays include western blotting for H1.4 protein loss, ChIP-seq for chromatin occupancy, ATAC-seq for accessibility, RT-qPCR for gene expression, and immunofluorescence for chromatin structure visualization. Cell proliferation and drug sensitivity assays evaluate functional outcomes, particularly relevant to lymphoma and leukemia models. For additional technical information or experimental design support, please contact Ascent Research.
