The DUSP4 Knockout HAP1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the human HAP1 cell line, targeting the dual-specificity phosphatase DUSP4. This polyclonal pool, generated via CRISPR/Cas9-mediated gene disruption, offers a heterogeneous loss-of-function model that avoids clonal artifacts and provides robust population-level insights. It is ideally suited for research applications requiring reliable ablation of DUSP4 function without single-cell cloning steps.
HAP1 is a near-haploid human cell line originating from the chronic myeloid leukemia line KBM-7, carrying a single copy of most chromosomes (with disomy of chromosome 15). This haploidy simplifies genetic manipulation and ensures that knockout alleles are directly expressed without diploid masking effects, making HAP1 a preferred host for functional genomic screens, haploid genetic studies, and cancer research. Its well-characterized signaling landscape supports reproducible examination of pathway perturbations.
DUSP4 acts as a key negative feedback regulator of the MAPK signaling cascades. It encodes a dual-specificity phosphatase that dephosphorylates threonine and tyrosine residues on the MAP kinases ERK1/2, JNK1/2, and p38??, thereby inactivating them. Transcription of DUSP4 is induced downstream of receptor tyrosine kinases (EGFR, FGFR) and stress/inflammatory stimuli, mediated by transcription factors ELK1 and AP-1. By directly interacting with and deactivating its MAPK substrates, DUSP4 tempers the RAS-RAF-MEK-ERK cascade and the JNK/p38 stress pathways. Knockout of DUSP4 removes this attenuating control, leading to sustained MAPK activation, enhanced cell proliferation, and increased survival signaling.
When introduced into HAP1 cells, DUSP4 disruption creates an efficacious platform for dissecting MAPK-driven cellular phenotypes. The homozygous knockout expression enforced by haploidy ensures unambiguous loss-of-function, facilitating clear linkage of sustained ERK, JNK, and p38 activity to downstream outcomes. This model is particularly valuable for studying oncogenic signaling, tumor cell proliferation, and drug resistance mechanisms, as well as for screening modulators of MAPK pathways in a genetically uniform background that simplifies data interpretation.
These DUSP4 knockout HAP1 cells are ideally suited for a range of experimental approaches. Western blotting for phospho-ERK, phospho-JNK, and phospho-p38 allows direct monitoring of MAPK activation status. Transcriptional output can be quantified using luciferase reporters driven by ELK1 or AP-1 response elements. Cell proliferation (MTT or BrdU assays), apoptosis (Annexin V staining), and drug sensitivity panels provide functional readouts. RNA-seq enables genome-wide transcriptome profiling. The polyclonal population supports pooled genetic screens and synthetic lethality studies in a near-haploid context. For additional information, please contact Ascent Research.
