ID3 Knockout HAP1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the HAP1 human near-haploid cell line. This product comprises a heterogeneous pool of cells with targeted disruption of the ID3 gene, generated without clonal isolation, making it suitable for pooled functional studies and screening applications.
HAP1 is a fibroblast-like cell line originating from the KBM-7 chronic myelogenous leukemia line, characterized by its near-haploid karyotype with single copies of most chromosomes and p53 deficiency. This genomic simplicity facilitates unambiguous gene targeting and functional genomics, establishing HAP1 as a preferred chassis for CRISPR-based screens.
ID3 encodes a dominant-negative helix-loop-helix protein that lacks a DNA-binding domain. It forms inactive heterodimers with E-proteins such as TCF3/E2A, TCF12/HEB, and TCF4/E2-2, thereby preventing their binding to E-box sequences and repressing differentiation-associated genes. ID3 expression is upregulated by BMP and TGF-?? ligands through Smad1/5/8 and Smad4, as well as by EGF and FGF pathways, and is transcriptionally induced by Egr-1. Downstream, it promotes proliferation by modulating cyclin D1 and p21 and inhibits pro-apoptotic factors.
In the p53-deficient HAP1 context, ID3 disruption removes a key survival signal, potentially derepressing E-protein activity and sensitizing cells to apoptosis. This allows dissection of ID3’s role in proliferation independent of p53-mediated checkpoints, making it a valuable model for studying oncogenic cooperation and therapeutic resistance.
This polyclonal knockout population is well-suited for functional genomics screens, cell cycle and apoptosis analyses, and cancer biology research. Standard assays include Western blot and RT-qPCR for ID3 expression, E-box luciferase reporter assays for transcriptional activity, and proliferation/apoptosis measurements via MTT, BrdU, and Annexin V staining. Co-immunoprecipitation and immunofluorescence can probe E-protein interactions. The cells also serve as a baseline for drug sensitivity testing and CRISPR-based screens. For additional technical inquiries, please contact Ascent Research.
