BIRC2 Knockout HAP1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population designed for loss-of-function studies of the BIRC2 gene in a human near-haploid cellular context. This product comprises a heterogeneous pool of HAP1 cells engineered via CRISPR/Cas9-mediated gene disruption, enabling the investigation of cIAP1 (cellular inhibitor of apoptosis protein 1) deficiency without clonal selection biases. The polyclonal format provides a robust population-level knockout model for interrogating BIRC2-dependent signaling networks and phenotypic responses in apoptosis, NF-??B activation, and related pathways.
The parental HAP1 cell line is a near-haploid human chronic myeloid leukemia line derived from KBM-7 cells. Its haploid karyotype simplifies genetic analysis and reduces confounding effects from heterozygous mutations, making it an ideal host for genetic perturbation. HAP1 cells retain functional apoptosis and innate immune signaling pathways, providing a relevant background for studying BIRC2, a central regulator of cell survival. The knockout pool is produced by transient expression of CRISPR/Cas9 components targeting BIRC2, followed by expansion of edited cells, ensuring retention of the host line??s growth characteristics and experimental tractability.
BIRC2 encodes cIAP1, an E3 ubiquitin ligase that critically governs both canonical and non-canonical NF-??B signaling as well as apoptosis. In unstimulated cells, cIAP1 constitutively ubiquitinates and targets NIK for degradation, suppressing non-canonical NF-??B activity. Upon TNF?? stimulation, cIAP1 is recruited to the TNFR1 complex via interaction with TRAF2 and RIPK1, where it catalyzes K63-linked and K11-linked ubiquitination events that scaffold the TAK1?CIKK complex, leading to I??B?? phosphorylation and subsequent activation of NF-??B p65. Additionally, cIAP1 positively modulates MAPK8/JNK signaling. Inhibition or loss of cIAP1, such as through SMAC mimetics, sensitizes cells to RIPK1-dependent apoptosis. Thus, BIRC2 knockout removes a key survival checkpoint, unveiling direct roles of upstream regulators like TNF??, IL-1??, LPS, and CD40 ligand, and downstream effectors including the IKK complex and NF-??B p65.
The BIRC2 knockout in HAP1 creates a simplified system to dissect cIAP1??s molecular interactions. Because HAP1 lacks a full diploid genome, any residual cIAP1 activity from unedited alleles is minimal, and the polyclonal nature ensures diverse mutation spectra that collectively ablate protein function. Researchers can use this model to study the consequences of impaired RIPK1 ubiquitination, NIK accumulation, and altered TRAF2/3-dependent signaling without interference from cIAP2 or XIAP compensation often seen in other cell lines. The model is particularly valuable for validating SMAC mimetic mechanisms and testing IAP antagonist sensitivity.
Typical applications include profiling apoptotic responses via Annexin V/PI flow cytometry and caspase activation assays, measuring NF-??B transcriptional activity with luciferase reporters, and assessing signaling intermediates by Western blotting for phosphorylated I??B??, p65, and JNK. The knockout cells are also suited for co-immunoprecipitation to map residual TNFR1 complex composition, drug combination screens with IAP inhibitors, and functional genomics studies that require a clean BIRC2-null background. For further details or inquiry, contact Ascent Research.
