The APBB1 Knockout HAP1 Polyclonal Cells from Ascent Research provide a CRISPR/Cas9-edited polyclonal cell population with targeted disruption of the APBB1 gene in the HAP1 human cell line. This knockout model offers a loss-of-function system for investigating the biological roles of the APBB1-encoded adaptor protein FE65, which functions as a transcriptional coactivator and scaffold in multiple signaling cascades. As a polyclonal knockout pool, this product is suitable for population-level functional studies without requiring single-cell clonal isolation.
The host HAP1 cell line is a near-haploid fibroblast-like cell derived from the KBM-7 chronic myeloid leukemia line, providing a simplified genetic background conducive to CRISPR-based modification and genetic screens. Its haploid karyotype reduces gene redundancy, enhancing the penetrance of knockout phenotypes and making it a valuable model for high-throughput functional genomics and cancer biology research.
APBB1 (FE65) is an adaptor protein that binds the intracellular domain of amyloid precursor protein (APP) following gamma-secretase cleavage, facilitating nuclear translocation of the AICD-FE65 complex. Within the nucleus, FE65 interacts with the histone acetyltransferase Tip60 and the transcription factor CP2 to coactivate transcription of genes such as BACE1, neprilysin, and GSK3B. FE65 also forms multiprotein assemblies with MINT2 (APBA2), LRP1, and ARH, integrating signals from the Notch and Wnt pathways. Upstream, FE65 is phosphorylated by Abl kinase, and its activity is regulated by APP processing, linking it to Alzheimer’s disease pathology and cell migration control.
In the HAP1 background, disruption of APBB1 abrogates FE65-dependent transcriptional coactivation and impairs APP intracellular signaling, leading to altered expression of downstream targets involved in cell motility and apoptosis. Given its origin from a leukemia line, this knockout model also permits dissection of FE65’s potential roles in cancer cell behavior, including adhesion and migration. The near-haploid genome ensures that knockout effects are not masked by a second functional allele, yielding clear loss-of-function phenotypes that are especially useful for genetic interaction studies and drug screening campaigns targeting Alzheimer’s-related pathways.
This polyclonal APBB1 knockout cell pool is suitable for a wide range of experimental approaches, including western blotting and co-immunoprecipitation to confirm protein complex disruption, luciferase reporter assays to assess transcriptional coactivation, and RT-qPCR or RNA-seq to profile gene expression changes. Functional studies such as migration and apoptosis assays can be applied to characterize the impact of FE65 loss on cellular phenotypes. The cells are also amenable to high-throughput genetic and compound screens, enabling drug target validation and identification of modulators of APP processing. For detailed protocols or further assistance, researchers may contact Ascent Research.
