EFR3A Knockout HAP1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout population targeting the EFR3A gene in the near-haploid HAP1 cell line. This heterogeneous pool of EFR3A-disrupted cells supports loss-of-function studies without clonal isolation, retaining population diversity for pooled screening applications that minimize clonal artifacts. Direct EFR3A disruption allows interrogation of phosphoinositide metabolism and membrane trafficking in a human cellular context, while the absence of selection markers preserves native physiology.
The HAP1 cell line, derived from KBM-7 chronic myeloid leukemia, is a near-haploid human line optimized for haploid genetic screens and functional genomics. Its single-allele genome simplifies loss-of-function analysis, while retaining intact membrane trafficking and phosphatidylinositol signaling pathways relevant to EFR3A function. Although of leukemic origin, HAP1 cells provide a versatile and genetically tractable platform for CRISPR-based knockout studies.
EFR3A encodes a scaffold protein that anchors the PI4KA lipid kinase complex at the plasma membrane and Golgi, driving phosphatidylinositol 4-phosphate (PI4P) synthesis. PI4P regulates membrane trafficking, endocytic recycling, and actin dynamics, and serves as precursor for PI(4,5)P2. EFR3A, in complex with TTC7A/B and FAM126A, recruits PI4KA under control of ARF GTPases and DHHC palmitoyltransferases. Downstream PI4P effectors include OSBP, CERT, and GOLPH3, linking EFR3A to growth factor receptor signals, actin organization, and intracellular transport. Disruption of EFR3A depletes PI4P pools, causing widespread defects in membrane-dependent processes and providing a powerful loss-of-function model.
In the HAP1 background, EFR3A knockout leverages haploid genetics to reveal phenotypes from single-allele disruption, such as altered PI4P distribution, impaired endocytic recycling, and changed surface receptor expression. The polyclonal population captures phenotypic robustness across a heterogeneous cell pool, enabling studies of PI4KA inhibitor sensitivity and synthetic interactions with other trafficking components. This system combines the cell line??s high-throughput compatibility with a physiologically relevant context for functional genomics and drug discovery targeting the PI4KA/EFR3A axis.
Applications include phosphoinositide metabolism investigations, membrane trafficking studies, and PI4K inhibitor drug screening. Key assays are immunofluorescence for PI4P, western blotting of PI4KA complex members, lipidomics, cell migration assays, and flow cytometry for surface receptor internalization. Additional uses involve drug sensitivity profiling and neurodevelopmental disease modeling given EFR3A links to epilepsy and schizophrenia. For technical details, contact Ascent Research.
