AP2B1 Knockout HEK293T Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout population targeting AP2B1, encoding the beta2-adaptin subunit of adaptor complex 2 (AP-2). This gene disruption model in HEK293T cells provides a loss-of-function system for studying clathrin-mediated endocytosis.
HEK293T is a human embryonic kidney epithelial line expressing SV40 large T antigen, known for high transfectability and robust protein expression. It is widely used for viral production and biochemical studies, and its adherent morphology suits imaging-based assays of receptor trafficking.
AP2B1 encodes beta2-adaptin, a core subunit of the heterotetrameric AP-2 complex that also comprises AP2A1/2 (alpha), AP2M1 (mu2), and AP2S1 (sigma2). Beta2-adaptin directly binds clathrin heavy chain and interacts with PI(4,5)P2 at the plasma membrane, bridging clathrin lattice assembly to cargo recruitment. The mu2 subunit recognizes tyrosine-based sorting motifs on receptors such as EGFR and TFRC, while accessory factors including Eps15 and epsin facilitate coat maturation. AP-2 activity is regulated by AAK1- and GAK-mediated phosphorylation of mu2, and complex endocytic function is critical for internalization of EGFR, TFRC, and LDL receptor (LDLR), as well as ligand-induced downregulation. Disruption of AP2B1 abrogates AP-2 complex assembly, impairing clathrin-coated pit formation and receptor internalization, thereby perturbing EGFR signaling and other pathways downstream of endocytosed cargo.
HEK293T cells provide a well-characterized system for studying clathrin-mediated endocytosis due to their robust EGFR expression and trafficking. AP2B1 knockout in this background yields a loss-of-function model in which EGF-induced EGFR degradation is blocked, enabling quantitative analysis of receptor retention at the cell surface and activation of compensatory internalization pathways. This model also facilitates investigation of AP-2 complex integrity through co-immunoprecipitation of remaining subunits and assessment of altered phospho-signaling networks by phospho-EGFR and phospho-ERK assays.
Typical applications include western blotting to monitor EGFR degradation kinetics, flow cytometry-based transferrin and LDL uptake assays, and immunofluorescence localization of clathrin adaptors. Live-cell imaging can capture internalization dynamics, while RNA-seq reveals transcriptional responses to sustained signaling. AP2B1 knockout cells are also valuable for validation of endocytosis inhibitors and drug delivery targeting. For further information or custom applications, contact Ascent Research.
