AP2B1 Gene - Adaptor Related Protein Complex 2 Subunit Beta 1 | Function, Mutations & Disease

The AP2B1 gene encodes the beta-1 subunit of the adaptor protein complex 2 (AP-2), a heterotetrameric complex that links clathrin to receptors in coated vesicles during clathrin-mediated endocytosis. AP-2 is critical for internalization of cell surface receptors, including transferrin receptor, LDL receptor, and G protein-coupled receptors. AP2B1 interacts with clathrin and accessory proteins to regulate cargo selection and vesicle formation. Mutations and altered expression of AP2B1 have been implicated in cancer, neurodegenerative disorders, and developmental abnormalities.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• Clathrin-mediated endocytosis (KEGG: hsa04144)

• Endocytosis (Reactome: R-HSA-199991)

• Transferrin recycling (Reactome: R-HSA-917977)

AP2B1 encodes the beta-1 subunit of the AP-2 adaptor complex. The protein contains an N-terminal trunk domain that binds cargo and clathrin, a hinge region, and a C-terminal ear domain that interacts with accessory proteins. It is ubiquitously expressed and essential for clathrin-mediated endocytosis. Structural studies show that AP2B1 adopts a flexible conformation to accommodate different cargo molecules. Post-translational modifications include phosphorylation, which regulates its interaction with clathrin and adaptor proteins.