BD Transduction Laboratories™ Purified Mouse Anti-Adaptin ε

Sorting of integral membrane proteins is mediated by vesicular trafficking between a variety of organelles. Two sorting signals are tyrosine-based and dileucine-based signals that interact with heterotetrameric adaptor protein complexes (AP-1, AP-2, AP-3, and AP-4), which are associated with the vesicle coats. These coatomers contain two large adaptin proteins (γ, α, σ, ε and β1, β2, β3, β4 respectively) that are noncovalently linked to one medium chain (µ1, µ2, µ3, µ4 respectively) and one small chain (σ1, σ2, σ3, σ4 respectively). The AP-1 and AP-3 complexes are involved in protein sorting from the TGN and endosomes, while AP-2 adaptor complexes are involved in clathrin-mediated endocytosis. AP-4 is associated with non-clathrin coated vesicles in the region of the TGN. This localization is disrupted by brefeldin A, indicating that AP-4 membrane attachment is regulated by small GTPases. The µ4 subunit of the AP-4 complex interacts with tyrosine-based signals on LAMP-2 during targeting to the endosomal-lysosomal system. Thus, AP-4 is a less abundant AP complex that may be important for vesicle trafficking from the Golgi to the endosomal-lysosomal system.