Enables protein C-terminus binding activity. Involved in positive regulation of neuron projection development and positive regulation of receptor-mediated endocytosis. Located in apical plasma membrane; basolateral plasma membrane; and clathrin-coated vesicle. Part of protein-containing complex. Orthologous to human AP2A1 (adaptor related protein complex 2 subunit alpha 1). [provided by Alliance of Genome Resources, Apr 2022]