Involved in clathrin-dependent synaptic vesicle endocytosis; neuron projection development; and synaptic vesicle budding from endosome. Located in axon; cell body; and synapse. Part of AP-2 adaptor complex. Is active in presynapse. Is expressed in central nervous system and retina. Orthologous to human BTBD8 (BTB domain containing 8). [provided by Alliance of Genome Resources, Apr 2022]