Enables several functions, including cargo receptor activity; hemoglobin binding activity; and identical protein binding activity. Involved in several processes, including cobalamin catabolic process; cobalamin transport; and endocytic hemoglobin import into cell. Located in several cellular components, including brush border membrane; clathrin-coated pit; and cytoplasmic vesicle. Part of receptor complex. Orthologous to human CUBN (cubilin). [provided by Alliance of Genome Resources, Apr 2022]