Predicted to enable calcium ion binding activity; cargo receptor activity; and cobalamin binding activity. Predicted to be involved in cobalamin metabolic process; cobalamin transport; and positive regulation of B cell activation. Predicted to act upstream of or within regulation of vitamin metabolic process. Predicted to be located in endoplasmic reticulum. Predicted to be integral component of plasma membrane. Predicted to be active in plasma membrane. Human ortholog(s) of this gene implicated in methylmalonic acidemia due to transcobalamin receptor defect. Orthologous to human CD320 (CD320 molecule). [provided by Alliance of Genome Resources, Apr 2022]