Enables heme binding activity and heme transmembrane transporter activity. Involved in heme transport. Predicted to be located in endoplasmic reticulum and nuclear envelope. Predicted to be active in endomembrane system and membrane. Is expressed in several structures, including central nervous system; neural retina; pharyngo-tympanic tube; and submandibular gland primordium. Orthologous to human PGRMC2 (progesterone receptor membrane component 2). [provided by Alliance of Genome Resources, Apr 2022]