Enables identical protein binding activity. Involved in positive regulation of transcription, DNA-templated and signal transduction. Acts upstream of or within BMP signaling pathway and cell adhesion. Located in endoplasmic reticulum-Golgi intermediate compartment. Is anchored component of plasma membrane. Is expressed in several structures, including future brain; gut; nervous system; sensory organ; and skeleton. Orthologous to human RGMB (repulsive guidance molecule BMP co-receptor b). [provided by Alliance of Genome Resources, Apr 2022]