Enables protein domain specific binding activity. Involved in regulation of protein-containing complex assembly. Located in Golgi apparatus; dendrite; and perinuclear region of cytoplasm. Used to study diabetes mellitus. Human ortholog(s) of this gene implicated in type 1 diabetes mellitus. Orthologous to human ICA1 (islet cell autoantigen 1). [provided by Alliance of Genome Resources, Apr 2022]