Enables vitamin D receptor binding activity. Acts upstream of or within negative regulation of osteoclast differentiation; positive regulation of ossification; and regulation of gene expression. Predicted to be located in cytosol. Predicted to be active in cytoplasm and nucleus. Is expressed in several structures, including Meckel's cartilage; genitourinary system; liver; orbito-sphenoid; and spleen. Orthologous to human TOB2 (transducer of ERBB2, 2). [provided by Alliance of Genome Resources, Apr 2022]