Enables transcription coactivator activity. Involved in several processes, including positive regulation of MAP kinase activity; positive regulation of branching involved in ureteric bud morphogenesis; and regulation of gene expression. Acts upstream of or within negative regulation of protein localization to nucleus; positive regulation of apoptotic signaling pathway; and regulation of transcription by RNA polymerase II. Located in chromatin and nucleus. Is expressed in several structures, including alimentary system; egg cylinder; genitourinary system; hair follicle; and nervous system. Orthologous to human MAGED1 (MAGE family member D1). [provided by Alliance of Genome Resources, Apr 2022]