Enables transcription coactivator activity. Acts upstream of or within positive regulation of transcription, DNA-templated. Predicted to be located in cytosol and nucleoplasm. Predicted to be active in nucleus. Is expressed in several structures, including 1st branchial arch; early conceptus; genitourinary system; nervous system; and sensory organ. Orthologous to human SERTAD2 (SERTA domain containing 2). [provided by Alliance of Genome Resources, Apr 2022]