Predicted to enable DNA binding activity; identical protein binding activity; and transcription coactivator activity. Predicted to be involved in negative regulation of DNA metabolic process and positive regulation of transcription initiation from RNA polymerase II promoter. Predicted to act upstream of or within SMAD protein signal transduction. Located in nucleus. Orthologous to human SUB1 (SUB1 regulator of transcription). [provided by Alliance of Genome Resources, Apr 2022]