Enables DNA-binding transcription factor activity, RNA polymerase II-specific; double-stranded DNA binding activity; and identical protein binding activity. Involved in positive regulation of transcription by RNA polymerase II. Located in nucleus. Human ortholog(s) of this gene implicated in Ayme-Gripp syndrome; cataract; and cataract 21 multiple types. Orthologous to human MAF (MAF bZIP transcription factor). [provided by Alliance of Genome Resources, Apr 2022]