Predicted to enable DNA-binding transcription activator activity, RNA polymerase II-specific and RNA polymerase II transcription regulatory region sequence-specific DNA binding activity. Predicted to be involved in regulation of transcription by RNA polymerase II. Predicted to act upstream of or within regulation of DNA-templated transcription. Predicted to be active in nucleus. Is expressed in several structures, including heart; liver and biliary system; nervous system; otic vesicle; and pleuroperitoneal region. Orthologous to human ATF5 (activating transcription factor 5).