Is an ortholog of human ARNT (aryl hydrocarbon receptor nuclear translocator). Exhibits DNA binding activity\; DNA-binding transcription factor activity\; and RNA polymerase II transcription factor binding activity. Contributes to sequence-specific DNA binding activity. Is involved in several processes, including cell fate specification\; neurogenesis\; and positive regulation of transcription by RNA polymerase II. Localizes to the RNA polymerase II transcription factor complex. Is expressed in the alimentary system\; the hypodermis\; and the nervous system.