Enables DNA-binding transcription activator activity, RNA polymerase II-specific; RNA polymerase II cis-regulatory region sequence-specific DNA binding activity; and RNA polymerase II-specific DNA-binding transcription factor binding activity. Involved in positive regulation of transcription by RNA polymerase II. Acts upstream of or within with a positive effect on apoptotic process; hypothalamus gonadotrophin-releasing hormone neuron development; and peripheral nervous system development. Acts upstream of or within several processes, including cell migration in hindbrain; male gonad development; and male mating behavior. Located in chromatin. Is expressed in several structures, including central nervous system; embryo ectoderm; genitourinary system; head mesenchyme derived from neural crest; and sensory organ. Orthologous to human NHLH2 (nescient helix-loop-helix 2). [provided by Alliance of Genome Resources, Apr 2022]