Enables DNA-binding transcription factor activity, RNA polymerase II-specific and RNA polymerase II cis-regulatory region sequence-specific DNA binding activity. Involved in cartilage condensation; chondrocyte differentiation; and positive regulation of chondrocyte differentiation. Acts upstream of or within several processes, including neurogenesis; regulation of timing of neuron differentiation; and regulation of transcription, DNA-templated. Located in nucleus. Part of transcription regulator complex. Is expressed in several structures, including alimentary system; genitourinary system; nervous system; respiratory system; and sensory organ. Orthologous to human SOX5 (SRY-box transcription factor 5). [provided by Alliance of Genome Resources, Apr 2022]