Acts early in neural crest formation, functioning redundantly with the other group E Sox factors sox8 and sox9 to induce neural crest progenitors. Acts downstream of wnt-signaling at the neural plate border. Involved in the specification of neural crest progenitors fated to form the pigment cell lineage (By similarity). Interacts with the sumoylation factors ube2i/ubc9 and sumo1. The transactivation domains TAM and TAC (for transactivation domain in the middle and at the C-terminus, respectively) are required to contact transcriptional coactivators and basal transcriptional machinery components and thereby induce gene transactivation. Sumoylated.