COUP-TF-interacting protein-2 (Ctip2): driving the coupé of sphingolipid biosynthesis in the epidermis.

Previous studies using chicken ovalbumin upstream promoter transcription factor (COUP-TF)-interacting protein 2 (Ctip2) knockout mice have demonstrated the importance of this transcription factor for the formation of the epidermal permeability barrier. Because sphingolipids are crucial in generating the barrier, in this issue Indra and colleagues show, perhaps not surprisingly, that Ctip2 has a key role in sphingolipid metabolism. Thus, Ctip2 gene ablation alters sphingolipid levels and expression of genes encoding sphingolipid-metabolizing enzymes, in some cases by direct binding to their promoters. Abnormalities in Ctip2 could therefore underlie skin disorders characterized by an aberrant epidermal permeability barrier.