Roles of TGFbeta signaling in epidermal/appendage development.

The transforming growth factor beta (TGFbeta) superfamily encompasses a number of structurally related proteins that can be divided into several subfamilies including TGFbetas, activins/inhibins and bone morphogenetic proteins (BMPs). The Smads are major intracellular mediators in transducing the signals of TGFbeta superfamily members, and are abundantly expressed in the developing epidermis and epidermal appendages. Moreover, the phenotypes of transgenic/knockout mice with altered components of the TGFbeta superfamily signaling pathway suggest that TGFbeta superfamily signaling is required for epidermal/appendage development. TGFbeta superfamily members are involved in most events during epidermal/appendage development through the TGFbeta signal transduction pathway and through cross talk with other signaling pathways. Future studies will be instrumental in defining the precise roles for TGFbeta superfamily signaling in epidermal/appendage development.