TAp63α induces AP-2γ as an early event in epidermal morphogenesis

Epidermal morphogenesis begins with the commitment of the single-layered surface ectoderm to initiate a stratification program, a process that requires the expression of the transcription factor TAp63 alpha. To determine the molecular mechanism by which TAp63 alpha induces genes associated with the commitment to stratification, such as K14, we have used a combination of in vitro and in vivo approaches. Our initial gene expression profiling studies suggested that TAp63 alpha could regulate one or more AP-2 genes, which have been implicated in development and maintenance of the epidermis. We now demonstrate that TAp63 alpha directly induces AP-2 gamma expression in embryonic epidermis, when commitment to stratification occurs. Furthermore, we show that, in the absence of AP-2 gamma, TAp63 alpha fails to induce K14 expression in vitro. Our data identify AP-2 gamma as the first in vivo target gene of TAp63 alpha, and provide novel insights into the molecular mechanisms associated with early events in epidermal morphogenesis. (c) 2005 Elsevier Inc. All rights reserved.