Differential altered stability and transcriptional activity of ΔNp63 mutants in distinct ectodermal dysplasias

Gareth Browne, Rita Cipollone, Anna Maria Lena, Valeria Serra, Huiqing Zhou, Hans van Bokhoven, Volker Dötsch, Daniele Merico, Roberto Mantovani, Alessandro Terrinoni, Richard A. Knight, Eleonora Candi, Gerry Melino

Research output: Contribution to journalArticle

Abstract

Heterozygous mutations of p63, a key transcription factor in epithelial development, are causative in a variety of human ectodermal dysplasia disorders. Although the mutation spectrum of these disorders displays a striking genotype-phenotype association, the molecular basis for this association is only superficially known. Here, we characterize the transcriptional activity and protein stability of ΔNp63 mutants (that is, mutants of a p63 isoform that lacks the N-terminal transactivation domain) that are found in ectrodactyly- ectodermal dysplasia-cleft syndrome (EEC), ankyloblepharon-ectodermal dysplasia-clefting syndrome (AEC) and nonsyndromic split-hand/split-foot malformation (SHFM). DNA-binding and sterile alpha motif (SAM) domain mutants accumulate in the skin of EEC and AEC syndrome patients, respectively, and show extended half lives in vitro. By contrast, C-terminal mutations found in SHFM patients have half-lives similar to that of the wild-type protein. The increased half-life of EEC and AEC mutant proteins was reverted by overexpression of wild-type ΔNp63. Interestingly, the mutant proteins exhibit normal binding to and degradation by the E3 ubiquitin ligase Itch. Finally, EEC and AEC mutant proteins have reduced transcriptional activity on several skin-specific gene promoters, whereas SHFM mutant proteins are transcriptionally active. Our results, therefore, provide evidence for a regulatory feedback mechanism for p63 that links transcriptional activity to regulation of protein homeostasis by an unknown mechanism. Disruption of this regulatory mechanism might contribute to the pathology of p63-related developmental disorders.

Original languageEnglish
Pages (from-to)2200-2207
Number of pages8
JournalJournal of Cell Science
Volume124
Issue number13
DOIs
Publication statusPublished - Jul 1 2011

Keywords

  • Ectodermal dysplasia protein
  • Itch
  • P63
  • Skin
  • Stability

ASJC Scopus subject areas

  • Cell Biology

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  • Cite this

    Browne, G., Cipollone, R., Lena, A. M., Serra, V., Zhou, H., van Bokhoven, H., Dötsch, V., Merico, D., Mantovani, R., Terrinoni, A., Knight, R. A., Candi, E., & Melino, G. (2011). Differential altered stability and transcriptional activity of ΔNp63 mutants in distinct ectodermal dysplasias. Journal of Cell Science, 124(13), 2200-2207. https://doi.org/10.1242/jcs.079327