Protein aggregation of the p63 transcription factor underlies severe skin fragility in AEC syndrome.

The p63 gene encodes a master regulator of epidermal commitment, development, and differentiation. Heterozygous mutations in the C-terminal domain of the p63 gene can cause ankyloblepharon-ectodermal defects-cleft lip/palate (AEC) syndrome, a life-threatening disorder characterized by skin fragility and severe, long-lasting skin erosions. Despite deep knowledge of p63 functions, little is known about mechanisms underlying disease pathology and possible treatments. Here, we show that multiple AEC-associated p63 mutations, but not those causative of other diseases, lead to thermodynamic protein destabilization, misfolding, and aggregation, similar to the known p53 gain-of-function mutants found in cancer. AEC mutant proteins exhibit impaired DNA binding and transcriptional activity, leading to dominant negative effects due to coaggregation with wild-type p63 and p73. Importantly, p63 aggregation occurs also in a conditional knock-in mouse model for the disorder, in which the misfolded p63 mutant protein leads to severe epidermal defects. Variants of p63 that abolish aggregation of the mutant proteins are able to rescue p63's transcriptional function in reporter assays as well as in a human fibroblast-to-keratinocyte conversion assay. Our studies reveal that AEC syndrome is a protein aggregation disorder and opens avenues for therapeutic intervention.This work was supported by Telethon Grants GGP09230 and GGP16235 (to C.M.), ERA-Net Research Program on Rare Diseases (ERARE-2) Skin-Dev (C.M.), Italian Association for Cancer Research Grant IG2011-N.11369 (to C.M.), Fondation Dind-Cottier pour la recherche sur la peau (C.M.), DFG Grant DO 545/8-1 (to V.D.), the Centre for Biomolecular Magnetic Resonance, and the Cluster of Excellence Frankfurt (Macromolecular Complexes). P.G. is supported by a Lichtenberg Professorship of the Volkswagen Foundation. C.R. is a PhD student in molecular oncology at the European School of Molecular Medicine

Mutant p63 causes defective expansion of ectodermal progenitor cells and impaired FGF signalling in AEC syndrome

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p63 regulates Satb1 to control tissue-specific chromatin remodeling during development of the epidermis

Genome organizer Satb1 is regulated by p63 and contributes to epidermal morphogenesis by remodeling chromatin structure and gene expression at the epidermal differentiation complex locus

A Multicassette Gateway Vector Set for High Throughput and Comparative Analyses in Ciona and Vertebrate Embryos

BACKGROUND: The past few years have seen a vast increase in the amount of genomic data available for a growing number of taxa, including sets of full length cDNA clones and cis-regulatory sequences. Large scale cross-species comparisons of protein function and cis-regulatory sequences may help to understand the emergence of specific traits during evolution. PRINCIPAL FINDINGS: To facilitate such comparisons, we developed a Gateway compatible vector set, which can be used to systematically dissect cis-regulatory sequences, and overexpress wild type or tagged proteins in a variety of chordate systems. It was developed and first characterised in the embryos of the ascidian Ciona intestinalis, in which large scale analyses are easier to perform than in vertebrates, owing to the very efficient embryo electroporation protocol available in this organism. Its use was then extended to fish embryos and cultured mammalian cells. CONCLUSION: This versatile vector set opens the way to the mid- to large-scale comparative analyses of protein function and cis-regulatory sequences across chordate evolution. A complete user manual is provided as supplemental material

p63 in Squamous Cell Carcinoma of the Skin: More Than a Stem Cell/Progenitor Marker

The p63 gene is often overexpressed in squamous cell carcinomas; however, how its overexpression contributes to tumor formation and expansion is still incompletely understood. Devos et al. report the development of a versatile mouse model demonstrating that p63 facilitates squamous cell carcinoma formation in skin and providing an excellent tool to dissect the relevance of its downstream signaling pathways in tumorigenesis

Research Techniques Made Simple: Identification and Characterization of Long Noncoding RNA in Dermatological Research

Long noncoding RNAs (lncRNAs) are a functionally heterogeneous and abundant class of RNAs acting in all cellular compartments that can form complexes with DNA, RNA, and proteins. Recent advances in high-throughput sequencing and techniques leading to the identification of DNA-RNA, RNA-RNA, and RNA-protein complexes have allowed the functional characterization of a small set of lncRNAs. However, characterization of the full repertoire of lncRNAs playing essential roles in a number of normal and dysfunctional cellular processes remains an important goal for future studies. Here we describe the most commonly used techniques to identify lncRNAs, and to characterize their biological functions. In addition, we provide examples of these techniques applied to cutaneous research in healthy skin, that is, epidermal differentiation, and in diseases such as cutaneous squamous cell carcinomas and psoriasis. As with protein-coding RNA transcripts, lncRNAs are differentially regulated in disease, and can serve as novel biomarkers for the diagnosis and prognosis of skin diseases