Project description:We performed a ChIP-seq analysis characterizing the p63 binding sites in primary keratinocytes obtained from E18.5 mice of 3 different genotypes (WT, TAp63-/-, and ΔNp63-/-). We aimed to identify the specific genomic regions bound by TAp63 and ΔNp63 in physiological conditions.
Project description:As a member of the p53/p63/p73 family, p63 is a transcriptional regulator that induces apoptosis, cell cycle arrest, or senescence. TAp63 protein, a p53-like master transcriptional regulator, plays an essential role in epithelial development because p63-null mice are born alive but die shortly after birth due to developmental defects. However, its molecular mechanism remains elusive. We identified these phosphorylation sites during a search for the targets of Cyclin G-associated kinase (GAK) in vitro. LCE1C was drastically upregulated by doxycycline-dependent expression of Myc-TAp63 wild-type (WT) proteins, but not non-phosphorylatable Myc-TAp63-T46A/T281A (AA) proteins.
Project description:We performed an RNA-seq analysis characterizing expression profiles in primary keratinocytes obtained from E18.5 mice of 3 different genotypes (WT, TAp63-/-, and ΔNp63-/-). We aimed to identify the specific transcriptional target genes regulated by TAp63 and ΔNp63 in physiological conditions.
Project description:We identified p63 target genes and binding sites responsible for ectodermal defects by genome-wide profiling of p63 binding using ChIP-seq and expression analysis in human primary keratinocytes from patients with p63 mutations. As proof of principle, we identified a novel de novo microdeletion causing limb defects (SHFM1) that includes a p63 binding site functioning as a cis-regulatory element to control expression of the distally located DLX5/DLX6 genes essential for limb development. Our data demonstrate that target genes and regulatory elements detected in this study can serve as powerful tools to identify causative mutations of unresolved ectodermal disorders. ChIP-seq profiles of p63 in primary human keratinocytes established from two different normal individuals.
Project description:iASPP (PPP1R13L) is an evolutionarily conserved regulator of p53 family members. In mice, iASPP deletion in keratin 14-expressing keratinocytes is sufficient to cause detrimental phenotypes with squamous epithelium abnormalities. In human skin, wild-type nuclear iASPP colocalizes with the key squamous differentiation regulatory factor, TP63, and iASPP mutations are associated with abnormalities in skin development. To clarify how iASPP modulates p63 genome occupancy, p63 ChIP-seq data from iASPP WT and iASPP KO primary mouse keratinocytes (MKC) were compared.
Project description:The p53 family member TP63 encodes two sets of isoforms, TAp63 and ∆Np63 isoforms, which are characterized by different N-termini and have diverse biological functions in epidermal morphogenesis and in cancer. In the skin, where their activities are best characterized, TAp63 prevents premature aging by regulating cellular senescence and genomic stability of stem cells, while ∆Np63 controls terminal differentiation of the basal cells in the epidermis. This functional diversity is surprising given that these isoforms share a high degree of similarity, including an identical DNA binding domain. To understand the mechanisms involved in the transcriptional programs leading to these diverse biological functions, we performed genome-wide analyses using p63-ChIP-seq and RNA-seq of TAp63-/- and ∆Np63-/- compared to wild-type primary mouse epidermal cells. Our data indicate that TAp63 and ∆Np63 recognize significantly different response elements on DNA and can physically and functionally interact with distinct transcription factors for the downstream regulation of their target genes. Our findings unveil previously uncharacterized transcriptomes activated by the p63 isoforms to regulate diverse biological functions in epidermal morphogenesis and homeostasis and cancer.
Project description:p63 mutations have been associated with several human hereditary disorders characterized by ectodermal dysplasia such as EEC syndrome, ADULT syndrome and AEC syndrome . The location and functional effects of the mutations that underlie these syndromes reveal a striking genotype-phenotype correlation. Unlike EEC and ADULT that result from missense mutations in the DNA-binding domain of p63, AEC is solely caused by missense mutations in the SAM domain of p63. We report a study on the TAp63a isoform, the first to be expressed during development of the embryonic epithelia, and on its naturally occurring Q540L mutant derived from an AEC patient. To assess the effects of the Q540L mutation, we generated stable cell lines expressing TAp63a wt, DeltaNp63 alpha or the TAp63 alpha-Q540L mutant protein and used them to systematically compare the cell growth regulatory activity of the mutant and wt p63 proteins and to generate, by microarray analysis, a comprehensive profile of differential gene expression. We found that the Q540L substitution impairs the transcriptional activity of TAp63a and causes misregulation of genes involved in the control of cell growth and epidermal differentiation. Experiment Overall Design: Three biological replicates of not induced TAp63 alpha wt, three biological replicates of induced TAp63 alpha wt, three biological replicates of not induced TAp63Q540L alpha mutant and two biological replicates of induced TAp63Q540L alpha mutant
Project description:p63 is critical for epithelial development yet little is known about the transcriptional programmes it regulates. The p63 transactivating (TA) isoforms contain an amino-terminal exon that encodes a p53-like transactivation domain, whereas ΔN-isoforms lack this domain but contain the common DNA binding domain (DBD), suggesting that TAp63 and ΔNp63 isoforms may have opposing functions. By characterising transcriptional changes and cellular effects following modulation of p63 expression, we have defined a vital role for p63 in cellular adhesion. Knockdown of p63 expression caused downregulation of cell adhesion-associated genes, cell detachment and anoikis in mammary epithelial cells and keratinocytes. Conversely, overexpression of the TAp63γ or ΔNp63α isoforms of p63 upregulated cell adhesion molecules, increased cellular adhesion and conferred resistance to anoikis.
Project description:p63 is critical for epithelial development yet little is known about the transcriptional programmes it regulates. The p63 transactivating (TA) isoforms contain an amino-terminal exon that encodes a p53-like transactivation domain, whereas ÎN-isoforms lack this domain but contain the common DNA binding domain (DBD), suggesting that TAp63 and ÎNp63 isoforms may have opposing functions. By characterising transcriptional changes and cellular effects following modulation of p63 expression, we have defined a vital role for p63 in cellular adhesion. Knockdown of p63 expression caused downregulation of cell adhesion-associated genes, cell detachment and anoikis in mammary epithelial cells and keratinocytes. Conversely, overexpression of the TAp63γ or ÎNp63α isoforms of p63 upregulated cell adhesion molecules, increased cellular adhesion and conferred resistance to anoikis. Total RNA was isolated 48 h after retroviral or adenoviral infection and was subjected to reverse transcription, labelling and hybridization. The knockdown samples were performed in duplicate with shRNA vector control, shRNA targetting all isoforms of p63 (shDBD) and shRNA targetting p63 isoforms containing the transactivating (TA) domains. The overexpression samples were performed in triplicate with vector control, overexpression of the ÎNp63α isoform, and overexpression of the TAp63γ isoforms.