ChIP-seq analysis comparing WT, TAp63-/-, and ΔNp63-/- primary murine keratinocytes

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. We performed a ChIP-seq analysis comparing differential bindings of p63 in 3 samples: WT, TAp63-/-, and ΔNp63-/- primary murine keratinocytes.