title: p63 induces key target genes required for epidermal morphogenesis.
abstract: Mice lacking p63, a single gene that encodes a group of transcription factors that either contain (TA) or lack (DeltaN) a transactivation domain, fail to develop stratified epithelia as well as epithelial appendages and limbs. DeltaNp63 isoforms are predominantly expressed during late embryonic and postnatal epidermal development, however, the function of these proteins remains elusive. Using an epidermal-specific inducible knockdown mouse model, we demonstrate that DeltaNp63 proteins are essential for maintaining basement membrane integrity and terminal differentiation of keratinocytes. Furthermore, we have identified two DeltaNp63alpha target genes that mediate these processes. We propose that DeltaNp63alpha initially induces expression of the extracellular matrix component Fras1, which is required for maintaining the integrity of the epidermal-dermal interface at the basement membrane. Subsequently, induction of IkappaB kinase-alpha by DeltaNp63alpha initiates epidermal terminal differentiation resulting in the formation of the spinous layer. Our data provide insights into the role of DeltaNp63alpha in epidermal morphogenesis and homeostasis, and may contribute to our understanding of the pathogenic mechanisms underlying disorders caused by p63 mutations.
authors.affiliation: Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: Maranke I
authors.initials: MI
authors.lastname: Koster
authors.forename: Daisy
authors.initials: D
authors.lastname: Dai
authors.forename: Barbara
authors.initials: B
authors.lastname: Marinari
authors.forename: Yuji
authors.initials: Y
authors.lastname: Sano
authors.forename: Antonio
authors.initials: A
authors.lastname: Costanzo
authors.forename: Michael
authors.initials: M
authors.lastname: Karin
authors.forename: Dennis R
authors.initials: DR
authors.lastname: Roop
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002454:Cell Differentiation / Q000235:genetics / Q000502:physiology; D002460:Cell Line; D017931:DNA Primers; D004817:Epidermis / Q000196:embryology*; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D020287:In Situ Nick-End Labeling; D015603:Keratinocytes / Q000166:cytology*; D051379:Mice; D008822:Mice, Transgenic; D008856:Microscopy, Fluorescence; D009024:Morphogenesis / Q000235:genetics* / Q000502:physiology; D010750:Phosphoproteins / Q000235:genetics*; D048328:Potoroidae; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015534:Trans-Activators / Q000235:genetics*; D014945:Wound Healing / Q000502:physiology
chemical_list: D017931:DNA Primers; D010750:Phosphoproteins; D015534:Trans-Activators; C486419:Trp63 protein, mouse