Differential PERP regulation by TP63 mutants provides insight into AEC pathogenesis.
Ankyloblepharon Ectodermal Dysplasia and Cleft Lip/Palate (AEC) or Hay-Wells Syndrome is an autosomal dominant disorder characterized by a variety of phenotypes in ectodermal derivatives, including severe skin erosions, ankyloblepharon, coarse and wiry hair, scalp dermatitis, and dystrophic nails. AEC is caused by mutations in the gene encoding the TP63 transcription factor, specifically in the Sterile Alpha Motif (SAM) domain. The exact mechanism, however, by which these specific TP63 mutations lead to the observed spectrum of phenotypes is unclear. Analysis of individual TP63 target genes provides a means to understand specific aspects of the phenotypes associated with AEC. PERP is a TP63 target critical for cell-cell adhesion due to its participation in desmosomal adhesion complexes. As PERP null mice display symptoms characteristic of ectodermal dysplasia syndromes, we hypothesized that PERP dysfunction might contribute to AEC. Using luciferase reporter assays, we demonstrate here that PERP induction is in fact compromised with some, but not all, AEC-patient derived TP63 mutants. Through analysis of skin biopsies from AEC patients, we show further that a subset of these display aberrant PERP expression, suggesting the possibility that PERP dysregulation is involved in the pathogenesis of this disease. These findings demonstrate that distinct AEC TP63 mutants can differentially compromise expression of downstream targets, providing a rationale for the variable spectra of symptoms seen in AEC patients. Elucidating how specific TP63 target genes contribute to the pathogenesis of AEC will ultimately help design novel approaches to diagnose and treat AEC.
Division of Radiation and Cancer Biology, Department of Radiation Oncology, Stanford University School of Medicine, 269 Campus Drive, Stanford,CA 94305-5152, USA.
Veronica G
VG
Beaudry
Navneeta
N
Pathak
Maranke I
MI
Koster
Laura D
LD
Attardi
D000015:Abnormalities, Multiple / Q000235:genetics / Q000503:physiopathology; D000818:Animals; D002478:Cells, Cultured; D002971:Cleft Lip / Q000235:genetics / Q000503:physiopathology*; D002972:Cleft Palate / Q000235:genetics / Q000503:physiopathology*; D004476:Ectodermal Dysplasia / Q000175:diagnosis / Q000235:genetics / Q000503:physiopathology*; D000078404:Epidermal Cells; D004817:Epidermis / Q000378:metabolism*; D005143:Eyelids / Q000002:abnormalities; D005347:Fibroblasts / Q000378:metabolism; D005786:Gene Expression Regulation; D016147:Genes, Tumor Suppressor; D006801:Humans; D007150:Immunohistochemistry; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D013577:Syndrome; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism*
D008565:Membrane Proteins; C416404:PERP protein, human; C115051:TP63 protein, human; D015534:Trans-Activators; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins