An autoregulatory loop directs the tissue-specific expression of p63 through a long-range evolutionarily conserved...

Area of Science:

• Developmental Biology
• Molecular Genetics
• Epithelial Biology

Background:

• p63, a p53 family member, is vital for stratified epithelial development and ectodermal structure formation.
• The precise genetic mechanisms governing p63's spatial expression during embryogenesis remain largely undefined.

Purpose of the Study:

• To identify and characterize the regulatory elements controlling p63 gene expression during embryonic development.
• To elucidate the molecular mechanisms underlying p63 autoregulation and its interaction with other transcription factors.

Main Methods:

• Genomic analysis to identify conserved cis-regulatory elements.
• Functional characterization of a novel enhancer using mouse embryogenesis models.
• Investigation of p63 and AP-2 transcription factor binding and activity on the enhancer.

Main Results:

• Identification of a conserved cis-regulatory element 160 kb downstream of the p63 first exon functioning as a keratinocyte-specific enhancer.
• Demonstration of a positive autoregulatory loop where p63 proteins bind and regulate the enhancer, controlling endogenous p63 expression.
• Evidence of AP-2 transcription factor cooperating with p63 to modulate enhancer activity.

Conclusions:

• A long-range autoregulatory loop involving p63 and AP-2 is critical for regulating p63 expression in embryonic and adult cells.
• This regulatory mechanism ensures proper spatial and temporal expression of p63, essential for epithelial development.