Genomic organization and amplification of the human plakoglobin gene (JUP)

Plakoglobin is a globular protein common to the intracellular plaques of adhesive junctions, predominantly desmosomes and adherens junctions. Recently, a number of pathogenic mutations have been described in other components of desmosomes, specifically in plakophilin 1, desmoplakin and desmoglein 1. The phenotype of affected patients mainly involves thickening of palm and sole skin (keratoderma). Although no human mutations in plakoglobin have been described thus far, this protein represents an excellent candidate for other human genetic disorders, possibly involving skin and heart, sites of high plakoglobin expression. To facilitate future mutation detection analyses in such conditions, we have characterized the intron-exon organization of the human plakoglobin gene, which comprises 13 distinct exons spanning approximately 17 kb on 17q21. We have also developed a PCR-based mutation detection strategy using primers placed on flanking introns followed by direct sequencing of the PCR products.