Gap Junction Protein Beta 4 (GJb4)

Gap junctions are conduits that allow the direct cell-to-cell passage of small cytoplasmic molecules, including ions, metabolic intermediates, and second messengers, and thereby mediate intercellular metabolic and electrical communication. Gap junction channels consist of connexin protein subunits, which are encoded by a multigene family. For additional background information on gap junction proteins.

The deletion in GJB4 leads to a frameshift and consequently a nonsense codon, resulting in a nonfunctional protein product that is truncated after the first transmembrane domain. The GJB4 deletion does not induce nonsense-mediated RNA decay, as mRNA transcripts could be detected in a skin biopsy from the patient by RT-PCR analysis.