Claudin-22 (CLDN22)

Claudin-22 is a member of the claudin family, encoding a tetraspan integral membrane protein involved in the assembly and function of tight junction strands in epithelial and endothelial cell sheets[1][5]. Tight junctions serve as barriers to solute and water movement, helping maintain cellular polarity and regulate paracellular permeability[1][5]. The protein is encoded by an intronless gene and overlaps the WWC2 gene on the opposite DNA strand[1]. Claudin-22 localizes to cell-cell junctions and engages in calcium-independent cell adhesion and structural molecule activities[1]. While the broader family of claudins is linked to diverse roles in diseases such as cancer and barrier dysfunction, direct evidence of Claudin-22’s unique pathological or therapeutic relevance is limited. The known clinical association is calvarial doughnut lesions with bone fragility[1]. There is ambiguity in nomenclature, as some sources confuse Claudin-21 and Claudin-22, which are distinct gene products. No drugs, biomarkers, or specific safety challenges have been documented for Claudin-22.

Other names

Claudin-22CLDN22