CLDN15 Gene: Claudin 15 - Function, Expression, and Disease Associations

CLDN15 (Claudin 15) is a protein-coding gene that belongs to the claudin family of tight junction proteins. Claudins are integral membrane proteins that form the backbone of tight junction strands, regulating paracellular ion permeability. CLDN15 is specifically involved in the selective permeability of cations, particularly sodium and potassium, in epithelial tissues. It plays a critical role in gastrointestinal tract function, including intestinal ion absorption and barrier maintenance. The gene is located on chromosome 7q22.1 and encodes a 228-amino acid protein with four transmembrane domains.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• Tight junction pathway (KEGG: hsa04530)

• Cell junction organization (Reactome: R-HSA-446728)

Claudin-15 is a 228-amino acid transmembrane protein with four membrane-spanning domains, two extracellular loops, and intracellular N- and C-termini. It localizes to tight junctions in epithelial cells, where it forms paracellular pores selective for cations, particularly Na+ and K+. The protein is essential for maintaining ion homeostasis in the gastrointestinal tract, especially in the small intestine and colon. Dysregulation of claudin-15 expression is associated with inflammatory bowel disease and colorectal cancer.