Calcium-activated Chloride Channel-2 in Human Epithelia

Calcium-activated chloride channels (CLCAs) are a family of multifunctional proteins that are widely distributed in tissues. To investigate the distribution of human CLCA-2 (hCLCA2) in human epithelia at the light and electron microscopic levels, we raised a primary antibody against a synthetic polypeptide sequence from natural hCLCA2. Corneal, skin, vaginal, esophageal, and laryngeal epithelia were immunopositive for hCLCA2 at the cytosolic aspect of the basal cells adjacent to the basement membrane. Epithelia of stomach and small intestine showed no hCLCA2 immunoreactivity. This study reports the cellular distribution of hCLCA2 in human epithelia and suggests its possible involvement in epithelial stratification and cell-substrate adhesion.