Calmodulin regulates the intracellular trafficking in epithelial cells.

In this study we have demonstrated the role of calmodulin in membrane trafficking. By means of specific calmodulin-antagonist (W13, N-(4-aminobutyl)-5-chloro-2-naphthalenesulfonamide) the transcytosis, recycling and receptor-mediated endocytosis of IgA were investigated. In W13 treated MDCK cells, exHpressing the polymeric immunoglobulin receptor (pIgR) and plated on polycarbonate filters (transwells), it has been shown that transcytosis of IgA was inhibited, the recycling was concomitantly increased and there were no modification on its internalization. Altogether, point to a role of calmodulin in regulating the function of endocytic compartment in epithelial cells.