Vesicle targeting and ion secretion in epithelial cells: implications for cystic fibrosis.

The cellular mechanisms that lead to the asymmetric distribution of ion transport proteins and the capacity for cAMP-stimulated Cl- secretion at the cell and organelle level are beginning to emerge. Testable models exist for many of the steps involved in the generation and maintenance of epithelial plasma membrane protein asymmetry. The challenge today for the cellular physiologist is to integrate these findings into an understanding of epithelial targeting phenomena and the manner in which these mechanisms are altered by disease states.