The cystic fibrosis transmembrane regulator forms macromolecular complexes with PDZ domain scaffold proteins.

Cystic fibrosis transmembrane regulator (CFTR), an epithelial Cl- channel defective in cystic fibrosis, is localized at the apical membrane of epithelial cells. CFTR interacts with a number of ion channels (outwardly rectifying chloride channels, epithelial sodium channels, and inwardly rectifying potassium channels), protein kinases A and C, and putative protein phosphatases and ATP transporters. These data suggest that CFTR may exist in macromolecular complexes with these and other scaffolding proteins at the apical membrane. PDZ domain proteins have been shown to localize and cluster CFTR in the Golgi and at the plasma membrane. This review highlights the role of PDZ domain proteins in regulating the trafficking and processing of CFTR.