Plasma membrane recycling in CFTR-expressing CHO cells

The hypothesis that the cystic fibrosis transmembrane conductance regulator (CFTR) participates in plasma membrane recycling was tested experimentally. Using CHO cells, we determined the effects of CFTR expression and of elevated intracellular cAMP on exocytosis, measured as the incorporation into the plasma membrane of endosomes pre-labelled with biotinylated wheat-germ agglutinin (WGA). CFTR expression was without effect on the rate of exocytosis. Furthermore, cAMP did not affect endosomal recycling to the plasma membrane in either CFTR-expressing or control cells. These findings suggest that CFTR is not involved in regulating plasma membrane recycling in all cells.