Abnormal regulation of ion channels by members of the ABC transport protein superfamily
has been implicated in hyperinsulinemic hypoglycemia and in excessive Na+ absorption by
airway epithelia in cystic fibrosis (CF). How ABC proteins regulate ion conductances is
unknown, but must generally involve either the number or activity of specific ion channels.
Here we report that the cystic fibrosis transmembrane conductance regulator (CFTR), which
is defective in CF, reverses the regulation of the activity of single epithelial sodium channels …