CFTR
Underlying Molecule Defect
CF is caused by mutations in the gene encoding the cystic
fibrosis transmembrane conductance regulator (CFTR) protein. CFTR is a
cAMP regulated chloride channel, which opens in response to
phosphorylation by ATP. CFTR is found in sweat and pancreatic ducts,
gut, seminiferous tubules, conducting airways and many other tissues.
Most often mutations lead to either CFTR not reaching the apical
membrane or alternatively reaching it, but having reduced function. This
results in impaired chloride transport at the apical surface of the
epithelial cells. In addition absorption of sodium from the airway
surface is increased in CF. CFTR negatively regulates the activity of
the sodium channel ENaC and mutations in CFTR alter this regulation
leading to the increased sodium absorption characteristic of CF. CFTR
also regulates many other proteins. For an excellent animated guide to
CFTR function
please click here.
For quick & easy reference to definitions of scientific and medical terms visit one of the on-line dictionaries