CFTR: Structure and function

Cystic fibrosis (CF) is the most common autosomal recessive disease in Caucasians. It is caused by abnormal fluid and electrolyte transport in exocrine epithelia. This abnormality results in clinical symptoms such as chronic obstructive pulmonary disease, pancreatic insufficiency and elevated sweat electrolyte levels. The gene responsible for the basic cellular defect, a lack of activation of the cAMP-mediated regulation of chloride (Cl^™) channels, was cloned in 1989, and its protein product was named cystic fibrosis transmembrane regulator (CFTR). The identification of the gene allowed for a rapid and powerful series of studies which addressed the structure and the function of CFTR, In this article, we review the work performed in laboratories scattered all over the world that concentrated on understanding the basic structure and complete function of this intriguing protein. We focus on a description of the experiments that not only provided a clearer understanding of the primary activity of CFTR, as a cAMP-acti- vated Cl^™ channel, but also uncovered some of the other cellular functions in which CFTR is involved.