CFTR | Cystic Fibrosis Transmembrane Conductance Regulator | ATP-Binding Cassette Sub-family C Member 7
ABC binding cassette superfamily of primary active transporters
CFTR is encoded by the CFTR gene. The protein consists of five domains. There are two transmembrane domains, each with six spans of alpha helices. These are each connected to a nucleotide binding domain (NBD) in the cytoplasm. The first NBD is connected to the second transmembrane domain by a regulatory "R" domain that is a unique feature of CFTR, not present in other ABC transporters. The ion channel only opens when its R-domain has been phosphorylated by PKA and ATP is bound at the NBDs. The carboxyl terminal of the protein is anchored to the cytoskeleton by a PDZ-interacting domain.
CFTR functions as an ATP-gated anion channel, that conducts chloride and thiocyanate ions across epithelial cell membranes. ATP-driven conformational changes in CFTR open and close a gate to allow transmembrane flow of anions down their electrochemical gradient. Mutations of the CFTR gene affecting chloride ion channel function lead to dysregulation of epithelial fluid transport in the lung, pancreas and other organs, resulting in cystic fibrosis.
Data and Applications