• is an online educational resource on the genetics of cystic fibrosis (CF) and the role of CF transmembrane conductance regulator (CFTR) in normal human physiology as well as in CF.
  • The information contained herein is intended for healthcare professionals working within the European Union (EU).
  • The content of this website has been developed independently by a group of CF healthcare professionals and is for general information purposes only.
  • All of the information about CFTR and CFTR modulators has been obtained from referenced sources and is in the public domain.
  • This website is not intended to promote or advocate a particular course of treatment or any specific drug, whether licensed or unlicensed, nor is it intended to imply or suggest that any drug be used for any purpose other than that which for which it is licensed in the EU.


  • While we endeavour to keep the information up to date and correct, we make no representations or warranties of any kind, express or implied, about the completeness, accuracy, reliability, suitability or availability with respect to the website or the information and related graphics, or products and treatments, contained on the website for any purpose. Any reliance you place on such information is therefore strictly at your own risk.
  • In no event will we be liable for any loss or damage including without limitation, indirect or consequential loss or damage, or any loss or damage whatsoever arising from, or in connection with, the use of this website.
  • Through this website you are able to link to other websites which are not under our control. We have no control over the nature, content and availability of those sites. The inclusion of any links does not necessarily imply a recommendation or endorse the views expressed within them.
  • Every effort is made to keep the website up and running smoothly. However, we take no responsibility for, and will not be liable for, the website being temporarily unavailable due to technical issues beyond our control.

Please see the full Terms & Conditions before using this website.


I have read and understood the above

About CF » Genetics and cell biology of CFTR » CFTR structure and regulation

CFTR structure and regulation

1 of 2

The CFTR protein is a member of the ABC transporter superfamily of proteins that use the energy from nucleotide hydrolysis to transport molecules across the membrane.1 CFTR is composed of five functional domains.1,2

TMDs or ‘transmembrane domains’:
Around 19% of CFTR is composed of TMD1 and TMD2, which form the channel pore allowing transport of chloride ions across the membrane.3

NBDs or ‘nucleotide-binding domains’:
These domains bind the nucleotide molecule ATP (a vehicle of chemical energy). Opening and closing of the channel (or ‘gating’) requires ATP to bind to these domains.4

Regulatory (‘R’) domain:
The R domain regulates channel activity and can be considered to be the ‘trigger’ governing whether the channel opens or closes, to activate the channel.1,2,4

Did you know?
Many CF-causing mutations occur in NBD1, including F508del, while fewer occur in NBD2.

The CFTR protein is composed of 1480 amino acids arranged into five functional domains that play a vital role in the regulation of chloride and bicarbonate ions across the membrane.1
1 of 2
  1. Patrick AE et al. Front Pharmacol 2012;3:162
  2. Rowe SM & Miller S. N Engl J Med 2005;352:1992–2001
  3. Riordan JR. Annu Rev Physiol 2005;67:701–18
  4. Paola Vergani et al. Nature 2005;433:876–80