CFTR Protein Structure: The CFTR gene sequence encodes 5 CFTR protein domains
The CFTR gene encodes a CFTR protein channel that is comprised of 1480 amino acids organized into 5 functional domains1,2:
- 2 membrane-spanning domains (MSD1 and MSD2)*
- 2 nucleotide-binding domains (NBD1 and NBD2)
- 1 regulatory domain (R)
*MSDs are also known as transmembrane domains (TMD1 and TMD2).3
CFTR mutations can occur in the gene sequence that encodes any of the 5 protein domains. However, many mutations occur in the sequence that encodes NBD1, including the F508del mutation. The location of the CFTR mutations can affect the formation or function of the CFTR protein.2
CFTR protein structure
- 2 MSDs, each composed of 6 transmembrane segments, form the CFTR channel pore2
- NBDs interact with nucleotides to regulate channel activity—opening and closing of the MSDs2,3
- The R domain also controls channel activity2
- Rowe SM, Miller S, Sorscher EJ. Cystic fibrosis. N Engl J Med. 2005;352(19):1992-2001.
- Welsh MJ, Smith AE. Molecular mechanisms of CFTR chloride channel dysfunction in cystic fibrosis. Cell. 1993;73(7):1251-1254.
- Patrick AE, Thomas PJ. Development of CFTR structure. Front Pharmacol. 2012;3:162. doi:10/3389/fphar.2012.00162.