What is the role of the CFTR protein?
Summary. The cystic fibrosis transmembrane conductance regulator (CFTR) protein helps to maintain the balance of salt and water on many surfaces in the body, such as the surface of the lung.
What protein is made by CFTR?
It is located on human chromosome 7 and consists of twenty-seven sequences of DNA that encode 1,480 amino acids. The CFTR gene produces the CFTR protein, which regulates the chloride ion content of epithelial cells that line the nasal cavity, lungs, and stomach.
Is the CFTR protein an integral protein?
CFTR is an integral membrane protein and is made of a single polypeptide chain of 1480 amino acids. The amino acids are grouped in five domains: two transmembrane segments, TMD1 and TMD2; two cytoplasmic nucleotide-binding domains, NBD1 and NBD2; and the regulatory (R) domain.
Where is the CFTR protein found?
CFTR is complex protein found on the surface membrane of cells in a wide variety of tissues where it functions as a regulated chloride ion channel. In the lung CFTR is found on the apical membrane of the cells lining the airways.
Why is CFTR an ABC transporter?
First, it is the only ATP-binding cassette (ABC) transporter that is known to be an ion channel—almost all others function as transport ATPases. Second, CFTR is the only ligand-gated channel that consumes its ligand (ATP) during the gating cycle—a consequence of its enzymatic activity as an ABC transporter.
How does CFTR affect cystic fibrosis?
In people with CF, mutations in the CFTR gene cause the CFTR protein to malfunction, leading to a buildup of thick mucus. that contains a mutation and one normal copy are considered CF carriers. CF carriers do not have the disease but can pass their copy of the defective gene. Each chromosome carries hundreds of genes.
What kind of transport does CFTR use?
Cystic fibrosis transmembrane conductance regulator (CFTR) is an ATP-gated anion channel with two remarkable distinctions. First, it is the only ATP-binding cassette (ABC) transporter that is known to be an ion channel—almost all others function as transport ATPases.
Is CFTR active or passive?
The cystic fibrosis transmembrane conductance regulator (CFTR) is a channel/enzyme which mediates passive diffusion of chloride and bicarbonate through epithelial cell membranes.
What is the most common CFTR mutation?
The most common CF mutation, F508del, is primarily considered to be a processing mutation. The F508del mutation removes a single amino acid from the CFTR protein. Without this building block, the CFTR protein cannot stay in the correct 3-D shape.
Is CFTR protein active or passive?
What causes CFTR mutation?
The most common CFTR mutation, present in approximately 70 percent of people with CF, is F508del. This mutation is caused by the deletion of three base pairs of the CFTR gene leading to the loss of an amino acid called phenylalanine, abbreviated F, in the CFTR protein.
Is CFTR active transport?
Among human ABC proteins, CFTR is thought to be unique in that it has no active transport function, but instead acts as a phosphorylation-regulated, ATP-gated anion channel [5. The ABC protein turned chloride channel whose failure causes cystic fibrosis.
What type of transport is CFTR?
How does CFTR use ATP?
Like other ABC transporters, CFTR uses ATP binding to its two nucleotide binding domains (NBDs) to drive conformational rearrangements of its transmembrane domains (2, 3). CFTR channel opening is linked to ATP binding to each of two sites at the interface of an NBD1-NBD2 dimer (2, 3).
Is CFTR a pump or channel?
CFTR is a member of the ATP-binding cassette (ABC) family of membrane transport proteins, most members of which function as ATP-dependent pumps. CFTR is unique among human ABC proteins in functioning not as a pump, but as an ion channel.
Why is CFTR described as a channel?
The CFTR gene provides instructions for making a protein called the cystic fibrosis transmembrane conductance regulator. This protein functions as a channel across the membrane of cells that produce mucus, sweat, saliva, tears, and digestive enzymes.
What is the function of the CFTR protein?
This protein is a channel that sits on the surface of cells and transports chloride and other molecules, such as bicarbonate. The gene that encodes the CFTR protein, which is also called CFTR, is located on chromosome 7. Mutations in this gene lead to CF.
What is the function of the CFTR ion channel?
In the lung, the CFTR ion channel moves chloride ions from inside the cell to outside the cell. To get out of the cell, the chloride ions move through the center of the tube formed by the CFTR protein.
Why study cystic fibrosis transmembrane conductance regulator structure?
Knowledge of cystic fibrosis transmembrane conductance regulator (CFTR) protein structure will contribute toward the understanding of CFTR function and CF biology, the mechanisms of action for CF drugs, and provide additional insight toward new drug discovery through structure-based drug design. 3 min read In this article
How many exons are there in the CFTR gene?
Located on the long (q) arm of chromosome 7 at position 31.2, the CFTR gene is comprised of 27 exons that encode its genetic sequence (1). An exon is a portion of a DNA that contains the code for a protein structure.