Why does the CFTR protein Misfold?

Why does the CFTR protein Misfold?

Class I mutations (such as G542X) lead to the premature termination of CFTR protein translation. Class II mutations include the common F508del (or ΔF508) which lead to the misfolding of CFTR protein and subsequent polyubiquitination and destruction by the cell proteasome.

How many kDa is CFTR?

Cystic fibrosis transmembrane conductance regulator (CFTR) is a chloride channel that in human is encoded by the CFTR gene. CFTR is a 168-kDa protein consisting in 12 transmembrane domains. CFTR functions as an ATP-gated chloride channel.

How does CFTR regulate ENaC?

According to a previously suggested model, ICOR is coactivated with CFTR by an autocrine mechanism based on CFTR-controlled cellular release of ATP16. ATP will be secreted to the apical side and bind to purinergic receptors, which couple to ICOR channels that may, in turn, inhibit ENaC.

What are CFTR potentiators?

Potentiators. The CFTR protein is shaped like a tunnel that can be closed by a gate. Potentiators are CFTR modulators that hold the gate open so chloride can flow through the cell membrane. The drug Kalydeco® (ivacaftor) is a potentiator. This drug can help patients with gating and conduction mutations in CFTR.

What is the function of CFTR?

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 is CFTR trafficking?

In the CFTR “life cycle”, there are four broad trafficking pathways that can be identified (i) biosynthesis, conformational maturation and trafficking from the endoplasmic reticulum (ER) to the plasma membrane, (ii) endocytic retrieval from the plasma membrane to early or sorting endosomes, (iii) recycling of …

How big is the CFTR gene?

The CFTR gene itself spans only 189.36 kb; however, the immediate promoter can be extended as far as 20.9 kb upstream, where the CTCF-dependent insulator element is located—the expanded promoter region includes the regulatory binding element required for proper gene expression (Blackledge et al. 2007).

Is CFTR a sodium channel?

One of CFTR’s primary roles in the lungs is to maintain homoeostasis of the airway surface liquid layer through its function as a chloride channel and its regulation of the epithelial sodium channel ENaC.

What is the normal function of CFTR?

Normal Function 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 does CFTR stand for?

How is CFTR regulated?

Cystic fibrosis transmembrane conductance regulator (CFTR) chloride channels are regulated tightly by protein kinases and phosphatases. The regulatory domain of CFTR has about 20 potential sites for phosphorylation by protein kinases A (PKA) and C (PKC).

Does everyone have the CFTR gene?

Every person has two copies of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. A person must inherit two copies of the CFTR gene that contain mutations — one copy from each parent — to have cystic fibrosis.