What is the function of CFTR? (details are important) (5 points)
Solution
Ans:- Cystic fibrosis transmembrane conductance regulator (CFTR) is a membrane protein and
chloride channel in vertebrates that is encoded by the CFTR gene.CFTR functions as a ATP
gated anion channel increasing the conductance for certain anions to flow down their
electrochemical gradient.ATP driven conformational changes in CFTR open and close a gate to
allow transmembrane flow of anions down their electrochemical gradient. Essentially CFTR is
an ion channel that evolved as a broken ABC transporter that leaks when in open
conformation.The CFTR is found in the epithelial cells of many organs including the lungs,liver
,pancreas,digestive tract ,reproductive tract and skin.Normally the protein moves chloride and
thiocyanate ions out of an epithelial cell covering mucus.Positively chargedsodium ions follow
passively increasing the total electrolyte concentration in the mucus resulting in the movement of
water out of the cell via osmosis.In sweat glands defective CSTR results in reduced transport of
sodium chloride and sodium thiocyanate in the reabsorptive duct and therefore saltier sweat..
What is the function of CFTR (details are important) (5 points).pdf
1. What is the function of CFTR? (details are important) (5 points)
Solution
Ans:- Cystic fibrosis transmembrane conductance regulator (CFTR) is a membrane protein and
chloride channel in vertebrates that is encoded by the CFTR gene.CFTR functions as a ATP
gated anion channel increasing the conductance for certain anions to flow down their
electrochemical gradient.ATP driven conformational changes in CFTR open and close a gate to
allow transmembrane flow of anions down their electrochemical gradient. Essentially CFTR is
an ion channel that evolved as a broken ABC transporter that leaks when in open
conformation.The CFTR is found in the epithelial cells of many organs including the lungs,liver
,pancreas,digestive tract ,reproductive tract and skin.Normally the protein moves chloride and
thiocyanate ions out of an epithelial cell covering mucus.Positively chargedsodium ions follow
passively increasing the total electrolyte concentration in the mucus resulting in the movement of
water out of the cell via osmosis.In sweat glands defective CSTR results in reduced transport of
sodium chloride and sodium thiocyanate in the reabsorptive duct and therefore saltier sweat.
