Question

What and how is CFTR used in membranes as a Cl- channel? How is it regulated by CAMP

Answer 1

Cystic fibrosis transmembrane conductance regulator (CFTR) is an ATP-gated anion channel with two transmembrane domains and two nucleotide binding domains.

Binding ATP to nucleotide binding domain associates these channels thereby opening the pore of the CFTR channels. When ATP is hydrolyzed, the nucleotide binding domains dissociate again and the pore closes.

Activation of the Adenosine A2B receptor by Adenosine leads to stimulation of Adenylate cyclase leading to an increase in cAMP, and subsequent activation of the protein kinase A. Phosphorylation of CFTR channels by PKA causes channel opening.