The Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Uses its C-Terminus to Regulate the A2B Adenosine Receptor.
CFTR is an apical membrane anion channel that regulates fluid homeostasis in many organs including the airways, colon, pancreas and sweat glands. In cystic fibrosis, CFTR dysfunction causes significant morbidity/mortality. Whilst CFTR's function as an ion channel has been well described, its ability to regulate other proteins is less understood. We have previously shown that plasma membrane CFTR increases the surface density of the adenosine 2B receptor (A2BR), but not of the β2 adrenergic receptor (β2AR), leading to an enhanced, adenosine-induced cAMP response in the presence of CFTR. In this study, we have found that the C-terminal PDZ-domain of both A2BR and CFTR were crucial for this interaction, and that replacing the C-terminus of A2BR with that of β2AR removed this CFTR-dependency. This observation extended to intact epithelia and disruption of the actin cytoskeleton prevented A2BR-induced but not β2AR-induced airway surface liquid (ASL) secretion. We also found that CFTR expression altered the organization of the actin cytoskeleton and PDZ-binding proteins in both HEK293T cells and in well-differentiated human bronchial epithelia. Furthermore, removal of CFTR's PDZ binding motif (ΔTRL) prevented actin rearrangement, suggesting that CFTR insertion in the plasma membrane results in local reorganization of actin, PDZ binding proteins and certain GPCRs.
Cystic Fibrosis Center/Marsico Lung Institute, 125 Mason Farm Road, The University of North Carolina, Chapel Hill, NC, 27599-7248, USA.
Michael J
MJ
Watson
Cystic Fibrosis Center/Marsico Lung Institute, 125 Mason Farm Road, The University of North Carolina, Chapel Hill, NC, 27599-7248, USA.
Shernita L
SL
Lee
Cystic Fibrosis Center/Marsico Lung Institute, 125 Mason Farm Road, The University of North Carolina, Chapel Hill, NC, 27599-7248, USA.|Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle-upon-Tyne, Northumberland, UK.
Abigail J
AJ
Marklew
Cystic Fibrosis Center/Marsico Lung Institute, 125 Mason Farm Road, The University of North Carolina, Chapel Hill, NC, 27599-7248, USA.
Rodney C
RC
Gilmore
Cystic Fibrosis Center/Marsico Lung Institute, 125 Mason Farm Road, The University of North Carolina, Chapel Hill, NC, 27599-7248, USA.|Cell Biology and Physiology, 111 Mason Farm Rd, The University of North Carolina, Chapel Hill, NC, 27599-7248, USA.
Martina
M
Gentzsch
Cystic Fibrosis Center/Marsico Lung Institute, 125 Mason Farm Road, The University of North Carolina, Chapel Hill, NC, 27599-7248, USA.
Maria F
MF
Sassano
Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle-upon-Tyne, Northumberland, UK.
Michael A
MA
Gray
Cystic Fibrosis Center/Marsico Lung Institute, 125 Mason Farm Road, The University of North Carolina, Chapel Hill, NC, 27599-7248, USA.|Cell Biology and Physiology, 111 Mason Farm Rd, The University of North Carolina, Chapel Hill, NC, 27599-7248, USA.
Robert
R
Tarran
D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D003550:Cystic Fibrosis / Q000378:metabolism*; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism; D004848:Epithelium / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D017136:Ion Transport / Q000502:physiology; D043704:Receptor, Adenosine A2B / Q000378:metabolism*; D020545:Respiratory Mucosa / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology
C505032:CFTR protein, human; D043704:Receptor, Adenosine A2B; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D000242:Cyclic AMP