scholarly journals Compartmentalized Cyclic Adenosine 3′,5′-Monophosphate at the Plasma Membrane Clusters PDE3A and Cystic Fibrosis Transmembrane Conductance Regulator into Microdomains

2010 ◽  
Vol 21 (6) ◽  
pp. 1097-1110 ◽  
Author(s):  
Himabindu Penmatsa ◽  
Weiqiang Zhang ◽  
Sunitha Yarlagadda ◽  
Chunying Li ◽  
Veronica G. Conoley ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Plasma Membrane ◽  
Gland Secretion ◽  
Macromolecular Complex ◽  
Transmembrane Conductance Regulator ◽  
Submucosal Gland ◽  
Transmembrane Conductance ◽  
Channel Function ◽  
Phosphodiesterase Type ◽  
Cystic Fibrosis Transmembrane

Formation of multiple-protein macromolecular complexes at specialized subcellular microdomains increases the specificity and efficiency of signaling in cells. In this study, we demonstrate that phosphodiesterase type 3A (PDE3A) physically and functionally interacts with cystic fibrosis transmembrane conductance regulator (CFTR) channel. PDE3A inhibition generates compartmentalized cyclic adenosine 3′,5′-monophosphate (cAMP), which further clusters PDE3A and CFTR into microdomains at the plasma membrane and potentiates CFTR channel function. Actin skeleton disruption reduces PDE3A–CFTR interaction and segregates PDE3A from its interacting partners, thus compromising the integrity of the CFTR-PDE3A–containing macromolecular complex. Consequently, compartmentalized cAMP signaling is lost. PDE3A inhibition no longer activates CFTR channel function in a compartmentalized manner. The physiological relevance of PDE3A–CFTR interaction was investigated using pig trachea submucosal gland secretion model. Our data show that PDE3A inhibition augments CFTR-dependent submucosal gland secretion and actin skeleton disruption decreases secretion.

scholarly journals Alteration of Membrane Cholesterol Content Plays a Key Role in Regulation of Cystic Fibrosis Transmembrane Conductance Regulator Channel Activity

2021 ◽  
Vol 12 ◽  
Author(s):  
Guiying Cui ◽  
Kirsten A. Cottrill ◽  
Kerry M. Strickland ◽  
Sarah A. Mashburn ◽  
Michael Koval ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Plasma Membrane ◽  
Cholesterol Content ◽  
Membrane Cholesterol ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Channel Function ◽  
Rat Thyroid ◽  
Cystic Fibrosis Transmembrane ◽  
Plasma Membrane Cholesterol

Altered cholesterol homeostasis in cystic fibrosis patients has been reported, although controversy remains. As a major membrane lipid component, cholesterol modulates the function of multiple ion channels by complicated mechanisms. However, whether cholesterol directly modulates cystic fibrosis transmembrane conductance regulator (CFTR) channel function remains unknown. To answer this question, we determined the effects of changing plasma membrane cholesterol levels on CFTR channel function utilizing polarized fischer rat thyroid (FRT) cells and primary human bronchial epithelial (HBE) cells. Treatment with methyl-β-cyclodextrin (MβCD) significantly reduced total cholesterol content in FRT cells, which significantly decreased forskolin (FSK)-mediated activation of both wildtype (WT-) and P67L-CFTR. This effect was also seen in HBE cells expressing WT-CFTR. Cholesterol modification by cholesterol oxidase and cholesterol esterase also distinctly affected activation of CFTR by FSK. In addition, alteration of cholesterol increased the potency of VX-770, a clinically used potentiator of CFTR, when both WT- and P67L-CFTR channels were activated at low FSK concentrations; this likely reflects the apparent shift in the sensitivity of WT-CFTR to FSK after alteration of membrane cholesterol. These results demonstrate that changes in the plasma membrane cholesterol level significantly modulate CFTR channel function and consequently may affect sensitivity to clinical therapeutics in CF patients.

CFTR involvement in chloride, bicarbonate, and liquid secretion by airway submucosal glands

1999 ◽  
Vol 277 (4) ◽  
pp. L694-L699 ◽  
Author(s):  
Stephen T. Ballard ◽  
Laura Trout ◽  
Zsuzsa Bebök ◽  
E. J. Sorscher ◽  
Angela Crews
Keyword(s):  
Cystic Fibrosis ◽  
Channel Blocker ◽  
Polyclonal Antibodies ◽  
Surface Epithelium ◽  
Transmembrane Conductance Regulator ◽  
Submucosal Gland ◽  
Transmembrane Conductance ◽  
Active Secretion ◽  
Submucosal Glands ◽  
Cystic Fibrosis Transmembrane

Previous studies demonstrated that ACh-induced liquid secretion by porcine bronchi is driven by active Cl− and H[Formula: see text] secretion. The present study was undertaken to determine whether this process was localized to submucosal glands and mediated by the cystic fibrosis transmembrane conductance regulator (CFTR). When excised, cannulated, and treated with ACh, porcine bronchi secreted 15.6 ± 0.6 μl ⋅ cm−2 ⋅ h−1. Removal of the surface epithelium did not significantly affect the rate of secretion, indicating that the source of the liquid was the submucosal glands. Pretreatment with diphenylamine-2-carboxylate, a relatively nonselective Cl−-channel blocker, significantly reduced liquid secretion by 86%, whereas pretreatment with DIDS, which inhibits a variety of Cl− channels but not CFTR, had no effect. When bronchi were pretreated with glibenclamide or 5-nitro-2-(3-phenylpropylamino)benzoic acid (both inhibitors of CFTR), the rate of ACh-induced liquid secretion was significantly reduced by 39 and 91%, respectively, compared with controls. Agents that blocked liquid secretion also caused disproportionate reductions in H[Formula: see text] secretion. Polyclonal antibodies to the CFTR bound preferentially to submucosal gland ducts and the surface epithelium, suggesting that this channel was localized to these sites. These data suggest that ACh-induced gland liquid secretion by porcine bronchi is driven by active secretion of both Cl− and H[Formula: see text] and is mediated by the CFTR.

scholarly journals Two Salt Bridges Differentially Contribute to the Maintenance of Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Channel Function

2013 ◽  
Vol 288 (28) ◽  
pp. 20758-20767 ◽  
Author(s):  
Guiying Cui ◽  
Cody S. Freeman ◽  
Taylor Knotts ◽  
Chengyu Z. Prince ◽  
Christopher Kuang ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Transmembrane Conductance Regulator ◽  
Salt Bridges ◽  
Transmembrane Conductance ◽  
Channel Function ◽  
Cystic Fibrosis Transmembrane

scholarly journals Differential thermostability and response to cystic fibrosis transmembrane conductance regulator potentiators of human and mouse F508del-CFTR

2019 ◽  
Vol 317 (1) ◽  
pp. L71-L86 ◽  
Author(s):  
Samuel J. Bose ◽  
Marcel J. C. Bijvelds ◽  
Yiting Wang ◽  
Jia Liu ◽  
Zhiwei Cai ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Plasma Membrane ◽  
Cho Cells ◽  
Mammalian Cells ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Membrane Expression ◽  
The Impact ◽  
Cystic Fibrosis Transmembrane ◽  
Human And Mouse

Cross-species comparative studies have highlighted differences between human and mouse cystic fibrosis transmembrane conductance regulator (CFTR), the epithelial Cl− channel defective in cystic fibrosis (CF). Here, we compare the impact of the most common CF mutation F508del on the function of human and mouse CFTR heterologously expressed in mammalian cells and their response to CFTR modulators using the iodide efflux and patch-clamp techniques. Once delivered to the plasma membrane, human F508del-CFTR exhibited a severe gating defect characterized by infrequent channel openings and was thermally unstable, deactivating within minutes at 37°C. By contrast, the F508del mutation was without effect on the gating pattern of mouse CFTR, and channel activity demonstrated thermostability at 37°C. Strikingly, at all concentrations tested, the clinically approved CFTR potentiator ivacaftor was without effect on the mouse F508del-CFTR Cl− channel. Moreover, eight CFTR potentiators, including ivacaftor, failed to generate CFTR-mediated iodide efflux from CHO cells expressing mouse F508del-CFTR. However, they all produced CFTR-mediated iodide efflux with human F508del-CFTR-expressing CHO cells, while fifteen CFTR correctors rescued the plasma membrane expression of both human and mouse F508del-CFTR. Interestingly, the CFTR potentiator genistein enhanced CFTR-mediated iodide efflux from CHO cells expressing either human or mouse F508del-CFTR, whereas it only potentiated human F508del-CFTR Cl− channels in cell-free membrane patches, suggesting that its action on mouse F508del-CFTR is indirect. Thus, the F508del mutation has distinct effects on human and mouse CFTR Cl− channels.

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