scholarly journals Transcytosis maintains CFTR apical polarity in the face of constitutive and mutation-induced basolateral missorting

2018 ◽  
Author(s):  
Aurélien Bidaud-Meynard ◽  
Florian Bossard ◽  
Andrea Schnúr ◽  
Ryosuke Fukuda ◽  
Guido Veit ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pdz Domain ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Airway Epithelia ◽  
Apical Polarity ◽  
The Face ◽  
Domain Protein ◽  
Polarized Delivery ◽  
Cystic Fibrosis Transmembrane

SUMMARYApical polarity of cystic fibrosis transmembrane conductance regulator (CFTR) is essential for solute and water transport in secretory epithelia and can be impaired in human diseases. Maintenance of apical polarity in the face of CFTR non-polarized delivery and compromised apical retention of mutant CFTRs lacking PDZ-domain protein (NHERF1) interaction, remains enigmatic. Here we show that basolateral CFTR delivery originates from biosynthetic (~35%) and endocytic (~65%) recycling missorting. Basolateral channels are retrieved via basolateral-to-apical transcytosis, enhancing CFTR apical expression by two-fold and suppressing its degradation. CFTR transcytosis is microtubule-dependent but independent of Myo5B-, Rab11- and NHERF1 binding to its C-terminal DTRL motif in airway epithelia. Increased basolateral delivery due to compromised apical recycling and accelerated internalization upon impaired NHERF1-CFTR association is largely counterbalanced by CFTR efficient basolateral internalization and apical transcytosis. Thus, transcytosis represents a previously unrecognized but indispensable mechanism for maintaining CFTR apical polarity by attenuating its constitutive and mutation-induced basolateral missorting.

Adenovirus 5–Fiber 35 Chimeric Vector Mediates Efficient Apical Correction of the Cystic Fibrosis Transmembrane Conductance Regulator Defect in Cystic Fibrosis Primary Airway Epithelia

2010 ◽  
Vol 21 (3) ◽  
pp. 251-269 ◽  
Author(s):  
Ophélia Granio ◽  
Katherine J.D. Ashbourne Excoffon ◽  
Petra Henning ◽  
Patricia Melin ◽  
Caroline Norez ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Airway Epithelia ◽  
Cystic Fibrosis Transmembrane ◽  
Adenovirus 5

scholarly journals Infection by Toxoplasma gondii, a severe parasite in neonates and AIDS patients, causes impaired anion secretion in airway epithelia

2015 ◽  
Vol 112 (14) ◽  
pp. 4435-4440 ◽  
Author(s):  
Hong-Mei Guo ◽  
Jiang-Mei Gao ◽  
Yu-Li Luo ◽  
Yan-Zi Wen ◽  
Yi-Lin Zhang ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Toxoplasma Gondii ◽  
Infected Mouse ◽  
Inflammatory Responses ◽  
Short Circuit ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Airway Epithelia ◽  
Anion Secretion ◽  
Cystic Fibrosis Transmembrane

The airway epithelia initiate and modulate the inflammatory responses to various pathogens. The cystic fibrosis transmembrane conductance regulator-mediated Cl− secretion system plays a key role in mucociliary clearance of inhaled pathogens. We have explored the effects of Toxoplasma gondii, an opportunistic intracellular protozoan parasite, on Cl− secretion of the mouse tracheal epithelia. In this study, ATP-induced Cl− secretion indicated the presence of a biphasic short-circuit current (Isc) response, which was mediated by a Ca2+-activated Cl− channel (CaCC) and the cystic fibrosis transmembrane conductance regulator. However, the ATP-evoked Cl− secretion in T. gondii-infected mouse tracheal epithelia and the elevation of [Ca2+]i in T. gondii-infected human airway epithelial cells were suppressed. Quantitative reverse transcription–PCR revealed that the mRNA expression level of the P2Y2 receptor (P2Y2-R) increased significantly in T. gondii-infected mouse tracheal cells. This revealed the influence that pathological changes in P2Y2-R had on the downstream signal, suggesting that P2Y2-R was involved in the mechanism underlying T. gondii infection in airways. These results link T. gondii infection as well as other pathogen infections to Cl− secretion, via P2Y2-R, which may provide new insights for the treatment of pneumonia caused by pathogens including T. gondii.

scholarly journals PDZ Domain Interaction Controls the Endocytic Recycling of the Cystic Fibrosis Transmembrane Conductance Regulator

2002 ◽  
Vol 277 (42) ◽  
pp. 40099-40105 ◽  
Author(s):  
Agnieszka Swiatecka-Urban ◽  
Marc Duhaime ◽  
Bonita Coutermarsh ◽  
Katherine H. Karlson ◽  
James Collawn ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pdz Domain ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Domain Interaction ◽  
Endocytic Recycling ◽  
Cystic Fibrosis Transmembrane

scholarly journals In vivo crystals reveal critical features of the interaction between cystic fibrosis transmembrane conductance regulator (CFTR) and the PDZ2 domain of Na+/H+ exchange cofactor NHERF1

2020 ◽  
Vol 295 (14) ◽  
pp. 4464-4476
Author(s):  
Eleanor R. Martin ◽  
Alessandro Barbieri ◽  
Robert C. Ford ◽  
Robert C. Robinson
Keyword(s):  
Cystic Fibrosis ◽  
Protein Interactions ◽  
Pdz Domain ◽  
Binding Motif ◽  
Transmembrane Conductance Regulator ◽  
Protein Protein Interactions ◽  
Reporter System ◽  
Transmembrane Conductance ◽  
Cystic Fibrosis Transmembrane

Crystallization of recombinant proteins has been fundamental to our understanding of protein function, dysfunction, and molecular recognition. However, this information has often been gleaned under extremely nonphysiological protein, salt, and H+ concentrations. Here, we describe the development of a robust Inka1-Box (iBox)–PAK4cat system that spontaneously crystallizes in several mammalian cell types. The semi-quantitative assay described here allows the measurement of in vivo protein-protein interactions using a novel GFP-linked reporter system that produces fluorescent readouts from protein crystals. We combined this assay with in vitro X-ray crystallography and molecular dynamics studies to characterize the molecular determinants of the interaction between the PDZ2 domain of Na+/H+ exchange regulatory cofactor NHE-RF1 (NHERF1) and cystic fibrosis transmembrane conductance regulator (CFTR), a protein complex pertinent to the genetic disease cystic fibrosis. These experiments revealed the crystal structure of the extended PDZ domain of NHERF1 and indicated, contrary to what has been previously reported, that residue selection at positions −1 and −3 of the PDZ-binding motif influences the affinity and specificity of the NHERF1 PDZ2-CFTR interaction. Our results suggest that this system could be utilized to screen additional protein-protein interactions, provided they can be accommodated within the spacious iBox-PAK4cat lattice.

scholarly journals Functional regulation of cystic fibrosis transmembrane conductance regulator-containing macromolecular complexes: a small-molecule inhibitor approach

2011 ◽  
Vol 435 (2) ◽  
pp. 451-462 ◽  
Author(s):  
Weiqiang Zhang ◽  
Himabindu Penmatsa ◽  
Aixia Ren ◽  
Chandanamali Punchihewa ◽  
Andrew Lemoff ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Small Molecule ◽  
Protein Interactions ◽  
Pdz Domain ◽  
Transmembrane Conductance Regulator ◽  
Protein Protein Interactions ◽  
Transmembrane Conductance ◽  
Macromolecular Complexes ◽  
Channel Function ◽  
Cystic Fibrosis Transmembrane

CFTR (cystic fibrosis transmembrane conductance regulator) has been shown to form multiple protein macromolecular complexes with its interacting partners at discrete subcellular microdomains to modulate trafficking, transport and signalling in cells. Targeting protein–protein interactions within these macromolecular complexes would affect the expression or function of the CFTR channel. We specifically targeted the PDZ domain-based LPA2 (type 2 lysophosphatidic acid receptor)–NHERF2 (Na+/H+ exchanger regulatory factor-2) interaction within the CFTR–NHERF2–LPA2-containing macromolecular complexes in airway epithelia and tested its regulatory role on CFTR channel function. We identified a cell-permeable small-molecule compound that preferentially inhibits the LPA2–NHERF2 interaction. We show that this compound can disrupt the LPA2–NHERF2 interaction in cells and thus compromises the integrity of macromolecular complexes. Functionally, it elevates cAMP levels in proximity to CFTR and upregulates its channel activity. The results of the present study demonstrate that CFTR Cl− channel function can be finely tuned by modulating PDZ domain-based protein–protein interactions within the CFTR-containing macromolecular complexes. The present study might help to identify novel therapeutic targets to treat diseases associated with dysfunctional CFTR Cl− channels.

scholarly journals Chaperone displacement from mutant cystic fibrosis transmembrane conductance regulator restores its function in human airway epithelia

2008 ◽  
Vol 22 (9) ◽  
pp. 3255-3263 ◽  
Author(s):  
Fei Sun ◽  
Zhibao Mi ◽  
Steven B. Condliffe ◽  
Carol A. Bertrand ◽  
Xiaoyan Gong ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Airway Epithelia ◽  
Human Airway ◽  
Cystic Fibrosis Transmembrane ◽  
Human Airway Epithelia

scholarly journals Sorting Nexin 27 (SNX27): A Novel Regulator of Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Trafficking

2018 ◽  
Author(s):  
Mark I. McDermott ◽  
William R. Thelin ◽  
Yun Chen ◽  
Patrick T. Lyons ◽  
Gabrielle Reilly ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Plasma Membrane ◽  
Cell Surface ◽  
Pdz Domain ◽  
Type I ◽  
Apical Surface ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Sorting Nexin ◽  
Cystic Fibrosis Transmembrane

AbstractThe underlying defect in cystic fibrosis is mutation of the cystic fibrosis transmembrane conductance regulator (CFTR), a cAMP-activated chloride channel expressed at the apical surface of lung epithelia. In addition to its export and maintenance at the cell surface, CFTR regulation involves repeated cycles of transport through the endosomal trafficking system, including endocytosis and recycling. Many of the known disease mutations cause CFTR intracellular trafficking defects that result in failure of ion channel delivery to the apical plasma membrane. Corrective maneuvers directed at improving transport to the plasma membrane are thwarted by rapid internalization and degradation of the mutant CFTR proteins. The molecular mechanisms involved in these processes are not completely understood but may involve protein-protein interactions with the C-terminal type I PDZ-binding motif of CFTR. Using a proteomic approach, we identify sorting nexin 27 (SNX27) as a novel CFTR binding partner in human airway epithelial Calu-3 cells. SNX27 and CFTR interact directly, with the SNX27 PDZ domain being both necessary and sufficient for this interaction. SNX27 co-localizes with internalized CFTR at sub-apical endosomal sites in polarized Calu-3 cells, and either knockdown of the endogenous SNX27, or over-expression of a dominant-negative SNX27 mutant, resulted in significant decreases in cell surface CFTR levels. CFTR internalization was not affected by SNX27 knockdown, but defects were observed in the recycling arm of CFTR trafficking through the endosomal system. Furthermore, knockdown of SNX27 in Calu-3 cells resulted in significant decreases in CFTR protein levels, consistent with degradation of the internalized pool. These data identify SNX27 as a physiologically significant regulator of CFTR trafficking and homeostasis in epithelial cells.

scholarly journals Reactive Oxygen Nitrogen Species Decrease Cystic Fibrosis Transmembrane Conductance Regulator Expression and cAMP-mediated Cl−Secretion in Airway Epithelia

2002 ◽  
Vol 277 (45) ◽  
pp. 43041-43049 ◽  
Author(s):  
Zsuzsa Bebok ◽  
Karoly Varga ◽  
James K. Hicks ◽  
Charles J. Venglarik ◽  
Timea Kovacs ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Reactive Oxygen ◽  
Transmembrane Conductance Regulator ◽  
Nitrogen Species ◽  
Transmembrane Conductance ◽  
Airway Epithelia ◽  
Cl Secretion ◽  
Cystic Fibrosis Transmembrane
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