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 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.

Dynasore inhibits removal of wild-type and ΔF508 cystic fibrosis transmembrane conductance regulator (CFTR) from the plasma membrane

2009 ◽  
Vol 421 (3) ◽  
pp. 377-385 ◽  
Author(s):  
Andrew Young ◽  
Martina Gentzsch ◽  
Cynthia Y. Abban ◽  
Ying Jia ◽  
Patricio I. Meneses ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Cell Surface ◽  
Small Molecule ◽  
Short Exposure ◽  
Growth Media ◽  
Transmembrane Conductance Regulator ◽  
Wild Type ◽  
Transmembrane Conductance ◽  
Δf508 Cftr ◽  
Cystic Fibrosis Transmembrane

Dynasore, a small molecule inhibitor of dynamin, was used to probe the role of dynamin in the endocytosis of wild-type and mutant CFTR (cystic fibrosis transmembrane conductance regulator). Internalization of both wild-type and ‘temperature-corrected’ ΔF508 CFTR was markedly inhibited by a short exposure to dynasore, implicating dynamin as a key element in the endocytic internalization of both wild-type and mutant CFTR. The inhibitory effect of dynasore was readily reversible upon washout of dynasore from the growth media. Corr-4 ({2-(5-chloro-2-methoxy-phenylamino)-4′-methyl-[4,5′]-bithiazolyl-2′-yl}-phenyl-methanonone), a pharmacological corrector of ΔF508 CFTR biosynthesis, caused a marked increase in the cell surface expression of mutant CFTR. Co-incubation of ΔF508 CFTR expressing cells with Corr-4 and dynasore caused a significantly greater level of cell surface CFTR than that observed in the presence of Corr-4 alone. These results argue that inhibiting the endocytic internalization of mutant CFTR provides a novel therapeutic target for augmenting the benefits of small molecule correctors of mutant CFTR biosynthesis.

scholarly journals Optimal correction of distinct CFTR folding mutants in rectal cystic fibrosis organoids

2016 ◽  
Vol 48 (2) ◽  
pp. 451-458 ◽  
Author(s):  
Johanna F. Dekkers ◽  
Ricardo A. Gogorza Gondra ◽  
Evelien Kruisselbrink ◽  
Annelotte M. Vonk ◽  
Hettie M. Janssens ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Small Molecule ◽  
Optimal Treatment ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Optimal Correction ◽  
Data Support ◽  
Pharmacological Correction ◽  
Cystic Fibrosis Transmembrane

Small-molecule therapies that restore defects in cystic fibrosis transmembrane conductance regulator (CFTR) gating (potentiators) or trafficking (correctors) are being developed for cystic fibrosis (CF) in a mutation-specific fashion. Options for pharmacological correction of CFTR-p.Phe508del (F508del) are being extensively studied but correction of other trafficking mutants that may also benefit from corrector treatment remains largely unknown.We studied correction of the folding mutants CFTR-p.Phe508del, -p.Ala455Glu (A455E) and -p.Asn1303Lys (N1303K) by VX-809 and 18 other correctors (C1–C18) using a functional CFTR assay in human intestinal CF organoids.Function of both CFTR-p.Phe508del and -p.Ala455Glu was enhanced by a variety of correctors but no residual or corrector-induced activity was associated with CFTR-p.Asn1303Lys. Importantly, VX-809-induced correction was most dominant for CFTR-p.Phe508del, while correction of CFTR-p.Ala455Glu was highest by a subgroup of compounds called bithiazoles (C4, C13, C14 and C17) and C5.These data support the development of mutation-specific correctors for optimal treatment of different CFTR trafficking mutants, and identify C5 and bithiazoles as the most promising compounds for correction of CFTR-p.Ala455Glu.

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
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