scholarly journals Phosphorylation-induced Conformational Changes of Cystic Fibrosis Transmembrane Conductance Regulator Monitored by Attenuated Total Reflection-Fourier Transform IR Spectroscopy and Fluorescence Spectroscopy

2003 ◽  
Vol 279 (7) ◽  
pp. 5528-5536 ◽  
Author(s):  
Vinciane Grimard ◽  
Canhui Li ◽  
Mohabir Ramjeesingh ◽  
Christine E. Bear ◽  
Erik Goormaghtigh ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Fourier Transform ◽  
Conformational Changes ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Fourier Transform Ir Spectroscopy ◽  
Fourier Transform Ir ◽  
Cystic Fibrosis Transmembrane

scholarly journals Molecular structure of the ATP-bound, phosphorylated human CFTR

2018 ◽  
Vol 115 (50) ◽  
pp. 12757-12762 ◽  
Author(s):  
Zhe Zhang ◽  
Fangyu Liu ◽  
Jue Chen
Keyword(s):  
Molecular Structure ◽  
Cystic Fibrosis ◽  
Conformational Changes ◽  
Anion Channel ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Common Features ◽  
Proper Functions ◽  
Cystic Fibrosis Transmembrane ◽  
Kinase A

The cystic fibrosis transmembrane conductance regulator (CFTR) is an anion channel important in maintaining proper functions of the lung, pancreas, and intestine. The activity of CFTR is regulated by ATP and protein kinase A-dependent phosphorylation. To understand the conformational changes elicited by phosphorylation and ATP binding, we present here the structure of phosphorylated, ATP-bound human CFTR, determined by cryoelectron microscopy to 3.2-Å resolution. This structure reveals the position of the R domain after phosphorylation. By comparing the structures of human CFTR and zebrafish CFTR determined under the same condition, we identified common features essential to channel gating. The differences in their structures indicate plasticity permitted in evolution to achieve the same function. Finally, the structure of CFTR provides a better understanding of why the G178R, R352Q, L927P, and G970R/D mutations would impede conformational changes of CFTR and lead to cystic fibrosis.

scholarly journals ATP hydrolysis-driven gating in cystic fibrosis transmembrane conductance regulator

2008 ◽  
Vol 364 (1514) ◽  
pp. 247-255 ◽  
Author(s):  
Daniella Muallem ◽  
Paola Vergani
Keyword(s):  
Cystic Fibrosis ◽  
Conformational Changes ◽  
Atp Hydrolysis ◽  
Atp Binding ◽  
Functional Difference ◽  
Transmembrane Conductance Regulator ◽  
Cellular Functions ◽  
Transmembrane Conductance ◽  
Binding Domains ◽  
Cystic Fibrosis Transmembrane

Proteins belonging to the ATP-binding cassette superfamily couple ATP binding and hydrolysis at conserved nucleotide-binding domains (NBDs) to diverse cellular functions. Most superfamily members are transporters, while cystic fibrosis transmembrane conductance regulator (CFTR), alone, is an ion channel. Despite this functional difference, recent results have suggested that CFTR shares a common molecular mechanism with other members. ATP binds to partial binding sites on the surface of the two NBDs, which then associate to form a NBD dimer, with complete composite catalytic sites now buried at the interface. ATP hydrolysis and γ-phosphate dissociation, with the loss of molecular contacts linking the two sides of the composite site, trigger dimer dissociation. The conformational signals generated by NBD dimer formation and dissociation are transmitted to the transmembrane domains where, in transporters, they drive the cycle of conformational changes that translocate the substrate across the membrane; in CFTR, they result in opening and closing (gating) of the ion-permeation pathway.

scholarly journals Molecular Dynamics Study of Cl- Permeation through Cystic Fibrosis Transmembrane Conductance Regulator (CFTR)

2021 ◽  
Author(s):  
Zhi Wei Zeng ◽  
Paul Linsdell ◽  
Régis Pomès
Keyword(s):  
Molecular Dynamics ◽  
Cystic Fibrosis ◽  
Conformational Changes ◽  
Ion Selectivity ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Helices ◽  
Transmembrane Conductance ◽  
Small Magnitude ◽  
Dynamics Simulations ◽  
Cystic Fibrosis Transmembrane

Abstract The recent elucidation of atomistic structures of Cl - channel CFTR provides opportunities for understanding the molecular basis of cystic fibrosis. Despite having been activated through phosphorylation and provided with ATP ligands, several near-atomistic cryo-EM structures of CFTR are in a closed state, as inferred from the lack of a continuous passage through a hydrophobic bottleneck region located in the extracellular portion of the pore. Here, we present repeated, microsecond-long molecular dynamics simulations of human CFTR solvated in a lipid bilayer and aqueous NaCl. At equilibrium, Cl - ions enter the channel through a lateral intracellular portal and bind to two distinct cationic sites inside the channel pore but do not traverse the narrow, de-wetted bottleneck. Simulations conducted in the presence of a strong hyperpolarizing electric field led to spontaneous chloride translocation events through the bottleneck region of the channel, suggesting that the protein relaxed to a functionally open state. Conformational changes of small magnitude involving transmembrane helices 1 and 6 preceded ion permeation through diverging exit routes at the extracellular end of the pore. Although permeating Cl - ions remain mostly hydrated, partial dehydration occurs at the binding sites and in the bottleneck. This portion of the pore undergoes wetting prior to Cl - translocation, suggesting that it acts as a hydrophobic gate. The observed Cl - pathway is largely consistent with the loci of mutations that alter channel conductance, anion binding, and ion selectivity, supporting the model of the open state of CFTR obtained in the present study.

scholarly journals Channel Gating Regulation by the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) First Cytosolic Loop

2015 ◽  
Vol 291 (4) ◽  
pp. 1854-1865 ◽  
Author(s):  
Annette Ehrhardt ◽  
W. Joon Chung ◽  
Louise C. Pyle ◽  
Wei Wang ◽  
Krzysztof Nowotarski ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Conformational Changes ◽  
Atp Hydrolysis ◽  
Channel Gating ◽  
Secretory Diarrhea ◽  
Chronic Obstructive ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Specific Domain ◽  
Cystic Fibrosis Transmembrane

In this study, we present data indicating a robust and specific domain interaction between the cystic fibrosis transmembrane conductance regulator (CFTR) first cytosolic loop (CL1) and nucleotide binding domain 1 (NBD1) that allows ion transport to proceed in a regulated fashion. We used co-precipitation and ELISA to establish the molecular contact and showed that binding kinetics were not altered by the common clinical mutation F508del. Both intrinsic ATPase activity and CFTR channel gating were inhibited severely by CL1 peptide, suggesting that NBD1/CL1 binding is a crucial requirement for ATP hydrolysis and channel function. In addition to cystic fibrosis, CFTR dysregulation has been implicated in the pathogenesis of prevalent diseases such as chronic obstructive pulmonary disease, acquired rhinosinusitis, pancreatitis, and lethal secretory diarrhea (e.g. cholera). On the basis of clinical relevance of the CFTR as a therapeutic target, a cell-free drug screen was established to identify modulators of NBD1/CL1 channel activity independent of F508del CFTR and pharmacologic rescue. Our findings support a targetable mechanism of CFTR regulation in which conformational changes in the NBDs cause reorientation of transmembrane domains via interactions with CL1 and result in channel gating.

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