1
|
Soya N, Xu H, Roldan A, Yang Z, Ye H, Jiang F, Premchandar A, Veit G, Cole SPC, Kappes J, Hegedüs T, Lukacs GL. Folding correctors can restore CFTR posttranslational folding landscape by allosteric domain-domain coupling. Nat Commun 2023; 14:6868. [PMID: 37891162 PMCID: PMC10611759 DOI: 10.1038/s41467-023-42586-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 10/16/2023] [Indexed: 10/29/2023] Open
Abstract
The folding/misfolding and pharmacological rescue of multidomain ATP-binding cassette (ABC) C-subfamily transporters, essential for organismal health, remain incompletely understood. The ABCC transporters core consists of two nucleotide binding domains (NBD1,2) and transmembrane domains (TMD1,2). Using molecular dynamic simulations, biochemical and hydrogen deuterium exchange approaches, we show that the mutational uncoupling or stabilization of NBD1-TMD1/2 interfaces can compromise or facilitate the CFTR(ABCC7)-, MRP1(ABCC1)-, and ABCC6-transporters posttranslational coupled domain-folding in the endoplasmic reticulum. Allosteric or orthosteric binding of VX-809 and/or VX-445 folding correctors to TMD1/2 can rescue kinetically trapped CFTR posttranslational folding intermediates of cystic fibrosis (CF) mutants of NBD1 or TMD1 by global rewiring inter-domain allosteric-networks. We propose that dynamic allosteric domain-domain communications not only regulate ABCC-transporters function but are indispensable to tune the folding landscape of their posttranslational intermediates. These allosteric networks can be compromised by CF-mutations, and reinstated by correctors, offering a framework for mechanistic understanding of ABCC-transporters (mis)folding.
Collapse
Affiliation(s)
- Naoto Soya
- Department of Physiology and Biochemistry, McGill University, Montréal, QC, Canada
| | - Haijin Xu
- Department of Physiology and Biochemistry, McGill University, Montréal, QC, Canada
| | - Ariel Roldan
- Department of Physiology and Biochemistry, McGill University, Montréal, QC, Canada
| | - Zhengrong Yang
- Heersink School of Medicine, University of Alabama School of Medicine, Birmingham, AL, USA
| | - Haoxin Ye
- Department of Physiology and Biochemistry, McGill University, Montréal, QC, Canada
| | - Fan Jiang
- Heersink School of Medicine, University of Alabama School of Medicine, Birmingham, AL, USA
| | - Aiswarya Premchandar
- Department of Physiology and Biochemistry, McGill University, Montréal, QC, Canada
| | - Guido Veit
- Department of Physiology and Biochemistry, McGill University, Montréal, QC, Canada
| | - Susan P C Cole
- Division of Cancer Biology and Genetics, Department of Pathology and Molecular Medicine, Queen's University Cancer Research Institute, Kingston, ON, Canada
| | - John Kappes
- Heersink School of Medicine, University of Alabama School of Medicine, Birmingham, AL, USA
| | - Tamás Hegedüs
- Department of Biophysics and Radiation Biology, Semmelweis University, 1085, Budapest, Hungary
- ELKH-SE Biophysical Virology Research Group, Eötvös Loránd Research Network, Budapest, Hungary
| | - Gergely L Lukacs
- Department of Physiology and Biochemistry, McGill University, Montréal, QC, Canada.
| |
Collapse
|
2
|
Soya N, Xu H, Roldan A, Yang Z, Ye H, Jiang F, Premchandar A, Veit G, Cole SPC, Kappes J, Hegedus T, Lukacs GL. Folding correctors can restore CFTR posttranslational folding landscape by allosteric domain-domain coupling. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.19.563107. [PMID: 37905074 PMCID: PMC10614980 DOI: 10.1101/2023.10.19.563107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
The folding/misfolding and pharmacological rescue of multidomain ATP-binding cassette (ABC) C-subfamily transporters, essential for organismal health, remain incompletely understood. The ABCC transporters core consists of two nucleotide binding domains (NBD1,2) and transmembrane domains (TMD1,2). Using molecular dynamic simulations, biochemical and hydrogen deuterium exchange approaches, we show that the mutational uncoupling or stabilization of NBD1-TMD1/2 interfaces can compromise or facilitate the CFTR(ABCC7)-, MRP1(ABCC1)-, and ABCC6-transporters posttranslational coupled domain-folding in the endoplasmic reticulum. Allosteric or orthosteric binding of VX-809 and/or VX-445 folding correctors to TMD1/2 can rescue kinetically trapped CFTR post-translational folding intermediates of cystic fibrosis (CF) mutants of NBD1 or TMD1 by global rewiring inter-domain allosteric-networks. We propose that dynamic allosteric domain-domain communications not only regulate ABCC-transporters function but are indispensable to tune the folding landscape of their post-translational intermediates. These allosteric networks can be compromised by CF-mutations, and reinstated by correctors, offering a framework for mechanistic understanding of ABCC-transporters (mis)folding. One-Sentence Summary Allosteric interdomain communication and its modulation are critical determinants of ABCC-transporters post-translational conformational biogenesis, misfolding, and pharmacological rescue.
Collapse
|
3
|
Bitran A, Park K, Serebryany E, Shakhnovich EI. Co-translational formation of disulfides guides folding of the SARS-CoV-2 receptor binding domain. Biophys J 2023; 122:3238-3253. [PMID: 37422697 PMCID: PMC10465708 DOI: 10.1016/j.bpj.2023.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 05/27/2023] [Accepted: 07/03/2023] [Indexed: 07/10/2023] Open
Abstract
Many secreted proteins, including viral proteins, contain multiple disulfide bonds. How disulfide formation is coupled to protein folding in the cell remains poorly understood at the molecular level. Here, we combine experiment and simulation to address this question as it pertains to the SARS-CoV-2 receptor binding domain (RBD). We show that the RBD can only refold reversibly if its native disulfides are present before folding. But in their absence, the RBD spontaneously misfolds into a nonnative, molten-globule-like state that is structurally incompatible with complete disulfide formation and that is highly prone to aggregation. Thus, the RBD native structure represents a metastable state on the protein's energy landscape with reduced disulfides, indicating that nonequilibrium mechanisms are needed to ensure native disulfides form before folding. Our atomistic simulations suggest that this may be achieved via co-translational folding during RBD secretion into the endoplasmic reticulum. Namely, at intermediate translation lengths, native disulfide pairs are predicted to come together with high probability, and thus, under suitable kinetic conditions, this process may lock the protein into its native state and circumvent highly aggregation-prone nonnative intermediates. This detailed molecular picture of the RBD folding landscape may shed light on SARS-CoV-2 pathology and molecular constraints governing SARS-CoV-2 evolution.
Collapse
Affiliation(s)
- Amir Bitran
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts; PhD Program in Biophysics, Harvard University, Cambridge, Massachusetts.
| | - Kibum Park
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts
| | - Eugene Serebryany
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts
| | - Eugene I Shakhnovich
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts.
| |
Collapse
|
4
|
Hwang TC, Braakman I, van der Sluijs P, Callebaut I. Structure basis of CFTR folding, function and pharmacology. J Cyst Fibros 2023; 22 Suppl 1:S5-S11. [PMID: 36216744 DOI: 10.1016/j.jcf.2022.09.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 09/19/2022] [Accepted: 09/26/2022] [Indexed: 11/05/2022]
Abstract
The root cause of cystic fibrosis (CF), the most common life-shortening genetic disease in the Caucasian population, is the loss of function of the CFTR protein, which serves as a phosphorylation-activated, ATP-gated anion channel in numerous epithelia-lining tissues. In the past decade, high-throughput drug screening has made a significant stride in developing highly effective CFTR modulators for the treatment of CF. Meanwhile, structural-biology studies have succeeded in solving the high-resolution three-dimensional (3D) structure of CFTR in different conformations. Here, we provide a brief overview of some striking features of CFTR folding, function and pharmacology, in light of its specific structural features within the ABC-transporter superfamily. A particular focus is given to CFTR's first nucleotide-binding domain (NBD1), because folding of NBD1 constitutes a bottleneck in the CFTR protein biogenesis pathway, and ATP binding to this domain plays a unique role in the functional stability of CFTR. Unraveling the molecular basis of CFTR folding, function, and pharmacology would inspire the development of next-generation mutation-specific CFTR modulators.
Collapse
Affiliation(s)
- Tzyh-Chang Hwang
- Institute of Pharmacology, School of Medicine, National Yang Ming Chiao Tung University, Taiwan; Department of Medical Pharmacology and Physiology, Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO, USA
| | - Ineke Braakman
- Cellular Protein Chemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Peter van der Sluijs
- Cellular Protein Chemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Isabelle Callebaut
- Sorbonne Université, Muséum National d'Histoire Naturelle, UMR CNRS 7590, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, 75005 Paris, France.
| |
Collapse
|
5
|
Bitran A, Park K, Serebryany E, Shakhnovich EI. Cotranslational formation of disulfides guides folding of the SARS COV-2 receptor binding domain. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2022:2022.11.10.516025. [PMID: 36380756 PMCID: PMC9665344 DOI: 10.1101/2022.11.10.516025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Many secreted proteins contain multiple disulfide bonds. How disulfide formation is coupled to protein folding in the cell remains poorly understood at the molecular level. Here, we combine experiment and simulation to address this question as it pertains to the SARS-CoV-2 receptor binding domain (RBD). We show that, whereas RBD can refold reversibly when its disulfides are intact, their disruption causes misfolding into a nonnative molten-globule state that is highly prone to aggregation and disulfide scrambling. Thus, non-equilibrium mechanisms are needed to ensure disulfides form prior to folding in vivo. Our simulations suggest that co-translational folding may accomplish this, as native disulfide pairs are predicted to form with high probability at intermediate lengths, ultimately committing the RBD to its metastable native state and circumventing nonnative intermediates. This detailed molecular picture of the RBD folding landscape may shed light on SARS-CoV-2 pathology and molecular constraints governing SARS-CoV-2 evolution.
Collapse
|
6
|
Molecular mechanisms of Cystic Fibrosis - how mutations lead to misfunction and guide therapy. Biosci Rep 2022; 42:231430. [PMID: 35707985 PMCID: PMC9251585 DOI: 10.1042/bsr20212006] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 06/03/2022] [Accepted: 06/13/2022] [Indexed: 11/17/2022] Open
Abstract
Cystic fibrosis, the most common autosomal recessive disorder in Caucasians, is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, which encodes a cAMP-activated chloride and bicarbonate channel that regulates ion and water transport in secretory epithelia. Although all mutations lead to the lack or reduction in channel function, the mechanisms through which this occurs are diverse – ranging from lack of full-length mRNA, reduced mRNA levels, impaired folding and trafficking, targeting to degradation, decreased gating or conductance, and reduced protein levels to decreased half-life at the plasma membrane. Here, we review the different molecular mechanisms that cause cystic fibrosis and detail how these differences identify theratypes that can inform the use of directed therapies aiming at correcting the basic defect. In summary, we travel through CFTR life cycle from the gene to function, identifying what can go wrong and what can be targeted in terms of the different types of therapeutic approaches.
Collapse
|
7
|
Padányi R, Farkas B, Tordai H, Kiss B, Grubmüller H, Soya N, Lukács GL, Kellermayer M, Hegedűs T. Nanomechanics combined with HDX reveals allosteric drug binding sites of CFTR NBD1. Comput Struct Biotechnol J 2022; 20:2587-2599. [PMID: 35685375 PMCID: PMC9160490 DOI: 10.1016/j.csbj.2022.05.036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 05/17/2022] [Accepted: 05/19/2022] [Indexed: 11/29/2022] Open
Abstract
Cystic fibrosis (CF) is a frequent genetic disease in Caucasians that is caused by the deletion of F508 (ΔF508) in the nucleotide binding domain 1 (NBD1) of the CF transmembrane conductance regulator (CFTR). The ΔF508 compromises the folding energetics of the NBD1, as well as the folding of three other CFTR domains. Combination of FDA approved corrector molecules can efficiently but incompletely rescue the ΔF508-CFTR folding and stability defect. Thus, new pharmacophores that would reinstate the wild-type-like conformational stability of the ΔF508-NBD1 would be highly beneficial. The most prominent molecule, 5-bromoindole-3-acetic acid (BIA) that can thermally stabilize the NBD1 has low potency and efficacy. To gain insights into the NBD1 (un)folding dynamics and BIA binding site localization, we combined molecular dynamics (MD) simulations, atomic force spectroscopy (AFM) and hydrogen-deuterium exchange (HDX) experiments. We found that the NBD1 α-subdomain with three adjacent strands from the β-subdomain plays an important role in early folding steps, when crucial non-native interactions are formed via residue F508. Our AFM and HDX experiments showed that BIA associates with this α-core region and increases the resistance of the ΔF508-NBD1 against mechanical unfolding, a phenomenon that could be exploited in future developments of folding correctors.
Collapse
Affiliation(s)
- Rita Padányi
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
| | - Bianka Farkas
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
| | - Hedvig Tordai
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
| | - Bálint Kiss
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
| | - Helmut Grubmüller
- Theoretical and Computational Biophysics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Naoto Soya
- Department of Physiology and Biochemistry, McGill University, Montréal, Quebec, Canada
| | - Gergely L. Lukács
- Department of Physiology and Biochemistry, McGill University, Montréal, Quebec, Canada
| | - Miklós Kellermayer
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
| | - Tamás Hegedűs
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
- ELKH-SE Molecular Biophysics Research Group, ELKH, Budapest, Hungary
- Corresponding author at: Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary.
| |
Collapse
|
8
|
Shishido H, Yoon JS, Skach WR. A small molecule high throughput screening platform to profile conformational properties of nascent, ribosome-bound proteins. Sci Rep 2022; 12:2509. [PMID: 35169219 PMCID: PMC8847357 DOI: 10.1038/s41598-022-06456-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Accepted: 01/18/2022] [Indexed: 12/16/2022] Open
Abstract
Genetic mutations cause a wide spectrum of human disease by disrupting protein folding, both during and after synthesis. Transient de-novo folding intermediates therefore represent potential drug targets for pharmacological correction of protein folding disorders. Here we develop a FRET-based high-throughput screening (HTS) assay in 1,536-well format capable of identifying small molecules that interact with nascent polypeptides and correct genetic, cotranslational folding defects. Ribosome nascent chain complexes (RNCs) containing donor and acceptor fluorophores were isolated from cell free translation reactions, immobilized on Nickel-NTA/IDA beads, and imaged by high-content microscopy. Quantitative FRET measurements obtained from as little as 0.4 attomole of protein/bead enabled rapid assessment of conformational changes with a high degree of reproducibility. Using this assay, we performed a pilot screen of ~ 50,000 small molecules to identify compounds that interact with RNCs containing the first nucleotide-binding domain (NBD1) of the cystic fibrosis transmembrane conductance regulator (CFTR) harboring a disease-causing mutation (A455E). Screen results yielded 133 primary hits and 1 validated hit that normalized FRET values of the mutant nascent peptide. This system provides a scalable, tractable, structure-based discovery platform for screening small molecules that bind to or impact the folding of protein substrates that are not amenable to traditional biochemical analyses.
Collapse
Affiliation(s)
- Hideki Shishido
- CFFT Lab, Cystic Fibrosis Foundation, 44 Hartwell Ave, Lexington, MA, 02421, USA.,Generate Biomedicines, Inc., 26 Landsdowne St, Cambridge, MA, 02139, USA
| | - Jae Seok Yoon
- CFFT Lab, Cystic Fibrosis Foundation, 44 Hartwell Ave, Lexington, MA, 02421, USA
| | - William R Skach
- Cystic Fibrosis Foundation, 4550 Montgomery Ave., Suite 1100N, Bethesda, MD, 20814, USA.
| |
Collapse
|
9
|
Williamson M, Casey M, Gabillard-Lefort C, Alharbi A, Teo YQJ, McElvaney NG, Reeves EP. Current evidence on the effect of highly effective CFTR modulation on interleukin-8 in cystic fibrosis. Expert Rev Respir Med 2021; 16:43-56. [PMID: 34726115 DOI: 10.1080/17476348.2021.2001333] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
INTRODUCTION Cystic fibrosis (CF) is a genetically inherited disease, with mortality and morbidity associated with respiratory disease. The inflammatory response in CF is characterized by excessive neutrophil influx to the airways, mainly due to the increased local production and retention of interleukin-8 (IL-8), a potent neutrophil chemoattractant. AREAS COVERED We discuss how the chemokine IL-8 dominates the inflammatory profile of the airways in CF lung disease. Cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapies are designed to correct the malfunctioning protein resulting from specific CFTR mutations. This review covers current evidence on the impact of CFTR impairment on levels of IL-8 and outlines the influence of effective CFTR modulation on inflammation in CF with a focus on cytokine production. Review of the literature was carried out using the PUBMED database, Google Scholar, and The Cochrane Library databases, using several appropriate generic terms. EXPERT OPINION Therapeutic interventions specifically targeting the defective CFTR protein have improved the outlook for CF. Accumulating studies on the effect of highly effective CFTR modulation on inflammation indicate an impact on IL-8 levels. Further studies are required to increase our knowledge of early onset innate inflammatory dysregulation and on anti-inflammatory mechanisms of CFTR modulators.
Collapse
Affiliation(s)
- Michael Williamson
- Royal College of Surgeons in Ireland, Irish Centre for Genetic Lung Disease, Department of Medicine, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin, Ireland
| | - Michelle Casey
- Royal College of Surgeons in Ireland, Irish Centre for Genetic Lung Disease, Department of Medicine, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin, Ireland
| | - Claudie Gabillard-Lefort
- Royal College of Surgeons in Ireland, Irish Centre for Genetic Lung Disease, Department of Medicine, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin, Ireland
| | - Aram Alharbi
- Royal College of Surgeons in Ireland, Irish Centre for Genetic Lung Disease, Department of Medicine, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin, Ireland
| | - Yu Qing Jolene Teo
- Royal College of Surgeons in Ireland, Irish Centre for Genetic Lung Disease, Department of Medicine, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin, Ireland
| | - Noel G McElvaney
- Royal College of Surgeons in Ireland, Irish Centre for Genetic Lung Disease, Department of Medicine, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin, Ireland
| | - Emer P Reeves
- Royal College of Surgeons in Ireland, Irish Centre for Genetic Lung Disease, Department of Medicine, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin, Ireland
| |
Collapse
|
10
|
Differential Effects of Oleuropein and Hydroxytyrosol on Aggregation and Stability of CFTR NBD1-ΔF508 Domain. JOURNAL OF RESPIRATION 2021. [DOI: 10.3390/jor1030019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Cystic Fibrosis (CF) is caused by loss of function mutations in the Cystic Fibrosis transmembrane conductance regulator (CFTR). The folding and assembly of CFTR is inefficient. Deletion of F508 in the first nucleotide binding domain (NBD1-ΔF508) further disrupts protein stability leading to endoplasmic reticulum retention and proteasomal degradation. Stabilization and prevention of NBD1-ΔF508 aggregation is critical to rescuing the folding and function of the entire CFTR channel. We report that the phenolic compounds Oleuropein and Hydroxytryosol reduce aggregation of NBD1-ΔF508. The NBD1-ΔF508 aggregate size was smaller in the presence of Hydroxytryosol as determined by dynamic light scattering. Neither phenolic compound increased the thermal stability of NBD1-ΔF508 as measured by differential scanning fluorimetry. Interestingly, Hydroxytyrosol inhibited the stabilizing effect of the indole compound BIA, a known stabilizer, on NBD1-ΔF508. Molecular docking studies predicted that Oleuropein preferred to bind in the F1-type core ATP-binding subdomain in NBD1. In contrast, Hydroxytyrosol preferred to bind in the α4/α5/α6 helical bundle of the ABCα subdomain of NBD1 next to the putative binding site for BIA. This result suggests that Hydroxytyrosol interferes with BIA binding, thus providing an explanation for the antagonistic effect on NBD1 stability upon incubation with both compounds. To our knowledge, these studies are the first to explore the effects of these two phenolic compounds on the aggregation and stability of NBD1-ΔF508 domain of CFTR.
Collapse
|
11
|
Scholl D, Sigoillot M, Overtus M, Martinez RC, Martens C, Wang Y, Pardon E, Laeremans T, Garcia-Pino A, Steyaert J, Sheppard DN, Hendrix J, Govaerts C. A topological switch in CFTR modulates channel activity and sensitivity to unfolding. Nat Chem Biol 2021; 17:989-997. [PMID: 34341587 DOI: 10.1038/s41589-021-00844-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 06/28/2021] [Indexed: 12/25/2022]
Abstract
The cystic fibrosis transmembrane conductance regulator (CFTR) anion channel is essential to maintain fluid homeostasis in key organs. Functional impairment of CFTR due to mutations in the cftr gene leads to cystic fibrosis. Here, we show that the first nucleotide-binding domain (NBD1) of CFTR can spontaneously adopt an alternate conformation that departs from the canonical NBD fold previously observed. Crystallography reveals that this conformation involves a topological reorganization of NBD1. Single-molecule fluorescence resonance energy transfer microscopy shows that the equilibrium between the conformations is regulated by adenosine triphosphate binding. However, under destabilizing conditions, such as the disease-causing mutation F508del, this conformational flexibility enables unfolding of the β-subdomain. Our data indicate that, in wild-type CFTR, this conformational transition of NBD1 regulates channel function, but, in the presence of the F508del mutation, it allows domain misfolding and subsequent protein degradation. Our work provides a framework to design conformation-specific therapeutics to prevent noxious transitions.
Collapse
Affiliation(s)
- Daniel Scholl
- SFMB, Université Libre de Bruxelles, Brussels, Belgium
| | | | - Marie Overtus
- SFMB, Université Libre de Bruxelles, Brussels, Belgium
| | | | - Chloé Martens
- SFMB, Université Libre de Bruxelles, Brussels, Belgium
| | - Yiting Wang
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Els Pardon
- VIB-VUB center for Structural Biology, VIB, Brussels, Belgium.,Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Toon Laeremans
- VIB-VUB center for Structural Biology, VIB, Brussels, Belgium.,Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Abel Garcia-Pino
- Cellular and Molecular Microbiology, Université Libre de Bruxelles, Gosselies, Belgium
| | - Jan Steyaert
- VIB-VUB center for Structural Biology, VIB, Brussels, Belgium.,Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - David N Sheppard
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Jelle Hendrix
- Dynamic Bioimaging Lab, Advanced Optical Microscopy Centre and Biomedical Research Institute, Hasselt University, Diepenbeek, Belgium.,Molecular Imaging and Photonics, Chemistry Department, KU Leuven, Leuven, Belgium
| | | |
Collapse
|
12
|
Veit G, Roldan A, Hancock MA, Da Fonte DF, Xu H, Hussein M, Frenkiel S, Matouk E, Velkov T, Lukacs GL. Allosteric folding correction of F508del and rare CFTR mutants by elexacaftor-tezacaftor-ivacaftor (Trikafta) combination. JCI Insight 2020; 5:139983. [PMID: 32853178 PMCID: PMC7526550 DOI: 10.1172/jci.insight.139983] [Citation(s) in RCA: 138] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 08/19/2020] [Indexed: 12/20/2022] Open
Abstract
Based on its clinical benefits, Trikafta — the combination of folding correctors VX-661 (tezacaftor), VX-445 (elexacaftor), and the gating potentiator VX-770 (ivacaftor) — was FDA approved for treatment of patients with cystic fibrosis (CF) carrying deletion of phenylalanine at position 508 (F508del) of the CF transmembrane conductance regulator (CFTR) on at least 1 allele. Neither the mechanism of action of VX-445 nor the susceptibility of rare CF folding mutants to Trikafta are known. Here, we show that, in human bronchial epithelial cells, VX-445 synergistically restores F508del-CFTR processing in combination with type I or II correctors that target the nucleotide binding domain 1 (NBD1) membrane spanning domains (MSDs) interface and NBD2, respectively, consistent with a type III corrector mechanism. This inference was supported by the VX-445 binding to and unfolding suppression of the isolated F508del-NBD1 of CFTR. The VX-661 plus VX-445 treatment restored F508del-CFTR chloride channel function in the presence of VX-770 to approximately 62% of WT CFTR in homozygous nasal epithelia. Substantial rescue of rare misprocessing mutations (S13F, R31C, G85E, E92K, V520F, M1101K, and N1303K), confined to MSD1, MSD2, NBD1, and NBD2 of CFTR, was also observed in airway epithelia, suggesting an allosteric correction mechanism and the possible application of Trikafta for patients with rare misfolding mutants of CFTR. Trikafta, the combination of type I corrector VX-661, type III corrector VX-445, and the potentiator VX-770, may be applied for various CFTR folding mutants.
Collapse
Affiliation(s)
| | | | - Mark A Hancock
- SPR-MS Facility, McGill University, Montréal, Quebec, Canada
| | | | | | - Maytham Hussein
- Department of Pharmacology & Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, Australia
| | | | - Elias Matouk
- Adult Cystic Fibrosis Clinic, Montreal Chest Institute, and
| | - Tony Velkov
- Department of Pharmacology & Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, Australia
| | - Gergely L Lukacs
- Department of Physiology and.,Department of Biochemistry, McGill University, Montréal, Quebec, Canada
| |
Collapse
|
13
|
Shishido H, Yoon JS, Yang Z, Skach WR. CFTR trafficking mutations disrupt cotranslational protein folding by targeting biosynthetic intermediates. Nat Commun 2020; 11:4258. [PMID: 32848127 PMCID: PMC7450043 DOI: 10.1038/s41467-020-18101-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 08/04/2020] [Indexed: 02/03/2023] Open
Abstract
Protein misfolding causes a wide spectrum of human disease, and therapies that target misfolding are transforming the clinical care of cystic fibrosis. Despite this success, however, very little is known about how disease-causing mutations affect the de novo folding landscape. Here we show that inherited, disease-causing mutations located within the first nucleotide-binding domain (NBD1) of the cystic fibrosis transmembrane conductance regulator (CFTR) have distinct effects on nascent polypeptides. Two of these mutations (A455E and L558S) delay compaction of the nascent NBD1 during a critical window of synthesis. The observed folding defect is highly dependent on nascent chain length as well as its attachment to the ribosome. Moreover, restoration of the NBD1 cotranslational folding defect by second site suppressor mutations also partially restores folding of full-length CFTR. These findings demonstrate that nascent folding intermediates can play an important role in disease pathogenesis and thus provide potential targets for pharmacological correction.
Collapse
Affiliation(s)
- Hideki Shishido
- CFFT Lab, Cystic Fibrosis Foundation, 44 Hartwell Ave, Lexington, MA, 02421, USA
| | - Jae Seok Yoon
- CFFT Lab, Cystic Fibrosis Foundation, 44 Hartwell Ave, Lexington, MA, 02421, USA
| | - Zhongying Yang
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, 3181 S.W. Sam Jackson Park Rd, Portland, OR, 97239, USA
| | - William R Skach
- Cystic Fibrosis Foundation, 4550 Montgomery Ave., Suite 1100N, Bethesda, MD, 20814, USA.
| |
Collapse
|
14
|
Bell SC, Mall MA, Gutierrez H, Macek M, Madge S, Davies JC, Burgel PR, Tullis E, Castaños C, Castellani C, Byrnes CA, Cathcart F, Chotirmall SH, Cosgriff R, Eichler I, Fajac I, Goss CH, Drevinek P, Farrell PM, Gravelle AM, Havermans T, Mayer-Hamblett N, Kashirskaya N, Kerem E, Mathew JL, McKone EF, Naehrlich L, Nasr SZ, Oates GR, O'Neill C, Pypops U, Raraigh KS, Rowe SM, Southern KW, Sivam S, Stephenson AL, Zampoli M, Ratjen F. The future of cystic fibrosis care: a global perspective. THE LANCET RESPIRATORY MEDICINE 2020; 8:65-124. [DOI: 10.1016/s2213-2600(19)30337-6] [Citation(s) in RCA: 351] [Impact Index Per Article: 87.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 07/19/2019] [Accepted: 08/14/2019] [Indexed: 02/06/2023]
|
15
|
Laselva O, Erwood S, Du K, Ivakine Z, Bear CE. Activity of lumacaftor is not conserved in zebrafish Cftr bearing the major cystic fibrosis-causing mutation. FASEB Bioadv 2019; 1:661-670. [PMID: 32123813 PMCID: PMC6996396 DOI: 10.1096/fba.2019-00039] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 05/02/2019] [Accepted: 08/30/2019] [Indexed: 12/11/2022] Open
Abstract
F508del-cystic fibrosis transmembrane conductance regulator (CFTR) is the major mutant responsible for cystic fibrosis (CF). ORKAMBI®, approved for patients bearing this mutant, contains lumacaftor (VX-809) that partially corrects F508del-CFTR's processing defect and ivacaftor (VX-770) that potentiates its defective channel activity. Unfortunately, the clinical efficacy of ORKAMBI® is modest, highlighting the need to understand how the small molecules work so that superior compounds can be developed. Because, human CFTR (hCFTR) and zebrafish Cftr (zCftr) are structurally conserved as determined in recent cryo-EM structural models, we hypothesized that the consequences of the major mutation and small molecule modulators would be similar for the two species of protein. As expected, like the F508del mutation in hCFTR, the homologous mutation in zCftr (F507del) is misprocessed, yet not as severely as the human mutant and this defect was restored by low-temperature (27°C) culture conditions. After rescue to the cell surface, F507del-zCftr exhibited regulated channel activity that was potentiated by ivacaftor. Surprisingly, lumacaftor failed to rescue misprocessing of the F507del-zCftr at either 37 or 27°C suggesting that future comparative studies with F508del-hCFTR would provide insight into its structure: function relationships. Interestingly, the robust rescue of F508del-zCftr at 27°C and availability of methods for in vivo screening in zebrafish present the opportunity to define the cellular pathways underlying rescue.
Collapse
Affiliation(s)
- Onofrio Laselva
- Programme in Molecular MedicineHospital for Sick ChildrenTorontoCanada
- Department of PhysiologyUniversity of TorontoTorontoCanada
| | - Steven Erwood
- Programme in Genetics and Genome BiologyHospital for Sick ChildrenTorontoCanada
| | - Kai Du
- Programme in Molecular MedicineHospital for Sick ChildrenTorontoCanada
| | - Zhenya Ivakine
- Programme in Genetics and Genome BiologyHospital for Sick ChildrenTorontoCanada
| | - Christine E. Bear
- Programme in Molecular MedicineHospital for Sick ChildrenTorontoCanada
- Department of PhysiologyUniversity of TorontoTorontoCanada
- Department of BiochemistryUniversity of TorontoTorontoCanada
| |
Collapse
|
16
|
de Wilde G, Gees M, Musch S, Verdonck K, Jans M, Wesse AS, Singh AK, Hwang TC, Christophe T, Pizzonero M, Van der Plas S, Desroy N, Cowart M, Stouten P, Nelles L, Conrath K. Identification of GLPG/ABBV-2737, a Novel Class of Corrector, Which Exerts Functional Synergy With Other CFTR Modulators. Front Pharmacol 2019; 10:514. [PMID: 31143125 PMCID: PMC6521598 DOI: 10.3389/fphar.2019.00514] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 04/24/2019] [Indexed: 01/28/2023] Open
Abstract
The deletion of phenylalanine at position 508 (F508del) in cystic fibrosis transmembrane conductance regulator (CFTR) causes a severe defect in folding and trafficking of the chloride channel resulting in its absence at the plasma membrane of epithelial cells leading to cystic fibrosis. Progress in the understanding of the disease increased over the past decades and led to the awareness that combinations of mechanistically different CFTR modulators are required to obtain meaningful clinical benefit. Today, there remains an unmet need for identification and development of more effective CFTR modulator combinations to improve existing therapies for patients carrying the F508del mutation. Here, we describe the identification of a novel F508del corrector using functional assays. We provide experimental evidence that the clinical candidate GLPG/ABBV-2737 represents a novel class of corrector exerting activity both on its own and in combination with VX809 or GLPG/ABBV-2222.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - Tzyh-Chang Hwang
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, United States
| | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Chen X, Zhu S, Zhenin M, Xu W, Bose SJ, Wong MPF, Leung GPH, Senderowitz H, Chen JH. A defective flexible loop contributes to the processing and gating defects of the predominant cystic fibrosis-causing mutation. FASEB J 2019; 33:5126-5142. [PMID: 30668920 DOI: 10.1096/fj.201801218rr] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
People with the genetic disease cystic fibrosis (CF) often carry a deletion mutation ΔF508 on the gene encoding the CF transmembrane conductance regulator (CFTR) Cl- channel. This mutation greatly reduces the CFTR maturation process and slows the channel opening rate. Here, we investigate whether residues near F508 contribute to these defects in ΔF508-CFTR. Most deletion mutations, but not alanine substitutions, of individual residues from positions 503 to 513 impaired CFTR maturation. Interestingly, only protein processing of ΔY512-CFTR, like that of ΔF508-CFTR, was greatly improved by low-temperature culture at 27°C or small-molecule corrector C18. The 2 mutant Cl- channels were equally slow to open, suggesting that they may share common structural flaws. Studies on the H3-H4 loop that links residues F508 and Y512 demonstrate that G509A/V510G mutations, moving G509 1 position backward in the loop, markedly enhanced ΔF508-CFTR maturation and opening rate while promoting protein stability and persistence of the H3 helix in ΔF508 nucleotide-binding domain 1. Moreover, V510A/S511A mutations noticeably increased ΔY512-CFTR maturation at 27°C and its opening rate. Thus, loop abnormalities may contribute to ΔF508- and ΔY512-CFTR defects. Importantly, correcting defects from G509 displacement in ΔF508-CFTR may offer a new avenue for drug discovery and CF treatments.-Chen, X., Zhu, S., Zhenin, M., Xu, W., Bose, S. J., Wong, M. P.-F., Leung, G. P. H., Senderowitz, H., Chen, J.-H. A defective flexible loop contributes to the processing and gating defects of the predominant cystic fibrosis-causing mutation.
Collapse
Affiliation(s)
- Xinying Chen
- School of Biomedical Sciences, University of Hong Kong, Hong Kong.,The University of Hong Kong Shenzhen Institute of Research and Innovation, Shenzhen, China
| | - Siyu Zhu
- School of Biomedical Sciences, University of Hong Kong, Hong Kong.,The University of Hong Kong Shenzhen Institute of Research and Innovation, Shenzhen, China
| | - Michael Zhenin
- Department of Chemistry, Bar Ilan University, Ramat-Gan, Israel
| | - Weiyi Xu
- School of Biomedical Sciences, University of Hong Kong, Hong Kong.,The University of Hong Kong Shenzhen Institute of Research and Innovation, Shenzhen, China
| | - Samuel J Bose
- School of Physiology, Pharmacology, and Neuroscience, University of Bristol, Bristol, United Kingdom; and
| | - Molly Pik-Fan Wong
- School of Biomedical Sciences, University of Hong Kong, Hong Kong.,The University of Hong Kong Shenzhen Institute of Research and Innovation, Shenzhen, China
| | - George P H Leung
- Department of Pharmacology and Pharmacy, University of Hong Kong, Hong Kong, China
| | | | - Jeng-Haur Chen
- School of Biomedical Sciences, University of Hong Kong, Hong Kong.,The University of Hong Kong Shenzhen Institute of Research and Innovation, Shenzhen, China
| |
Collapse
|
18
|
Differential Scanning Fluorimetry and Hydrogen Deuterium Exchange Mass Spectrometry to Monitor the Conformational Dynamics of NBD1 in Cystic Fibrosis. Methods Mol Biol 2019; 1873:53-67. [PMID: 30341603 DOI: 10.1007/978-1-4939-8820-4_4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cystic fibrosis (CF) is one of the most common, lethal autosomal recessive diseases in Caucasians with a life expectancy of 37-47 years. The CF transmembrane conductance regulator (CFTR) is a plasma membrane ion channel, confined to apical membrane of epithelia, and ensures transepithelial water and solute movement across secretory epithelia in several organs. Numerous CF mutations, including the most prevalent deletion of F508 (ΔF508) in the nucleotide binding domain 1 (NBD1) leads to CFTR global misfolding and premature intracellular degradation at the endoplasmic reticulum (ER). To better understand the misfolding mechanism caused by CF-causing point mutations in the NBD1, which is poorly understood, differential scanning fluorimetry (DSF) and hydrogen deuterium exchange coupled with mass spectrometry (HDX-MS) are the choice of techniques. These established methods can measure the conformational dynamics of the NBD1 globally and at peptide resolution level by monitoring backbone amide HDX, respectively, and will be instrumental to evaluate the mechanism of action of CF mutations and folding correctors that rescue CFTR folding defects via stabilizing the mutant NBD1.
Collapse
|
19
|
Wang C, Aleksandrov AA, Yang Z, Forouhar F, Proctor EA, Kota P, An J, Kaplan A, Khazanov N, Boël G, Stockwell BR, Senderowitz H, Dokholyan NV, Riordan JR, Brouillette CG, Hunt JF. Ligand binding to a remote site thermodynamically corrects the F508del mutation in the human cystic fibrosis transmembrane conductance regulator. J Biol Chem 2018; 293:17685-17704. [PMID: 29903914 PMCID: PMC6240863 DOI: 10.1074/jbc.ra117.000819] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 05/31/2018] [Indexed: 01/07/2023] Open
Abstract
Many disease-causing mutations impair protein stability. Here, we explore a thermodynamic strategy to correct the disease-causing F508del mutation in the human cystic fibrosis transmembrane conductance regulator (hCFTR). F508del destabilizes nucleotide-binding domain 1 (hNBD1) in hCFTR relative to an aggregation-prone intermediate. We developed a fluorescence self-quenching assay for compounds that prevent aggregation of hNBD1 by stabilizing its native conformation. Unexpectedly, we found that dTTP and nucleotide analogs with exocyclic methyl groups bind to hNBD1 more strongly than ATP and preserve electrophysiological function of full-length F508del-hCFTR channels at temperatures up to 37 °C. Furthermore, nucleotides that increase open-channel probability, which reflects stabilization of an interdomain interface to hNBD1, thermally protect full-length F508del-hCFTR even when they do not stabilize isolated hNBD1. Therefore, stabilization of hNBD1 itself or of one of its interdomain interfaces by a small molecule indirectly offsets the destabilizing effect of the F508del mutation on full-length hCFTR. These results indicate that high-affinity binding of a small molecule to a remote site can correct a disease-causing mutation. We propose that the strategies described here should be applicable to identifying small molecules to help manage other human diseases caused by mutations that destabilize native protein conformation.
Collapse
Affiliation(s)
- Chi Wang
- From the Departments of Biological Sciences and
| | - Andrei A. Aleksandrov
- the Department of Biochemistry and Biophysics, School of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Zhengrong Yang
- the Department of Chemistry, University of Alabama, Birmingham, Alabama 35294, and
| | | | - Elizabeth A. Proctor
- the Department of Biochemistry and Biophysics, School of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Pradeep Kota
- the Department of Biochemistry and Biophysics, School of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Jianli An
- the Department of Chemistry, University of Alabama, Birmingham, Alabama 35294, and
| | - Anna Kaplan
- From the Departments of Biological Sciences and
| | - Netaly Khazanov
- the Department of Chemistry, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | | | - Brent R. Stockwell
- From the Departments of Biological Sciences and ,Chemistry, Columbia University, New York, New York 10027
| | - Hanoch Senderowitz
- the Department of Chemistry, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Nikolay V. Dokholyan
- the Department of Biochemistry and Biophysics, School of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599
| | - John R. Riordan
- the Department of Biochemistry and Biophysics, School of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599
| | | | - John F. Hunt
- From the Departments of Biological Sciences and , To whom correspondence should be addressed. Tel.:
212-854-5443; Fax:
212-865-8246; E-mail:
| |
Collapse
|
20
|
Hoffmann B, Elbahnsi A, Lehn P, Décout JL, Pietrucci F, Mornon JP, Callebaut I. Combining theoretical and experimental data to decipher CFTR 3D structures and functions. Cell Mol Life Sci 2018; 75:3829-3855. [PMID: 29779042 PMCID: PMC11105360 DOI: 10.1007/s00018-018-2835-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 05/04/2018] [Accepted: 05/07/2018] [Indexed: 12/15/2022]
Abstract
Cryo-electron microscopy (cryo-EM) has recently provided invaluable experimental data about the full-length cystic fibrosis transmembrane conductance regulator (CFTR) 3D structure. However, this experimental information deals with inactive states of the channel, either in an apo, quiescent conformation, in which nucleotide-binding domains (NBDs) are widely separated or in an ATP-bound, yet closed conformation. Here, we show that 3D structure models of the open and closed forms of the channel, now further supported by metadynamics simulations and by comparison with the cryo-EM data, could be used to gain some insights into critical features of the conformational transition toward active CFTR forms. These critical elements lie within membrane-spanning domains but also within NBD1 and the N-terminal extension, in which conformational plasticity is predicted to occur to help the interaction with filamin, one of the CFTR cellular partners.
Collapse
Affiliation(s)
- Brice Hoffmann
- Sorbonne Université, Muséum National d'Histoire Naturelle, UMR CNRS 7590, IRD, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, 75005, Paris, France
- Iktos, Paris, France
| | - Ahmad Elbahnsi
- Sorbonne Université, Muséum National d'Histoire Naturelle, UMR CNRS 7590, IRD, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, 75005, Paris, France
| | - Pierre Lehn
- INSERM U1078, SFR ScInBioS, Université de Bretagne Occidentale, Brest, France
| | | | - Fabio Pietrucci
- Sorbonne Université, Muséum National d'Histoire Naturelle, UMR CNRS 7590, IRD, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, 75005, Paris, France
| | - Jean-Paul Mornon
- Sorbonne Université, Muséum National d'Histoire Naturelle, UMR CNRS 7590, IRD, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, 75005, Paris, France.
| | - Isabelle Callebaut
- Sorbonne Université, Muséum National d'Histoire Naturelle, UMR CNRS 7590, IRD, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, 75005, Paris, France
| |
Collapse
|
21
|
Cai H, Qing X, Niringiyumukiza JD, Zhan X, Mo D, Zhou Y, Shang X. CFTR variants and renal abnormalities in males with congenital unilateral absence of the vas deferens (CUAVD): a systematic review and meta-analysis of observational studies. Genet Med 2018; 21:826-836. [PMID: 30214069 PMCID: PMC6752674 DOI: 10.1038/s41436-018-0262-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 07/26/2018] [Indexed: 12/17/2022] Open
Abstract
PURPOSE CFTR variant is the main genetic contributor to congenital (unilateral/bilateral) absence of the vas deferens (CAVD/CUAVD/CBAVD). We performed a systematic review to elucidate the genetic link between CFTR variants, CUAVD, and the associated risk of renal abnormality (RA). METHODS We searched relevant databases for eligible articles reporting CFTR variants in CUAVD. The frequency of CFTR variants and RA, and the odds ratios (ORs) for common alleles and RA risk, were pooled under random-/fixed-effect models. Subgroup analyses and heterogeneity tests were performed. RESULTS Twenty-three studies were included. Among CUAVD patients, 46% had at least one CFTR variant, with 27% having one and 5% having two. The allele frequency in CUAVD was 4% for F508del and 9% for 5T. The summary OR for 5T risk in CUAVD was 5.79 compared with normal controls and 2.82 compared with non-CAVD infertile males. The overall incidence of RA was 22% in CUAVD. The pooled OR for RA risk among CUAVD patients was 4.85 compared with CBAVD patients. CONCLUSION CFTR variants are common in CUAVD, and the 5T allele may be associated with increased CUAVD risk. CUAVD patients bear a higher RA risk than CBAVD patients, but this is not associated with CFTR variants.
Collapse
Affiliation(s)
- Hongcai Cai
- Family Planning Research Institute/Center of Reproductive Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Xingrong Qing
- Department of Gynecology, Jiangmen Central Hospital, Affiliated Jiangmen Hospital of Sun Yat-sen University, Jiangmen, Guangdong, China
| | - Jean Damascene Niringiyumukiza
- Family Planning Research Institute/Center of Reproductive Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Xuxin Zhan
- Department of Reproductive Medicine, Xi'an No. 4 Hospital, Xi'an, Shaanxi, China
| | - Dunsheng Mo
- Department of Urology, Liuzhou Worker's Hospital, Fourth Affiliated Hospital of Guangxi Medical University, Liuzhou, Guangxi, China
| | - Yuanzhong Zhou
- School of Public Health, Zunyi Medical University, Guizhou, Zunyi, China
| | - Xuejun Shang
- Department of Andrology, Jinling Hospital Affiliated to Southern Medical University, Nanjing, China. .,Department of Andrology, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China.
| |
Collapse
|
22
|
Yang Z, Hildebrandt E, Jiang F, Aleksandrov AA, Khazanov N, Zhou Q, An J, Mezzell AT, Xavier BM, Ding H, Riordan JR, Senderowitz H, Kappes JC, Brouillette CG, Urbatsch IL. Structural stability of purified human CFTR is systematically improved by mutations in nucleotide binding domain 1. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1193-1204. [PMID: 29425673 DOI: 10.1016/j.bbamem.2018.02.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 01/19/2018] [Accepted: 02/05/2018] [Indexed: 12/17/2022]
Abstract
The Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) is an ABC transporter containing two transmembrane domains forming a chloride ion channel, and two nucleotide binding domains (NBD1 and NBD2). CFTR has presented a formidable challenge to obtain monodisperse, biophysically stable protein. Here we report a comprehensive study comparing effects of single and multiple NBD1 mutations on stability of both the NBD1 domain alone and on purified full length human CFTR. Single mutations S492P, A534P, I539T acted additively, and when combined with M470V, S495P, and R555K cumulatively yielded an NBD1 with highly improved structural stability. Strategic combinations of these mutations strongly stabilized the domain to attain a calorimetric Tm > 70 °C. Replica exchange molecular dynamics simulations on the most stable 6SS-NBD1 variant implicated fluctuations, electrostatic interactions and side chain packing as potential contributors to improved stability. Progressive stabilization of NBD1 directly correlated with enhanced structural stability of full-length CFTR protein. Thermal unfolding of the stabilized CFTR mutants, monitored by changes in intrinsic fluorescence, demonstrated that Tm could be shifted as high as 67.4 °C in 6SS-CFTR, more than 20 °C higher than wild-type. H1402S, an NBD2 mutation, conferred CFTR with additional thermal stability, possibly by stabilizing an NBD-dimerized conformation. CFTR variants with NBD1-stabilizing mutations were expressed at the cell surface in mammalian cells, exhibited ATPase and channel activity, and retained these functions to higher temperatures. The capability to produce enzymatically active CFTR with improved structural stability amenable to biophysical and structural studies will advance mechanistic investigations and future cystic fibrosis drug development.
Collapse
Affiliation(s)
- Zhengrong Yang
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Ellen Hildebrandt
- Department of Cell Biology and Biochemistry, Center for Membrane Protein Research, Texas Tech University Health Sciences Center, 3601 4th Street, Stop 6540, Lubbock, TX 79430, USA
| | - Fan Jiang
- Department of Medicine, University of Alabama at Birmingham, 701 19th Street South, Birmingham, AL 35294-0007, USA
| | - Andrei A Aleksandrov
- Department of Biochemistry and Biophysics and Cystic Fibrosis Treatment and Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Netaly Khazanov
- Department of Chemistry, Bar-Ilan University, Ramat-Gan, 5290002, Israel
| | - Qingxian Zhou
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jianli An
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Andrew T Mezzell
- Department of Medicine, University of Alabama at Birmingham, 701 19th Street South, Birmingham, AL 35294-0007, USA
| | - Bala M Xavier
- Department of Cell Biology and Biochemistry, Center for Membrane Protein Research, Texas Tech University Health Sciences Center, 3601 4th Street, Stop 6540, Lubbock, TX 79430, USA
| | - Haitao Ding
- Department of Medicine, University of Alabama at Birmingham, 701 19th Street South, Birmingham, AL 35294-0007, USA
| | - John R Riordan
- Department of Biochemistry and Biophysics and Cystic Fibrosis Treatment and Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Hanoch Senderowitz
- Department of Chemistry, Bar-Ilan University, Ramat-Gan, 5290002, Israel
| | - John C Kappes
- Department of Medicine, University of Alabama at Birmingham, 701 19th Street South, Birmingham, AL 35294-0007, USA; Birmingham Veterans Affairs Medical Center, Research Service, Birmingham, AL 35233, USA
| | | | - Ina L Urbatsch
- Department of Cell Biology and Biochemistry, Center for Membrane Protein Research, Texas Tech University Health Sciences Center, 3601 4th Street, Stop 6540, Lubbock, TX 79430, USA.
| |
Collapse
|
23
|
Speeding Up the Identification of Cystic Fibrosis Transmembrane Conductance Regulator-Targeted Drugs: An Approach Based on Bioinformatics Strategies and Surface Plasmon Resonance. Molecules 2018; 23:molecules23010120. [PMID: 29316712 PMCID: PMC6017603 DOI: 10.3390/molecules23010120] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 12/29/2017] [Accepted: 01/04/2018] [Indexed: 01/09/2023] Open
Abstract
Cystic fibrosis (CF) is mainly caused by the deletion of Phe 508 (ΔF508) in the cystic fibrosis transmembrane conductance regulator (CFTR) protein that is thus withheld in the endoplasmic reticulum and rapidly degraded by the ubiquitin/proteasome system. New drugs able to rescue ΔF508-CFTR trafficking are eagerly awaited. An integrated bioinformatics and surface plasmon resonance (SPR) approach was here applied to investigate the rescue mechanism(s) of a series of CFTR-ligands including VX809, VX770 and some aminoarylthiazole derivatives (AAT). Computational studies tentatively identified a large binding pocket in the ΔF508-CFTR nucleotide binding domain-1 (NBD1) and predicted all the tested compounds to bind to three sub-regions of this main pocket. Noticeably, the known CFTR chaperone keratin-8 (K8) seems to interact with some residues located in one of these sub-pockets, potentially interfering with the binding of some ligands. SPR results corroborated all these computational findings. Moreover, for all the considered ligands, a statistically significant correlation was determined between their binding capability to ΔF508-NBD1 measured by SPR and the pockets availability measured by computational studies. Taken together, these results demonstrate a strong agreement between the in silico prediction and the SPR-generated binding data, suggesting a path to speed up the identification of new drugs for the treatment of cystic fibrosis.
Collapse
|
24
|
Callebaut I, Hoffmann B, Mornon JP. The implications of CFTR structural studies for cystic fibrosis drug development. Curr Opin Pharmacol 2017; 34:112-118. [PMID: 29096277 DOI: 10.1016/j.coph.2017.09.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 09/12/2017] [Accepted: 09/14/2017] [Indexed: 02/08/2023]
Abstract
Development of Cystic Fibrosis Transmembrane conductance Regulator (CFTR) modulators, targeting the root cause of cystic fibrosis (CF), represents a challenge in the era of personalized medicine, as CFTR mutations lead to a variety of phenotypes, which likely require different, specific treatments. CF drug development is also complicated by the need to preserve the right balance between stability and flexibility, required for optimal function of the CFTR protein. In this review, we highlight how structural data can be exploited in this context to understand the molecular mechanisms of disease-associated mutations, to characterize the mechanisms of action of known modulators and to rationalize the search for novel, specific compounds.
Collapse
Affiliation(s)
- Isabelle Callebaut
- CNRS UMR7590, Sorbonne Universités, Université Pierre et Marie Curie - Paris 6 - MNHN - IRD - IUC, Paris, France.
| | - Brice Hoffmann
- CNRS UMR7590, Sorbonne Universités, Université Pierre et Marie Curie - Paris 6 - MNHN - IRD - IUC, Paris, France
| | - Jean-Paul Mornon
- CNRS UMR7590, Sorbonne Universités, Université Pierre et Marie Curie - Paris 6 - MNHN - IRD - IUC, Paris, France
| |
Collapse
|
25
|
Simhaev L, McCarty NA, Ford RC, Senderowitz H. Molecular Dynamics Flexible Fitting Simulations Identify New Models of the Closed State of the Cystic Fibrosis Transmembrane Conductance Regulator Protein. J Chem Inf Model 2017; 57:1932-1946. [DOI: 10.1021/acs.jcim.7b00091] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Luba Simhaev
- Department
of Chemistry, Bar Ilan University, Ramat-Gan 5290002, Israel
| | - Nael A. McCarty
- Division
of Pulmonology, Allergy/Immunology, Cystic Fibrosis, and Sleep, Department
of Pediatrics, Emory + Children’s Center for Cystic Fibrosis
and Airways Disease Research, Emory University School of Medicine and Children’s Healthcare of Atlanta, 2015 Uppergate Drive, Atlanta, Georgia 30322, United States
| | - Robert C. Ford
- Faculty
of Biology Medicine and Health, University of Manchester, Oxford
Road, Manchester, M13 9PL, U.K
| | | |
Collapse
|
26
|
Vernon RM, Chong PA, Lin H, Yang Z, Zhou Q, Aleksandrov AA, Dawson JE, Riordan JR, Brouillette CG, Thibodeau PH, Forman-Kay JD. Stabilization of a nucleotide-binding domain of the cystic fibrosis transmembrane conductance regulator yields insight into disease-causing mutations. J Biol Chem 2017; 292:14147-14164. [PMID: 28655774 DOI: 10.1074/jbc.m116.772335] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 06/16/2017] [Indexed: 11/06/2022] Open
Abstract
Characterization of the second nucleotide-binding domain (NBD2) of the cystic fibrosis transmembrane conductance regulator (CFTR) has lagged behind research into the NBD1 domain, in part because NBD1 contains the F508del mutation, which is the dominant cause of cystic fibrosis. Research on NBD2 has also been hampered by the overall instability of the domain and the difficulty of producing reagents. Nonetheless, multiple disease-causing mutations reside in NBD2, and the domain is critical for CFTR function, because channel gating involves NBD1/NBD2 dimerization, and NBD2 contains the catalytically active ATPase site in CFTR. Recognizing the paucity of structural and biophysical data on NBD2, here we have defined a bioinformatics-based method for manually identifying stabilizing substitutions in NBD2, and we used an iterative process of screening single substitutions against thermal melting points to both produce minimally mutated stable constructs and individually characterize mutations. We present a range of stable constructs with minimal mutations to help inform further research on NBD2. We have used this stabilized background to study the effects of NBD2 mutations identified in cystic fibrosis (CF) patients, demonstrating that mutants such as N1303K and G1349D are characterized by lower stability, as shown previously for some NBD1 mutations, suggesting a potential role for NBD2 instability in the pathology of CF.
Collapse
Affiliation(s)
- Robert M Vernon
- From the Program in Molecular Medicine, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - P Andrew Chong
- From the Program in Molecular Medicine, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Hong Lin
- From the Program in Molecular Medicine, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Zhengrong Yang
- Center for Structural Biology and Department of Chemistry, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Qingxian Zhou
- Center for Structural Biology and Department of Chemistry, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Andrei A Aleksandrov
- Department of Biochemistry and Biophysics, Cystic Fibrosis Treatment and Research Center, University of North Carolina, Chapel Hill, North Carolina 27599, and
| | - Jennifer E Dawson
- From the Program in Molecular Medicine, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - John R Riordan
- Department of Biochemistry and Biophysics, Cystic Fibrosis Treatment and Research Center, University of North Carolina, Chapel Hill, North Carolina 27599, and
| | - Christie G Brouillette
- Center for Structural Biology and Department of Chemistry, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Patrick H Thibodeau
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15219
| | - Julie D Forman-Kay
- From the Program in Molecular Medicine, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada,; Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada.
| |
Collapse
|
27
|
Hudson RP, Dawson JE, Chong PA, Yang Z, Millen L, Thomas PJ, Brouillette CG, Forman-Kay JD. Direct Binding of the Corrector VX-809 to Human CFTR NBD1: Evidence of an Allosteric Coupling between the Binding Site and the NBD1:CL4 Interface. Mol Pharmacol 2017; 92:124-135. [PMID: 28546419 DOI: 10.1124/mol.117.108373] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 05/17/2017] [Indexed: 01/06/2023] Open
Abstract
Understanding the mechanism of action of modulator compounds for the cystic fibrosis transmembrane conductance regulator (CFTR) is key for the optimization of therapeutics as well as obtaining insights into the molecular mechanisms of CFTR function. We demonstrate the direct binding of VX-809 to the first nucleotide-binding domain (NBD1) of human CFTR. Disruption of the interaction between C-terminal helices and the NBD1 core upon VX-809 binding is observed from chemical shift changes in the NMR spectra of residues in the helices and on the surface of β-strands S3, S9, and S10. Binding to VX-809 leads to a significant negative shift in NBD1 thermal melting temperature (Tm), pointing to direct VX-809 interaction shifting the NBD1 conformational equilibrium. An inter-residue correlation analysis of the chemical shift changes provides evidence of allosteric coupling between the direct binding site and the NBD1:CL4 interface, thus enabling effects on the interface in the absence of direct binding in that location. These NMR binding data and the negative Tm shifts are very similar to those previously reported by us for binding of the dual corrector-potentiator CFFT-001 to NBD1 (Hudson et al., 2012), suggesting that the two compounds may share some aspects of their mechanisms of action. Although previous studies have shown an important role for VX-809 in modulating the conformation of the first membrane spanning domain (Aleksandrov et al., 2012; Ren et al., 2013), this additional mode of VX-809 binding provides insight into conformational dynamics and allostery within CFTR.
Collapse
Affiliation(s)
- Rhea P Hudson
- Molecular Medicine, Hospital for Sick Children, Toronto, Ontario, Canada (R.P.H, J.E.D., P.A.C., J.D.F.-K.); Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada (J.D.F.-K.); Center for Structural Biology (Z.Y., C.G.B.) and Department of Chemistry (C.G.B.), University of Alabama at Birmingham, Birmingham, Alabama; and Department of Physiology, UT Southwestern Medical Center, Dallas, Texas (L.M., P.J.T.)
| | - Jennifer E Dawson
- Molecular Medicine, Hospital for Sick Children, Toronto, Ontario, Canada (R.P.H, J.E.D., P.A.C., J.D.F.-K.); Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada (J.D.F.-K.); Center for Structural Biology (Z.Y., C.G.B.) and Department of Chemistry (C.G.B.), University of Alabama at Birmingham, Birmingham, Alabama; and Department of Physiology, UT Southwestern Medical Center, Dallas, Texas (L.M., P.J.T.)
| | - P Andrew Chong
- Molecular Medicine, Hospital for Sick Children, Toronto, Ontario, Canada (R.P.H, J.E.D., P.A.C., J.D.F.-K.); Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada (J.D.F.-K.); Center for Structural Biology (Z.Y., C.G.B.) and Department of Chemistry (C.G.B.), University of Alabama at Birmingham, Birmingham, Alabama; and Department of Physiology, UT Southwestern Medical Center, Dallas, Texas (L.M., P.J.T.)
| | - Zhengrong Yang
- Molecular Medicine, Hospital for Sick Children, Toronto, Ontario, Canada (R.P.H, J.E.D., P.A.C., J.D.F.-K.); Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada (J.D.F.-K.); Center for Structural Biology (Z.Y., C.G.B.) and Department of Chemistry (C.G.B.), University of Alabama at Birmingham, Birmingham, Alabama; and Department of Physiology, UT Southwestern Medical Center, Dallas, Texas (L.M., P.J.T.)
| | - Linda Millen
- Molecular Medicine, Hospital for Sick Children, Toronto, Ontario, Canada (R.P.H, J.E.D., P.A.C., J.D.F.-K.); Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada (J.D.F.-K.); Center for Structural Biology (Z.Y., C.G.B.) and Department of Chemistry (C.G.B.), University of Alabama at Birmingham, Birmingham, Alabama; and Department of Physiology, UT Southwestern Medical Center, Dallas, Texas (L.M., P.J.T.)
| | - Philip J Thomas
- Molecular Medicine, Hospital for Sick Children, Toronto, Ontario, Canada (R.P.H, J.E.D., P.A.C., J.D.F.-K.); Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada (J.D.F.-K.); Center for Structural Biology (Z.Y., C.G.B.) and Department of Chemistry (C.G.B.), University of Alabama at Birmingham, Birmingham, Alabama; and Department of Physiology, UT Southwestern Medical Center, Dallas, Texas (L.M., P.J.T.)
| | - Christie G Brouillette
- Molecular Medicine, Hospital for Sick Children, Toronto, Ontario, Canada (R.P.H, J.E.D., P.A.C., J.D.F.-K.); Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada (J.D.F.-K.); Center for Structural Biology (Z.Y., C.G.B.) and Department of Chemistry (C.G.B.), University of Alabama at Birmingham, Birmingham, Alabama; and Department of Physiology, UT Southwestern Medical Center, Dallas, Texas (L.M., P.J.T.)
| | - Julie D Forman-Kay
- Molecular Medicine, Hospital for Sick Children, Toronto, Ontario, Canada (R.P.H, J.E.D., P.A.C., J.D.F.-K.); Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada (J.D.F.-K.); Center for Structural Biology (Z.Y., C.G.B.) and Department of Chemistry (C.G.B.), University of Alabama at Birmingham, Birmingham, Alabama; and Department of Physiology, UT Southwestern Medical Center, Dallas, Texas (L.M., P.J.T.).
| |
Collapse
|
28
|
Meng X, Wang Y, Wang X, Wrennall JA, Rimington TL, Li H, Cai Z, Ford RC, Sheppard DN. Two Small Molecules Restore Stability to a Subpopulation of the Cystic Fibrosis Transmembrane Conductance Regulator with the Predominant Disease-causing Mutation. J Biol Chem 2017; 292:3706-3719. [PMID: 28087700 PMCID: PMC5339754 DOI: 10.1074/jbc.m116.751537] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 01/12/2017] [Indexed: 12/17/2022] Open
Abstract
Cystic fibrosis (CF) is caused by mutations that disrupt the plasma membrane expression, stability, and function of the cystic fibrosis transmembrane conductance regulator (CFTR) Cl- channel. Two small molecules, the CFTR corrector lumacaftor and the potentiator ivacaftor, are now used clinically to treat CF, although some studies suggest that they have counteracting effects on CFTR stability. Here, we investigated the impact of these compounds on the instability of F508del-CFTR, the most common CF mutation. To study individual CFTR Cl- channels, we performed single-channel recording, whereas to assess entire CFTR populations, we used purified CFTR proteins and macroscopic CFTR Cl- currents. At 37 °C, low temperature-rescued F508del-CFTR more rapidly lost function in cell-free membrane patches and showed altered channel gating and current flow through open channels. Compared with purified wild-type CFTR, the full-length F508del-CFTR was about 10 °C less thermostable. Lumacaftor partially stabilized purified full-length F508del-CFTR and slightly delayed deactivation of individual F508del-CFTR Cl- channels. By contrast, ivacaftor further destabilized full-length F508del-CFTR and accelerated channel deactivation. Chronic (prolonged) co-incubation of F508del-CFTR-expressing cells with lumacaftor and ivacaftor deactivated macroscopic F508del-CFTR Cl- currents. However, at the single-channel level, chronic co-incubation greatly increased F508del-CFTR channel activity and temporal stability in most, but not all, cell-free membrane patches. We conclude that chronic lumacaftor and ivacaftor co-treatment restores stability in a small subpopulation of F508del-CFTR Cl- channels but that the majority remain destabilized. A fuller understanding of these effects and the characterization of the small F508del-CFTR subpopulation might be crucial for CF therapy development.
Collapse
Affiliation(s)
- Xin Meng
- From the Faculty of Biology, Medicine and Health, School of Biological Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PL, United Kingdom and
| | - Yiting Wang
- the School of Physiology, Pharmacology, and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, United Kingdom
| | - Xiaomeng Wang
- From the Faculty of Biology, Medicine and Health, School of Biological Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PL, United Kingdom and
| | - Joe A Wrennall
- the School of Physiology, Pharmacology, and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, United Kingdom
| | - Tracy L Rimington
- From the Faculty of Biology, Medicine and Health, School of Biological Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PL, United Kingdom and
| | - Hongyu Li
- the School of Physiology, Pharmacology, and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, United Kingdom
| | - Zhiwei Cai
- the School of Physiology, Pharmacology, and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, United Kingdom
| | - Robert C Ford
- From the Faculty of Biology, Medicine and Health, School of Biological Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PL, United Kingdom and
| | - David N Sheppard
- the School of Physiology, Pharmacology, and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, United Kingdom
| |
Collapse
|
29
|
Callebaut I, Hoffmann B, Lehn P, Mornon JP. Molecular modelling and molecular dynamics of CFTR. Cell Mol Life Sci 2017; 74:3-22. [PMID: 27717958 PMCID: PMC11107702 DOI: 10.1007/s00018-016-2385-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 09/28/2016] [Indexed: 12/11/2022]
Abstract
The cystic fibrosis transmembrane conductance regulator (CFTR) protein is a member of the ATP-binding cassette (ABC) transporter superfamily that functions as an ATP-gated channel. Considerable progress has been made over the last years in the understanding of the molecular basis of the CFTR functions, as well as dysfunctions causing the common genetic disease cystic fibrosis (CF). This review provides a global overview of the theoretical studies that have been performed so far, especially molecular modelling and molecular dynamics (MD) simulations. A special emphasis is placed on the CFTR-specific evolution of an ABC transporter framework towards a channel function, as well as on the understanding of the effects of disease-causing mutations and their specific modulation. This in silico work should help structure-based drug discovery and design, with a view to develop CFTR-specific pharmacotherapeutic approaches for the treatment of CF in the context of precision medicine.
Collapse
Affiliation(s)
- Isabelle Callebaut
- UMR CNRS 7590, Museum National d'Histoire Naturelle, IRD UMR 206, IUC, Case 115, IMPMC, Sorbonne Universités, UPMC Univ Paris 06, 4 Place Jussieu, 75005, Paris Cedex 05, France.
| | - Brice Hoffmann
- UMR CNRS 7590, Museum National d'Histoire Naturelle, IRD UMR 206, IUC, Case 115, IMPMC, Sorbonne Universités, UPMC Univ Paris 06, 4 Place Jussieu, 75005, Paris Cedex 05, France
| | - Pierre Lehn
- INSERM U1078, SFR ScInBioS, Université de Bretagne Occidentale, Brest, France
| | - Jean-Paul Mornon
- UMR CNRS 7590, Museum National d'Histoire Naturelle, IRD UMR 206, IUC, Case 115, IMPMC, Sorbonne Universités, UPMC Univ Paris 06, 4 Place Jussieu, 75005, Paris Cedex 05, France
| |
Collapse
|
30
|
Cystic fibrosis lung environment and Pseudomonas aeruginosa infection. BMC Pulm Med 2016; 16:174. [PMID: 27919253 PMCID: PMC5139081 DOI: 10.1186/s12890-016-0339-5] [Citation(s) in RCA: 223] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 11/24/2016] [Indexed: 12/20/2022] Open
Abstract
Background The airways of patients with cystic fibrosis (CF) are highly complex, subject to various environmental conditions as well as a distinct microbiota. Pseudomonas aeruginosa is recognized as one of the most important pulmonary pathogens and the predominant cause of morbidity and mortality in CF. A multifarious interplay between the host, pathogens, microbiota, and the environment shapes the course of the disease. There have been several excellent reviews detailing CF pathology, Pseudomonas and the role of environment in CF but only a few reviews connect these entities with regards to influence on the overall course of the disease. A holistic understanding of contributing factors is pertinent to inform new research and therapeutics. Discussion In this article, we discuss the deterministic alterations in lung physiology as a result of CF. We also revisit the impact of those changes on the microbiota, with special emphasis on P. aeruginosa and the influence of other non-genetic factors on CF. Substantial past and current research on various genetic and non-genetic aspects of cystic fibrosis has been reviewed to assess the effect of different factors on CF pulmonary infection. A thorough review of contributing factors in CF and the alterations in lung physiology indicate that CF lung infection is multi-factorial with no isolated cause that should be solely targeted to control disease progression. A combinatorial approach may be required to ensure better disease outcomes. Conclusion CF lung infection is a complex disease and requires a broad multidisciplinary approach to improve CF disease outcomes. A holistic understanding of the underlying mechanisms and non-genetic contributing factors in CF is central to development of new and targeted therapeutic strategies.
Collapse
|
31
|
Schneider EK, Reyes-Ortega F, Li J, Velkov T. Can Cystic Fibrosis Patients Finally Catch a Breath With Lumacaftor/Ivacaftor? Clin Pharmacol Ther 2016; 101:130-141. [PMID: 27804127 DOI: 10.1002/cpt.548] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 10/24/2016] [Accepted: 10/25/2016] [Indexed: 12/13/2022]
Abstract
Cystic fibrosis (CF) is a life-limiting disease caused by defective or deficient cystic fibrosis transmembrane conductance regulator (CFTR) activity. The recent US Food and Drug Administration (FDA) approval of lumacaftor combined with ivacaftor (Orkambi) targets patients with the F508del-CFTR. The question remains: Is this breakthrough combination therapy the "magic-bullet" cure for the vast majority of patients with CF? This review covers the contemporary clinical and scientific knowledge-base for lumacaftor/ivacaftor and highlights the emerging issues from recent conflicting literature reports.
Collapse
Affiliation(s)
- E K Schneider
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences; Monash University, Parkville, Victoria, Australia
| | - F Reyes-Ortega
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences; Monash University, Parkville, Victoria, Australia
| | - J Li
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences; Monash University, Parkville, Victoria, Australia.,Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - T Velkov
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences; Monash University, Parkville, Victoria, Australia
| |
Collapse
|
32
|
Abstract
Cystic fibrosis (CF) is a monogenic autosomal recessive disorder that affects about 70,000 people worldwide. The clinical manifestations of the disease are caused by defects in the cystic fibrosis transmembrane conductance regulator (CFTR) protein. The discovery of the CFTR gene in 1989 has led to a sophisticated understanding of how thousands of mutations in the CFTR gene affect the structure and function of the CFTR protein. Much progress has been made over the past decade with the development of orally bioavailable small molecule drugs that target defective CFTR proteins caused by specific mutations. Furthermore, there is considerable optimism about the prospect of gene replacement or editing therapies to correct all mutations in cystic fibrosis. The recent approvals of ivacaftor and lumacaftor represent the genesis of a new era of precision medicine in the treatment of this condition. These drugs are having a positive impact on the lives of people with cystic fibrosis and are potentially disease modifying. This review provides an update on advances in our understanding of the structure and function of the CFTR, with a focus on state of the art targeted drugs that are in development.
Collapse
Affiliation(s)
- Bradley S Quon
- Centre for Heart Lung Innovation and Division of Respiratory Medicine, Department of Medicine, University of British Columbia, Vancouver, BC, Canada, V6Z 1Y6
| | - Steven M Rowe
- Gregory Fleming James Cystic Fibrosis Research Center, Department of Medicine, Pediatrics and Cell Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| |
Collapse
|
33
|
Tang C, Lew S, He D. Using a second-order differential model to fit data without baselines in protein isothermal chemical denaturation. Protein Sci 2016; 25:898-904. [PMID: 26757366 DOI: 10.1002/pro.2878] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 12/21/2015] [Accepted: 12/23/2015] [Indexed: 11/06/2022]
Abstract
In vitro protein stability studies are commonly conducted via thermal or chemical denaturation/renaturation of protein. Conventional data analyses on the protein unfolding/(re)folding require well-defined pre- and post-transition baselines to evaluate Gibbs free-energy change associated with the protein unfolding/(re)folding. This evaluation becomes problematic when there is insufficient data for determining the pre- or post-transition baselines. In this study, fitting on such partial data obtained in protein chemical denaturation is established by introducing second-order differential (SOD) analysis to overcome the limitations that the conventional fitting method has. By reducing numbers of the baseline-related fitting parameters, the SOD analysis can successfully fit incomplete chemical denaturation data sets with high agreement to the conventional evaluation on the equivalent completed data, where the conventional fitting fails in analyzing them. This SOD fitting for the abbreviated isothermal chemical denaturation further fulfills data analysis methods on the insufficient data sets conducted in the two prevalent protein stability studies.
Collapse
Affiliation(s)
- Chuanning Tang
- Key Laboratory of Cell Proliferation and Regulation of Ministry of Education, Beijing Normal University, Beijing, 100875, China
| | - Scott Lew
- Neotein Therapeutics, New York, New York, 10706, USA
| | - Dacheng He
- Key Laboratory of Cell Proliferation and Regulation of Ministry of Education, Beijing Normal University, Beijing, 100875, China
| |
Collapse
|
34
|
Hall JD, Wang H, Byrnes LJ, Shanker S, Wang K, Efremov IV, Chong PA, Forman-Kay JD, Aulabaugh AE. Binding screen for cystic fibrosis transmembrane conductance regulator correctors finds new chemical matter and yields insights into cystic fibrosis therapeutic strategy. Protein Sci 2016; 25:360-73. [PMID: 26444971 DOI: 10.1002/pro.2821] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 10/01/2015] [Indexed: 11/08/2022]
Abstract
The most common mutation in cystic fibrosis (CF) patients is deletion of F508 (ΔF508) in the first nucleotide binding domain (NBD1) of the CF transmembrane conductance regulator (CFTR). ΔF508 causes a decrease in the trafficking of CFTR to the cell surface and reduces the thermal stability of isolated NBD1; it is well established that both of these effects can be rescued by additional revertant mutations in NBD1. The current paradigm in CF small molecule drug discovery is that, like revertant mutations, a path may exist to ΔF508 CFTR correction through a small molecule chaperone binding to NBD1. We, therefore, set out to find small molecule binders of NBD1 and test whether it is possible to develop these molecules into potent binders that increase CFTR trafficking in CF-patient-derived human bronchial epithelial cells. Several fragments were identified that bind NBD1 at either the CFFT-001 site or the BIA site. However, repeated attempts to improve the affinity of these fragments resulted in only modest gains. Although these results cannot prove that there is no possibility of finding a high-affinity small molecule binder of NBD1, they are discouraging and lead us to hypothesize that the nature of these two binding sites, and isolated NBD1 itself, may not contain the features needed to build high-affinity interactions. Future work in this area may, therefore, require constructs including other domains of CFTR in addition to NBD1, if high-affinity small molecule binding is to be achieved.
Collapse
Affiliation(s)
- Justin D Hall
- Structural Biology and Biophysics Group, Pfizer, Groton, Connecticut, 06340
| | - Hong Wang
- Structural Biology and Biophysics Group, Pfizer, Groton, Connecticut, 06340
| | - Laura J Byrnes
- Structural Biology and Biophysics Group, Pfizer, Groton, Connecticut, 06340
| | - Suman Shanker
- Structural Biology and Biophysics Group, Pfizer, Groton, Connecticut, 06340
| | - Kelong Wang
- Structural Biology and Biophysics Group, Pfizer, Groton, Connecticut, 06340
| | - Ivan V Efremov
- Worldwide Medicinal Chemistry, , Pfizer, Cambridge, Massachusetts, 02140
| | - P Andrew Chong
- Molecular Structure and Function Program, Hospital for Sick Kids, Toronto, Ontario, M5G 0A4, Canada.,Department of Biochemistry, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
| | - Julie D Forman-Kay
- Molecular Structure and Function Program, Hospital for Sick Kids, Toronto, Ontario, M5G 0A4, Canada.,Department of Biochemistry, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
| | - Ann E Aulabaugh
- Structural Biology and Biophysics Group, Pfizer, Groton, Connecticut, 06340
| |
Collapse
|
35
|
Estácio SG, Martiniano HFMC, Faísca PFN. Thermal unfolding simulations of NBD1 domain variants reveal structural motifs associated with the impaired folding of F508del-CFTR. MOLECULAR BIOSYSTEMS 2016; 12:2834-48. [DOI: 10.1039/c6mb00193a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The deletion of phenylalanine 508 reshapes the conformational space of the NBD1 domain that populates unique intermediate states that provide insights into the molecular events that underlie the impaired folding of F508del-NBD1.
Collapse
Affiliation(s)
- Sílvia G. Estácio
- BioISI – Biosystems & Integrative Sciences Institute
- Faculdade de Ciências
- Universidade de Lisboa
- 1749-016 Lisboa
- Portugal
| | - Hugo F. M. C. Martiniano
- BioISI – Biosystems & Integrative Sciences Institute
- Faculdade de Ciências
- Universidade de Lisboa
- 1749-016 Lisboa
- Portugal
| | - Patrícia F. N. Faísca
- BioISI – Biosystems & Integrative Sciences Institute
- Faculdade de Ciências
- Universidade de Lisboa
- 1749-016 Lisboa
- Portugal
| |
Collapse
|
36
|
Gong X, Ahner A, Roldan A, Lukacs GL, Thibodeau PH, Frizzell RA. Non-native Conformers of Cystic Fibrosis Transmembrane Conductance Regulator NBD1 Are Recognized by Hsp27 and Conjugated to SUMO-2 for Degradation. J Biol Chem 2015; 291:2004-2017. [PMID: 26627832 DOI: 10.1074/jbc.m115.685628] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Indexed: 12/24/2022] Open
Abstract
A newly identified pathway for selective degradation of the common mutant of the cystic fibrosis transmembrane conductance regulator (CFTR), F508del, is initiated by binding of the small heat shock protein, Hsp27. Hsp27 collaborates with Ubc9, the E2 enzyme for protein SUMOylation, to selectively degrade F508del CFTR via the SUMO-targeted ubiquitin E3 ligase, RNF4 (RING finger protein 4) (1). Here, we ask what properties of CFTR are sensed by the Hsp27-Ubc9 pathway by examining the ability of NBD1 (locus of the F508del mutation) to mimic the disposal of full-length (FL) CFTR. Similar to FL CFTR, F508del NBD1 expression was reduced 50-60% by Hsp27; it interacted preferentially with the mutant and was modified primarily by SUMO-2. Mutation of the consensus SUMOylation site, Lys(447), obviated Hsp27-mediated F508del NBD1 SUMOylation and degradation. As for FL CFTR and NBD1 in vivo, SUMO modification using purified components in vitro was greater for F508del NBD1 versus WT and for the SUMO-2 paralog. Several findings indicated that Hsp27-Ubc9 targets the SUMOylation of a transitional, non-native conformation of F508del NBD1: (a) its modification decreased as [ATP] increased, reflecting stabilization of the nucleotide-binding domain by ligand binding; (b) a temperature-induced increase in intrinsic fluorescence, which reflects formation of a transitional NBD1 conformation, was followed by its SUMO modification; and (c) introduction of solubilizing or revertant mutations to stabilize F508del NBD1 reduced its SUMO modification. These findings indicate that the Hsp27-Ubc9 pathway recognizes a non-native conformation of mutant NBD1, which leads to its SUMO-2 conjugation and degradation by the ubiquitin-proteasome system.
Collapse
Affiliation(s)
| | | | - Ariel Roldan
- the Department of Physiology, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Gergely L Lukacs
- the Department of Physiology, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Patrick H Thibodeau
- Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261 and
| | | |
Collapse
|
37
|
Zhenin M, Noy E, Senderowitz H. REMD Simulations Reveal the Dynamic Profile and Mechanism of Action of Deleterious, Rescuing, and Stabilizing Perturbations to NBD1 from CFTR. J Chem Inf Model 2015; 55:2349-64. [PMID: 26418372 DOI: 10.1021/acs.jcim.5b00312] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Cystic Fibrosis (CF) is a lethal, genetic disease caused by mutations to the CFTR chloride channel. The most common CF causing mutation is the deletion of F508 from the first Nucleotide Binding Domain (F508del-NBD1). This mutation leads to a thermally unstable domain and a misfolded, nonfunctioning CFTR. Replica Exchange MD simulations were used to simulate seven NBD1 constructs including wt and F508del-NBD1 both alone and in the presence of known rescuing mutations as well as F508del-NBD1 in complex with a known small (ligand) stabilizer. Analyzing the resulting trajectories suggests that differences in the biochemical properties of the constructs result from local and coupled differences in their dynamic profiles. A comparative analysis of these profiles as well as of the resulting trajectories reveals how the different perturbations exert their deleterious, rescuing, and stabilizing effects on NBD1. These simulations may therefore be useful for the design and mechanism-of-action analysis of new NBD1 stabilizers.
Collapse
Affiliation(s)
- Michael Zhenin
- Department of Chemistry, Bar Ilan University , Ramat-Gan 52900, Israel
| | - Efrat Noy
- Department of Chemistry, Bar Ilan University , Ramat-Gan 52900, Israel
| | | |
Collapse
|
38
|
Farinha CM, Matos P. Repairing the basic defect in cystic fibrosis - one approach is not enough. FEBS J 2015; 283:246-64. [PMID: 26416076 DOI: 10.1111/febs.13531] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 09/21/2015] [Accepted: 09/23/2015] [Indexed: 12/16/2022]
Abstract
Cystic fibrosis has attracted much attention in recent years due to significant advances in the pharmacological targeting of the basic defect underlying this recessive disorder: the deficient functional expression of mutant cystic fibrosis transmembrane conductance regulator (CFTR) chloride channels at the apical membrane of epithelial cells. However, increasing evidence points to the reduced efficacy of single treatments, thus reinforcing the need to combine several therapeutic strategies to effectively target the multiple basic defect(s). Protein-repair therapies that use potentiators (activating membrane-located CFTR) or correctors (promoting the relocation of intracellular-retained trafficking mutants of CFTR) in frequent mutations such as F508del and G551D have been put forward and made their way to the clinic with moderate to good efficiency. However, alternative (or additional) approaches targeting the membrane stability of mutant proteins, or correcting the cellular phenotype through a direct effect upon other ion channels (affecting the overall electrolyte transport or simply promoting alternative chloride transport) or targeting less frequent mutations (splicing variants, for example), have been proposed and tested in the field of cystic fibrosis (CF). Here, we cover the different strategies that rely on novel findings concerning the CFTR interactome and signalosome through which it might be possible to further influence the cellular trafficking and post-translational modification machinery (to increase rescued CFTR abundance and membrane stability). We also highlight the new data on strategies aiming at the regulation of sodium absorption or to increase chloride transport through alternative channels. The development and implementation of these complementary approaches will pave the way to combinatorial therapeutic strategies with increased benefit to CF patients.
Collapse
Affiliation(s)
- Carlos M Farinha
- BioISI - Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisboa, Portugal
| | - Paulo Matos
- BioISI - Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisboa, Portugal.,Department of Human Genetics, National Health Institute 'Dr. Ricardo Jorge', Lisboa, Portugal
| |
Collapse
|
39
|
Characterizing diverse orthologues of the cystic fibrosis transmembrane conductance regulator protein for structural studies. Biochem Soc Trans 2015; 43:894-900. [DOI: 10.1042/bst20150081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
As an ion channel, the cystic fibrosis transmembrane conductance regulator (CFTR) protein occupies a unique niche within the ABC family. Orthologues of CFTR are extant throughout the animal kingdom from sharks to platypods to sheep, where the osmoregulatory function of the protein has been applied to differing lifestyles and diverse organ systems. In humans, loss-of-function mutations to CFTR cause the disease cystic fibrosis, which is a significant health burden in populations of white European descent. Orthologue screening has proved fruitful in the pursuit of high-resolution structural data for several membrane proteins, and we have applied some of the princples developed in previous studies to the expression and purification of CFTR. We have overexpressed this protein, along with evolutionarily diverse orthologues, in Saccharomyces cerevisiae and developed a purification to isolate it in quantities sufficient for structural and functional studies.
Collapse
|
40
|
Solomon GM, Marshall SG, Ramsey BW, Rowe SM. Breakthrough therapies: Cystic fibrosis (CF) potentiators and correctors. Pediatr Pulmonol 2015; 50 Suppl 40:S3-S13. [PMID: 26097168 PMCID: PMC4620567 DOI: 10.1002/ppul.23240] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 05/29/2015] [Accepted: 06/03/2015] [Indexed: 12/28/2022]
Abstract
Cystic Fibrosis is caused by mutations in the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) gene resulting in abnormal protein function. Recent advances of targeted molecular therapies and high throughput screening have resulted in multiple drug therapies that target many important mutations in the CFTR protein. In this review, we provide the latest results and current progress of CFTR modulators for the treatment of cystic fibrosis, focusing on potentiators of CFTR channel gating and Phe508del processing correctors for the Phe508del CFTR mutation. Special emphasis is placed on the molecular basis underlying these new therapies and emerging results from the latest clinical trials. The future directions for augmenting the rescue of Phe508del with CFTR modulators are also emphasized.
Collapse
Affiliation(s)
- George M Solomon
- Department of Medicine and the Gregory Fleming James Cystic Fibrosis Research Center, Birmingham, Alabama
| | - Susan G Marshall
- Division of Pulmonary Medicine, Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington
| | - Bonnie W Ramsey
- Division of Pulmonary Medicine, Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington.,Center for Clinical and Translational Research, Seattle Children's Research Institute, Seattle, Washington
| | - Steven M Rowe
- Department of Medicine and the Gregory Fleming James Cystic Fibrosis Research Center, Birmingham, Alabama.,Departments of Medicine, Pediatrics, Cell Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
| |
Collapse
|
41
|
Thermal stability of purified and reconstituted CFTR in a locked open channel conformation. Protein Expr Purif 2015; 116:159-66. [PMID: 26384709 DOI: 10.1016/j.pep.2015.09.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 09/11/2015] [Accepted: 09/14/2015] [Indexed: 11/20/2022]
Abstract
CFTR is unique among ABC transporters as the only one functioning as an ion channel and from a human health perspective because mutations in its gene cause cystic fibrosis. Although considerable advances have been made towards understanding CFTR's mechanism of action and the impact of mutations, the lack of a high-resolution 3D structure has hindered progress. The large multi-domain membrane glycoprotein is normally present at low copy number and when over expressed at high levels it aggregates strongly, limiting the production of stable mono-disperse preparations. While the reasons for the strong self-association are not fully understood, its relatively low thermal stability seems likely to be one. The major CF causing mutation, ΔF508, renders the protein very thermally unstable and therefore a great deal of attention has been paid to this property of CFTR. Multiple second site mutations of CFTR in NBD1 where F508 normally resides and small molecule binders of the domain increase the thermal stability of the mutant. These manipulations also stabilize the wild-type protein. Here we have applied ΔF508-stabilizing changes and other modifications to generate wild-type constructs that express at much higher levels in scaled-up suspension cultures of mammalian cells. After purification and reconstitution into liposomes these proteins are active in a locked-open conformation at temperatures as high as 50 °C and remain monodisperse at 4 °C in detergent or lipid for at least a week. The availability of adequate amounts of these and related stable active preparations of homogeneous CFTR will enable stalled structural and ligand binding studies to proceed.
Collapse
|
42
|
Chong PA, Farber PJ, Vernon RM, Hudson RP, Mittermaier AK, Forman-Kay JD. Deletion of Phenylalanine 508 in the First Nucleotide-binding Domain of the Cystic Fibrosis Transmembrane Conductance Regulator Increases Conformational Exchange and Inhibits Dimerization. J Biol Chem 2015; 290:22862-78. [PMID: 26149808 DOI: 10.1074/jbc.m115.641134] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Indexed: 12/17/2022] Open
Abstract
Deletion of Phe-508 (F508del) in the first nucleotide-binding domain (NBD1) of the cystic fibrosis transmembrane conductance regulator (CFTR) results in destabilization of the domain, intramolecular interactions involving the domain, and the entire channel. The destabilization caused by F508del manifests itself in defective channel processing and channel gating defects. Here, we present NMR studies of the effect of F508del and the I539T stabilizing mutation on NBD1 dynamics, with a view to understanding these changes in stability. Qualitatively, F508del NMR spectra exhibit significantly more peak broadening than WT spectra due to the enhanced intermediate time scale (millisecond to microsecond) motions in the mutant. Unexpectedly, studies of fast (nanosecond to picosecond) motions revealed that F508del NBD1 tumbles more rapidly in solution than WT NBD1. Whereas F508del tumbles at a rate nearly consistent with the monomeric state, the WT protein tumbles significantly more slowly. Paramagnetic relaxation enhancement experiments confirm that NBD1 homodimerizes in solution in the expected head-to-tail orientation. NMR spectra of WT NBD1 reveal significant concentration-dependent chemical shift perturbations consistent with NBD1 dimerization. Chemical shift analysis suggests that the more rapid tumbling of F508del is the result of an impaired ability to dimerize. Based on previously published crystal structures and NMR spectra of various NBD1 mutants, we propose that deletion of Phe-508 affects Q-loop conformational sampling in a manner that inhibits dimerization. These results provide a potential mechanism for inhibition of channel opening by F508del and support the dimer interface as a target for cystic fibrosis therapeutics.
Collapse
Affiliation(s)
- P Andrew Chong
- From the Molecular Structure and Function Program, Hospital for Sick Children, and
| | - Patrick J Farber
- From the Molecular Structure and Function Program, Hospital for Sick Children, and
| | - Robert M Vernon
- From the Molecular Structure and Function Program, Hospital for Sick Children, and
| | - Rhea P Hudson
- From the Molecular Structure and Function Program, Hospital for Sick Children, and
| | | | - Julie D Forman-Kay
- From the Molecular Structure and Function Program, Hospital for Sick Children, and Department of Biochemistry, University of Toronto, Toronto, Ontario M5G 1X8 and
| |
Collapse
|
43
|
Kim SJ, Yoon JS, Shishido H, Yang Z, Rooney LA, Barral JM, Skach WR. Translational tuning optimizes nascent protein folding in cells. Science 2015; 348:444-8. [DOI: 10.1126/science.aaa3974] [Citation(s) in RCA: 160] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
44
|
Cholon DM, Quinney NL, Fulcher ML, Esther CR, Das J, Dokholyan NV, Randell SH, Boucher RC, Gentzsch M. Potentiator ivacaftor abrogates pharmacological correction of ΔF508 CFTR in cystic fibrosis. Sci Transl Med 2015; 6:246ra96. [PMID: 25101886 DOI: 10.1126/scitranslmed.3008680] [Citation(s) in RCA: 256] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cystic fibrosis (CF) is caused by mutations in the CF transmembrane conductance regulator (CFTR). Newly developed "correctors" such as lumacaftor (VX-809) that improve CFTR maturation and trafficking and "potentiators" such as ivacaftor (VX-770) that enhance channel activity may provide important advances in CF therapy. Although VX-770 has demonstrated substantial clinical efficacy in the small subset of patients with a mutation (G551D) that affects only channel activity, a single compound is not sufficient to treat patients with the more common CFTR mutation, ΔF508. Thus, patients with ΔF508 will likely require treatment with both correctors and potentiators to achieve clinical benefit. However, whereas the effectiveness of acute treatment with this drug combination has been demonstrated in vitro, the impact of chronic therapy has not been established. In studies of human primary airway epithelial cells, we found that both acute and chronic treatment with VX-770 improved CFTR function in cells with the G551D mutation, consistent with clinical studies. In contrast, chronic VX-770 administration caused a dose-dependent reversal of VX-809-mediated CFTR correction in ΔF508 homozygous cultures. This result reflected the destabilization of corrected ΔF508 CFTR by VX-770, markedly increasing its turnover rate. Chronic VX-770 treatment also reduced mature wild-type CFTR levels and function. These findings demonstrate that chronic treatment with CFTR potentiators and correctors may have unexpected effects that cannot be predicted from short-term studies. Combining these drugs to maximize rescue of ΔF508 CFTR may require changes in dosing and/or development of new potentiator compounds that do not interfere with CFTR stability.
Collapse
Affiliation(s)
- Deborah M Cholon
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Nancy L Quinney
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - M Leslie Fulcher
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Charles R Esther
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. Division of Pediatric Pulmonology, Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Jhuma Das
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Nikolay V Dokholyan
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Scott H Randell
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Richard C Boucher
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Martina Gentzsch
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
| |
Collapse
|
45
|
Mornon JP, Hoffmann B, Jonic S, Lehn P, Callebaut I. Full-open and closed CFTR channels, with lateral tunnels from the cytoplasm and an alternative position of the F508 region, as revealed by molecular dynamics. Cell Mol Life Sci 2015; 72:1377-403. [PMID: 25287046 PMCID: PMC11113974 DOI: 10.1007/s00018-014-1749-2] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Revised: 09/28/2014] [Accepted: 09/29/2014] [Indexed: 12/17/2022]
Abstract
In absence of experimental 3D structures, several homology models, based on ABC exporter 3D structures, have provided significant insights into the molecular mechanisms underlying the function of the cystic fibrosis transmembrane conductance regulator (CFTR) protein, a chloride channel whose defects are associated with cystic fibrosis (CF). Until now, these models, however, did not furnished much insights into the continuous way that ions could follow from the cytosol to the extracellular milieu in the open form of the channel. Here, we have built a refined model of CFTR, based on the outward-facing Sav1866 experimental 3D structure and integrating the evolutionary and structural information available today. Molecular dynamics simulations revealed significant conformational changes, resulting in a full-open channel, accessible from the cytosol through lateral tunnels displayed in the long intracellular loops (ICLs). At the same time, the region of nucleotide-binding domain 1 in contact with one of the ICLs and carrying amino acid F508, the deletion of which is the most common CF-causing mutation, was found to adopt an alternative but stable position. Then, in a second step, this first stable full-open conformation evolved toward another stable state, in which only a limited displacement of the upper part of the transmembrane helices leads to a closure of the channel, in a conformation very close to that adopted by the Atm1 ABC exporter, in an inward-facing conformation. These models, supported by experimental data, provide significant new insights into the CFTR structure-function relationships and into the possible impact of CF-causing mutations.
Collapse
Affiliation(s)
- Jean-Paul Mornon
- IMPMC, Sorbonne Universités, UPMC Univ Paris 06, UMR CNRS 7590, Museum National d’Histoire Naturelle, IRD UMR 206, IUC, Case 115, 4 Place Jussieu, 75005 Paris Cedex 05, France
| | - Brice Hoffmann
- IMPMC, Sorbonne Universités, UPMC Univ Paris 06, UMR CNRS 7590, Museum National d’Histoire Naturelle, IRD UMR 206, IUC, Case 115, 4 Place Jussieu, 75005 Paris Cedex 05, France
| | - Slavica Jonic
- IMPMC, Sorbonne Universités, UPMC Univ Paris 06, UMR CNRS 7590, Museum National d’Histoire Naturelle, IRD UMR 206, IUC, Case 115, 4 Place Jussieu, 75005 Paris Cedex 05, France
| | - Pierre Lehn
- INSERM U1078, SFR ScInBioS, Université de Bretagne Occidentale, Brest, France
| | - Isabelle Callebaut
- IMPMC, Sorbonne Universités, UPMC Univ Paris 06, UMR CNRS 7590, Museum National d’Histoire Naturelle, IRD UMR 206, IUC, Case 115, 4 Place Jussieu, 75005 Paris Cedex 05, France
| |
Collapse
|
46
|
Proctor EA, Kota P, Aleksandrov AA, He L, Riordan JR, Dokholyan NV. Rational Coupled Dynamics Network Manipulation Rescues Disease-Relevant Mutant Cystic Fibrosis Transmembrane Conductance Regulator. Chem Sci 2015; 6:1237-1246. [PMID: 25685315 PMCID: PMC4324596 DOI: 10.1039/c4sc01320d] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Many cellular functions necessary for life are tightly regulated by protein allosteric conformational change, and correlated dynamics between protein regions has been found to contribute to the function of proteins not previously considered allosteric. The ability to map and control such dynamic coupling would thus create opportunities for the extension of current therapeutic design strategy. Here, we present an approach to determine the networks of residues involved in the transfer of correlated motion across a protein, and apply our approach to rescue disease-causative mutant cystic fibrosis transmembrane regulator (CFTR) ion channels, ΔF508 and ΔI507, which together constitute over 90% of cystic fibrosis cases. We show that these mutations perturb dynamic coupling within the first nucleotide-binding domain (NBD1), and uncover a critical residue that mediates trans-domain coupled dynamics. By rationally designing a mutation to this residue, we improve aberrant dynamics of mutant CFTR as well as enhance surface expression and function of both mutants, demonstrating the rescue of a disease mutation by rational correction of aberrant protein dynamics.
Collapse
Affiliation(s)
- Elizabeth A Proctor
- Curriculum in Bioinformatics and Computational Biology, University of North Carolina, Chapel Hill, NC 27599, USA ; Program in Molecular and Cellular Biophysics, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Pradeep Kota
- Program in Molecular and Cellular Biophysics, University of North Carolina, Chapel Hill, NC 27599, USA ; Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Andrei A Aleksandrov
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, USA ; Cystic Fibrosis Treatment and Research Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Lihua He
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, USA ; Cystic Fibrosis Treatment and Research Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - John R Riordan
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, USA ; Cystic Fibrosis Treatment and Research Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Nikolay V Dokholyan
- Curriculum in Bioinformatics and Computational Biology, University of North Carolina, Chapel Hill, NC 27599, USA ; Program in Molecular and Cellular Biophysics, University of North Carolina, Chapel Hill, NC 27599, USA ; Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, USA ; Cystic Fibrosis Treatment and Research Center, University of North Carolina, Chapel Hill, NC 27599, USA
| |
Collapse
|
47
|
Pasyk S, Molinski S, Ahmadi S, Ramjeesingh M, Huan LJ, Chin S, Du K, Yeger H, Taylor P, Moran MF, Bear CE. The major cystic fibrosis causing mutation exhibits defective propensity for phosphorylation. Proteomics 2014; 15:447-61. [PMID: 25330774 DOI: 10.1002/pmic.201400218] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 09/24/2014] [Accepted: 10/16/2014] [Indexed: 11/11/2022]
Abstract
The major cystic fibrosis causing mutation, F508del-CFTR (where CFTR is cystic fibrosis transmembrane conductance regulator), impairs biosynthetic maturation of the CFTR protein, limiting its expression as a phosphorylation-dependent channel on the cell surface. The maturation defect can be partially rescued by low-temperature (27°C) cell culture conditions or small-molecule corrector compounds. Following its partial rescue, the open probability of F508del-CFTR is enhanced by the potentiator compound, VX-770. However, the channel activity of rescued F508del-CFTR remains less than that of the Wt-CFTR protein in the presence of VX-770. In this study, we asked if there are allosteric effects of F508del on the phosphorylation-regulated R domain. To identify defects in the R domain, we compared the phosphorylation status at protein kinase A sites in the R domain of Wt and F508del-CFTR. Here we show that phosphorylation of Ser-660, quantified by SRM-MS, is reduced in F508del-CFTR. Although the generation of a phosphomimic at this site (substituting aspartic acid for serine) did not modify the maturation defect, it did enhance F508del-CFTR channel function after pharmacological rescue with corrector VX-809, and treatment with the potentiator, VX-770. These findings support the concept that defective phosphorylation of F508del-CFTR partially accounts for its altered channel activity at the cell surface.
Collapse
Affiliation(s)
- Stan Pasyk
- Programme in Molecular Structure and Function, Research Institute, The Hospital for Sick Children, Toronto, ON, Canada; Department of Biochemistry, The University of Toronto, Toronto, ON, Canada
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
48
|
He L, Aleksandrov AA, An J, Cui L, Yang Z, Brouillette CG, Riordan JR. Restoration of NBD1 thermal stability is necessary and sufficient to correct ∆F508 CFTR folding and assembly. J Mol Biol 2014; 427:106-20. [PMID: 25083918 DOI: 10.1016/j.jmb.2014.07.026] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 07/09/2014] [Accepted: 07/11/2014] [Indexed: 11/29/2022]
Abstract
Cystic fibrosis transmembrane conductance regulator (CFTR) (ABCC7), unique among ABC exporters as an ion channel, regulates ion and fluid transport in epithelial tissues. Loss of function due to mutations in the cftr gene causes cystic fibrosis. The most common cystic-fibrosis-causing mutation, the deletion of F508 (ΔF508) from the first nucleotide binding domain (NBD1) of CFTR, results in misfolding of the protein and clearance by cellular quality control systems. The ΔF508 mutation has two major impacts on CFTR: reduced thermal stability of NBD1 and disruption of its interface with membrane-spanning domains (MSDs). It is unknown if these two defects are independent and need to be targeted separately. To address this question, we varied the extent of stabilization of NBD1 using different second-site mutations and NBD1 binding small molecules with or without NBD1/MSD interface mutation. Combinations of different NBD1 changes had additive corrective effects on ∆F508 maturation that correlated with their ability to increase NBD1 thermostability. These effects were much larger than those caused by interface modification alone and accounted for most of the correction achieved by modifying both the domain and the interface. Thus, NBD1 stabilization plays a dominant role in overcoming the ΔF508 defect. Furthermore, the dual target approach resulted in a locked-open ion channel that was constitutively active in the absence of the normally obligatory dependence on phosphorylation by protein kinase A. Thus, simultaneous targeting of both the domain and the interface, as well as being non-essential for correction of biogenesis, may disrupt normal regulation of channel function.
Collapse
Affiliation(s)
- Lihua He
- Department of Biochemistry and Biophysics, Cystic Fibrosis Treatment and Research Center, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Andrei A Aleksandrov
- Department of Biochemistry and Biophysics, Cystic Fibrosis Treatment and Research Center, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Jianli An
- Center for Structural Biology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Liying Cui
- Department of Biochemistry and Biophysics, Cystic Fibrosis Treatment and Research Center, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Zhengrong Yang
- Center for Structural Biology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA; Department of Chemistry, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Christie G Brouillette
- Center for Structural Biology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA; Department of Chemistry, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - John R Riordan
- Department of Biochemistry and Biophysics, Cystic Fibrosis Treatment and Research Center, University of North Carolina, Chapel Hill, NC, 27599, USA.
| |
Collapse
|
49
|
Yang Z, Wang C, Zhou Q, An J, Hildebrandt E, Aleksandrov LA, Kappes JC, DeLucas LJ, Riordan JR, Urbatsch IL, Hunt JF, Brouillette CG. Membrane protein stability can be compromised by detergent interactions with the extramembranous soluble domains. Protein Sci 2014; 23:769-89. [PMID: 24652590 PMCID: PMC4093953 DOI: 10.1002/pro.2460] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 03/07/2014] [Accepted: 03/17/2014] [Indexed: 11/06/2022]
Abstract
Detergent interaction with extramembranous soluble domains (ESDs) is not commonly considered an important determinant of integral membrane protein (IMP) behavior during purification and crystallization, even though ESDs contribute to the stability of many IMPs. Here we demonstrate that some generally nondenaturing detergents critically destabilize a model ESD, the first nucleotide-binding domain (NBD1) from the human cystic fibrosis transmembrane conductance regulator (CFTR), a model IMP. Notably, the detergents show equivalent trends in their influence on the stability of isolated NBD1 and full-length CFTR. We used differential scanning calorimetry (DSC) and circular dichroism (CD) spectroscopy to monitor changes in NBD1 stability and secondary structure, respectively, during titration with a series of detergents. Their effective harshness in these assays mirrors that widely accepted for their interaction with IMPs, i.e., anionic > zwitterionic > nonionic. It is noteworthy that including lipids or nonionic detergents is shown to mitigate detergent harshness, as will limiting contact time. We infer three thermodynamic mechanisms from the observed thermal destabilization by monomer or micelle: (i) binding to the unfolded state with no change in the native structure (all detergent classes); (ii) native state binding that alters thermodynamic properties and perhaps conformation (nonionic detergents); and (iii) detergent binding that directly leads to denaturation of the native state (anionic and zwitterionic). These results demonstrate that the accepted model for the harshness of detergents applies to their interaction with an ESD. It is concluded that destabilization of extramembranous soluble domains by specific detergents will influence the stability of some IMPs during purification.
Collapse
Affiliation(s)
- Zhengrong Yang
- Department of Chemistry, University of Alabama at BirminghamBirmingham, Alabama
- Center for Structural Biology, University of Alabama at BirminghamBirmingham, Alabama
| | - Chi Wang
- Department of Biological Sciences, Columbia UniversityNew York, New York
| | - Qingxian Zhou
- Center for Structural Biology, University of Alabama at BirminghamBirmingham, Alabama
| | - Jianli An
- Center for Structural Biology, University of Alabama at BirminghamBirmingham, Alabama
| | - Ellen Hildebrandt
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences CenterLubbock, Texas
| | - Luba A Aleksandrov
- Department of Biochemistry and Biophysics, The University of North Carolina at Chapel HillChapel Hill, North Carolina
- Cystic Fibrosis Treatment and Research Center, The University of North Carolina at Chapel HillChapel Hill, North Carolina
| | - John C Kappes
- Department of Medicine, University of Alabama at BirminghamBirmingham, Alabama
- Birmingham Veterans Affairs Medical Center, Research ServiceBirmingham, Alabama
| | - Lawrence J DeLucas
- Center for Structural Biology, University of Alabama at BirminghamBirmingham, Alabama
- Department of Optometry, University of Alabama at BirminghamBirmingham, Alabama
| | - John R Riordan
- Department of Biochemistry and Biophysics, The University of North Carolina at Chapel HillChapel Hill, North Carolina
- Cystic Fibrosis Treatment and Research Center, The University of North Carolina at Chapel HillChapel Hill, North Carolina
| | - Ina L Urbatsch
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences CenterLubbock, Texas
- Center for Membrane Protein Research, Texas Tech University Health Sciences CenterLubbock, TX
| | - John F Hunt
- Department of Biological Sciences, Columbia UniversityNew York, New York
| | - Christie G Brouillette
- Department of Chemistry, University of Alabama at BirminghamBirmingham, Alabama
- Center for Structural Biology, University of Alabama at BirminghamBirmingham, Alabama
| |
Collapse
|
50
|
Decoding F508del misfolding in cystic fibrosis. Biomolecules 2014; 4:498-509. [PMID: 24970227 PMCID: PMC4101494 DOI: 10.3390/biom4020498] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 04/11/2014] [Accepted: 04/25/2014] [Indexed: 01/13/2023] Open
Abstract
The functional deficiency of the cystic fibrosis transmembrane conductance regulator (CFTR), a plasma membrane chloride channel, leads to the development of cystic fibrosis. The deletion of a phenylalanine at residue 508 (F508del) is the most common cause of CFTR misfolding leading to the disease. The F508del misfolding originates in the first nucleotide-binding domain (NBD1), which induces a global conformational change in CFTR through NBD1’s interactions with other domains. Such global misfolding produces a mutant chloride channel that is impaired in exocytic trafficking, peripheral stability, and channel gating. The nature and atomic details of F508del misfolding have been subject to extensive research during the past decade. Current data support a central role for NBD1 in F508del misfolding and rescue. Many cis-acting NBD1 second-site mutations rescue F508del misfolding in the context of full-length CFTR. While some of these mutations appear to specifically counteract the F508del-induced misfolding, others release certain inherent conformational constraints of the human wild-type CFTR. Several small-molecule correctors were recently found to act on key interdomain interfaces of F508del CFTR. Potential rational approaches have been proposed in an attempt to develop highly effective small molecule modulators that improve the cell surface functional expression of F508del CFTR.
Collapse
|