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van der Sluijs P, Hoelen H, Schmidt A, Braakman I. The Folding Pathway of ABC Transporter CFTR: Effective and Robust. J Mol Biol 2024; 436:168591. [PMID: 38677493 DOI: 10.1016/j.jmb.2024.168591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Revised: 04/16/2024] [Accepted: 04/23/2024] [Indexed: 04/29/2024]
Abstract
De novo protein folding into a native three-dimensional structure is indispensable for biological function, is instructed by its amino acid sequence, and occurs along a vectorial trajectory. The human proteome contains thousands of membrane-spanning proteins, whose biosynthesis begins on endoplasmic reticulum-associated ribosomes. Nearly half of all membrane proteins traverse the membrane more than once, including therapeutically important protein families such as solute carriers, G-protein-coupled receptors, and ABC transporters. These mediate a variety of functions like signal transduction and solute transport and are often of vital importance for cell function and tissue homeostasis. Missense mutations in multispan membrane proteins can lead to misfolding and cause disease; an example is the ABC transporter Cystic Fibrosis Transmembrane Conductance Regulator (CFTR). Even though our understanding of multispan membrane-protein folding still is rather rudimental, the cumulative knowledge of 20 years of basic research on CFTR folding has led to development of drugs that modulate the misfolded protein. This has provided the prospect of a life without CF to the vast majority of patients. In this review we describe our understanding of the folding pathway of CFTR in cells, which is modular and tolerates many defects, making it effective and robust. We address how modulator drugs affect folding and function of CFTR, and distinguish protein stability from its folding process. Since the domain architecture of (mammalian) ABC transporters are highly conserved, we anticipate that the insights we discuss here for folding of CFTR may lay the groundwork for understanding the general rules of ABC-transporter folding.
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Affiliation(s)
- Peter van der Sluijs
- Cellular Protein Chemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, 3584 CH Utrecht, the Netherlands.
| | - Hanneke Hoelen
- Cellular Protein Chemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, 3584 CH Utrecht, the Netherlands; Present address: GenDx, Yalelaan 48, 3584 CM Utrecht, The Netherlands
| | - Andre Schmidt
- Cellular Protein Chemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, 3584 CH Utrecht, the Netherlands; 3D-Pharmxchange, Tilburg, the Netherlands
| | - Ineke Braakman
- Cellular Protein Chemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, 3584 CH Utrecht, the Netherlands
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Thakur S, Ankita, Dash S, Verma R, Kaur C, Kumar R, Mazumder A, Singh G. Understanding CFTR Functionality: A Comprehensive Review of Tests and Modulator Therapy in Cystic Fibrosis. Cell Biochem Biophys 2024; 82:15-34. [PMID: 38048024 DOI: 10.1007/s12013-023-01200-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 11/13/2023] [Indexed: 12/05/2023]
Abstract
Cystic fibrosis is a genetic disorder inherited in an autosomal recessive manner. It is caused by a mutation in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene on chromosome 7, which leads to abnormal regulation of chloride and bicarbonate ions in cells that line organs like the lungs and pancreas. The CFTR protein plays a crucial role in regulating chloride ion flow, and its absence or malfunction causes the production of thick mucus that affects several organs. There are more than 2000 identified mutations that are classified into seven categories based on their dysfunction mechanisms. In this article, we have conducted a thorough examination and consolidation of the diverse array of tests essential for the quantification of CFTR functionality. Furthermore, we have engaged in a comprehensive discourse regarding the recent advancements in CFTR modulator therapy, a pivotal approach utilized for the management of cystic fibrosis, alongside its concomitant relevance in evaluating CFTR functionality.
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Affiliation(s)
- Shorya Thakur
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, Panjab, India
| | - Ankita
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, Panjab, India
| | - Shubham Dash
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, Panjab, India
| | - Rupali Verma
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, Panjab, India
| | - Charanjit Kaur
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, Panjab, India
| | - Rajesh Kumar
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, Panjab, India
| | - Avijit Mazumder
- Noida Institute of Engineering and Technology (Pharmacy Institute), Greater Noida, UP, India
| | - Gurvinder Singh
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, Panjab, India.
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Yeh HI, Sutcliffe KJ, Sheppard DN, Hwang TC. CFTR Modulators: From Mechanism to Targeted Therapeutics. Handb Exp Pharmacol 2024; 283:219-247. [PMID: 35972584 DOI: 10.1007/164_2022_597] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
People with cystic fibrosis (CF) suffer from a multi-organ disorder caused by loss-of-function variants in the gene encoding the epithelial anion channel cystic fibrosis transmembrane conductance regulator (CFTR). Tremendous progress has been made in both basic and clinical sciences over the past three decades since the identification of the CFTR gene. Over 90% of people with CF now have access to therapies targeting dysfunctional CFTR. This success was made possible by numerous studies in the field that incrementally paved the way for the development of small molecules known as CFTR modulators. The advent of CFTR modulators transformed this life-threatening illness into a treatable disease by directly binding to the CFTR protein and correcting defects induced by pathogenic variants. In this chapter, we trace the trajectory of structural and functional studies that brought CF therapies from bench to bedside, with an emphasis on mechanistic understanding of CFTR modulators.
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Affiliation(s)
- Han-I Yeh
- Department of Pharmacology, National Yang Ming Chiao Tung University, Taipei City, Taiwan
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, USA
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO, USA
| | - Katy J Sutcliffe
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - David N Sheppard
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Tzyh-Chang Hwang
- Department of Pharmacology, National Yang Ming Chiao Tung University, Taipei City, Taiwan.
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, USA.
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO, USA.
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Moss MJ, Chamness LM, Clark PL. The Effects of Codon Usage on Protein Structure and Folding. Annu Rev Biophys 2023; 53:10.1146/annurev-biophys-030722-020555. [PMID: 38134335 PMCID: PMC11227313 DOI: 10.1146/annurev-biophys-030722-020555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2023]
Abstract
The rate of protein synthesis is slower than many folding reactions and varies depending on the synonymous codons encoding the protein sequence. Synonymous codon substitutions thus have the potential to regulate cotranslational protein folding mechanisms, and a growing number of proteins have been identified with folding mechanisms sensitive to codon usage. Typically, these proteins have complex folding pathways and kinetically stable native structures. Kinetically stable proteins may fold only once over their lifetime, and thus, codon-mediated regulation of the pioneer round of protein folding can have a lasting impact. Supporting an important role for codon usage in folding, conserved patterns of codon usage appear in homologous gene families, hinting at selection. Despite these exciting developments, there remains few experimental methods capable of quantifying translation elongation rates and cotranslational folding mechanisms in the cell, which challenges the development of a predictive understanding of how biology uses codons to regulate protein folding. Expected final online publication date for the Annual Review of Biophysics, Volume 53 is May 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- McKenze J Moss
- Department of Chemistry & Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA; , ,
| | - Laura M Chamness
- Department of Chemistry & Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA; , ,
| | - Patricia L Clark
- Department of Chemistry & Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA; , ,
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Taniguchi S, Ono Y, Doi Y, Taniguchi S, Matsuura Y, Iwasaki A, Hirata N, Fukuda R, Inoue K, Yamaguchi M, Tashiro A, Egami D, Aoki S, Kondoh Y, Honda K, Osada H, Kumeta H, Saio T, Okiyoneda T. Identification of α-Tocopherol succinate as an RFFL-substrate interaction inhibitor inducing peripheral CFTR stabilization and apoptosis. Biochem Pharmacol 2023; 215:115730. [PMID: 37543348 DOI: 10.1016/j.bcp.2023.115730] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 07/06/2023] [Accepted: 07/31/2023] [Indexed: 08/07/2023]
Abstract
The E3 ubiquitin ligase RFFL is an apoptotic inhibitor highly expressed in cancers and its knockdown suppresses cancer cell growth and sensitizes to chemotherapy. RFFL also participates in peripheral protein quality control which removes the functional cell surface ΔF508-CFTR channel and reduces the efficacy of pharmaceutical therapy for cystic fibrosis (CF). Although RFFL inhibitors have therapeutic potential for both cancer and CF, they remain undiscovered. Here, a chemical array screening has identified α-tocopherol succinate (αTOS) as an RFFL ligand. NMR analysis revealed that αTOS directly binds to RFFL's substrate-binding region without affecting the E3 enzymatic activity. Consequently, αTOS inhibits the RFFL-substrate interaction, ΔF508-CFTR ubiquitination and elimination from the plasma membrane of epithelial cells, resulting in the increased functional CFTR channel. Among the α-tocopherol (αTOL) analogs we tested, only αTOS inhibited the RFFL-substrate interaction and increased the cell surface ΔF508-CFTR, depending on RFFL expression. Similarly, the unique proapoptotic effect of αTOS was dependent on RFFL expression. Thus, unlike other αTOL analogs, αTOS acts as an RFFL protein-protein interaction inhibitor which may explain its unique biological properties among αTOL analogs. Moreover, αTOS may act as a CFTR stabilizer, a novel class of drugs that extend cell surface ΔF508-CFTR lifetime.
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Affiliation(s)
- Sachiho Taniguchi
- Department of Biomedical Sciences, School of Biological and Environmental Sciences, Kwansei Gakuin University, Hyogo 669-1337, Japan
| | - Yuji Ono
- Department of Biomedical Sciences, School of Biological and Environmental Sciences, Kwansei Gakuin University, Hyogo 669-1337, Japan
| | - Yukako Doi
- Department of Biomedical Sciences, School of Biological and Environmental Sciences, Kwansei Gakuin University, Hyogo 669-1337, Japan
| | - Shogo Taniguchi
- Department of Biomedical Sciences, School of Biological and Environmental Sciences, Kwansei Gakuin University, Hyogo 669-1337, Japan
| | - Yuta Matsuura
- Department of Biomedical Sciences, School of Biological and Environmental Sciences, Kwansei Gakuin University, Hyogo 669-1337, Japan
| | - Ayuka Iwasaki
- Department of Biomedical Sciences, School of Biological and Environmental Sciences, Kwansei Gakuin University, Hyogo 669-1337, Japan
| | - Noriaki Hirata
- Department of Biomedical Sciences, School of Biological and Environmental Sciences, Kwansei Gakuin University, Hyogo 669-1337, Japan
| | - Ryosuke Fukuda
- Department of Biomedical Sciences, School of Biological and Environmental Sciences, Kwansei Gakuin University, Hyogo 669-1337, Japan
| | - Keitaro Inoue
- Department of Bioscience and Bioinformatics, Graduate School of Computer Science and Systems Engineering, Kyushu Institute of Technology, Fukuoka 820-8502, Japan
| | - Miho Yamaguchi
- Department of Bioscience and Bioinformatics, Graduate School of Computer Science and Systems Engineering, Kyushu Institute of Technology, Fukuoka 820-8502, Japan
| | - Anju Tashiro
- Department of Bioscience and Bioinformatics, Graduate School of Computer Science and Systems Engineering, Kyushu Institute of Technology, Fukuoka 820-8502, Japan
| | - Daichi Egami
- Department of Bioscience and Bioinformatics, Graduate School of Computer Science and Systems Engineering, Kyushu Institute of Technology, Fukuoka 820-8502, Japan
| | - Shunsuke Aoki
- Department of Bioscience and Bioinformatics, Graduate School of Computer Science and Systems Engineering, Kyushu Institute of Technology, Fukuoka 820-8502, Japan
| | - Yasumitsu Kondoh
- Chemical Resource Development Unit, RIKEN Center for Sustainable Resource Science, Saitama 351-0198, Japan
| | - Kaori Honda
- Chemical Resource Development Unit, RIKEN Center for Sustainable Resource Science, Saitama 351-0198, Japan
| | - Hiroyuki Osada
- Chemical Resource Development Unit, RIKEN Center for Sustainable Resource Science, Saitama 351-0198, Japan
| | - Hiroyuki Kumeta
- Faculty of Advanced Life Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan
| | - Tomohide Saio
- Institute of Advanced Medical Sciences, Tokushima University, Tokushima 770-8503, Japan
| | - Tsukasa Okiyoneda
- Department of Biomedical Sciences, School of Biological and Environmental Sciences, Kwansei Gakuin University, Hyogo 669-1337, Japan.
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Oliver KE, Carlon MS, Pedemonte N, Lopes-Pacheco M. The revolution of personalized pharmacotherapies for cystic fibrosis: what does the future hold? Expert Opin Pharmacother 2023; 24:1545-1565. [PMID: 37379072 PMCID: PMC10528905 DOI: 10.1080/14656566.2023.2230129] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 06/16/2023] [Accepted: 06/23/2023] [Indexed: 06/29/2023]
Abstract
INTRODUCTION Cystic fibrosis (CF), a potentially fatal genetic disease, is caused by loss-of-function mutations in the gene encoding for the CFTR chloride/bicarbonate channel. Modulator drugs rescuing mutant CFTR traffic and function are now in the clinic, providing unprecedented breakthrough therapies for people with CF (PwCF) carrying specific genotypes. However, several CFTR variants are unresponsive to these therapies. AREA COVERED We discussed several therapeutic approaches that are under development to tackle the fundamental cause of CF, including strategies targeting defective CFTR mRNA and/or protein expression and function. Alternatively, defective chloride secretion and dehydration in CF epithelia could be restored by exploiting pharmacological modulation of alternative targets, i.e., ion channels/transporters that concur with CFTR to maintain the airway surface liquid homeostasis (e.g., ENaC, TMEM16A, SLC26A4, SLC26A9, and ATP12A). Finally, we assessed progress and challenges in the development of gene-based therapies to replace or correct the mutant CFTR gene. EXPERT OPINION CFTR modulators are benefiting many PwCF responsive to these drugs, yielding substantial improvements in various clinical outcomes. Meanwhile, the CF therapy development pipeline continues to expand with the development of novel CFTR modulators and alternative therapeutic strategies with the ultimate goal of providing effective therapies for all PwCF in the foreseeable future.
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Affiliation(s)
- Kathryn E. Oliver
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA
- Center for Cystic Fibrosis and Airways Disease Research, Emory University and Children’s Healthcare of Atlanta, Atlanta, Georgia, USA
| | - Marianne S. Carlon
- Laboratory of Respiratory Diseases and Thoracic Surgery (BREATHE), Department of Chronic Diseases and Metabolism, KU Leuven, Leuven, Belgium
- Center for Molecular Medicine, KU Leuven, Leuven, Belgium
| | | | - Miquéias Lopes-Pacheco
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisbon, Lisbon, Portugal
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Bongiorno R, Ludovico A, Moran O, Baroni D. Elexacaftor Mediates the Rescue of F508del CFTR Functional Expression Interacting with MSD2. Int J Mol Sci 2023; 24:12838. [PMID: 37629017 PMCID: PMC10454486 DOI: 10.3390/ijms241612838] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 08/09/2023] [Accepted: 08/11/2023] [Indexed: 08/27/2023] Open
Abstract
Cystic fibrosis (CF) is one of the most frequent lethal autosomal recessive diseases affecting the Caucasian population. It is caused by loss of function variants of the cystic fibrosis transmembrane conductance regulator (CFTR), a membrane protein located on the apical side of epithelial cells. The most prevalent CF-causing mutation, the deletion of phenylalanine at position 508 (F508del), is characterized by folding and trafficking defects, resulting in the decreased functional expression of the protein on the plasma membrane. Two classes of small-molecule modulators, termed potentiators and correctors, respectively, have been developed to rescue either the gating or the cellular processing of defective F508del CFTR. Kaftrio, a next-generation triple-combination drug, consisting of the potentiator ivacaftor (VX770) and the two correctors tezacaftor (VX661) and elexacaftor (VX445), has been demonstrated to be a life-changing therapeutic modality for the majority of people with CF worldwide. While the mechanism of action of VX770 and VX661 is almost known, the precise mechanism of action and binding site of VX445 have not been conclusively determined. We investigated the activity of VX445 on mutant F508del to identify the protein domains whose expression is mostly affected by this corrector and to disclose its mechanisms of action. Our biochemical analyses revealed that VX445 specifically improves the expression and the maturation of MSD2, heterologously expressed in HEK 293 cells, and confirmed that its effect on the functional expression of defective F508del CFTR is additive either with type I or type II CFTR correctors. We are confident that our study will help to make a step forward in the comprehension of the etiopathology of the CF disease, as well as to give new information for the development and testing of combinations of even more effective correctors able to target mutation-specific defects of the CFTR protein.
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Affiliation(s)
| | | | | | - Debora Baroni
- Istituto di Biofisica, CNR, Via De Marini, 6, 16149 Genova, Italy; (R.B.); (A.L.); (O.M.)
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McKee AG, McDonald EF, Penn WD, Kuntz CP, Noguera K, Chamness LM, Roushar FJ, Meiler J, Oliver KE, Plate L, Schlebach JP. General trends in the effects of VX-661 and VX-445 on the plasma membrane expression of clinical CFTR variants. Cell Chem Biol 2023; 30:632-642.e5. [PMID: 37253358 PMCID: PMC10330547 DOI: 10.1016/j.chembiol.2023.05.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 02/17/2023] [Accepted: 05/05/2023] [Indexed: 06/01/2023]
Abstract
Cystic fibrosis (CF) is caused by mutations that compromise the expression and/or function of the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel. Most people with CF harbor a common misfolded variant (ΔF508) that can be partially rescued by therapeutic "correctors" that restore its expression. Nevertheless, many other CF variants are insensitive to correctors. Using deep mutational scanning, we quantitatively compare the effects of two correctors on the plasma membrane expression of 129 CF variants. Though structural calculations suggest corrector binding provides similar stabilization to most variants, it's those with intermediate expression and mutations near corrector binding pockets that exhibit the greatest response. Deviations in sensitivity appear to depend on the degree of variant destabilization and the timing of misassembly. Combining correctors appears to rescue more variants by doubling the binding energy and stabilizing distinct cotranslational folding transitions. These results provide an overview of rare CF variant expression and establish new tools for precision pharmacology.
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Affiliation(s)
- Andrew G McKee
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | - Eli F McDonald
- Department of Chemistry, Vanderbilt University, Nashville, TN 37232, USA; Center for Structural Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Wesley D Penn
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | - Charles P Kuntz
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | - Karen Noguera
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | - Laura M Chamness
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | - Francis J Roushar
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | - Jens Meiler
- Department of Chemistry, Vanderbilt University, Nashville, TN 37232, USA; Center for Structural Biology, Vanderbilt University, Nashville, TN 37232, USA; Institute for Drug Development, Leipzig University, Leipzig, SAC 04109, Germany
| | - Kathryn E Oliver
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Lars Plate
- Department of Chemistry, Vanderbilt University, Nashville, TN 37232, USA; Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232, USA
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Chen J, Thrasher K, Fu L, Wang W, Aghamohammadzadeh S, Wen H, Tang L, Keeling KM, Falk Libby E, Bedwell DM, Rowe SM. The synthetic aminoglycoside ELX-02 induces readthrough of G550X-CFTR producing superfunctional protein that can be further enhanced by CFTR modulators. Am J Physiol Lung Cell Mol Physiol 2023; 324:L756-L770. [PMID: 37014818 PMCID: PMC10202470 DOI: 10.1152/ajplung.00038.2023] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 03/29/2023] [Accepted: 04/02/2023] [Indexed: 04/05/2023] Open
Abstract
Ten percent of cystic fibrosis (CF) patients carry a premature termination codon (PTC); no mutation-specific therapies exist for these individuals. ELX-02, a synthetic aminoglycoside, suppresses translation termination at PTCs (i.e., readthrough) by promoting the insertion of an amino acid at the PTC and restoring expression of full-length CFTR protein. The identity of amino acids inserted at PTCs affects the processing and function of the resulting full-length CFTR protein. We examined readthrough of the rare G550X-CFTR nonsense mutation due to its unique properties. We found that forskolin-induced swelling in G550X patient-derived intestinal organoids (PDOs) was significantly higher than in G542X PDOs (both UGA PTCs) with ELX-02 treatment, indicating greater CFTR function from the G550X allele. Using mass spectrometry, we identified tryptophan as the sole amino acid inserted in the G550X position during ELX-02- or G418-mediated readthrough, which differs from the three amino acids (cysteine, arginine, and tryptophan) inserted in the G542X position after treatment with G418. Compared with wild-type CFTR, Fischer rat thyroid (FRT) cells expressing the G550W-CFTR variant protein exhibited significantly increased forskolin-activated Cl- conductance, and G550W-CFTR channels showed increased PKA sensitivity and open probability. After treatment with ELX-02 and CFTR correctors, CFTR function rescued from the G550X allele in FRTs reached 20-40% of the wild-type level. These results suggest that readthrough of G550X produces greater CFTR function because of gain-of-function properties of the CFTR readthrough product that stem from its location in the signature LSGGQ motif found in ATP-binding cassette (ABC) transporters. G550X may be a particularly sensitive target for translational readthrough therapy.NEW & NOTEWORTHY We found that forskolin-induced swelling in G550X-CFTR patient-derived intestinal organoids (PDOs) was significantly higher than in G542X-CFTR PDOs after treatment with ELX-02. Tryptophan (W) was the sole amino acid inserted in the G550X position after readthrough. Resulting G550W-CFTR protein exhibited supernormal CFTR activity, PKA sensitivity, and open probability. These results show that aminoglycoside-induced readthrough of G550X produces greater CFTR function because of the gain-of-function properties of the CFTR readthrough product.
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Affiliation(s)
- Jianguo Chen
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
- Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Kari Thrasher
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, United States
- Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Lianwu Fu
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, United States
- Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Wei Wang
- Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | | | - Hui Wen
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
- Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Liping Tang
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
- Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Kim M Keeling
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, United States
- Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Emily Falk Libby
- Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - David M Bedwell
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, United States
- Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Steven M Rowe
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
- Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama, United States
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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.
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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.
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11
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Im J, Hillenaar T, Yeoh HY, Sahasrabudhe P, Mijnders M, van Willigen M, Hagos A, de Mattos E, van der Sluijs P, Braakman I. ABC-transporter CFTR folds with high fidelity through a modular, stepwise pathway. Cell Mol Life Sci 2023; 80:33. [PMID: 36609925 PMCID: PMC9825563 DOI: 10.1007/s00018-022-04671-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 11/01/2022] [Accepted: 11/28/2022] [Indexed: 01/09/2023]
Abstract
The question how proteins fold is especially pointed for large multi-domain, multi-spanning membrane proteins with complex topologies. We have uncovered the sequence of events that encompass proper folding of the ABC transporter CFTR in live cells by combining kinetic radiolabeling with protease-susceptibility assays. We found that CFTR folds in two clearly distinct stages. The first, co-translational, stage involves folding of the 2 transmembrane domains TMD1 and TMD2, plus one nucleotide-binding domain, NBD1. The second stage is a simultaneous, post-translational increase in protease resistance for both TMDs and NBD2, caused by assembly of these domains onto NBD1. Our assays probe every 2-3 residues (on average) in CFTR. This in-depth analysis at amino-acid level allows detailed analysis of domain folding and importantly also the next level: assembly of the domains into native, folded CFTR. Defects and changes brought about by medicines, chaperones, or mutations also are amenable to analysis. We here show that the well-known disease-causing mutation F508del, which established cystic fibrosis as protein-folding disease, caused co-translational misfolding of NBD1 but not TMD1 nor TMD2 in stage 1, leading to absence of stage-2 folding. Corrector drugs rescued stage 2 without rescuing NBD1. Likewise, the DxD motif in NBD1 that was identified to be required for export of CFTR from the ER we found to be required already upstream of export as CFTR mutated in this motif phenocopies F508del CFTR. The highly modular and stepwise folding process of such a large, complex protein explains the relatively high fidelity and correctability of its folding.
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Affiliation(s)
- Jisu Im
- Cellular Protein Chemistry, Faculty of Science, Bijvoet Centre for Biomolecular Research, Science for Life, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Tamara Hillenaar
- Cellular Protein Chemistry, Faculty of Science, Bijvoet Centre for Biomolecular Research, Science for Life, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Hui Ying Yeoh
- Cellular Protein Chemistry, Faculty of Science, Bijvoet Centre for Biomolecular Research, Science for Life, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands ,Present Address: Center of Translational Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Priyanka Sahasrabudhe
- Cellular Protein Chemistry, Faculty of Science, Bijvoet Centre for Biomolecular Research, Science for Life, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands ,Present Address: Navigo Proteins GmbH, 06120 Halle, Germany
| | - Marjolein Mijnders
- Cellular Protein Chemistry, Faculty of Science, Bijvoet Centre for Biomolecular Research, Science for Life, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands ,Present Address: Princess Máxima Center for Pediatric Oncology, 3584 CS Utrecht, The Netherlands
| | - Marcel van Willigen
- Cellular Protein Chemistry, Faculty of Science, Bijvoet Centre for Biomolecular Research, Science for Life, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands ,Present Address: Julius Clinical Ltd, 3703 CD Zeist, The Netherlands
| | - Azib Hagos
- Cellular Protein Chemistry, Faculty of Science, Bijvoet Centre for Biomolecular Research, Science for Life, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Eduardo de Mattos
- Cellular Protein Chemistry, Faculty of Science, Bijvoet Centre for Biomolecular Research, Science for Life, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Peter van der Sluijs
- Cellular Protein Chemistry, Faculty of Science, Bijvoet Centre for Biomolecular Research, Science for Life, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Ineke Braakman
- Cellular Protein Chemistry, Faculty of Science, Bijvoet Centre for Biomolecular Research, Science for Life, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
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12
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Schenkel M, Ravamehr-Lake D, Czerniak T, Saenz JP, Krainer G, Schlierf M, Deber CM. Impact of cholesterol and Lumacaftor on the folding of CFTR helical hairpins. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2023; 1865:184078. [PMID: 36279907 DOI: 10.1016/j.bbamem.2022.184078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 10/17/2022] [Accepted: 10/18/2022] [Indexed: 11/07/2022]
Abstract
Cystic fibrosis (CF) is caused by mutations in the gene that codes for the chloride channel cystic fibrosis transmembrane conductance regulator (CFTR). Recent advances in CF treatment have included use of small-molecule drugs known as modulators, such as Lumacaftor (VX-809), but their detailed mechanism of action and interplay with the surrounding lipid membranes, including cholesterol, remain largely unknown. To examine these phenomena and guide future modulator development, we prepared a set of wild type (WT) and mutant helical hairpin constructs consisting of CFTR transmembrane (TM) segments 3 and 4 and the intervening extracellular loop (termed TM3/4 hairpins) that represent minimal membrane protein tertiary folding units. These hairpin variants, including CF-phenotypic loop mutants E217G and Q220R, and membrane-buried mutant V232D, were reconstituted into large unilamellar phosphatidylcholine (POPC) vesicles, and into corresponding vesicles containing 70 mol% POPC +30 mol% cholesterol, and studied by single-molecule FRET and circular dichroism experiments. We found that the presence of 30 mol% cholesterol induced an increase in helicity of all TM3/4 hairpins, suggesting an increase in bilayer cross-section and hence an increase in the depth of membrane insertion compared to pure POPC vesicles. Importantly, when we added the corrector VX-809, regardless of the presence or absence of cholesterol, all mutants displayed folding and helicity largely indistinguishable from the WT hairpin. Fluorescence spectroscopy measurements suggest that the corrector alters lipid packing and water accessibility. We propose a model whereby VX-809 shields the protein from the lipid environment in a mutant-independent manner such that the WT scaffold prevails. Such 'normalization' to WT conformation is consistent with the action of VX-809 as a protein-folding chaperone.
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Affiliation(s)
- Mathias Schenkel
- B CUBE - Center for Molecular Bioengineering, TU Dresden, Tatzberg 41, 01307 Dresden, Germany
| | - Dorna Ravamehr-Lake
- Division of Molecular Medicine, Research Institute, Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Tomasz Czerniak
- B CUBE - Center for Molecular Bioengineering, TU Dresden, Tatzberg 41, 01307 Dresden, Germany
| | - James P Saenz
- B CUBE - Center for Molecular Bioengineering, TU Dresden, Tatzberg 41, 01307 Dresden, Germany
| | - Georg Krainer
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, CB2 1EW Cambridge, UK.
| | - Michael Schlierf
- B CUBE - Center for Molecular Bioengineering, TU Dresden, Tatzberg 41, 01307 Dresden, Germany.
| | - Charles M Deber
- Division of Molecular Medicine, Research Institute, Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada.
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13
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Baatallah N, Elbahnsi A, Chevalier B, Castanier S, Mornon JP, Pranke I, Edelman A, Sermet-Gaudelus I, Callebaut I, Hinzpeter A. Acting on the CFTR Membrane-Spanning Domains Interface Rescues Some Misfolded Mutants. Int J Mol Sci 2022; 23:ijms232416225. [PMID: 36555865 PMCID: PMC9780841 DOI: 10.3390/ijms232416225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/09/2022] [Accepted: 12/13/2022] [Indexed: 12/24/2022] Open
Abstract
ABC transporters are large membrane proteins sharing a complex architecture, which comprises two nucleotide-binding domains (NBDs) and two membrane-spanning domains (MSDs). These domains are susceptible to mutations affecting their folding and assembly. In the CFTR (ABCC7) protein, a groove has been highlighted in the MSD1 at the level of the membrane inner leaflet, containing both multiple mutations affecting folding and a binding site for pharmaco-chaperones that stabilize this region. This groove is also present in ABCB proteins, however it is covered by a short elbow helix, while in ABCC proteins it remains unprotected, due to a lower position of the elbow helix in the presence of the ABCC-specific lasso motif. Here, we identified a MSD1 second-site mutation located in the vicinity of the CFTR MSD1 groove that partially rescued the folding defect of cystic fibrosis causing mutations located within MSD1, while having no effect on the most frequent mutation, F508del, located within NBD1. A model of the mutated protein 3D structure suggests additional interaction between MSD1 and MSD2, strengthening the assembly at the level of the MSD intracellular loops. Altogether, these results provide insightful information in understanding key features of the folding and function of the CFTR protein in particular, and more generally, of type IV ABC transporters.
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Affiliation(s)
- Nesrine Baatallah
- INSERM, U1151, Institut Necker Enfants Malades (INEM), Faculté de Médecine, Université Paris Cité, CNRS, UMR 8253, 75015 Paris, France
| | - Ahmad Elbahnsi
- Sorbonne Université, Muséum National d’Histoire Naturelle, UMR CNRS 7590, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, 75005 Paris, France
| | - Benoit Chevalier
- INSERM, U1151, Institut Necker Enfants Malades (INEM), Faculté de Médecine, Université Paris Cité, CNRS, UMR 8253, 75015 Paris, France
| | - Solène Castanier
- INSERM, U1151, Institut Necker Enfants Malades (INEM), Faculté de Médecine, Université Paris Cité, CNRS, UMR 8253, 75015 Paris, France
| | - Jean-Paul Mornon
- Sorbonne Université, Muséum National d’Histoire Naturelle, UMR CNRS 7590, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, 75005 Paris, France
| | - Iwona Pranke
- INSERM, U1151, Institut Necker Enfants Malades (INEM), Faculté de Médecine, Université Paris Cité, CNRS, UMR 8253, 75015 Paris, France
| | - Aleksander Edelman
- INSERM, U1151, Institut Necker Enfants Malades (INEM), Faculté de Médecine, Université Paris Cité, CNRS, UMR 8253, 75015 Paris, France
| | - Isabelle Sermet-Gaudelus
- INSERM, U1151, Institut Necker Enfants Malades (INEM), Faculté de Médecine, Université Paris Cité, CNRS, UMR 8253, 75015 Paris, France
| | - 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
- Correspondence: (I.C.); (A.H.)
| | - Alexandre Hinzpeter
- INSERM, U1151, Institut Necker Enfants Malades (INEM), Faculté de Médecine, Université Paris Cité, CNRS, UMR 8253, 75015 Paris, France
- Correspondence: (I.C.); (A.H.)
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14
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Sagarika P, Yadav K, Sahi C. Volleying plasma membrane proteins from birth to death: Role of J-domain proteins. Front Mol Biosci 2022; 9:1072242. [PMID: 36589230 PMCID: PMC9798423 DOI: 10.3389/fmolb.2022.1072242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 12/02/2022] [Indexed: 12/23/2022] Open
Abstract
The function, stability, and turnover of plasma membrane (PM) proteins are crucial for cellular homeostasis. Compared to soluble proteins, quality control of plasma membrane proteins is extremely challenging. Failure to meet the high quality control standards is detrimental to cellular and organismal health. J-domain proteins (JDPs) are among the most diverse group of chaperones that collaborate with other chaperones and protein degradation machinery to oversee cellular protein quality control (PQC). Although fragmented, the available literature from different models, including yeast, mammals, and plants, suggests that JDPs assist PM proteins with their synthesis, folding, and trafficking to their destination as well as their degradation, either through endocytic or proteasomal degradation pathways. Moreover, some JDPs interact directly with the membrane to regulate the stability and/or functionality of proteins at the PM. The deconvoluted picture emerging is that PM proteins are relayed from one JDP to another throughout their life cycle, further underscoring the versatility of the Hsp70:JDP machinery in the cell.
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15
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Hillenaar T, Beekman J, van der Sluijs P, Braakman I. Redefining Hypo- and Hyper-Responding Phenotypes of CFTR Mutants for Understanding and Therapy. Int J Mol Sci 2022; 23:ijms232315170. [PMID: 36499495 PMCID: PMC9735543 DOI: 10.3390/ijms232315170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 11/11/2022] [Accepted: 11/23/2022] [Indexed: 12/03/2022] Open
Abstract
Mutations in CFTR cause misfolding and decreased or absent ion-channel function, resulting in the disease Cystic Fibrosis. Fortunately, a triple-modulator combination therapy (Trikafta) has been FDA-approved for 178 mutations, including all patients who have F508del on one allele. That so many CFTR mutants respond well to modulators developed for a single mutation is due to the nature of the folding process of this multidomain protein. We have addressed the question 'What characterizes the exceptions: the mutants that functionally respond either not or extremely well'. A functional response is the product of the number of CFTR molecules on the cell surface, open probability, and conductivity of the CFTR chloride channel. By combining biosynthetic radiolabeling with protease-susceptibility assays, we have followed CF-causing mutants during the early and late stages of folding in the presence and absence of modulators. Most CFTR mutants showed typical biochemical responses for each modulator, such as a TMD1 conformational change or an increase in (cell-surface) stability, regardless of a functional response. These modulators thus should still be considered for hypo-responder genotypes. Understanding both biochemical and functional phenotypes of outlier mutations will boost our insights into CFTR folding and misfolding, and lead to improved therapeutic strategies.
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Affiliation(s)
- Tamara Hillenaar
- Cellular Protein Chemistry, Bijvoet Centre for Biomolecular Research, Science for Life, Faculty of Science, Utrecht University, 3584 CS Utrecht, The Netherlands; (T.H.); (P.v.d.S.)
| | - Jeffrey Beekman
- Department of Pediatric Pulmonology, Wilhelmina Children’s Hospital, University Medical Center Utrecht, Utrecht University, Member of ERN-LUNG, 3584 EA Utrecht, The Netherlands;
- Regenerative Medicine Center Utrecht, University Medical Center Utrecht, Utrecht University, 3584 CT Utrecht, The Netherlands
- Centre for Living Technologies, Alliance TU/e, WUR, UU, UMC Utrecht, 3584 CB Utrecht, The Netherlands
| | - Peter van der Sluijs
- Cellular Protein Chemistry, Bijvoet Centre for Biomolecular Research, Science for Life, Faculty of Science, Utrecht University, 3584 CS Utrecht, The Netherlands; (T.H.); (P.v.d.S.)
| | - Ineke Braakman
- Cellular Protein Chemistry, Bijvoet Centre for Biomolecular Research, Science for Life, Faculty of Science, Utrecht University, 3584 CS Utrecht, The Netherlands; (T.H.); (P.v.d.S.)
- Correspondence: ; Tel.: +31-30-253-2759
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16
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Moni SS, Al Basheer A. Molecular targets for cystic fibrosis and therapeutic potential of monoclonal antibodies. Saudi Pharm J 2022; 30:1736-1747. [PMID: 36601503 PMCID: PMC9805982 DOI: 10.1016/j.jsps.2022.10.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 10/01/2022] [Indexed: 12/24/2022] Open
Abstract
Cystic fibrosis (CF) is a genetic disease that affects the exocrine glands and is caused by cystic fibrosis transmembrane conductance regulator gene (CFTR) mutations. Lung disease is the leading cause of morbidity in patients. Target-specific treatment of CF has been achieved using monoclonal antibodies (mAbs). The purpose of this article is to discuss the possibility of treating CF with mAbs through their significant target specificity. We searched electronic databases in Web of Science, PubMed, EMBASE, Scopus, and Google Scholar from 1984 to 2021. We discussed the critical role of targeted therapy in cystic fibrosis, as it will be more effective at suppressing the molecular networks. After conducting a critical review of the available literature, we concluded that it is critical to understand the fundamental molecular mechanisms underlying CF prior to incorporating biologics into the therapy regimen. Omalizumab, Mepolizumab, Benralizumab, Dupilumab and KB001-A have been successfully screened for asthma-complicated CF, and their efficacies have been well reported. Despite the availability of effective targeted biologics, treating CF has remained a difficult task, particularly when it comes to reduction of secondary inflammatory mediators. This review emphasizes the overall views on CF, the immunological mechanism of CF, and the prospective therapeutic use of mAbs as potential targeted biologics for enhancing the overall status of human health.
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17
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Bacalhau M, Ferreira FC, Kmit A, Souza FR, da Silva VD, Pimentel AS, Amaral MD, Buarque CD, Lopes-Pacheco M. Identification of novel F508del-CFTR traffic correctors among triazole derivatives. Eur J Pharmacol 2022; 938:175396. [PMID: 36410419 DOI: 10.1016/j.ejphar.2022.175396] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 11/14/2022] [Accepted: 11/15/2022] [Indexed: 11/21/2022]
Abstract
The most prevalent cystic fibrosis (CF)-causing mutation - F508del - impairs the folding of CFTR protein, resulting in its defective trafficking and premature degradation. Small molecules termed correctors may rescue F508del-CFTR and therefore constitute promising pharmacotherapies acting on the fundamental cause of the disease. Here, we screened a collection of triazole compounds to identify novel F508del-CFTR correctors. The functional primary screen identified four hit compounds (LSO-18, LSO-24, LSO-28, and LSO-39), which were further validated and demonstrated to rescue F508del-CFTR processing, plasma membrane trafficking, and function. To interrogate their mechanism of action (MoA), we examined their additivity to the clinically approved drugs VX-661 and VX-445, low temperature, and genetic revertants of F508del-CFTR. Rescue of F508del-CFTR processing and function by LSO-18, LSO-24, and LSO-28, but not by LSO-39, was additive to VX-661, whereas LSO-28 and LSO-39, but not LSO-18 nor LSO-24, were additive to VX-445. All compounds under investigation demonstrated additive rescue of F508del-CFTR processing and function to low temperature as well as to rescue by genetic revertants G550E and 4RK. Nevertheless, none of these compounds was able to rescue processing nor function of DD/AA-CFTR, and LSO-39 (similarly to VX-661) exhibited no additivity to genetic revertant R1070W. From these findings, we suggest that LSO-39 (like VX-661) has a putative binding site at the NBD1:ICL4 interface, LSO-18 and LSO-24 seem to share the MoA with VX-445, and LSO-28 appears to act by a different MoA. Altogether, these findings represent an encouraging starting point to further exploit this chemical series for the development of novel CFTR correctors.
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Affiliation(s)
- Mafalda Bacalhau
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisbon, Lisbon, Portugal
| | - Filipa C Ferreira
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisbon, Lisbon, Portugal
| | - Arthur Kmit
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisbon, Lisbon, Portugal
| | - Felipe R Souza
- Department of Chemistry, Pontifical Catholic University of Rio de Janeiro (PUC-Rio), Rio de Janeiro, Brazil
| | - Verônica D da Silva
- Department of Chemistry, Pontifical Catholic University of Rio de Janeiro (PUC-Rio), Rio de Janeiro, Brazil
| | - André S Pimentel
- Department of Chemistry, Pontifical Catholic University of Rio de Janeiro (PUC-Rio), Rio de Janeiro, Brazil
| | - Margarida D Amaral
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisbon, Lisbon, Portugal
| | - Camilla D Buarque
- Department of Chemistry, Pontifical Catholic University of Rio de Janeiro (PUC-Rio), Rio de Janeiro, Brazil
| | - Miquéias Lopes-Pacheco
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisbon, Lisbon, Portugal.
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18
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Taheri-Ledari M, Zandieh A, Shariatpanahi SP, Eslahchi C. Assignment of structural domains in proteins using diffusion kernels on graphs. BMC Bioinformatics 2022; 23:369. [PMID: 36076174 PMCID: PMC9461149 DOI: 10.1186/s12859-022-04902-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 08/23/2022] [Indexed: 11/10/2022] Open
Abstract
Though proposing algorithmic approaches for protein domain decomposition has been of high interest, the inherent ambiguity to the problem makes it still an active area of research. Besides, accurate automated methods are in high demand as the number of solved structures for complex proteins is on the rise. While majority of the previous efforts for decomposition of 3D structures are centered on the developing clustering algorithms, employing enhanced measures of proximity between the amino acids has remained rather uncharted. If there exists a kernel function that in its reproducing kernel Hilbert space, structural domains of proteins become well separated, then protein structures can be parsed into domains without the need to use a complex clustering algorithm. Inspired by this idea, we developed a protein domain decomposition method based on diffusion kernels on protein graphs. We examined all combinations of four graph node kernels and two clustering algorithms to investigate their capability to decompose protein structures. The proposed method is tested on five of the most commonly used benchmark datasets for protein domain assignment plus a comprehensive non-redundant dataset. The results show a competitive performance of the method utilizing one of the diffusion kernels compared to four of the best automatic methods. Our method is also able to offer alternative partitionings for the same structure which is in line with the subjective definition of protein domain. With a competitive accuracy and balanced performance for the simple and complex structures despite relying on a relatively naive criterion to choose optimal decomposition, the proposed method revealed that diffusion kernels on graphs in particular, and kernel functions in general are promising measures to facilitate parsing proteins into domains and performing different structural analysis on proteins. The size and interconnectedness of the protein graphs make them promising targets for diffusion kernels as measures of affinity between amino acids. The versatility of our method allows the implementation of future kernels with higher performance. The source code of the proposed method is accessible at https://github.com/taherimo/kludo . Also, the proposed method is available as a web application from https://cbph.ir/tools/kludo .
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Affiliation(s)
- Mohammad Taheri-Ledari
- Department of Bioinformatics, Institute of Biochemistry and Biophysics (IBB), University of Tehran, Tehran, Iran
| | - Amirali Zandieh
- Department of Biophysics, Institute of Biochemistry and Biophysics (IBB), University of Tehran, Tehran, Iran
| | - Seyed Peyman Shariatpanahi
- Department of Biophysics, Institute of Biochemistry and Biophysics (IBB), University of Tehran, Tehran, Iran
| | - Changiz Eslahchi
- Department of Computer and Data Sciences, Faculty of Mathematical Sciences, Shahid Beheshti University, Tehran, Iran. .,School of Biological Sciences, Institute for Research in Fundamental Sciences (IPM), Tehran, Iran.
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19
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Pranke IM, Chevalier B, Premchandar A, Baatallah N, Tomaszewski KF, Bitam S, Tondelier D, Golec A, Stolk J, Lukacs GL, Hiemstra PS, Dadlez M, Lomas DA, Irving JA, Delaunay-Moisan A, van Anken E, Hinzpeter A, Sermet-Gaudelus I, Edelman A. Keratin 8 is a scaffolding and regulatory protein of ERAD complexes. Cell Mol Life Sci 2022; 79:503. [PMID: 36045259 DOI: 10.1007/s00018-022-04528-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 08/08/2022] [Accepted: 08/12/2022] [Indexed: 11/03/2022]
Abstract
Early recognition and enhanced degradation of misfolded proteins by the endoplasmic reticulum (ER) quality control and ER-associated degradation (ERAD) cause defective protein secretion and membrane targeting, as exemplified for Z-alpha-1-antitrypsin (Z-A1AT), responsible for alpha-1-antitrypsin deficiency (A1ATD) and F508del-CFTR (cystic fibrosis transmembrane conductance regulator) responsible for cystic fibrosis (CF). Prompted by our previous observation that decreasing Keratin 8 (K8) expression increased trafficking of F508del-CFTR to the plasma membrane, we investigated whether K8 impacts trafficking of soluble misfolded Z-A1AT protein. The subsequent goal of this study was to elucidate the mechanism underlying the K8-dependent regulation of protein trafficking, focusing on the ERAD pathway. The results show that diminishing K8 concentration in HeLa cells enhances secretion of both Z-A1AT and wild-type (WT) A1AT with a 13-fold and fourfold increase, respectively. K8 down-regulation triggers ER failure and cellular apoptosis when ER stress is jointly elicited by conditional expression of the µs heavy chains, as previously shown for Hrd1 knock-out. Simultaneous K8 silencing and Hrd1 knock-out did not show any synergistic effect, consistent with K8 acting in the Hrd1-governed ERAD step. Fractionation and co-immunoprecipitation experiments reveal that K8 is recruited to ERAD complexes containing Derlin2, Sel1 and Hrd1 proteins upon expression of Z/WT-A1AT and F508del-CFTR. Treatment of the cells with c407, a small molecule inhibiting K8 interaction, decreases K8 and Derlin2 recruitment to high-order ERAD complexes. This was associated with increased Z-A1AT secretion in both HeLa and Z-homozygous A1ATD patients' respiratory cells. Overall, we provide evidence that K8 acts as an ERAD modulator. It may play a scaffolding protein role for early-stage ERAD complexes, regulating Hrd1-governed retrotranslocation initiation/ubiquitination processes. Targeting K8-containing ERAD complexes is an attractive strategy for the pharmacotherapy of A1ATD.
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Affiliation(s)
- Iwona Maria Pranke
- Inserm, U1151, CNRS UMR 8253, Université de Paris, 160 rue de Vaugirard, 75015, Paris, France.
| | - Benoit Chevalier
- Inserm, U1151, CNRS UMR 8253, Université de Paris, 160 rue de Vaugirard, 75015, Paris, France
| | - Aiswarya Premchandar
- Laboratory of Mass Spectrometry, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02106, Warsaw, Poland
| | - Nesrine Baatallah
- Inserm, U1151, CNRS UMR 8253, Université de Paris, 160 rue de Vaugirard, 75015, Paris, France
| | - Kamil F Tomaszewski
- Inserm, U1151, CNRS UMR 8253, Université de Paris, 160 rue de Vaugirard, 75015, Paris, France
| | - Sara Bitam
- Inserm, U1151, CNRS UMR 8253, Université de Paris, 160 rue de Vaugirard, 75015, Paris, France
| | - Danielle Tondelier
- Inserm, U1151, CNRS UMR 8253, Université de Paris, 160 rue de Vaugirard, 75015, Paris, France
| | - Anita Golec
- Inserm, U1151, CNRS UMR 8253, Université de Paris, 160 rue de Vaugirard, 75015, Paris, France
| | - Jan Stolk
- Department of Pulmonology, Leiden University Medical Center, Leiden, The Netherlands
| | - Gergely L Lukacs
- Department of Physiology, McGill University, Montréal, QC, Canada.,Department of Biochemistry, McGill University, Montréal, QC, Canada
| | - Pieter S Hiemstra
- Department of Pulmonology, Leiden University Medical Center, Leiden, The Netherlands
| | - Michal Dadlez
- Laboratory of Mass Spectrometry, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02106, Warsaw, Poland
| | - David A Lomas
- UCL Respiratory and the Institute of Structural and Molecular Biology, University College London, London, WC1E 6JF, UK
| | - James A Irving
- UCL Respiratory and the Institute of Structural and Molecular Biology, University College London, London, WC1E 6JF, UK
| | - Agnes Delaunay-Moisan
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France
| | - Eelco van Anken
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milan, Italy
| | - Alexandre Hinzpeter
- Inserm, U1151, CNRS UMR 8253, Université de Paris, 160 rue de Vaugirard, 75015, Paris, France
| | - Isabelle Sermet-Gaudelus
- Inserm, U1151, CNRS UMR 8253, Université de Paris, 160 rue de Vaugirard, 75015, Paris, France.,Cystic Fibrosis Center, Hôpital Necker Enfants Malades, Assistance Publique Hôpitaux de Paris, Paris, France
| | - Aleksander Edelman
- Inserm, U1151, CNRS UMR 8253, Université de Paris, 160 rue de Vaugirard, 75015, Paris, France.
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20
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Cotranslational folding and assembly of the dimeric Escherichia coli inner membrane protein EmrE. Proc Natl Acad Sci U S A 2022; 119:e2205810119. [PMID: 35994672 PMCID: PMC9436324 DOI: 10.1073/pnas.2205810119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In recent years, it has become clear that many homo- and heterodimeric cytoplasmic proteins in both prokaryotic and eukaryotic cells start to dimerize cotranslationally (i.e., while at least one of the two chains is still attached to the ribosome). Whether this is also possible for integral membrane proteins is, however, unknown. Here, we apply force profile analysis (FPA)-a method where a translational arrest peptide (AP) engineered into the polypeptide chain is used to detect force generated on the nascent chain during membrane insertion-to demonstrate cotranslational interactions between a fully membrane-inserted monomer and a nascent, ribosome-tethered monomer of the Escherichia coli inner membrane protein EmrE. Similar cotranslational interactions are also seen when the two monomers are fused into a single polypeptide. Further, we uncover an apparent intrachain interaction between E14 in transmembrane helix 1 (TMH1) and S64 in TMH3 that forms at a precise nascent chain length during cotranslational membrane insertion of an EmrE monomer. Like soluble proteins, inner membrane proteins thus appear to be able to both start to fold and start to dimerize during the cotranslational membrane insertion process.
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21
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Ensinck MM, Carlon MS. One Size Does Not Fit All: The Past, Present and Future of Cystic Fibrosis Causal Therapies. Cells 2022; 11:cells11121868. [PMID: 35740997 PMCID: PMC9220995 DOI: 10.3390/cells11121868] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 05/25/2022] [Accepted: 05/28/2022] [Indexed: 02/04/2023] Open
Abstract
Cystic fibrosis (CF) is the most common monogenic disorder, caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. Over the last 30 years, tremendous progress has been made in understanding the molecular basis of CF and the development of treatments that target the underlying defects in CF. Currently, a highly effective CFTR modulator treatment (Kalydeco™/Trikafta™) is available for 90% of people with CF. In this review, we will give an extensive overview of past and ongoing efforts in the development of therapies targeting the molecular defects in CF. We will discuss strategies targeting the CFTR protein (i.e., CFTR modulators such as correctors and potentiators), its cellular environment (i.e., proteostasis modulation, stabilization at the plasma membrane), the CFTR mRNA (i.e., amplifiers, nonsense mediated mRNA decay suppressors, translational readthrough inducing drugs) or the CFTR gene (gene therapies). Finally, we will focus on how these efforts can be applied to the 15% of people with CF for whom no causal therapy is available yet.
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Affiliation(s)
- Marjolein M. Ensinck
- Molecular Virology and Gene Therapy, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Flanders, Belgium;
| | - Marianne S. Carlon
- Molecular Virology and Gene Therapy, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Flanders, Belgium;
- Laboratory of Respiratory Diseases and Thoracic Surgery (BREATHE), Department of Chronic Diseases and Metabolism, KU Leuven, 3000 Leuven, Flanders, Belgium
- Correspondence:
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22
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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.
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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.
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23
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McDonald EF, Sabusap CMP, Kim M, Plate L. Distinct proteostasis states drive pharmacologic chaperone susceptibility for Cystic Fibrosis Transmembrane Conductance Regulator misfolding mutants. Mol Biol Cell 2022; 33:ar62. [PMID: 35389766 PMCID: PMC9561855 DOI: 10.1091/mbc.e21-11-0578] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Pharmacological chaperones represent a class of therapeutic compounds for treating protein misfolding diseases. One of the most prominent examples is the FDA-approved pharmacological chaperone lumacaftor (VX-809), which has transformed cystic fibrosis (CF) therapy. CF is a fatal disease caused by mutations in the CF transmembrane conductance regulator (CFTR). VX-809 corrects folding of F508del CFTR, the most common patient mutation, yet F508del exhibits only mild VX-809 response. In contrast, rarer mutations P67L and L206W are hyperresponsive to VX-809, while G85E is nonresponsive. Despite the clinical success of VX-809, the mechanistic origin for the distinct susceptibility of mutants remains unclear. Here we use interactomics to characterize the impact of VX-809 on proteostasis interactions of P67L and L206W and compare these with F508del and G85E. We determine that hyperresponsive mutations P67L and L206W exhibit decreased interactions with proteasomal and autophagy degradation machinery compared with F508del and G85E. We then show inhibiting the proteasome attenuates P67L and L206W VX-809 response. Our data suggest a previously unidentified but required role for protein degradation in VX-809 correction. Furthermore, we present an approach for identifying proteostasis characteristics of mutant-specific therapeutic response to pharmacological chaperones.
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Affiliation(s)
| | | | - Minsoo Kim
- Department of Chemistry.,Chemical and Physical Biology Program
| | - Lars Plate
- Department of Chemistry.,Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
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24
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Rescue of Mutant CFTR Trafficking Defect by the Investigational Compound MCG1516A. Cells 2022; 11:cells11010136. [PMID: 35011698 PMCID: PMC8750248 DOI: 10.3390/cells11010136] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Revised: 12/20/2021] [Accepted: 12/22/2021] [Indexed: 01/27/2023] Open
Abstract
Although some therapeutic progress has been achieved in developing small molecules that correct F508del-CFTR defects, the mechanism of action (MoA) of these compounds remain poorly elucidated. Here, we investigated the effects and MoA of MCG1516A, a newly developed F508del-CFTR corrector. MCG1516A effects on wild-type (WT) and F508del-CFTR were assessed by immunofluorescence microscopy, and biochemical and functional assays both in cell lines and in intestinal organoids. To shed light on the MoA of MCG1516A, we evaluated its additivity to the FDA-approved corrector VX-661, low temperature, genetic revertants of F508del-CFTR (G550E, R1070W, and 4RK), and the traffic-null variant DD/AA. Finally, we explored the ability of MCG1516A to rescue trafficking and function of other CF-causing mutations. We found that MCG1516A rescues F508del-CFTR with additive effects to VX-661. A similar behavior was observed for WT-CFTR. Under low temperature incubation, F508del-CFTR demonstrated an additivity in processing and function with VX-661, but not with MCG1516A. In contrast, both compounds promoted additional effects to low temperature to WT-CFTR. MCG1516A demonstrated additivity to genetic revertant R1070W, while VX-661 was additive to G550E and 4RK. Nevertheless, none of these compounds rescued DD/AA trafficking. Both MCG1516A and VX-661 rescued CFTR processing of L206W- and R334W-CFTR with greater effects when these compounds were combined. In summary, the absence of additivity of MCG1516A to genetic revertant G550E suggests a putative binding site for this compound on NBD1:NBD2 interface. Therefore, a combination of MCG1516A with compounds able to rescue DD/AA traffic, or mimicking the actions of revertant R1070W (e.g., VX-661), could enhance correction of F508del-CFTR defects.
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25
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Farinha CM, Gentzsch M. Revisiting CFTR Interactions: Old Partners and New Players. Int J Mol Sci 2021; 22:13196. [PMID: 34947992 PMCID: PMC8703571 DOI: 10.3390/ijms222413196] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 12/02/2021] [Accepted: 12/03/2021] [Indexed: 01/07/2023] Open
Abstract
Remarkable progress in CFTR research has led to the therapeutic development of modulators that rescue the basic defect in cystic fibrosis. There is continuous interest in studying CFTR molecular disease mechanisms as not all cystic fibrosis patients have a therapeutic option available. Addressing the basis of the problem by comprehensively understanding the critical molecular associations of CFTR interactions remains key. With the availability of CFTR modulators, there is interest in comprehending which interactions are critical to rescue CFTR and which are altered by modulators or CFTR mutations. Here, the current knowledge on interactions that govern CFTR folding, processing, and stability is summarized. Furthermore, we describe protein complexes and signal pathways that modulate the CFTR function. Primary epithelial cells display a spatial control of the CFTR interactions and have become a common system for preclinical and personalized medicine studies. Strikingly, the novel roles of CFTR in development and differentiation have been recently uncovered and it has been revealed that specific CFTR gene interactions also play an important role in transcriptional regulation. For a comprehensive understanding of the molecular environment of CFTR, it is important to consider CFTR mutation-dependent interactions as well as factors affecting the CFTR interactome on the cell type, tissue-specific, and transcriptional levels.
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Affiliation(s)
- Carlos M. Farinha
- BioISI—Biosystems and Integrative Sciences Institute, Faculty of Sciences, University of Lisboa, 1749-016 Lisboa, Portugal
| | - Martina Gentzsch
- Marsico Lung Institute and Cystic Fibrosis Research Center, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
- Department of Pediatrics, Division of Pediatric Pulmonology, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
- Department of Cell Biology and Physiology, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
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26
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Baatallah N, Elbahnsi A, Mornon JP, Chevalier B, Pranke I, Servel N, Zelli R, Décout JL, Edelman A, Sermet-Gaudelus I, Callebaut I, Hinzpeter A. Pharmacological chaperones improve intra-domain stability and inter-domain assembly via distinct binding sites to rescue misfolded CFTR. Cell Mol Life Sci 2021; 78:7813-7829. [PMID: 34714360 PMCID: PMC11071985 DOI: 10.1007/s00018-021-03994-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 10/11/2021] [Accepted: 10/15/2021] [Indexed: 12/14/2022]
Abstract
Protein misfolding is involved in a large number of diseases, among which cystic fibrosis. Complex intra- and inter-domain folding defects associated with mutations in the cystic fibrosis transmembrane regulator (CFTR) gene, among which p.Phe508del (F508del), have recently become a therapeutical target. Clinically approved correctors such as VX-809, VX-661, and VX-445, rescue mutant protein. However, their binding sites and mechanisms of action are still incompletely understood. Blind docking onto the 3D structures of both the first membrane-spanning domain (MSD1) and the first nucleotide-binding domain (NBD1), followed by molecular dynamics simulations, revealed the presence of two potential VX-809 corrector binding sites which, when mutated, abrogated rescue. Network of amino acids in the lasso helix 2 and the intracellular loops ICL1 and ICL4 allosterically coupled MSD1 and NBD1. Corrector VX-445 also occupied two potential binding sites on MSD1 and NBD1, the latter being shared with VX-809. Binding of both correctors on MSD1 enhanced the allostery between MSD1 and NBD1, hence the increased efficacy of the corrector combination. These correctors improve both intra-domain folding by stabilizing fragile protein-lipid interfaces and inter-domain assembly via distant allosteric couplings. These results provide novel mechanistic insights into the rescue of misfolded proteins by small molecules.
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Affiliation(s)
- Nesrine Baatallah
- INSERM, U1151, Institut Necker Enfants Malades, INEM, Paris, France
- CNRS UMR 8253 - Faculté de Médecine, Université de Paris, Paris, France
| | - Ahmad Elbahnsi
- Sorbonne Université, Muséum National d'Histoire Naturelle, UMR CNRS 7590, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, 75005, Paris, France
- Department of Applied Physics of Science for Life Laboratory, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Jean-Paul Mornon
- Sorbonne Université, Muséum National d'Histoire Naturelle, UMR CNRS 7590, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, 75005, Paris, France
| | - Benoit Chevalier
- INSERM, U1151, Institut Necker Enfants Malades, INEM, Paris, France
- CNRS UMR 8253 - Faculté de Médecine, Université de Paris, Paris, France
| | - Iwona Pranke
- INSERM, U1151, Institut Necker Enfants Malades, INEM, Paris, France
- CNRS UMR 8253 - Faculté de Médecine, Université de Paris, Paris, France
| | - Nathalie Servel
- INSERM, U1151, Institut Necker Enfants Malades, INEM, Paris, France
- CNRS UMR 8253 - Faculté de Médecine, Université de Paris, Paris, France
| | - Renaud Zelli
- Univ. Grenoble Alpes, CNRS, DPM, 38000, Grenoble, France
| | | | - Aleksander Edelman
- INSERM, U1151, Institut Necker Enfants Malades, INEM, Paris, France
- CNRS UMR 8253 - Faculté de Médecine, Université de Paris, Paris, France
| | - Isabelle Sermet-Gaudelus
- INSERM, U1151, Institut Necker Enfants Malades, INEM, Paris, France
- CNRS UMR 8253 - Faculté de Médecine, Université de Paris, Paris, France
| | - 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.
| | - Alexandre Hinzpeter
- INSERM, U1151, Institut Necker Enfants Malades, INEM, Paris, France.
- CNRS UMR 8253 - Faculté de Médecine, Université de Paris, Paris, France.
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27
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Pereira C, Mazein A, Farinha CM, Gray MA, Kunzelmann K, Ostaszewski M, Balaur I, Amaral MD, Falcao AO. CyFi-MAP: an interactive pathway-based resource for cystic fibrosis. Sci Rep 2021; 11:22223. [PMID: 34782688 PMCID: PMC8592983 DOI: 10.1038/s41598-021-01618-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 10/27/2021] [Indexed: 12/11/2022] Open
Abstract
Cystic fibrosis (CF) is a life-threatening autosomal recessive disease caused by more than 2100 mutations in the CF transmembrane conductance regulator (CFTR) gene, generating variability in disease severity among individuals with CF sharing the same CFTR genotype. Systems biology can assist in the collection and visualization of CF data to extract additional biological significance and find novel therapeutic targets. Here, we present the CyFi-MAP-a disease map repository of CFTR molecular mechanisms and pathways involved in CF. Specifically, we represented the wild-type (wt-CFTR) and the F508del associated processes (F508del-CFTR) in separate submaps, with pathways related to protein biosynthesis, endoplasmic reticulum retention, export, activation/inactivation of channel function, and recycling/degradation after endocytosis. CyFi-MAP is an open-access resource with specific, curated and continuously updated information on CFTR-related pathways available online at https://cysticfibrosismap.github.io/ . This tool was developed as a reference CF pathway data repository to be continuously updated and used worldwide in CF research.
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Affiliation(s)
- Catarina Pereira
- Faculty of Sciences, BioISI-Biosystems Integrative Sciences Institute, University of Lisboa, Campo Grande, 1749-016, Lisbon, Portugal
- LASIGE, Faculty of Sciences, University of Lisboa, Campo Grande, 1749-016, Lisbon, Portugal
| | - Alexander Mazein
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, 6 Avenue du Swing, 4367, Belvaux, Luxembourg
- CIRI UMR5308, CNRS-ENS-UCBL-INSERM, European Institute for Systems Biology and Medicine, Université de Lyon, 50 Avenue Tony Garnier, 69007, Lyon, France
| | - Carlos M Farinha
- Faculty of Sciences, BioISI-Biosystems Integrative Sciences Institute, University of Lisboa, Campo Grande, 1749-016, Lisbon, Portugal
| | - Michael A Gray
- Biosciences Institute, University Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | | | - Marek Ostaszewski
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, 6 Avenue du Swing, 4367, Belvaux, Luxembourg
| | - Irina Balaur
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, 6 Avenue du Swing, 4367, Belvaux, Luxembourg
- CIRI UMR5308, CNRS-ENS-UCBL-INSERM, European Institute for Systems Biology and Medicine, Université de Lyon, 50 Avenue Tony Garnier, 69007, Lyon, France
| | - Margarida D Amaral
- Faculty of Sciences, BioISI-Biosystems Integrative Sciences Institute, University of Lisboa, Campo Grande, 1749-016, Lisbon, Portugal
| | - Andre O Falcao
- Faculty of Sciences, BioISI-Biosystems Integrative Sciences Institute, University of Lisboa, Campo Grande, 1749-016, Lisbon, Portugal.
- LASIGE, Faculty of Sciences, University of Lisboa, Campo Grande, 1749-016, Lisbon, Portugal.
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28
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Pinto MC, Silva IAL, Figueira MF, Amaral MD, Lopes-Pacheco M. Pharmacological Modulation of Ion Channels for the Treatment of Cystic Fibrosis. J Exp Pharmacol 2021; 13:693-723. [PMID: 34326672 PMCID: PMC8316759 DOI: 10.2147/jep.s255377] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 06/30/2021] [Indexed: 12/12/2022] Open
Abstract
Cystic fibrosis (CF) is a life-shortening monogenic disease caused by mutations in the gene encoding the CF transmembrane conductance regulator (CFTR) protein, an anion channel that transports chloride and bicarbonate across epithelia. Despite clinical progress in delaying disease progression with symptomatic therapies, these individuals still develop various chronic complications in lungs and other organs, which significantly restricts their life expectancy and quality of life. The development of high-throughput assays to screen drug-like compound libraries have enabled the discovery of highly effective CFTR modulator therapies. These novel therapies target the primary defect underlying CF and are now approved for clinical use for individuals with specific CF genotypes. However, the clinically approved modulators only partially reverse CFTR dysfunction and there is still a considerable number of individuals with CF carrying rare CFTR mutations who remain without any effective CFTR modulator therapy. Accordingly, additional efforts have been pursued to identify novel and more potent CFTR modulators that may benefit a larger CF population. The use of ex vivo individual-derived specimens has also become a powerful tool to evaluate novel drugs and predict their effectiveness in a personalized medicine approach. In addition to CFTR modulators, pro-drugs aiming at modulating alternative ion channels/transporters are under development to compensate for the lack of CFTR function. These therapies may restore normal mucociliary clearance through a mutation-agnostic approach (ie, independent of CFTR mutation) and include inhibitors of the epithelial sodium channel (ENaC), modulators of the calcium-activated channel transmembrane 16A (TMEM16, or anoctamin 1) or of the solute carrier family 26A member 9 (SLC26A9), and anionophores. The present review focuses on recent progress and challenges for the development of ion channel/transporter-modulating drugs for the treatment of CF.
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Affiliation(s)
- Madalena C Pinto
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisboa, Lisboa, Portugal
| | - Iris A L Silva
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisboa, Lisboa, Portugal
| | - Miriam F Figueira
- Marsico Lung Institute/Cystic Fibrosis Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Margarida D Amaral
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisboa, Lisboa, Portugal
| | - Miquéias Lopes-Pacheco
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisboa, Lisboa, Portugal
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29
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Villamizar O, Waters SA, Scott T, Grepo N, Jaffe A, Morris KV. Mesenchymal Stem Cell exosome delivered Zinc Finger Protein activation of cystic fibrosis transmembrane conductance regulator. J Extracell Vesicles 2021; 10:e12053. [PMID: 33532041 PMCID: PMC7825549 DOI: 10.1002/jev2.12053] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 12/13/2020] [Accepted: 12/16/2020] [Indexed: 02/06/2023] Open
Abstract
Cystic fibrosis is a genetic disorder that results in a multi-organ disease with progressive respiratory decline which leads to premature death. Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene disrupts the capacity of the protein to function as a channel, transporting chloride ions and bicarbonate across epithelial cell membranes. Small molecule treatments targeted at potentiating or correcting CFTR have shown clinical benefits, but are only effective for a small percentage of individuals with specific CFTR mutations. To overcome this limitation, we engineered stromal-derived mesenchymal stem cells (MSC) and HEK293 cells to produce exosomes containing a novel CFTR Zinc Finger Protein fusion with transcriptional activation domains VP64, P65 and Rta to target the CFTR promoter (CFZF-VPR) and activate transcription. Treatment with CFZF-VPR results in robust activation of CFTR transcription in patient derived Human Bronchial Epithelial cells (HuBEC). We also find that CFZF-VPR can be packaged into MSC and HEK293 cell exosomes and delivered to HuBEC cells to potently activate CFTR expression. Connexin 43 appeared to be required for functional release of CFZF-VPR from exosomes. The observations presented here demonstrate that MSC derived exosomes can be used to deliver a packaged zinc finger activator to target cells and activate CFTR. The novel approach presented here offers a next-generation genetic therapy that may one day prove effective in treating patients afflicted with Cystic fibrosis.
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Affiliation(s)
- Olga Villamizar
- Center for Gene Therapy City of Hope-Beckman Research Institute at the City of Hope Duarte California USA
| | - Shafagh A Waters
- Faculty of Medicine School of Women's & Children's Health University of New South Wales (UNSW) Sydney NSW Australia.,Molecular and Integrative Cystic Fibrosis Research Centre (miCF_RC) Faculty of Medicine University of New South Wales Sydney NSW Australia.,Department of Respiratory Medicine Sydney Children's Hospital Sydney NSW Australia
| | - Tristan Scott
- Center for Gene Therapy City of Hope-Beckman Research Institute at the City of Hope Duarte California USA
| | - Nicole Grepo
- Center for Gene Therapy City of Hope-Beckman Research Institute at the City of Hope Duarte California USA
| | - Adam Jaffe
- Faculty of Medicine School of Women's & Children's Health University of New South Wales (UNSW) Sydney NSW Australia.,Molecular and Integrative Cystic Fibrosis Research Centre (miCF_RC) Faculty of Medicine University of New South Wales Sydney NSW Australia.,Department of Respiratory Medicine Sydney Children's Hospital Sydney NSW Australia
| | - Kevin V Morris
- Center for Gene Therapy City of Hope-Beckman Research Institute at the City of Hope Duarte California USA.,School of Medical Science Griffith University, Gold Coast Campus 1 Parklands Dr Southport QLD Australia
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30
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Poothong J, Jang I, Kaufman RJ. Defects in Protein Folding and/or Quality Control Cause Protein Aggregation in the Endoplasmic Reticulum. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2021; 59:115-143. [PMID: 34050864 DOI: 10.1007/978-3-030-67696-4_6] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Protein aggregation is now a common hallmark of numerous human diseases, most of which involve cytosolic aggregates including Aβ (AD) and ⍺-synuclein (PD) in Alzheimer's disease and Parkinson's disease. However, it is also evident that protein aggregation can also occur in the lumen of the endoplasmic reticulum (ER) that leads to specific diseases due to loss of protein function or detrimental effects on the host cell, the former is inherited in a recessive manner where the latter are dominantly inherited. However, the mechanisms of protein aggregation, disaggregation and degradation in the ER are not well understood. Here we provide an overview of factors that cause protein aggregation in the ER and how the ER handles aggregated proteins. Protein aggregation in the ER can result from intrinsic properties of the protein (hydrophobic residues in the ER), oxidative stress or nutrient depletion. The ER has quality control mechanisms [chaperone functions, ER-associated protein degradation (ERAD) and autophagy] to ensure only correctly folded proteins exit the ER and enter the cis-Golgi compartment. Perturbation of protein folding in the ER activates the unfolded protein response (UPR) that evolved to increase ER protein folding capacity and efficiency and degrade misfolded proteins. Accumulation of misfolded proteins in the ER to a level that exceeds the ER-chaperone folding capacity is a major factor that exacerbates protein aggregation. The most significant ER resident protein that prevents protein aggregation in the ER is the heat shock protein 70 (HSP70) homologue, BiP/GRP78, which is a peptide-dependent ATPase that binds unfolded/misfolded proteins and releases them upon ATP binding. Since exogenous factors can also reduce protein misfolding and aggregation in the ER, such as chemical chaperones and antioxidants, these treatments have potential therapeutic benefit for ER protein aggregation-associated diseases.
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Affiliation(s)
- Juthakorn Poothong
- Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Insook Jang
- Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Randal J Kaufman
- Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA.
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31
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Prins S, Langron E, Hastings C, Hill EJ, Stefan AC, Griffin LD, Vergani P. Fluorescence assay for simultaneous quantification of CFTR ion-channel function and plasma membrane proximity. J Biol Chem 2020; 295:16529-16544. [PMID: 32934006 PMCID: PMC7864054 DOI: 10.1074/jbc.ra120.014061] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 08/21/2020] [Indexed: 11/21/2022] Open
Abstract
The cystic fibrosis transmembrane conductance regulator (CFTR) is a plasma membrane anion channel that plays a key role in controlling transepithelial fluid movement. Excessive activation results in intestinal fluid loss during secretory diarrheas, whereas CFTR mutations underlie cystic fibrosis (CF). Anion permeability depends both on how well CFTR channels work (permeation/gating) and on how many are present at the membrane. Recently, treatments with two drug classes targeting CFTR-one boosting ion-channel function (potentiators) and the other increasing plasma membrane density (correctors)-have provided significant health benefits to CF patients. Here, we present an image-based fluorescence assay that can rapidly and simultaneously estimate both CFTR ion-channel function and the protein's proximity to the membrane. We monitor F508del-CFTR, the most common CF-causing variant, and confirm rescue by low temperature, CFTR-targeting drugs and second-site revertant mutation R1070W. In addition, we characterize a panel of 62 CF-causing mutations. Our measurements correlate well with published data (electrophysiology and biochemistry), further confirming validity of the assay. Finally, we profile effects of acute treatment with approved potentiator drug VX-770 on the rare-mutation panel. Mapping the potentiation profile on CFTR structures raises mechanistic hypotheses on drug action, suggesting that VX-770 might allow an open-channel conformation with an alternative arrangement of domain interfaces. The assay is a valuable tool for investigation of CFTR molecular mechanisms, allowing accurate inferences on gating/permeation. In addition, by providing a two-dimensional characterization of the CFTR protein, it could better inform development of single-drug and precision therapies addressing the root cause of CF disease.
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Affiliation(s)
- Stella Prins
- Department of Neuroscience, Physiology, and Pharmacology, University College London, London, United Kingdom
| | - Emily Langron
- Department of Neuroscience, Physiology, and Pharmacology, University College London, London, United Kingdom
| | - Cato Hastings
- CoMPLEX, University College London, London, United Kingdom
| | - Emily J Hill
- Department of Neuroscience, Physiology, and Pharmacology, University College London, London, United Kingdom
| | - Andra C Stefan
- Natural Sciences, University College London, London, United Kingdom
| | | | - Paola Vergani
- Department of Neuroscience, Physiology, and Pharmacology, University College London, London, United Kingdom.
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32
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Discovery of novel VX-809 hybrid derivatives as F508del-CFTR correctors by molecular modeling, chemical synthesis and biological assays. Eur J Med Chem 2020; 208:112833. [DOI: 10.1016/j.ejmech.2020.112833] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 09/04/2020] [Accepted: 09/05/2020] [Indexed: 11/21/2022]
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33
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Phillips BP, Miller EA. Ribosome-associated quality control of membrane proteins at the endoplasmic reticulum. J Cell Sci 2020; 133:133/22/jcs251983. [PMID: 33247003 PMCID: PMC7116877 DOI: 10.1242/jcs.251983] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Protein synthesis is an energetically costly, complex and risky process. Aberrant protein biogenesis can result in cellular toxicity and disease, with membrane-embedded proteins being particularly challenging for the cell. In order to protect the cell from consequences of defects in membrane proteins, quality control systems act to maintain protein homeostasis. The majority of these pathways act post-translationally; however, recent evidence reveals that membrane proteins are also subject to co-translational quality control during their synthesis in the endoplasmic reticulum (ER). This newly identified quality control pathway employs components of the cytosolic ribosome-associated quality control (RQC) machinery but differs from canonical RQC in that it responds to biogenesis state of the substrate rather than mRNA aberrations. This ER-associated RQC (ER-RQC) is sensitive to membrane protein misfolding and malfunctions in the ER insertion machinery. In this Review, we discuss the advantages of co-translational quality control of membrane proteins, as well as potential mechanisms of substrate recognition and degradation. Finally, we discuss some outstanding questions concerning future studies of ER-RQC of membrane proteins.
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Affiliation(s)
- Ben P Phillips
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
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34
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Sun S, Mariappan M. C-terminal tail length guides insertion and assembly of membrane proteins. J Biol Chem 2020; 295:15498-15510. [PMID: 32878985 DOI: 10.1074/jbc.ra120.012992] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 08/27/2020] [Indexed: 11/06/2022] Open
Abstract
A large number of newly synthesized membrane proteins in the endoplasmic reticulum (ER) are assembled into multiprotein complexes, but little is known about the mechanisms required for assembly membrane proteins. It has been suggested that membrane chaperones might exist, akin to the molecular chaperones that stabilize and direct the assembly of soluble protein complexes, but the mechanisms by which these proteins would bring together membrane protein components is unclear. Here, we have identified that the tail length of the C-terminal transmembrane domains (C-TMDs) determines efficient insertion and assembly of membrane proteins in the ER. We found that membrane proteins with C-TMD tails shorter than ∼60 amino acids are poorly inserted into the ER membrane, which suggests that translation is terminated before they are recognized by the Sec61 translocon for insertion. These C-TMDs with insufficient hydrophobicity are post-translationally recognized and retained by the Sec61 translocon complex, providing a time window for efficient assembly with TMDs from partner proteins. Retained TMDs that fail to assemble with their cognate TMDs are slowly translocated into the ER lumen and are recognized by the ER-associated degradation (ERAD) pathway for removal. In contrast, C-TMDs with sufficient hydrophobicity or tails longer than ∼80 residues are quickly released from the Sec61 translocon into the membrane or the ER lumen, resulting in inefficient assembly with partner TMDs. Thus, our data suggest that C-terminal tails harbor crucial signals for both the insertion and assembly of membrane proteins.
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Affiliation(s)
- Sha Sun
- Frome the Department of Cell Biology, Nanobiology Institute, Yale School of Medicine, Yale West Campus, West Haven, Connecticut, USA
| | - Malaiyalam Mariappan
- Frome the Department of Cell Biology, Nanobiology Institute, Yale School of Medicine, Yale West Campus, West Haven, Connecticut, USA.
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35
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Sarkadi B, Homolya L, Hegedűs T. The ABCG2/BCRP transporter and its variants - from structure to pathology. FEBS Lett 2020; 594:4012-4034. [PMID: 33015850 DOI: 10.1002/1873-3468.13947] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 08/27/2020] [Accepted: 09/21/2020] [Indexed: 12/13/2022]
Abstract
The ABCG2 protein has a key role in the transport of a wide range of structurally dissimilar endo- and xenobiotics in the human body, especially in the tissue barriers and the metabolizing or secreting organs. The human ABCG2 gene harbors a high number of polymorphisms and mutations, which may significantly modulate its expression and function. Recent high-resolution structural data, complemented with molecular dynamic simulations, may significantly help to understand intramolecular movements and substrate handling, as well as the effects of mutations on the membrane transporter function of ABCG2. As reviewed here, structural alterations may result not only in direct alterations in drug binding and transporter activity, but also in improper folding or problems in the carefully regulated process of trafficking, including vesicular transport, endocytosis, recycling, and degradation. Here, we also review the clinical importance of altered ABCG2 expression and function in general drug metabolism, cancer multidrug resistance, and impaired uric acid excretion, leading to gout.
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Affiliation(s)
- Balázs Sarkadi
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary.,Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
| | - László Homolya
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary
| | - Tamás Hegedűs
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
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36
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Brecker M, Khakhina S, Schubert TJ, Thompson Z, Rubenstein RC. The Probable, Possible, and Novel Functions of ERp29. Front Physiol 2020; 11:574339. [PMID: 33013490 PMCID: PMC7506106 DOI: 10.3389/fphys.2020.574339] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 08/14/2020] [Indexed: 12/16/2022] Open
Abstract
The luminal endoplasmic reticulum (ER) protein of 29 kDa (ERp29) is a ubiquitously expressed cellular agent with multiple critical roles. ERp29 regulates the biosynthesis and trafficking of several transmembrane and secretory proteins, including the cystic fibrosis transmembrane conductance regulator (CFTR), the epithelial sodium channel (ENaC), thyroglobulin, connexin 43 hemichannels, and proinsulin. ERp29 is hypothesized to promote ER to cis-Golgi cargo protein transport via COP II machinery through its interactions with the KDEL receptor; this interaction may facilitate the loading of ERp29 clients into COP II vesicles. ERp29 also plays a role in ER stress (ERS) and the unfolded protein response (UPR) and is implicated in oncogenesis. Here, we review the vast array of ERp29’s clients, its role as an ER to Golgi escort protein, and further suggest ERp29 as a potential target for therapies related to diseases of protein misfolding and mistrafficking.
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Affiliation(s)
- Margaret Brecker
- Cystic Fibrosis Center, The Children’s Hospital of Philadelphia, Philadelphia, PA, United States
| | - Svetlana Khakhina
- Cystic Fibrosis Center, The Children’s Hospital of Philadelphia, Philadelphia, PA, United States
| | - Tyler J. Schubert
- Cystic Fibrosis Center, The Children’s Hospital of Philadelphia, Philadelphia, PA, United States
| | - Zachary Thompson
- Cystic Fibrosis Center, The Children’s Hospital of Philadelphia, Philadelphia, PA, United States
| | - Ronald C. Rubenstein
- Cystic Fibrosis Center, The Children’s Hospital of Philadelphia, Philadelphia, PA, United States
- Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, United States
- Division of Allergy and Pulmonary Medicine, Department of Pediatrics, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
- *Correspondence: Ronald C. Rubenstein, ;
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37
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Ensinck M, De Keersmaecker L, Heylen L, Ramalho AS, Gijsbers R, Farré R, De Boeck K, Christ F, Debyser Z, Carlon MS. Phenotyping of Rare CFTR Mutations Reveals Distinct Trafficking and Functional Defects. Cells 2020; 9:E754. [PMID: 32204475 PMCID: PMC7140603 DOI: 10.3390/cells9030754] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 03/16/2020] [Accepted: 03/16/2020] [Indexed: 12/19/2022] Open
Abstract
Background. The most common CFTR mutation, F508del, presents with multiple cellular defects. However, the possible multiple defects caused by many rarer CFTR mutations are not well studied. We investigated four rare CFTR mutations E60K, G85E, E92K and A455E against well-characterized mutations, F508del and G551D, and their responses to corrector VX-809 and/or potentiator VX-770. Methods. Using complementary assays in HEK293T stable cell lines, we determined maturation by Western blotting, trafficking by flow cytometry using extracellular 3HA-tagged CFTR, and function by halide-sensitive YFP quenching. In the forskolin-induced swelling assay in intestinal organoids, we validated the effect of tagged versus endogenous CFTR. Results. Treatment with VX-809 significantly restored maturation, PM localization and function of both E60K and E92K. Mechanistically, VX-809 not only raised the total amount of CFTR, but significantly increased the traffic efficiency, which was not the case for A455E. G85E was refractory to VX-809 and VX-770 treatment. Conclusions. Since no single model or assay allows deciphering all defects at once, we propose a combination of phenotypic assays to collect rapid and early insights into the multiple defects of CFTR variants.
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Affiliation(s)
- Marjolein Ensinck
- Molecular Virology and Gene Therapy, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Flanders, Belgium; (M.E.); (L.D.K.); (L.H.); (R.G.); (F.C.); (Z.D.)
| | - Liesbeth De Keersmaecker
- Molecular Virology and Gene Therapy, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Flanders, Belgium; (M.E.); (L.D.K.); (L.H.); (R.G.); (F.C.); (Z.D.)
| | - Lise Heylen
- Molecular Virology and Gene Therapy, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Flanders, Belgium; (M.E.); (L.D.K.); (L.H.); (R.G.); (F.C.); (Z.D.)
| | - Anabela S. Ramalho
- CF Centre, Woman and Child Unit, Department of Development and Regeneration, KU Leuven, 3000 Leuven, Flanders, Belgium;
| | - Rik Gijsbers
- Molecular Virology and Gene Therapy, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Flanders, Belgium; (M.E.); (L.D.K.); (L.H.); (R.G.); (F.C.); (Z.D.)
- Leuven Viral Vector Core, KU Leuven, 3000 Leuven, Flanders, Belgium
| | - Ricard Farré
- Translational Research in Gastrointestinal Disorders (TARGID), KU Leuven, 3000 Leuven, Flanders, Belgium;
| | - Kris De Boeck
- University Hospital Leuven, 3000 Leuven, Flanders, Belgium;
| | - Frauke Christ
- Molecular Virology and Gene Therapy, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Flanders, Belgium; (M.E.); (L.D.K.); (L.H.); (R.G.); (F.C.); (Z.D.)
| | - Zeger Debyser
- Molecular Virology and Gene Therapy, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Flanders, Belgium; (M.E.); (L.D.K.); (L.H.); (R.G.); (F.C.); (Z.D.)
| | - Marianne S. Carlon
- Molecular Virology and Gene Therapy, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Flanders, Belgium; (M.E.); (L.D.K.); (L.H.); (R.G.); (F.C.); (Z.D.)
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38
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Baaklini I, Gonçalves CDC, Lukacs GL, Young JC. Selective Binding of HSC70 and its Co-Chaperones to Structural Hotspots on CFTR. Sci Rep 2020; 10:4176. [PMID: 32144307 PMCID: PMC7060200 DOI: 10.1038/s41598-020-61107-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 02/07/2020] [Indexed: 12/17/2022] Open
Abstract
Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) channel cause cystic fibrosis. Chaperones, including HSC70, DNAJA1 and DNAJA2, play key roles in both the folding and degradation of wild-type and mutant CFTR at multiple cellular locations. DNAJA1 and HSC70 promote the folding of newly synthesized CFTR at the endoplasmic reticulum (ER), but are required for the rapid turnover of misfolded channel at the plasma membrane (PM). DNAJA2 and HSC70 are also involved in the ER-associated degradation (ERAD) of misfolded CFTR, while they assist the refolding of destabilized channel at the PM. These outcomes may depend on the binding of chaperones to specific sites within CFTR, which would be exposed in non-native states. A CFTR peptide library was used to identify binding sites for HSC70, DNAJA1 and DNAJA2, validated by competition and functional assays. Each chaperone had a distinct binding pattern, and sites were distributed between the surfaces of the CFTR cytosolic domains, and domain interfaces known to be important for channel assembly. The accessibility of sites to chaperones will depend on the degree of CFTR folding or unfolding. Different folded states may be recognized by unique combinations of HSC70, DNAJA1 and DNAJA2, leading to divergent biological effects.
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Affiliation(s)
- Imad Baaklini
- McGill University, Department of Biochemistry, Montreal, H3G 1Y6, Canada
| | | | - Gergely L Lukacs
- McGill University, Department of Biochemistry, Montreal, H3G 1Y6, Canada.,McGill University, Department of Physiology, Montreal, H3G 1Y6, Canada
| | - Jason C Young
- McGill University, Department of Biochemistry, Montreal, H3G 1Y6, Canada.
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39
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Lopes-Pacheco M. CFTR Modulators: The Changing Face of Cystic Fibrosis in the Era of Precision Medicine. Front Pharmacol 2020; 10:1662. [PMID: 32153386 PMCID: PMC7046560 DOI: 10.3389/fphar.2019.01662] [Citation(s) in RCA: 262] [Impact Index Per Article: 65.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 12/19/2019] [Indexed: 12/22/2022] Open
Abstract
Cystic fibrosis (CF) is a lethal inherited disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene, which result in impairment of CFTR mRNA and protein expression, function, stability or a combination of these. Although CF leads to multifaceted clinical manifestations, the respiratory disorder represents the major cause of morbidity and mortality of these patients. The life expectancy of CF patients has substantially lengthened due to early diagnosis and improvements in symptomatic therapeutic regimens. Quality of life remains nevertheless limited, as these individuals are subjected to considerable clinical, psychosocial and economic burdens. Since the discovery of the CFTR gene in 1989, tremendous efforts have been made to develop therapies acting more upstream on the pathogenesis cascade, thereby overcoming the underlying dysfunctions caused by CFTR mutations. In this line, the advances in cell-based high-throughput screenings have been facilitating the fast-tracking of CFTR modulators. These modulator drugs have the ability to enhance or even restore the functional expression of specific CF-causing mutations, and they have been classified into five main groups depending on their effects on CFTR mutations: potentiators, correctors, stabilizers, read-through agents, and amplifiers. To date, four CFTR modulators have reached the market, and these pharmaceutical therapies are transforming patients' lives with short- and long-term improvements in clinical outcomes. Such breakthroughs have paved the way for the development of novel CFTR modulators, which are currently under experimental and clinical investigations. Furthermore, recent insights into the CFTR structure will be useful for the rational design of next-generation modulator drugs. This review aims to provide a summary of recent developments in CFTR-directed therapeutics. Barriers and future directions are also discussed in order to optimize treatment adherence, identify feasible and sustainable solutions for equitable access to these therapies, and continue to expand the pipeline of novel modulators that may result in effective precision medicine for all individuals with CF.
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Affiliation(s)
- Miquéias Lopes-Pacheco
- Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisbon, Lisbon, Portugal
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40
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Poskanzer SA, Thies J, Collins CJ, Myers CT, Dayuha R, Duong P, Yi F, Chang IJ, Ochs HD, Torgerson TR, Hahn SH. The co-occurrence of Wilson disease and X-linked agammaglobulinemia in one family highlights the promising diagnostic potential of proteolytic analysis. Mol Genet Genomic Med 2020; 8:e1172. [PMID: 32067425 PMCID: PMC7196455 DOI: 10.1002/mgg3.1172] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 01/28/2020] [Accepted: 01/30/2020] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND We report the first case of a family with co-occurrence of Wilson disease (WD), an autosomal recessive disorder of copper metabolism, and X-linked agammaglobulinemia (XLA), a primary immunodeficiency disorder (PIDD) that features marked reduction in circulating B lymphocytes and serum immunoglobulins. METHODS AND RESULTS Through utilization of a multiplexed biomarker peptide quantification method known as the immuno-SRM assay, we were able to simultaneously and independently identify which family members are affected with WD and which are affected with XLA using dried blood spots (DBS). CONCLUSION Being able to delineate multiple diagnoses using proteolytic analysis from a single DBS provides support for implementation of this methodology for clinical diagnostic use as well as large-scale population screening, such as newborn screening (NBS). This could allow for early identification and treatment of affected individuals with WD or XLA, which have been shown to reduce morbidity and decrease mortality in these two populations.
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Affiliation(s)
- Sheri A Poskanzer
- School of Medicine, Department of Pediatrics, University of Washington, Seattle, WA, USA.,Biochemical Genetics, Seattle Children's Hospital, Seattle, WA, USA
| | - Jenny Thies
- Biochemical Genetics, Seattle Children's Hospital, Seattle, WA, USA
| | | | - Candace T Myers
- Department of Laboratories, Seattle Children's Hospital, Seattle, WA, USA
| | | | - Phi Duong
- Seattle Children's Research Institute, Seattle, WA, USA
| | - Fan Yi
- Seattle Children's Research Institute, Seattle, WA, USA
| | - Irene J Chang
- School of Medicine, Department of Pediatrics, University of Washington, Seattle, WA, USA.,Biochemical Genetics, Seattle Children's Hospital, Seattle, WA, USA.,Seattle Children's Research Institute, Seattle, WA, USA
| | - Hans D Ochs
- School of Medicine, Department of Pediatrics, University of Washington, Seattle, WA, USA.,Seattle Children's Research Institute, Seattle, WA, USA
| | - Troy R Torgerson
- School of Medicine, Department of Pediatrics, University of Washington, Seattle, WA, USA.,Seattle Children's Research Institute, Seattle, WA, USA
| | - Si Houn Hahn
- School of Medicine, Department of Pediatrics, University of Washington, Seattle, WA, USA.,Biochemical Genetics, Seattle Children's Hospital, Seattle, WA, USA.,Seattle Children's Research Institute, Seattle, WA, USA
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41
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Pedemonte N, Bertozzi F, Caci E, Sorana F, Di Fruscia P, Tomati V, Ferrera L, Rodríguez-Gimeno A, Berti F, Pesce E, Sondo E, Gianotti A, Scudieri P, Bandiera T, Galietta LJV. Discovery of a picomolar potency pharmacological corrector of the mutant CFTR chloride channel. SCIENCE ADVANCES 2020; 6:eaay9669. [PMID: 32128418 PMCID: PMC7034990 DOI: 10.1126/sciadv.aay9669] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 12/04/2019] [Indexed: 06/10/2023]
Abstract
F508del, the most frequent mutation causing cystic fibrosis (CF), results in mistrafficking and premature degradation of the CFTR chloride channel. Small molecules named correctors may rescue F508del-CFTR and therefore represent promising drugs to target the basic defect in CF. We screened a carefully designed chemical library to find F508del-CFTR correctors. The initial active compound resulting from the primary screening underwent extensive chemical optimization. The final compound, ARN23765, showed an extremely high potency in bronchial epithelial cells from F508del homozygous patients, with an EC50 of 38 picomolar, which is more than 5000-fold lower compared to presently available corrector drugs. ARN23765 also showed high efficacy, synergy with other types of correctors, and compatibility with chronic VX-770 potentiator. Besides being a promising drug, particularly suited for drug combinations, ARN23765 represents a high-affinity probe for CFTR structure-function studies.
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Affiliation(s)
| | - Fabio Bertozzi
- D3 PharmaChemistry, Fondazione Istituto Italiano di Tecnologia, Genova, Italy
| | - Emanuela Caci
- UOC Genetica Medica, IRCCS Istituto Giannina Gaslini, 16147 Genova, Italy
| | - Federico Sorana
- D3 PharmaChemistry, Fondazione Istituto Italiano di Tecnologia, Genova, Italy
| | - Paolo Di Fruscia
- D3 PharmaChemistry, Fondazione Istituto Italiano di Tecnologia, Genova, Italy
| | - Valeria Tomati
- UOC Genetica Medica, IRCCS Istituto Giannina Gaslini, 16147 Genova, Italy
| | - Loretta Ferrera
- UOC Genetica Medica, IRCCS Istituto Giannina Gaslini, 16147 Genova, Italy
| | | | - Francesco Berti
- D3 PharmaChemistry, Fondazione Istituto Italiano di Tecnologia, Genova, Italy
| | - Emanuela Pesce
- UOC Genetica Medica, IRCCS Istituto Giannina Gaslini, 16147 Genova, Italy
| | - Elvira Sondo
- UOC Genetica Medica, IRCCS Istituto Giannina Gaslini, 16147 Genova, Italy
| | - Ambra Gianotti
- UOC Genetica Medica, IRCCS Istituto Giannina Gaslini, 16147 Genova, Italy
| | - Paolo Scudieri
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Tiziano Bandiera
- D3 PharmaChemistry, Fondazione Istituto Italiano di Tecnologia, Genova, Italy
| | - Luis J. V. Galietta
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
- Department of Translational Medical Sciences (DISMET), University of Naples Federico II, Naples, Italy
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42
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Towards next generation therapies for cystic fibrosis: Folding, function and pharmacology of CFTR. J Cyst Fibros 2020; 19 Suppl 1:S25-S32. [PMID: 31902693 PMCID: PMC7052731 DOI: 10.1016/j.jcf.2019.12.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 12/16/2019] [Accepted: 12/18/2019] [Indexed: 12/19/2022]
Abstract
The treatment of cystic fibrosis (CF) has been transformed by orally-bioavailable small molecule modulators of the cystic fibrosis transmembrane conductance regulator (CFTR), which restore function to CF mutants. However, CFTR modulators are not available to all people with CF and better modulators are required to prevent disease progression. Here, we review selectively recent advances in CFTR folding, function and pharmacology. We highlight ensemble and single-molecule studies of CFTR folding, which provide new insight into CFTR assembly, its perturbation by CF mutations and rescue by CFTR modulators. We discuss species-dependent differences in the action of the F508del-CFTR mutation on CFTR expression, stability and function, which might influence pharmacological studies of CFTR modulators in CF animal models. Finally, we illuminate the identification of combinations of two CFTR potentiators (termed co-potentiators), which restore therapeutically-relevant levels of CFTR activity to rare CF mutations. Thus, mechanistic studies of CFTR folding, function and pharmacology inform the development of highly effective CFTR modulators.
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Krainer G, Schenkel M, Hartmann A, Ravamehr-Lake D, Deber CM, Schlierf M. CFTR transmembrane segments are impaired in their conformational adaptability by a pathogenic loop mutation and dynamically stabilized by Lumacaftor. J Biol Chem 2019; 295:1985-1991. [PMID: 31882543 DOI: 10.1074/jbc.ac119.011360] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 12/20/2019] [Indexed: 12/20/2022] Open
Abstract
The cystic fibrosis transmembrane conductance regulator (CFTR) is an ion channel protein that is defective in individuals with cystic fibrosis (CF). To advance the rational design of CF therapies, it is important to elucidate how mutational defects in CFTR lead to its impairment and how pharmacological compounds interact with and alter CFTR. Here, using a helical-hairpin construct derived from CFTR's transmembrane (TM) helices 3 and 4 (TM3/4) and their intervening loop, we investigated the structural effects of a patient-derived CF-phenotypic mutation, E217G, located in the loop region of CFTR's membrane-spanning domain. Employing a single-molecule FRET assay to probe the folding status of reconstituted hairpins in lipid bilayers, we found that the E217G hairpin exhibits an altered adaptive packing behavior stemming from an additional GXXXG helix-helix interaction motif created in the mutant hairpin. This observation suggested that the misfolding and functional defects caused by the E217G mutation arise from an impaired conformational adaptability of TM helical segments in CFTR. The addition of the small-molecule corrector Lumacaftor exerts a helix stabilization effect not only on the E217G mutant hairpin, but also on WT TM3/4 and other mutations in the hairpin. This finding suggests a general mode of action for Lumacaftor through which this corrector efficiently improves maturation of various CFTR mutants.
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Affiliation(s)
- Georg Krainer
- B CUBE-Center for Molecular Bioengineering, Technische Universität Dresden, Tatzberg 41, 01307 Dresden, Germany.
| | - Mathias Schenkel
- B CUBE-Center for Molecular Bioengineering, Technische Universität Dresden, Tatzberg 41, 01307 Dresden, Germany
| | - Andreas Hartmann
- B CUBE-Center for Molecular Bioengineering, Technische Universität Dresden, Tatzberg 41, 01307 Dresden, Germany
| | - Dorna Ravamehr-Lake
- Division of Molecular Medicine, Research Institute, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada; Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Charles M Deber
- Division of Molecular Medicine, Research Institute, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada; Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada.
| | - Michael Schlierf
- B CUBE-Center for Molecular Bioengineering, Technische Universität Dresden, Tatzberg 41, 01307 Dresden, Germany; Cluster of Excellence Physics of Life, TU Dresden, 01062 Dresden, Germany.
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Amico G, Brandas C, Moran O, Baroni D. Unravelling the Regions of Mutant F508del-CFTR More Susceptible to the Action of Four Cystic Fibrosis Correctors. Int J Mol Sci 2019; 20:ijms20215463. [PMID: 31683989 PMCID: PMC6862496 DOI: 10.3390/ijms20215463] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 10/24/2019] [Accepted: 10/29/2019] [Indexed: 02/06/2023] Open
Abstract
Cystic fibrosis (CF) is a genetic disease associated with the defective function of the cystic fibrosis transmembrane conductance regulator (CFTR) protein that causes obstructive disease and chronic bacterial infections in airway epithelia. The most prevalent CF-causing mutation, the deletion of phenylalanine at position 508 (F508del), leads to CFTR misfolding, trafficking defects and premature degradation. A number of correctors that are able to partially rescue F508del-CFTR processing defects have been identified. Clinical trials have demonstrated that, unfortunately, mono-therapy with the best correctors identified to date does not ameliorate lung function or sweat chloride concentration in homozygous F508del patients. Understanding the mechanisms exerted by currently available correctors to increase mutant F508del-CFTR expression is essential for the development of new CF-therapeutics. We investigated the activity of correctors on the mutant F508del and wild type (WT) CFTR to identify the protein domains whose expression is mostly affected by the action of correctors, and we investigated their mechanisms of action. We found that the four correctors under study, lumacaftor (VX809), the quinazoline derivative VX325, the bithiazole compound corr4a, and the new molecule tezacaftor (VX661), do not influence either the total expression or the maturation of the WT-CFTR transiently expressed in human embryonic kidney 293 (HEK293) cells. Contrarily, they significantly enhance the expression and the maturation of the full length F508del molecule. Three out of four correctors, VX809, VX661 and VX325, seem to specifically improve the expression and the maturation of the mutant CFTR N-half (M1N1, residues 1–633). By contrast, the CFTR C-half (M2N2, residues 837–1480) appears to be the region mainly affected by corr4a. VX809 was shown to stabilize both the WT- and F508del-CFTR N-half isoforms, while VX661 and VX325 demonstrated the ability to enhance the stability only of the mutant F508del polypeptide.
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Affiliation(s)
- Giulia Amico
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, 16149 Genova, Italy.
| | - Chiara Brandas
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, 16149 Genova, Italy.
| | - Oscar Moran
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, 16149 Genova, Italy.
| | - Debora Baroni
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, 16149 Genova, Italy.
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Villamizar O, Waters SA, Scott T, Saayman S, Grepo N, Urak R, Davis A, Jaffe A, Morris KV. Targeted Activation of Cystic Fibrosis Transmembrane Conductance Regulator. Mol Ther 2019; 27:1737-1748. [PMID: 31383454 PMCID: PMC6822231 DOI: 10.1016/j.ymthe.2019.07.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Revised: 06/24/2019] [Accepted: 07/03/2019] [Indexed: 01/05/2023] Open
Abstract
Cystic fibrosis (CF) is caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. The majority of CFTR mutations result in impaired chloride channel function as only a fraction of the mutated CFTR reaches the plasma membrane. The development of a therapeutic approach that facilitates increased cell-surface expression of CFTR could prove clinically relevant. Here, we evaluate and contrast two molecular approaches to activate CFTR expression. We find that an RNA-guided nuclease null Cas9 (dCas9) fused with a tripartite activator, VP64-p65-Rta can activate endogenous CFTR in cultured human nasal epithelial cells from CF patients. We also find that targeting BGas, a long non-coding RNA involved in transcriptionally modulating CFTR expression with a gapmer, induced both strong knockdown of BGas and concordant activation of CFTR. Notably, the gapmer can be delivered to target cells when generated as electrostatic particles with recombinant HIV-Tat cell penetrating peptide (CPP), when packaged into exosomes, or when loaded into lipid nanoparticles (LNPs). Treatment of patient-derived human nasal epithelial cells containing F508del with gapmer-CPP, gapmer-exosomes, or LNPs resulted in increased expression and function of CFTR. Collectively, these observations suggest that CRISPR/dCas-VPR (CRISPR) and BGas-gapmer approaches can target and specifically activate CFTR.
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Affiliation(s)
- Olga Villamizar
- Center for Gene Therapy, City of Hope-Beckman Research Institute at the City of Hope, Duarte, CA 91010, USA
| | - Shafagh A Waters
- Faculty of Medicine, School of Women's & Children's Health, University of New South Wales (UNSW), Sydney, NSW, Australia; Molecular and Integrative Cystic Fibrosis Research Centre (miCF_RC), School of Women's & Children's Health, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Tristan Scott
- Center for Gene Therapy, City of Hope-Beckman Research Institute at the City of Hope, Duarte, CA 91010, USA
| | - Sheena Saayman
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Nicole Grepo
- Center for Gene Therapy, City of Hope-Beckman Research Institute at the City of Hope, Duarte, CA 91010, USA
| | - Ryan Urak
- Center for Gene Therapy, City of Hope-Beckman Research Institute at the City of Hope, Duarte, CA 91010, USA
| | - Alicia Davis
- Center for Gene Therapy, City of Hope-Beckman Research Institute at the City of Hope, Duarte, CA 91010, USA
| | - Adam Jaffe
- Faculty of Medicine, School of Women's & Children's Health, University of New South Wales (UNSW), Sydney, NSW, Australia; Molecular and Integrative Cystic Fibrosis Research Centre (miCF_RC), School of Women's & Children's Health, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia; Department of Respiratory Medicine, Sydney Children's Hospital, Sydney, NSW, Australia
| | - Kevin V Morris
- Center for Gene Therapy, City of Hope-Beckman Research Institute at the City of Hope, Duarte, CA 91010, USA.
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Krainer G, Keller S, Schlierf M. Structural dynamics of membrane-protein folding from single-molecule FRET. Curr Opin Struct Biol 2019; 58:124-137. [DOI: 10.1016/j.sbi.2019.05.025] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 05/27/2019] [Indexed: 12/15/2022]
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Kim Chiaw P, Hantouche C, Wong MJH, Matthes E, Robert R, Hanrahan JW, Shrier A, Young JC. Hsp70 and DNAJA2 limit CFTR levels through degradation. PLoS One 2019; 14:e0220984. [PMID: 31408507 PMCID: PMC6692068 DOI: 10.1371/journal.pone.0220984] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Accepted: 07/26/2019] [Indexed: 11/18/2022] Open
Abstract
Cystic Fibrosis is caused by mutations in the CFTR anion channel, many of which cause its misfolding and degradation. CFTR folding depends on the Hsc70 and Hsp70 chaperones and their co-chaperone DNAJA1, but Hsc70/Hsp70 is also involved in CFTR degradation. Here, we address how these opposing functions are balanced. DNAJA2 and DNAJA1 were both important for CFTR folding, however overexpressing DNAJA2 but not DNAJA1 enhanced CFTR degradation at the endoplasmic reticulum by Hsc70/Hsp70 and the E3 ubiquitin ligase CHIP. Excess Hsp70 also promoted CFTR degradation, but this occurred through the lysosomal pathway and required CHIP but not complex formation with HOP and Hsp90. Notably, the Hsp70 inhibitor MKT077 enhanced levels of mature CFTR and the most common disease variant ΔF508-CFTR, by slowing turnover and allowing delayed maturation, respectively. MKT077 also boosted the channel activity of ΔF508-CFTR when combined with the corrector compound VX809. Thus, the Hsp70 system is the major determinant of CFTR degradation, and its modulation can partially relieve the misfolding phenotype.
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Affiliation(s)
- Patrick Kim Chiaw
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada
- Groupe de Recherche Axé sur la Structure des Protéines, McGill University, Montreal, Quebec, Canada
| | - Christine Hantouche
- Groupe de Recherche Axé sur la Structure des Protéines, McGill University, Montreal, Quebec, Canada
- Department of Physiology, McGill University, Montreal, Quebec, Canada
| | - Michael J. H. Wong
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada
- Groupe de Recherche Axé sur la Structure des Protéines, McGill University, Montreal, Quebec, Canada
| | - Elizabeth Matthes
- Groupe de Recherche Axé sur la Structure des Protéines, McGill University, Montreal, Quebec, Canada
- Department of Physiology, McGill University, Montreal, Quebec, Canada
| | - Renaud Robert
- Groupe de Recherche Axé sur la Structure des Protéines, McGill University, Montreal, Quebec, Canada
- Department of Physiology, McGill University, Montreal, Quebec, Canada
| | - John W. Hanrahan
- Groupe de Recherche Axé sur la Structure des Protéines, McGill University, Montreal, Quebec, Canada
- Department of Physiology, McGill University, Montreal, Quebec, Canada
| | - Alvin Shrier
- Groupe de Recherche Axé sur la Structure des Protéines, McGill University, Montreal, Quebec, Canada
- Department of Physiology, McGill University, Montreal, Quebec, Canada
| | - Jason C. Young
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada
- Groupe de Recherche Axé sur la Structure des Protéines, McGill University, Montreal, Quebec, Canada
- * E-mail:
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Spanò V, Montalbano A, Carbone A, Scudieri P, Galietta LJV, Barraja P. An overview on chemical structures as ΔF508-CFTR correctors. Eur J Med Chem 2019; 180:430-448. [PMID: 31326599 DOI: 10.1016/j.ejmech.2019.07.037] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 07/09/2019] [Accepted: 07/10/2019] [Indexed: 10/26/2022]
Abstract
Deletion of phenylalanine at position 508 (F508del) in the CFTR protein, is the most common mutation causing cystic fibrosis (CF). F508del causes misfolding and rapid degradation of CFTR protein a defect that can be targeted with pharmacological agents termed "correctors". Correctors belong to various chemical classes but are generally small molecules based on nitrogen sulfur or oxygen heterocycles. The mechanism of action of correctors is generally unknown but there is experimental evidence that some of them can directly act on mutant CFTR improving folding and stability. Here we overview the characteristics of the various F508del correctors described so far to obtain indications on key chemical structures and modifications that are required for mutant protein rescue.
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Affiliation(s)
- Virginia Spanò
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Via Archirafi 32, 90123, Palermo, Italy
| | - Alessandra Montalbano
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Via Archirafi 32, 90123, Palermo, Italy
| | - Anna Carbone
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Via Archirafi 32, 90123, Palermo, Italy
| | - Paolo Scudieri
- Telethon Institute of Genetics and Medicine (TIGEM), Campi Flegrei 34, 80078, Pozzuoli, NA, Italy
| | - Luis J V Galietta
- Telethon Institute of Genetics and Medicine (TIGEM), Campi Flegrei 34, 80078, Pozzuoli, NA, Italy; Department of Translational Medical Sciences (DISMET), University of Naples, "Federico II", 80131, Naples, Italy
| | - Paola Barraja
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Via Archirafi 32, 90123, Palermo, Italy.
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Huang Y, Arora K, Mun KS, Yang F, Moon C, Yarlagadda S, Jegga A, Weaver T, Naren AP. Targeting DNAJB9, a novel ER luminal co-chaperone, to rescue ΔF508-CFTR. Sci Rep 2019; 9:9808. [PMID: 31285458 PMCID: PMC6614449 DOI: 10.1038/s41598-019-46161-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 06/19/2019] [Indexed: 01/30/2023] Open
Abstract
The molecular mechanism of Endoplasmic Reticulum-associated degradation (ERAD) of Cystic fibrosis transmembrane-conductance regulator (CFTR) is largely unknown. Particularly, it is unknown what ER luminal factor(s) are involved in ERAD. Herein, we used ProtoArray to identify an ER luminal co-chaperone, DNAJB9, which can directly interact with CFTR. For both WT- and ΔF508 (deletion of phenylalanine at position 508, the most common CF-causing mutant)-CFTR, knockdown of DNAJB9 by siRNA increased their expression levels on the cell surface and, consequently, upregulated their function. Furthermore, genetic ablation of DNAJB9 in WT mice increased CFTR expression and enhanced CFTR-dependent fluid secretion in enteroids. Importantly, DNAJB9 deficiency upregulated enteroids' fluid secretion in CF mice (homozygous for ΔF508), and silencing one allele of DNAJB9 is sufficient to rescue ΔF508-CFTR in vitro and in vivo, suggesting that DNAJB9 may be a rate-limiting factor in CFTR ERAD pathway. Our studies identified the first ER luminal co-chaperone involved in CFTR ERAD, and DNAJB9 could be a novel therapeutic target for CF.
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Affiliation(s)
- Yunjie Huang
- Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, United States
| | - Kavisha Arora
- Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, United States
| | - Kyu Shik Mun
- Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, United States
| | - Fanmuyi Yang
- Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, United States
| | - ChangSuk Moon
- Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, United States
| | - Sunitha Yarlagadda
- Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, United States
| | - Anil Jegga
- Division of Biomedical Informatics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, United States
| | - Timothy Weaver
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, United States
| | - Anjaparavanda P Naren
- Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, United States.
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50
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Donato M, Geisler M. HSP
90 and co‐chaperones: a multitaskers’ view on plant hormone biology. FEBS Lett 2019; 593:1415-1430. [DOI: 10.1002/1873-3468.13499] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 06/12/2019] [Accepted: 06/12/2019] [Indexed: 12/30/2022]
Affiliation(s)
- Martin Donato
- Department of Biology University of Fribourg Switzerland
| | - Markus Geisler
- Department of Biology University of Fribourg Switzerland
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