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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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2
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Meneses DG, Dos Santos FR, Botelho AJ, Bispo LM, Matos CG, Propheta VGS, Rodrigues AF, Oliveira GU, da Silva AM, Gurgel RQ. Diagnosis of cystic fibrosis: a high heterogeneity of symptoms and genotypes in a Brazil population. BMC Pediatr 2024; 24:422. [PMID: 38956483 PMCID: PMC11218259 DOI: 10.1186/s12887-024-04891-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2023] [Accepted: 06/19/2024] [Indexed: 07/04/2024] Open
Abstract
INTRODUCTION In highly multiracial populations with inadequate newborn screening, knowledge of the various phenotypic presentations of Cystic Fibrosis (CF) can help reach an early diagnosis. This study aims to describe phenotypes and genotypes at the time of CF diagnosis in a state in the Northeast Region of Brazil. METHODS Retrospective cross-sectional study. Clinical data were extracted from the medical records of CF patients. Clinical, laboratory, and genotypic characteristics were described for patients admitted to a tertiary referral center between 2007 and 2021. RESULTS Fifty-eight (58) patients were included in the study, 53.5% of whom were diagnosed through clinical suspicion. The median age at diagnosis was 4.7 months (IQR: 1.5-14.8 months). Five patients had false-negative results in the newborn screening. Faltering growth was the most frequent clinical manifestation. Bronchiectasis and a history of pneumonia predominated in those older than ten, while thinness, underweight, and electrolyte imbalances were more frequent in children under two. Sequencing of the CFTR gene identified 27 genotypes, with at least one class I-III variant in all patients, and nine variants that are rare, previously undescribed, or have uncertain significance (619delA, T12991, K162Q, 3195del6, 1678del > T, 124del123bp, 3121-3113 A > T). The most frequent alleles were p.Phe508del, p.Gly542*, p.Arg334Trp, and p.Ser549Arg. CONCLUSIONS Malnutrition and electrolyte imbalances were the most frequent phenotypes for children < 2 years and were associated with genotypes including 2 class I-III variants. Rare and previously undescribed variants were identified. The p.Gly542*, p.Arg334Trp, and p.Ser549Arg alleles were among the most frequent variants in this population.
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Affiliation(s)
- Daniela Gois Meneses
- Department of Medicine, Federal University of Sergipe, Aracaju, Sergipe, Brazil.
- Health Sciences Graduate Program, Federal University of Sergipe, Aracaju, Sergipe, Brazil.
- Center for Biological and Health Sciences (NPGME), University Hospital, Federal University of Sergipe, Rua Cláudio Batista 505, Palestina, Aracaju, Sergipe, CEP 49060-025, Brazil.
| | - Fábia Regina Dos Santos
- Health Sciences Graduate Program, Federal University of Sergipe, Aracaju, Sergipe, Brazil
- Center for Biological and Health Sciences (NPGME), University Hospital, Federal University of Sergipe, Rua Cláudio Batista 505, Palestina, Aracaju, Sergipe, CEP 49060-025, Brazil
| | - Anne Jardim Botelho
- Health Sciences Graduate Program, Federal University of Sergipe, Aracaju, Sergipe, Brazil
- Center for Biological and Health Sciences (NPGME), University Hospital, Federal University of Sergipe, Rua Cláudio Batista 505, Palestina, Aracaju, Sergipe, CEP 49060-025, Brazil
| | - Luciana Mota Bispo
- Center for Biological and Health Sciences (NPGME), University Hospital, Federal University of Sergipe, Rua Cláudio Batista 505, Palestina, Aracaju, Sergipe, CEP 49060-025, Brazil
| | - Camilla Guerra Matos
- Center for Biological and Health Sciences (NPGME), University Hospital, Federal University of Sergipe, Rua Cláudio Batista 505, Palestina, Aracaju, Sergipe, CEP 49060-025, Brazil
| | - Vynicius Goltran Sobral Propheta
- Center for Biological and Health Sciences (NPGME), University Hospital, Federal University of Sergipe, Rua Cláudio Batista 505, Palestina, Aracaju, Sergipe, CEP 49060-025, Brazil
| | - Alexia Ferreira Rodrigues
- Center for Biological and Health Sciences (NPGME), University Hospital, Federal University of Sergipe, Rua Cláudio Batista 505, Palestina, Aracaju, Sergipe, CEP 49060-025, Brazil
| | - Géssica Uruga Oliveira
- Center for Biological and Health Sciences (NPGME), University Hospital, Federal University of Sergipe, Rua Cláudio Batista 505, Palestina, Aracaju, Sergipe, CEP 49060-025, Brazil
| | - Angela Maria da Silva
- Department of Medicine, Federal University of Sergipe, Aracaju, Sergipe, Brazil
- Health Sciences Graduate Program, Federal University of Sergipe, Aracaju, Sergipe, Brazil
| | - Ricardo Queiroz Gurgel
- Department of Medicine, Federal University of Sergipe, Aracaju, Sergipe, Brazil
- Health Sciences Graduate Program, Federal University of Sergipe, Aracaju, Sergipe, Brazil
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3
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Rajasekaran N, Kaiser CM. Navigating the complexities of multi-domain protein folding. Curr Opin Struct Biol 2024; 86:102790. [PMID: 38432063 DOI: 10.1016/j.sbi.2024.102790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 02/11/2024] [Accepted: 02/12/2024] [Indexed: 03/05/2024]
Abstract
Proteome complexity has expanded tremendously over evolutionary time, enabling biological diversification. Much of this complexity is achieved by combining a limited set of structural units into long polypeptides. This widely used evolutionary strategy poses challenges for folding of the resulting multi-domain proteins. As a consequence, their folding differs from that of small single-domain proteins, which generally fold quickly and reversibly. Co-translational processes and chaperone interactions are important aspects of multi-domain protein folding. In this review, we discuss some of the recent experimental progress toward understanding these processes.
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Affiliation(s)
| | - Christian M Kaiser
- Department of Biology, Johns Hopkins University, Baltimore, MD, United States; Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands.
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4
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Anglès F, Gupta V, Wang C, Balch WE. COPII cage assembly factor Sec13 integrates information flow regulating endomembrane function in response to human variation. Sci Rep 2024; 14:10160. [PMID: 38698045 PMCID: PMC11065896 DOI: 10.1038/s41598-024-60687-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 04/26/2024] [Indexed: 05/05/2024] Open
Abstract
How information flow is coordinated for managing transit of 1/3 of the genome through endomembrane pathways by the coat complex II (COPII) system in response to human variation remains an enigma. By examining the interactome of the COPII cage-assembly component Sec13, we show that it is simultaneously associated with multiple protein complexes that facilitate different features of a continuous program of chromatin organization, transcription, translation, trafficking, and degradation steps that are differentially sensitive to Sec13 levels. For the trafficking step, and unlike other COPII components, reduction of Sec13 expression decreased the ubiquitination and degradation of wild-type (WT) and F508del variant cargo protein cystic fibrosis transmembrane conductance regulator (CFTR) leading to a striking increase in fold stability suggesting that the events differentiating export from degradation are critically dependent on COPII cage assembly at the ER Golgi intermediate compartment (ERGIC) associated recycling and degradation step linked to COPI exchange. Given Sec13's multiple roles in protein complex assemblies that change in response to its expression, we suggest that Sec13 serves as an unanticipated master regulator coordinating information flow from the genome to the proteome to facilitate spatial covariant features initiating and maintaining design and function of membrane architecture in response to human variation.
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Affiliation(s)
- Frédéric Anglès
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Vijay Gupta
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Chao Wang
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - William E Balch
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Rd, La Jolla, CA, 92037, USA.
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5
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Ferreira FC, Amaral MD, Bacalhau M, Lopes-Pacheco M. PTI-801 (posenacaftor) shares a common mechanism with VX-445 (elexacaftor) to rescue p.Phe508del-CFTR. Eur J Pharmacol 2024; 967:176390. [PMID: 38336013 DOI: 10.1016/j.ejphar.2024.176390] [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: 08/22/2023] [Revised: 01/05/2024] [Accepted: 02/01/2024] [Indexed: 02/12/2024]
Abstract
The deletion of a phenylalanine at position 508 (p.Phe508del) in the CFTR anion channel is the most prevalent variant in people with Cystic Fibrosis (CF). This variant impairs folding and stability of the CF transmembrane conductance regulator (CFTR) protein, resulting in its defective trafficking and premature degradation. Over the last years, therapeutic accomplishments have been attained in developing small molecules that partially correct p.Phe508del-CFTR defects; however, the mechanism of action (MoA) of these compounds has only started to be uncovered. In this study, we employed biochemical, fluorescence microscopy, and functional assays to examine the efficacy and properties of PTI-801, a newly developed p.Phe508del-CFTR corrector. To exploit its MoA, we assessed PTI-801 effects in combination with low temperature, genetic revertants of p.Phe508del-CFTR (the in cis p.Val510Asp, p.Gly550Glu, p.Arg1070Trp, and 4RK) and other correctors. Our results demonstrated that PTI-801 rescues p.Phe508del-CFTR processing, PM trafficking, and channel function (upon agonist stimulation) with greater correction effects in combination with ABBV-2222, FDL-169, VX-661, or VX-809, but not with VX-445. Although PTI-801 exhibited no potentiator activity on low temperature- and corrector-rescued p.Phe508del-CFTR, this compound displayed similar behavior to that of VX-445 on genetic revertants. Such evidence associated with the lack of additivity when PTI-801 and VX-445 were combined indicates that they share a common binding site to correct p.Phe508del-CFTR defects. Despite the high efficacy of PTI-801 in combination with ABBV-2222, FDL-169, VX-661, or VX-809, these dual corrector combinations only partially restored p.Phe508del-CFTR conformational stability, as shown by the lower half-life of the mutant protein compared to that of WT-CFTR. In summary, PTI-801 likely shares a common MoA with VX-445 in rescuing p.Phe508del-CFTR, thus being a feasible alternative for the development of novel corrector combinations with greater capacity to rescue mutant CFTR folding and stability.
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Affiliation(s)
- Filipa C Ferreira
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisbon, 1749-016, Lisbon, Portugal
| | - Margarida D Amaral
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisbon, 1749-016, Lisbon, Portugal
| | - Mafalda Bacalhau
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisbon, 1749-016, Lisbon, Portugal
| | - Miquéias Lopes-Pacheco
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisbon, 1749-016, Lisbon, Portugal.
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6
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Farinha CM, Santos L, Ferreira JF. Cell type-specific regulation of CFTR trafficking-on the verge of progress. Front Cell Dev Biol 2024; 12:1338892. [PMID: 38505263 PMCID: PMC10949533 DOI: 10.3389/fcell.2024.1338892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 02/21/2024] [Indexed: 03/21/2024] Open
Abstract
Trafficking of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) protein is a complex process that starts with its biosynthesis and folding in the endoplasmic reticulum. Exit from the endoplasmic reticulum (ER) is coupled with the acquisition of a compact structure that can be processed and traffic through the secretory pathway. Once reaching its final destination-the plasma membrane, CFTR stability is regulated through interaction with multiple protein partners that are involved in its post-translation modification, connecting the channel to several signaling pathways. The complexity of the process is further boosted when analyzed in the context of the airway epithelium. Recent advances have characterized in detail the different cell types that compose the surface epithelium and shifted the paradigm on which cells express CFTR and on their individual and combined contribution to the total expression (and function) of this chloride/bicarbonate channel. Here we review CFTR trafficking and its relationship with the knowledge on the different cell types of the airway epithelia. We explore the crosstalk between these two areas and discuss what is still to be clarified and how this can be used to develop more targeted therapies for CF.
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Affiliation(s)
- Carlos M. Farinha
- Faculty of Sciences, BioISI—Biosystems and Integrative Sciences Institute, University of Lisboa, Lisboa, Portugal
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7
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Ferreira FC, Buarque CD, Lopes-Pacheco M. Organic Synthesis and Current Understanding of the Mechanisms of CFTR Modulator Drugs Ivacaftor, Tezacaftor, and Elexacaftor. Molecules 2024; 29:821. [PMID: 38398574 PMCID: PMC10891718 DOI: 10.3390/molecules29040821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 02/02/2024] [Accepted: 02/06/2024] [Indexed: 02/25/2024] Open
Abstract
The monogenic rare disease Cystic Fibrosis (CF) is caused by mutations in the gene encoding the CF transmembrane conductance (CFTR) protein, an anion channel expressed at the apical plasma membrane of epithelial cells. The discovery and subsequent development of CFTR modulators-small molecules acting on the basic molecular defect in CF-have revolutionized the standard of care for people with CF (PwCF), thus drastically improving their clinical features, prognosis, and quality of life. Currently, four of these drugs are approved for clinical use: potentiator ivacaftor (VX-770) alone or in combination with correctors lumacaftor, (VX-809), tezacaftor (VX-661), and elexacaftor (VX-445). Noteworthily, the triple combinatorial therapy composed of ivacaftor, tezacaftor, and elexacaftor constitutes the most effective modulator therapy nowadays for the majority of PwCF. In this review, we exploit the organic synthesis of ivacaftor, tezacaftor, and elexacaftor by providing a retrosynthetic drug analysis for these CFTR modulators. Furthermore, we describe the current understanding of the mechanisms of action (MoA's) of these compounds by discussing several studies that report the key findings on the molecular mechanisms underlying their action on the CFTR protein.
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Affiliation(s)
- Filipa C. Ferreira
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisbon, 1749-016 Lisbon, Portugal
| | - Camilla D. Buarque
- Department of Chemistry, Pontifical Catholic University of Rio de Janeiro (PUC-Rio), Rio de Janeiro 22435-900, RJ, Brazil
| | - Miquéias Lopes-Pacheco
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisbon, 1749-016 Lisbon, Portugal
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8
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Riepe C, Wąchalska M, Deol KK, Amaya AK, Porteus MH, Olzmann JA, Kopito RR. Small-molecule correctors divert CFTR-F508del from ERAD by stabilizing sequential folding states. Mol Biol Cell 2024; 35:ar15. [PMID: 38019608 PMCID: PMC10881158 DOI: 10.1091/mbc.e23-08-0336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 11/13/2023] [Accepted: 11/20/2023] [Indexed: 12/01/2023] Open
Abstract
Over 80% of people with cystic fibrosis (CF) carry the F508del mutation in the cystic fibrosis transmembrane conductance regulator (CFTR), a chloride ion channel at the apical plasma membrane (PM) of epithelial cells. F508del impairs CFTR folding causing it to be destroyed by endoplasmic reticulum associated degradation (ERAD). Small-molecule correctors, which act as pharmacological chaperones to divert CFTR-F508del from ERAD, are the primary strategy for treating CF, yet corrector development continues with only a rudimentary understanding of how ERAD targets CFTR-F508del. We conducted genome-wide CRISPR/Cas9 knockout screens to systematically identify the molecular machinery that underlies CFTR-F508del ERAD. Although the ER-resident ubiquitin ligase, RNF5 was the top E3 hit, knocking out RNF5 only modestly reduced CFTR-F508del degradation. Sublibrary screens in an RNF5 knockout background identified RNF185 as a redundant ligase and demonstrated that CFTR-F508del ERAD is robust. Gene-drug interaction experiments illustrated that correctors tezacaftor (VX-661) and elexacaftor (VX-445) stabilize sequential, RNF5-resistant folding states. We propose that binding of correctors to nascent CFTR-F508del alters its folding landscape by stabilizing folding states that are not substrates for RNF5-mediated ubiquitylation.
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Affiliation(s)
- Celeste Riepe
- Department of Biology, Stanford University, Stanford, CA 94305
| | - Magda Wąchalska
- Department of Biology, Stanford University, Stanford, CA 94305
| | - Kirandeep K. Deol
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 94720
- Chan Zuckerberg Biohub Network, San Francisco, CA 94158
| | - Anais K. Amaya
- Department of Pediatrics, Stanford University, Stanford, CA 94305
| | | | - James A. Olzmann
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 94720
- Chan Zuckerberg Biohub Network, San Francisco, CA 94158
| | - Ron R. Kopito
- Department of Biology, Stanford University, Stanford, CA 94305
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9
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Kleizen B, de Mattos E, Papaioannou O, Monti M, Tartaglia GG, van der Sluijs P, Braakman I. Transmembrane Helices 7 and 8 Confer Aggregation Sensitivity to the Cystic Fibrosis Transmembrane Conductance Regulator. Int J Mol Sci 2023; 24:15741. [PMID: 37958724 PMCID: PMC10648718 DOI: 10.3390/ijms242115741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 10/18/2023] [Accepted: 10/19/2023] [Indexed: 11/15/2023] Open
Abstract
The Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) is a large multi-spanning membrane protein that is susceptible to misfolding and aggregation. We have identified here the region responsible for this instability. Temperature-induced aggregation of C-terminally truncated versions of CFTR demonstrated that all truncations up to the second transmembrane domain (TMD2), including the R region, largely resisted aggregation. Limited proteolysis identified a folded structure that was prone to aggregation and consisted of TMD2 and at least part of the Regulatory Region R. Only when both TM7 (TransMembrane helix 7) and TM8 were present, TMD2 fragments became as aggregation-sensitive as wild-type CFTR, in line with increased thermo-instability of late CFTR nascent chains and in silico prediction of aggregation propensity. In accord, isolated TMD2 was degraded faster in cells than isolated TMD1. We conclude that TMD2 extended at its N-terminus with part of the R region forms a protease-resistant structure that induces heat instability in CFTR and may be responsible for its limited intracellular stability.
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Affiliation(s)
- Bertrand Kleizen
- Cellular Protein Chemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, 3584 CH Utrecht, The Netherlands; (B.K.); (E.d.M.); (O.P.); (P.v.d.S.)
| | - Eduardo de Mattos
- Cellular Protein Chemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, 3584 CH Utrecht, The Netherlands; (B.K.); (E.d.M.); (O.P.); (P.v.d.S.)
| | - Olga Papaioannou
- Cellular Protein Chemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, 3584 CH Utrecht, The Netherlands; (B.K.); (E.d.M.); (O.P.); (P.v.d.S.)
| | - Michele Monti
- Center for Life Nano- & Neuro-Science, Fondazione Istituto Italiano di Tecnologia (IIT), 00161 Rome, Italy; (M.M.); (G.G.T.)
- Centre for Human Technologies (CHT), Istituto Italiano di Tecnologia (IIT), 16152 Genoa, Italy
| | - Gian Gaetano Tartaglia
- Center for Life Nano- & Neuro-Science, Fondazione Istituto Italiano di Tecnologia (IIT), 00161 Rome, Italy; (M.M.); (G.G.T.)
- Centre for Human Technologies (CHT), Istituto Italiano di Tecnologia (IIT), 16152 Genoa, Italy
| | - Peter van der Sluijs
- Cellular Protein Chemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, 3584 CH Utrecht, The Netherlands; (B.K.); (E.d.M.); (O.P.); (P.v.d.S.)
| | - Ineke Braakman
- Cellular Protein Chemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, 3584 CH Utrecht, The Netherlands; (B.K.); (E.d.M.); (O.P.); (P.v.d.S.)
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10
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McDonald EF, Meiler J, Plate L. CFTR Folding: From Structure and Proteostasis to Cystic Fibrosis Personalized Medicine. ACS Chem Biol 2023; 18:2128-2143. [PMID: 37730207 PMCID: PMC10595991 DOI: 10.1021/acschembio.3c00310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 08/02/2023] [Indexed: 09/22/2023]
Abstract
Cystic fibrosis (CF) is a lethal genetic disease caused by mutations in the chloride ion channel cystic fibrosis transmembrane conductance regulator (CFTR). Class-II mutants of CFTR lack intermolecular interactions important for CFTR structural stability and lead to misfolding. Misfolded CFTR is detected by a diverse suite of proteostasis factors that preferentially bind and route mutant CFTR toward premature degradation, resulting in reduced plasma membrane CFTR levels and impaired chloride ion conductance associated with CF. CF treatment has been vastly improved over the past decade by the availability of small molecules called correctors. Correctors directly bind CFTR, stabilize its structure by conferring thermodynamically favorable interactions that compensate for mutations, and thereby lead to downstream folding fidelity. However, each of over 100 Class-II CF causing mutations causes unique structural defects and shows a unique response to drug treatment, described as theratype. Understanding CFTR structural defects, the proteostasis factors evaluating those defects, and the stabilizing effects of CFTR correctors will illuminate a path toward personalized medicine for CF. Here, we review recent advances in our understanding of CFTR folding, focusing on structure, corrector binding sites, the mechanisms of proteostasis factors that evaluate CFTR, and the implications for CF personalized medicine.
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Affiliation(s)
- Eli Fritz McDonald
- Department
of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
- Center
for Structural Biology, Vanderbilt University, Nashville, Tennessee 37240, United States
| | - Jens Meiler
- Department
of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
- Center
for Structural Biology, Vanderbilt University, Nashville, Tennessee 37240, United States
- Department
of Pharmacology, Vanderbilt University, Nashville, Tennessee 37240, United States
- Institute
for Drug Discovery, Leipzig University, Leipzig, SAC 04103, Germany
| | - Lars Plate
- Department
of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
- Department
of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37235, United States
- Department
of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
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11
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Riepe C, Wąchalska M, Deol KK, Amaya AK, Porteus MH, Olzmann JA, Kopito RR. Small molecule correctors divert CFTR-F508del from ERAD by stabilizing sequential folding states. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.15.556420. [PMID: 37745470 PMCID: PMC10515913 DOI: 10.1101/2023.09.15.556420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
Over 80% of people with cystic fibrosis (CF) carry the F508del mutation in the cystic fibrosis transmembrane conductance regulator (CFTR), a chloride ion channel at the apical plasma membrane (PM) of epithelial cells. F508del impairs CFTR folding causing it to be destroyed by endoplasmic reticulum associated degradation (ERAD). Small molecule correctors, which act as pharmacological chaperones to divert CFTR-F508del from ERAD, are the primary strategy for treating CF, yet corrector development continues with only a rudimentary understanding of how ERAD targets CFTR-F508del. We conducted genome-wide CRISPR/Cas9 knockout screens to systematically identify the molecular machinery that underlies CFTR-F508del ERAD. Although the ER-resident ubiquitin ligase, RNF5 was the top E3 hit, knocking out RNF5 only modestly reduced CFTR-F508del degradation. Sublibrary screens in an RNF5 knockout background identified RNF185 as a redundant ligase, demonstrating that CFTR-F508del ERAD is highly buffered. Gene-drug interaction experiments demonstrated that correctors tezacaftor (VX-661) and elexacaftor (VX-445) stabilize sequential, RNF5-resistant folding states. We propose that binding of correctors to nascent CFTR-F508del alters its folding landscape by stabilizing folding states that are not substrates for RNF5-mediated ubiquitylation.
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Affiliation(s)
- Celeste Riepe
- Department of Biology, Stanford University, Stanford, CA, USA 94305
| | - Magda Wąchalska
- Department of Biology, Stanford University, Stanford, CA, USA 94305
| | - Kirandeep K. Deol
- Department of Molecular and Cell Biology, University of California, Berkeley, CA USA 94720
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA USA 94720
- Chan Zuckerberg Biohub, San Francisco, CA, USA 94158
| | - Anais K. Amaya
- Department of Pediatrics, Stanford University, Stanford, CA, USA 94305
| | | | - James A. Olzmann
- Department of Molecular and Cell Biology, University of California, Berkeley, CA USA 94720
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA USA 94720
- Chan Zuckerberg Biohub, San Francisco, CA, USA 94158
| | - Ron R. Kopito
- Department of Biology, Stanford University, Stanford, CA, USA 94305
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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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Iazzi M, Sadeghi S, Gupta GD. A Proteomic Survey of the Cystic Fibrosis Transmembrane Conductance Regulator Surfaceome. Int J Mol Sci 2023; 24:11457. [PMID: 37511222 PMCID: PMC10380767 DOI: 10.3390/ijms241411457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 07/08/2023] [Accepted: 07/12/2023] [Indexed: 07/30/2023] Open
Abstract
The aim of this review article is to collate recent contributions of proteomic studies to cystic fibrosis transmembrane conductance regulator (CFTR) biology. We summarize advances from these studies and create an accessible resource for future CFTR proteomic efforts. We focus our attention on the CFTR interaction network at the cell surface, thus generating a CFTR 'surfaceome'. We review the main findings about CFTR interactions and highlight several functional categories amongst these that could lead to the discovery of potential biomarkers and drug targets for CF.
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Affiliation(s)
| | | | - Gagan D. Gupta
- Department of Chemistry and Biology, Toronto Metropolitan University, Toronto, ON M5B 2K3, Canada
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Edkins AL, Zweckstetter M, Sawarkar R. Tenth International Symposium on the Hsp90 chaperone machine : Switzerland, October 19-23, 2022. Cell Stress Chaperones 2023; 28:231-237. [PMID: 37071341 PMCID: PMC10111302 DOI: 10.1007/s12192-023-01342-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/21/2023] [Indexed: 04/19/2023] Open
Abstract
Hsp90 is a molecular chaperone responsible for regulating proteostasis under physiological and pathological conditions. Its central role in a range of diseases and potential as a drug target has focused efforts to understand its mechanisms and biological functions and to identify modulators that may form the basis for therapies. The 10th international conference on the Hsp90 chaperone machine was held in Switzerland in October 2022. The meeting was organized by Didier Picard (Geneva, Switzerland) and Johannes Buchner (Garching, Germany) with an advisory committee of Olivier Genest, Mehdi Mollapour, Ritwick Sawarkar, and Patricija van Oosten-Hawle. This was a much anticipated first in-person meeting of the Hsp90 community since 2018 after the COVID-19 pandemic led to the postponement of the 2020 meeting. The conference remained true to the tradition of sharing novel data ahead of publication, providing unparalleled depth of insight for both experts and newcomers to the field.
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Affiliation(s)
- Adrienne L. Edkins
- Biomedical Biotechnology Research Unit (BioBRU), Department of Microbiology and Biochemistry, Rhodes University, Makhanda, South Africa
| | - Markus Zweckstetter
- German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany
- Department for NMR-Based Structural Biology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Ritwick Sawarkar
- Medical Research Council (MRC) and Department of Genetics, University of Cambridge, Cambridge, UK
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