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Peters KW, Gong X, Frizzell RA. Cystic Fibrosis Transmembrane Conductance Regulator Folding Mutations Reveal Differences in Corrector Efficacy Linked to Increases in Immature Cystic Fibrosis Transmembrane Conductance Regulator Expression. Front Physiol 2021; 12:695767. [PMID: 34764878 PMCID: PMC8576290 DOI: 10.3389/fphys.2021.695767] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 07/05/2021] [Indexed: 11/17/2022] Open
Abstract
Background: Most cystic fibrosis is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene that lead to protein misfolding and degradation by the ubiquitin–proteasome system. Previous studies demonstrated that PIAS4 facilitates the modification of wild-type (WT) and F508del CFTR by small ubiquitin-like modifier (SUMO)-1, enhancing CFTR biogenesis by slowing immature CFTR degradation and producing increased immature CFTR band B. Methods: We evaluated two correction strategies using misfolding mutants, including the common variant, F508del. We examined the effects on mutant expression of co-expression with PIAS4 (E3 SUMO ligase), and/or the corrector, C18. To study the impact of these correction conditions, we transfected CFBE410- cells, a bronchial epithelial cell line, with a CFTR mutant plus: (1) empty vector, (2) empty vector plus overnight 5 μM C18, (3) PIAS4, and (4) PIAS4 plus C18. We assessed expression at steady state by immunoblot of CFTR band B, and if present, band C, and the corresponding C:B band ratio. The large PIAS4-induced increase in band B expression allowed us to ask whether C18 could act on the now abundant immature protein to enhance correction above the control level, as reported by the C:B ratio. Results: The data fell into three mutant CFTR categories as follows: (1) intransigent: no observable band C under any condition (i.e., C:B = 0); (2) throughput responsive: a C:B ratio less than control, but suggesting that the increased band C resulted from PIAS4-induced increases in band B production; and (3) folding responsive: a C:B ratio greater than control, reflecting C18-induced folding greater than that expected from increased throughput due to the PIAS4-induced band B level. Conclusion: These results suggest that the immature forms of CFTR folding intermediates occupy different loci within the energetic/kinetic folding landscape of CFTR. The evaluation of their properties could assist in the development of correctors that can target the more difficult-to-fold mutant conformations that occupy different sites within the CFTR folding pathway.
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Affiliation(s)
- Kathryn W Peters
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Xiaoyan Gong
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Raymond A Frizzell
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
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Hernandez SM, Tikhonova EB, Karamyshev AL. Protein-Protein Interactions in Alpha-Synuclein Biogenesis: New Potential Targets in Parkinson's Disease. Front Aging Neurosci 2020; 12:72. [PMID: 32256340 PMCID: PMC7092629 DOI: 10.3389/fnagi.2020.00072] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Accepted: 02/27/2020] [Indexed: 12/14/2022] Open
Abstract
Parkinson’s disease (PD) is a debilitating neurodegenerative disorder defined by a loss of dopamine-producing neurons in the substantia nigra in the brain. It is associated with cytosolic inclusions known as Lewy bodies. The major component of Lewy bodies is aggregated alpha-synuclein. The molecular mechanism of alpha-synuclein aggregation is not known. Our conceptual model is that alpha-synuclein aggregates due to a dysregulation of its interactions with other protein partners that are required for its biogenesis. In this mini review article, we identified alpha-synuclein interactions using both current literature and predictive pathway analysis. Alterations of these interactions may be crucial elements for the molecular mechanism of the protein aggregation and related pathology in the disease. Identification of alpha-synuclein interactions provides valuable tools to understand PD pathology and find new pharmacological targets for disease treatment.
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Affiliation(s)
- Sarah M Hernandez
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX, United States
| | - Elena B Tikhonova
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX, United States
| | - Andrey L Karamyshev
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX, United States
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Dukovski D, Villella A, Bastos C, King R, Finley D, Kelly JW, Morimoto RI, Hartl FU, Munoz B, Lee PS, Zecevic M, Miller JP. Amplifiers co-translationally enhance CFTR biosynthesis via PCBP1-mediated regulation of CFTR mRNA. J Cyst Fibros 2020; 19:733-741. [PMID: 32067958 DOI: 10.1016/j.jcf.2020.02.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 02/01/2020] [Accepted: 02/06/2020] [Indexed: 12/21/2022]
Abstract
BACKGROUND Cystic fibrosis (CF) is a recessive disorder caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. We previously described a first-in-class CFTR modulator that functions as an amplifier to selectively increase CFTR expression and function. The amplifier mechanism is distinct from and complementary to corrector and potentiator classes of CFTR modulators. Here we characterize the mechanism by which amplifiers increase CFTR mRNA, protein, and activity. METHODS Biochemical studies elucidated the action of amplifiers on CFTR mRNA abundance and translation and defined the role of an amplifier-binding protein that was identified using chemical proteomics. RESULTS Amplifiers stabilize CFTR mRNA through a process that requires only the translated sequence of CFTR and involves translational elongation. Amplifiers enrich ER-associated CFTR mRNA and increase its translational efficiency through increasing the fraction of CFTR mRNA associated with polysomes. Pulldowns identified the poly(rC)-binding protein 1 (PCBP1) as directly binding to amplifier. A PCBP1 consensus element was identified within the CFTR open reading frame that binds PCBP1. This sequence proved necessary for amplifier responsiveness. CONCLUSIONS Small molecule amplifiers co-translationally increase CFTR mRNA stability. They enhance translation through addressing the inherently inefficient membrane targeting of CFTR mRNA. Amplifiers bind directly to PCBP1, show enhanced affinity in the presence of bound RNA, and require a PCBP1 consensus element within CFTR mRNA to elicit translational effects. These modulators represent a promising new and mechanistically novel class of CFTR therapeutic. They may be useful as a monotherapy or in combination with other CFTR modulators.
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Affiliation(s)
- Danijela Dukovski
- Proteostasis Therapeutics, Inc., 80 Guest St, Suite 500, Boston, MA 02135, United States
| | - Adriana Villella
- Proteostasis Therapeutics, Inc., 80 Guest St, Suite 500, Boston, MA 02135, United States
| | - Cecilia Bastos
- Proteostasis Therapeutics, Inc., 80 Guest St, Suite 500, Boston, MA 02135, United States
| | - Randall King
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, United States
| | - Daniel Finley
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, United States
| | - Jeffery W Kelly
- Departments of Molecular Medicine and Chemistry, The Scripps Research Institute, La Jolla, CA 92037, United States
| | - Richard I Morimoto
- Department of Molecular Bioscience, Rice Institute for Biomedical Research, Northwestern University, Evanston, IL, United States
| | - F Ulrich Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany
| | - Benito Munoz
- Proteostasis Therapeutics, Inc., 80 Guest St, Suite 500, Boston, MA 02135, United States
| | - Po-Shun Lee
- Proteostasis Therapeutics, Inc., 80 Guest St, Suite 500, Boston, MA 02135, United States
| | - Marija Zecevic
- Proteostasis Therapeutics, Inc., 80 Guest St, Suite 500, Boston, MA 02135, United States
| | - John Preston Miller
- Proteostasis Therapeutics, Inc., 80 Guest St, Suite 500, Boston, MA 02135, United States.
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Riemma G, Laganà AS, Schiattarella A, Garzon S, Cobellis L, Autiero R, Licciardi F, Della Corte L, La Verde M, De Franciscis P. Ion Channels in The Pathogenesis of Endometriosis: A Cutting-Edge Point of View. Int J Mol Sci 2020; 21:E1114. [PMID: 32046116 DOI: 10.3390/ijms21031114] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 01/24/2020] [Accepted: 02/05/2020] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Ion channels play a crucial role in many physiological processes. Several subtypes are expressed in the endometrium. Endometriosis is strictly correlated to estrogens and it is evident that expression and functionality of different ion channels are estrogen-dependent, fluctuating between the menstrual phases. However, their relationship with endometriosis is still unclear. OBJECTIVE To summarize the available literature data about the role of ion channels in the etiopathogenesis of endometriosis. METHODS A search on PubMed and Medline databases was performed from inception to November 2019. RESULTS Cystic fibrosis transmembrane conductance regulator (CFTR), transient receptor potentials (TRPs), aquaporins (AQPs), and chloride channel (ClC)-3 expression and activity were analyzed. CFTR expression changed during the menstrual phases and was enhanced in endometriosis samples; its overexpression promoted endometrial cell proliferation, migration, and invasion throughout nuclear factor kappa-light-chain-enhancer of activated B cells-urokinase plasminogen activator receptor (NFκB-uPAR) signaling pathway. No connection between TRPs and the pathogenesis of endometriosis was found. AQP5 activity was estrogen-increased and, through phosphatidylinositol-3-kinase and protein kinase B (PI3K/AKT), helped in vivo implantation of ectopic endometrium. In vitro, AQP9 participated in extracellular signal-regulated kinases/p38 mitogen-activated protein kinase (ERK/p38 MAPK) pathway and helped migration and invasion stimulating matrix metalloproteinase (MMP)2 and MMP9. ClC-3 was also overexpressed in ectopic endometrium and upregulated MMP9. CONCLUSION Available evidence suggests a pivotal role of CFTR, AQPs, and ClC-3 in endometriosis etiopathogenesis. However, data obtained are not sufficient to establish a direct role of ion channels in the etiology of the disease. Further studies are needed to clarify this relationship.
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