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Susorov D, Echeverria D, Khvorova A, Korostelev AA. mRNA-specific readthrough of nonsense codons by antisense oligonucleotides (R-ASOs). Nucleic Acids Res 2024:gkae624. [PMID: 39011883 DOI: 10.1093/nar/gkae624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 06/14/2024] [Accepted: 07/04/2024] [Indexed: 07/17/2024] Open
Abstract
Nonsense mutations account for >10% of human genetic disorders, including cystic fibrosis, Alagille syndrome, and Duchenne muscular dystrophy. A nonsense mutation results in the expression of a truncated protein, and therapeutic strategies aim to restore full-length protein expression. Most strategies under development, including small-molecule aminoglycosides, suppressor tRNAs, or the targeted degradation of termination factors, lack mRNA target selectivity and may poorly differentiate between nonsense and normal stop codons, resulting in off-target translation errors. Here, we demonstrate that antisense oligonucleotides can stimulate readthrough of disease-causing nonsense codons, resulting in high yields of full-length protein in mammalian cellular lysate. Readthrough efficiency depends on the sequence context near the stop codon and on the precise targeting position of an oligonucleotide, whose interaction with mRNA inhibits peptide release to promote readthrough. Readthrough-inducing antisense oligonucleotides (R-ASOs) enhance the potency of non-specific readthrough agents, including aminoglycoside G418 and suppressor tRNA, enabling a path toward target-specific readthrough of nonsense mutations in CFTR, JAG1, DMD, BRCA1 and other mutant genes. Finally, through systematic chemical engineering, we identify heavily modified fully functional R-ASO variants, enabling future therapeutic development.
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Affiliation(s)
- Denis Susorov
- RNA Therapeutics Institute, UMass Chan Medical School, 368 Plantation Street, Worcester, MA 01605, USA
| | - Dimas Echeverria
- RNA Therapeutics Institute, UMass Chan Medical School, 368 Plantation Street, Worcester, MA 01605, USA
| | - Anastasia Khvorova
- RNA Therapeutics Institute, UMass Chan Medical School, 368 Plantation Street, Worcester, MA 01605, USA
| | - Andrei A Korostelev
- RNA Therapeutics Institute, UMass Chan Medical School, 368 Plantation Street, Worcester, MA 01605, USA
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2
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Mott TM, Wulffraat GC, Eddins AJ, Mehl RA, Senning EN. Fluorescence labeling strategies for the study of ion channel and receptor cell surface expression: A comprehensive toolkit for extracellular labeling of TRPV1. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.09.593209. [PMID: 39005265 PMCID: PMC11244879 DOI: 10.1101/2024.05.09.593209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
Regulation of ion channel expression on the plasma membrane is a major determinant of neuronal excitability, and identifying the underlying mechanisms of this expression is critical to our understanding of neurons. A critical aspect of measuring changes in ion channel expression is uniquely identifying ion channels located on the cell surface. To accomplish this goal we demonstrate two orthogonal strategies to label extracellular sites of the ion channel TRPV1 that minimally perturb the function of the channel: 1) We use the amber codon suppression technique to introduce a non-canonical amino acid (ncAA) with tetrazine click chemistry compatible with a trans-cyclooctene coupled fluorescent dye. 2) By inserting the circularly permutated HaloTag (cpHaloTag) in an extracellular loop of TRPV1, we incorporate a click-chemistry site for a chloroalkane-linked fluorescent dye of our choosing. Optimization of ncAA insertion sites was accomplished by screening residue positions between the S1 and S2 transmembrane domains with elevated missense variants in the human population, and we identified T468 as a rapid labeling site (∼5 minutes) based on functional as well as biochemical assays in HEK293T/17 cells. After several rounds of adapting the linker lengths and backbone placement of cpHaloTag on the extracellular side of TRPV1, our efforts led to a channel construct that robustly expressed as a fully functional TRPV1exCellHalo fusion with intact wild-type gating properties. The TRPV1exCellHalo construct was used in a single molecule experiment to track TRPV1 on the cell surface and validate studies that show decreased mobility of the channel upon activation. The success of these extracellular label TRPV1 (exCellTRPV1) constructs as tools to track surface expression of the channel will shed significant light on the mechanisms regulating expression and provide a general scheme to introduce similar modifications to other cell surface receptors.
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3
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Ojha R, Krug S, Jones P, Koestler BJ. Intact and mutated Shigella diguanylate cyclases increase c-di-GMP. J Biol Chem 2024:107525. [PMID: 38960033 DOI: 10.1016/j.jbc.2024.107525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Revised: 05/31/2024] [Accepted: 06/21/2024] [Indexed: 07/05/2024] Open
Abstract
The intracellular human pathogen Shigella invades the colonic epithelium to cause disease. Prior to invasion, this bacterium navigates through different environments within the human body, including the stomach and the small intestine. To adapt to changing environments, Shigella uses the bacterial second messenger c-di-GMP signaling system, synthesized by diguanylate cyclases (DGCs) encoding GGDEF domains. Shigella flexneri encodes a total of 9 GGDEF or GGDEF-EAL domain enzymes in its genome, but 5 of these genes have acquired mutations that presumably inactivated the c-di-GMP synthesis activity of these enzymes. In this study, we examined individual S. flexneri DGCs for their role in c-di-GMP synthesis and pathogenesis. We individually expressed each of the 4 intact DGCs in an S. flexneri strain where these 4 DGCs had been deleted (Δ4DGC). We found that the 4 S. flexneri intact DGCs synthesize c-di-GMP at different levels in vitro and during infection of tissue-cultured cells. We also found that dgcF and dgcI expression significantly reduces invasion and plaque formation, and dgcF expression increases acid sensitivity, and that these phenotypes did not correspond with measured c-di-GMP levels. However, deletion of these 4 DGCs did not eliminate S. flexneri c-di-GMP, and we found that dgcE, dgcQ, and dgcN, which all have nonsense mutations prior to the GGDEF domain, still produce c-di-GMP. These S. flexneri degenerate DGC pseudogenes are expressed as multiple proteins, consistent with multiple start codons within the gene. We propose that both intact and degenerate DGCs contribute to S. flexneri c-di-GMP signaling.
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Affiliation(s)
- Ruchi Ojha
- Department of Biological Sciences, Western Michigan University, Kalamazoo, MI 49008
| | - Stefanie Krug
- Department of Microbiology, University of Washington, Seattle, WA 98109
| | - Prentiss Jones
- Department of Pathology, Western Michigan University Homer Stryker, M.D. School of Medicine, Kalamazoo, MI 49007
| | - Benjamin J Koestler
- Department of Biological Sciences, Western Michigan University, Kalamazoo, MI 49008
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4
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Zhang Z, Khanal N, Dykstra AB, Daris K. Stop-Codon Readthrough in Therapeutic Protein Candidates Expressed from Mammalian Cells. J Pharm Sci 2024; 113:1498-1505. [PMID: 38342339 DOI: 10.1016/j.xphs.2024.02.006] [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: 01/02/2024] [Revised: 02/03/2024] [Accepted: 02/04/2024] [Indexed: 02/13/2024]
Abstract
Stop codon readthroughs were examined in 48 recombinant therapeutic protein candidates produced from multiple clones of Chinese hamster ovary cells, using peptide mapping with LC-MS/MS detection. We found that stop codon readthrough is a common phenomenon occurring in most of these candidates, with levels varying from below the detection limit of ∼0.001 % to ∼1 %. The readthrough propensity depends on the stop codon being used, as well as the nucleotides surrounding it. The amino acids misincorporated into the stop position can be well-predicted by a third-base wobble mismatch and a first-base U/G mismatch during codon recognition, i.e., tyrosine or glutamine insertion for the UAA and UAG stop codons, and tryptophan, cysteine or arginine insertion for the UGA stop codon. Data shown in this report demonstrate the importance of optimizing the DNA sequence near the stop codon, and the importance of detecting stop codon readthroughs during the development of a therapeutic product.
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Affiliation(s)
- Zhongqi Zhang
- Process Development, Amgen Inc. Thousand Oaks, CA 91320, USA.
| | - Neelam Khanal
- Process Development, Amgen Inc. Thousand Oaks, CA 91320, USA
| | | | - Kristi Daris
- Process Development, Amgen Inc. Thousand Oaks, CA 91320, USA
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Keyl A, Kwas V, Lewandowska M, Herrfurth C, Kunst L, Feussner I. AtMYB41 acts as a dual-function transcription factor that regulates the formation of lipids in an organ- and development-dependent manner. PLANT BIOLOGY (STUTTGART, GERMANY) 2024; 26:568-582. [PMID: 38634447 DOI: 10.1111/plb.13650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Accepted: 04/02/2024] [Indexed: 04/19/2024]
Abstract
The plant cuticle controls non-stomatal water loss and can serve as a barrier against biotic agents, whereas the heteropolymer suberin and its associated waxes are deposited constitutively at specific cell wall locations. While several transcription factors controlling cuticle formation have been identified, those involved in the transcriptional regulation of suberin biosynthesis remain poorly characterized. The major goal of this study was to further analyse the function of the R2R3-Myeloblastosis (MYB) transcription factor AtMYB41 in formation of the cuticle, suberin, and suberin-associated waxes throughout plant development. For functional analysis, the organ-specific expression pattern of AtMYB41 was analysed and Atmyb41ge alleles were generated using the CRISPR/Cas9 system. These were investigated for root growth and water permeability upon stress. In addition, the fatty acid, wax, cutin, and suberin monomer composition of different organs was evaluated by gas chromatography. The characterization of Atmyb41ge mutants revealed that AtMYB41 negatively regulates the production of cuticular lipids and fatty acid biosynthesis in leaves and seeds, respectively. Remarkably, biochemical analyses indicate that AtMYB41 also positively regulates the formation of cuticular waxes in stems of Arabidopsis thaliana. Overall, these results suggest that the AtMYB41 acts as a negative regulator of cuticle and fatty acid biosynthesis in leaves and seeds, respectively, but also as a positive regulator of wax production in A. thaliana stems.
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Affiliation(s)
- A Keyl
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute, University of Goettingen, Goettingen, Germany
| | - V Kwas
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute, University of Goettingen, Goettingen, Germany
| | - M Lewandowska
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute, University of Goettingen, Goettingen, Germany
| | - C Herrfurth
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute, University of Goettingen, Goettingen, Germany
- Service Unit for Metabolomics and Lipidomics, Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, Goettingen, Germany
| | - L Kunst
- Department of Botany, University of British Columbia, Vancouver, BC, Canada
| | - I Feussner
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute, University of Goettingen, Goettingen, Germany
- Service Unit for Metabolomics and Lipidomics, Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, Goettingen, Germany
- Department of Plant Biochemistry, Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, Goettingen, Germany
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Bernabéu-Herrero ME, Patel D, Bielowka A, Zhu J, Jain K, Mackay IS, Chaves Guerrero P, Emanuelli G, Jovine L, Noseda M, Marciniak SJ, Aldred MA, Shovlin CL. Mutations causing premature termination codons discriminate and generate cellular and clinical variability in HHT. Blood 2024; 143:2314-2331. [PMID: 38457357 PMCID: PMC11181359 DOI: 10.1182/blood.2023021777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 02/22/2024] [Accepted: 02/22/2024] [Indexed: 03/10/2024] Open
Abstract
ABSTRACT For monogenic diseases caused by pathogenic loss-of-function DNA variants, attention focuses on dysregulated gene-specific pathways, usually considering molecular subtypes together within causal genes. To better understand phenotypic variability in hereditary hemorrhagic telangiectasia (HHT), we subcategorized pathogenic DNA variants in ENG/endoglin, ACVRL1/ALK1, and SMAD4 if they generated premature termination codons (PTCs) subject to nonsense-mediated decay. In 3 patient cohorts, a PTC-based classification system explained some previously puzzling hemorrhage variability. In blood outgrowth endothelial cells (BOECs) derived from patients with ACVRL1+/PTC, ENG+/PTC, and SMAD4+/PTC genotypes, PTC-containing RNA transcripts persisted at low levels (8%-23% expected, varying between replicate cultures); genes differentially expressed to Bonferroni P < .05 in HHT+/PTC BOECs clustered significantly only to generic protein terms (isopeptide-bond/ubiquitin-like conjugation) and pulse-chase experiments detected subtle protein maturation differences but no evidence for PTC-truncated protein. BOECs displaying highest PTC persistence were discriminated in unsupervised hierarchical clustering of near-invariant housekeeper genes, with patterns compatible with higher cellular stress in BOECs with >11% PTC persistence. To test directionality, we used a HeLa reporter system to detect induction of activating transcription factor 4 (ATF4), which controls expression of stress-adaptive genes, and showed that ENG Q436X but not ENG R93X directly induced ATF4. AlphaFold accurately modeled relevant ENG domains, with AlphaMissense suggesting that readthrough substitutions would be benign for ENG R93X and other less rare ENG nonsense variants but more damaging for Q436X. We conclude that PTCs should be distinguished from other loss-of-function variants, PTC transcript levels increase in stressed cells, and readthrough proteins and mechanisms provide promising research avenues.
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Affiliation(s)
- Maria E. Bernabéu-Herrero
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
- NIHR Imperial Biomedical Research Centre, London, United Kingdom
| | - Dilipkumar Patel
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
- NIHR Imperial Biomedical Research Centre, London, United Kingdom
| | - Adrianna Bielowka
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
- NIHR Imperial Biomedical Research Centre, London, United Kingdom
| | - JiaYi Zhu
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Kinshuk Jain
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
- NIHR Imperial Biomedical Research Centre, London, United Kingdom
| | - Ian S. Mackay
- Ear, Nose and Throat Surgery, Charing Cross and Royal Brompton Hospitals, London, United Kingdom
| | | | - Giulia Emanuelli
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Luca Jovine
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | - Michela Noseda
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Stefan J. Marciniak
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
- Royal Papworth Hospital NHS Foundation Trust, Cambridge, United Kingdom
| | - Micheala A. Aldred
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN
| | - Claire L. Shovlin
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
- NIHR Imperial Biomedical Research Centre, London, United Kingdom
- Specialist Medicine, Imperial College Healthcare NHS Trust, London, United Kingdom
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Deng L, Zhou YL, Cai Z, Zhu J, Li Z, Bao Z. Massively parallel CRISPR-assisted homologous recombination enables saturation editing of full-length endogenous genes in yeast. SCIENCE ADVANCES 2024; 10:eadj9382. [PMID: 38748797 PMCID: PMC11095455 DOI: 10.1126/sciadv.adj9382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Accepted: 04/10/2024] [Indexed: 05/19/2024]
Abstract
Performing saturation editing of chromosomal genes will enable the study of genetic variants in situ and facilitate protein and cell engineering. However, current in vivo editing of endogenous genes either lacks flexibility or is limited to discrete codons and short gene fragments, preventing a comprehensive exploration of genotype-phenotype relationships. To enable facile saturation editing of full-length genes, we used a protospacer adjacent motif-relaxed Cas9 variant and homology-directed repair to achieve above 60% user-defined codon replacement efficiencies in Saccharomyces cerevisiae genome. Coupled with massively parallel DNA design and synthesis, we developed a saturation gene editing method termed CRISPR-Cas9- and homology-directed repair-assisted saturation editing (CHASE) and achieved highly saturated codon swapping of long genomic regions. By applying CHASE to massively edit a well-studied global transcription factor gene, we found known and unreported genetic variants affecting an industrially relevant microbial trait. The user-defined codon editing capability and wide targeting windows of CHASE substantially expand the scope of saturation gene editing.
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Affiliation(s)
- Lei Deng
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310058, Zhejiang, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 311215, Zhejiang, China
- Institute of Bioengineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310058, Zhejiang, China
| | - Yi-Lian Zhou
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310058, Zhejiang, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 311215, Zhejiang, China
- Institute of Bioengineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310058, Zhejiang, China
| | - Zhenkun Cai
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310058, Zhejiang, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 311215, Zhejiang, China
- Institute of Bioengineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310058, Zhejiang, China
| | - Jie Zhu
- Bota Biosciences, Hangzhou 311222, Zhejiang, China
| | - Zenan Li
- Bota Biosciences, Hangzhou 311222, Zhejiang, China
| | - Zehua Bao
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310058, Zhejiang, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 311215, Zhejiang, China
- Institute of Bioengineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310058, Zhejiang, China
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8
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Girardo B, Schopfer LM, Yue Y, Lockridge O, Larson MA. Polyaminated, acetylated and stop codon readthrough of recombinant Francisella tularensis universal stress protein in Escherichia coli. PLoS One 2024; 19:e0299701. [PMID: 38683788 PMCID: PMC11057771 DOI: 10.1371/journal.pone.0299701] [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: 11/09/2023] [Accepted: 02/14/2024] [Indexed: 05/02/2024] Open
Abstract
Recombinant Francisella tularensis universal stress protein with a C-terminal histidine-tag (rUsp/His6) was expressed in Escherichia coli. Endogenous F. tularensis Usp has a predicted molecular mass of 30 kDa, but rUsp/His6 had an apparent molecular weight of 33 kDa based on Western blot analyses. To determine the source of the higher molecular weight for rUsp/His6, post translational modifications were examined. Tryptic peptides of purified rUsp/His6 were subjected to liquid chromatography tandem mass spectrometry (LC-MS/MS) and fragmentation spectra were searched for acetylated lysines and polyaminated glutamines. Of the 24 lysines in rUsp/His6, 10 were acetylated (K63, K68, K72, K129, K175, K201, K208, K212, K233, and K238) and three of the four glutamines had putrescine, spermidine and spermine adducts (Q55, Q60 and Q267). The level of post-translational modification was substoichiometric, eliminating the possibility that these modifications were the sole contributor to the 3 kDa extra mass of rUsp/His6. LC-MS/MS revealed that stop codon readthrough had occurred resulting in the unexpected addition of 20 extra amino acids at the C-terminus of rUsp/His6, after the histidine tag. Further, the finding of polyaminated glutamines in rUsp/His6 indicated that E. coli is capable of transglutaminase activity.
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Affiliation(s)
- Benjamin Girardo
- Pathology and Microbiology Department, University of Nebraska Medical Center, Omaha, NE, United States of America
| | - Lawrence M. Schopfer
- Eppley Institute, University of Nebraska Medical Center, Omaha, NE, United States of America
| | - Yinshi Yue
- Pathology and Microbiology Department, University of Nebraska Medical Center, Omaha, NE, United States of America
| | - Oksana Lockridge
- Eppley Institute, University of Nebraska Medical Center, Omaha, NE, United States of America
| | - Marilynn A. Larson
- Pathology and Microbiology Department, University of Nebraska Medical Center, Omaha, NE, United States of America
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Premchandar A, Ming R, Baiad A, Da Fonte DF, Xu H, Faubert D, Veit G, Lukacs GL. Readthrough-induced misincorporated amino acid ratios guide mutant-specific therapeutic approaches for two CFTR nonsense mutations. Front Pharmacol 2024; 15:1389586. [PMID: 38725656 PMCID: PMC11079177 DOI: 10.3389/fphar.2024.1389586] [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: 02/21/2024] [Accepted: 03/28/2024] [Indexed: 05/12/2024] Open
Abstract
Cystic fibrosis (CF) is a monogenic disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. Premature termination codons (PTCs) represent ∼9% of CF mutations that typically cause severe expression defects of the CFTR anion channel. Despite the prevalence of PTCs as the underlying cause of genetic diseases, understanding the therapeutic susceptibilities of their molecular defects, both at the transcript and protein levels remains partially elucidated. Given that the molecular pathologies depend on the PTC positions in CF, multiple pharmacological interventions are required to suppress the accelerated nonsense-mediated mRNA decay (NMD), to correct the CFTR conformational defect caused by misincorporated amino acids, and to enhance the inefficient stop codon readthrough. The G418-induced readthrough outcome was previously investigated only in reporter models that mimic the impact of the local sequence context on PTC mutations in CFTR. To identify the misincorporated amino acids and their ratios for PTCs in the context of full-length CFTR readthrough, we developed an affinity purification (AP)-tandem mass spectrometry (AP-MS/MS) pipeline. We confirmed the incorporation of Cys, Arg, and Trp residues at the UGA stop codons of G542X, R1162X, and S1196X in CFTR. Notably, we observed that the Cys and Arg incorporation was favored over that of Trp into these CFTR PTCs, suggesting that the transcript sequence beyond the proximity of PTCs and/or other factors can impact the amino acid incorporation and full-length CFTR functional expression. Additionally, establishing the misincorporated amino acid ratios in the readthrough CFTR PTCs aided in maximizing the functional rescue efficiency of PTCs by optimizing CFTR modulator combinations. Collectively, our findings contribute to the understanding of molecular defects underlying various CFTR nonsense mutations and provide a foundation to refine mutation-dependent therapeutic strategies for various CF-causing nonsense mutations.
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Affiliation(s)
| | - Ruiji Ming
- Department of Physiology, McGill University, Montréal, QC, Canada
| | - Abed Baiad
- Department of Physiology, McGill University, Montréal, QC, Canada
| | | | - Haijin Xu
- Department of Physiology, McGill University, Montréal, QC, Canada
| | - Denis Faubert
- IRCM Mass Spectrometry and Proteomics Platform, Institut de Recherches Cliniques de Montréal, Montréal, QC, Canada
| | - Guido Veit
- Department of Physiology, McGill University, Montréal, QC, Canada
| | - Gergely L. Lukacs
- Department of Physiology, McGill University, Montréal, QC, Canada
- Department of Biochemistry, McGill University, Montréal, QC, Canada
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10
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Ojha R, Krug S, Jones P, Koestler BJ. Intact and Degenerate Diguanylate Cyclases regulate Shigella Cyclic di-GMP. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.08.588579. [PMID: 38645013 PMCID: PMC11030455 DOI: 10.1101/2024.04.08.588579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
The intracellular human pathogen Shigella invades the colonic epithelium to cause disease. Prior to invasion, this bacterium navigates through different environments within the human body, including the stomach and the small intestine. To adapt to changing environments, Shigella uses the bacterial second messenger c-di-GMP signaling system, synthesized by diguanylate cyclases (DGCs) encoding GGDEF domains. Shigella flexneri encodes a total of 9 GGDEF or GGDEF-EAL domain enzymes in its genome, but 5 of these genes have acquired mutations that presumably inactivated the c-di-GMP synthesis activity of these enzymes. In this study, we examined individual S. flexneri DGCs for their role in c-di-GMP synthesis and pathogenesis. We individually expressed each of the 4 intact DGCs in an S. flexneri strain where these 4 DGCs had been deleted (Δ4DGC). We found that the 4 S. flexneri intact DGCs synthesize c-di-GMP at different levels in vitro and during infection of tissue-cultured cells. We also found that dgcF and dgcI expression significantly reduces invasion and plaque formation, and dgcF expression increases acid sensitivity, and that these phenotypes did not correspond with measured c-di-GMP levels. However, deletion of these 4 DGCs did not eliminate S. flexneri c-di-GMP, and we found that dgcE, dgcQ, and dgcN , which all have nonsense mutations prior to the GGDEF domain, still produce c-di-GMP. These S. flexneri degenerate DGC genes are expressed as multiple proteins, consistent with multiple start codons within the gene. We propose that both intact and degenerate DGCs contribute to S. flexneri c-di-GMP signaling.
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11
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Mangkalaphiban K, Fu L, Du M, Thrasher K, Keeling KM, Bedwell DM, Jacobson A. Extended stop codon context predicts nonsense codon readthrough efficiency in human cells. Nat Commun 2024; 15:2486. [PMID: 38509072 PMCID: PMC10954755 DOI: 10.1038/s41467-024-46703-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] [Received: 08/01/2023] [Accepted: 03/06/2024] [Indexed: 03/22/2024] Open
Abstract
Protein synthesis terminates when a stop codon enters the ribosome's A-site. Although termination is efficient, stop codon readthrough can occur when a near-cognate tRNA outcompetes release factors during decoding. Seeking to understand readthrough regulation we used a machine learning approach to analyze readthrough efficiency data from published HEK293T ribosome profiling experiments and compared it to comparable yeast experiments. We obtained evidence for the conservation of identities of the stop codon, its context, and 3'-UTR length (when termination is compromised), but not the P-site codon, suggesting a P-site tRNA role in readthrough regulation. Models trained on data from cells treated with the readthrough-promoting drug, G418, accurately predicted readthrough of premature termination codons arising from CFTR nonsense alleles that cause cystic fibrosis. This predictive ability has the potential to aid development of nonsense suppression therapies by predicting a patient's likelihood of improvement in response to drugs given their nonsense mutation sequence context.
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Affiliation(s)
- Kotchaphorn Mangkalaphiban
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, 368 Plantation Street, Worcester, MA, 01655, USA
- Department of Genomics and Computational Biology, UMass Chan Medical School, 368 Plantation Street, Worcester, MA, 01655, USA
| | - Lianwu Fu
- Department of Biochemistry and Molecular Genetics, Heersink School of Medicine, The University of Alabama at Birmingham, 845 19th Street South, Birmingham, AL, 35294, USA
| | - Ming Du
- Department of Biochemistry and Molecular Genetics, Heersink School of Medicine, The University of Alabama at Birmingham, 845 19th Street South, Birmingham, AL, 35294, USA
| | - Kari Thrasher
- Department of Biochemistry and Molecular Genetics, Heersink School of Medicine, The University of Alabama at Birmingham, 845 19th Street South, Birmingham, AL, 35294, USA
| | - Kim M Keeling
- Department of Biochemistry and Molecular Genetics, Heersink School of Medicine, The University of Alabama at Birmingham, 845 19th Street South, Birmingham, AL, 35294, USA
| | - David M Bedwell
- Department of Biochemistry and Molecular Genetics, Heersink School of Medicine, The University of Alabama at Birmingham, 845 19th Street South, Birmingham, AL, 35294, USA
| | - Allan Jacobson
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, 368 Plantation Street, Worcester, MA, 01655, USA.
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12
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Montague SJ, Price J, Pennycott K, Pavey NJ, Martin EM, Thirlwell I, Kemble S, Monteiro C, Redmond-Motteram L, Lawson N, Reynolds K, Fratter C, Bignell P, Groenheide A, Huskens D, de Laat B, Pike JA, Poulter NS, Thomas SG, Lowe GC, Lancashire J, Harrison P, Morgan NV. Comprehensive functional characterization of a novel ANO6 variant in a new patient with Scott syndrome. J Thromb Haemost 2024:S1538-7836(24)00127-2. [PMID: 38492852 DOI: 10.1016/j.jtha.2024.02.021] [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: 10/11/2023] [Revised: 02/09/2024] [Accepted: 02/29/2024] [Indexed: 03/18/2024]
Abstract
BACKGROUND Scott syndrome is a mild platelet-type bleeding disorder, first described in 1979, with only 3 unrelated families identified through defective phosphatidylserine (PS) exposure and confirmed by sequencing. The syndrome is distinguished by impaired surface exposure of procoagulant PS on platelets after stimulation. To date, platelet function and thrombin generation in this condition have not been extensively characterized. OBJECTIVES Genetic and functional studies were undertaken in a consanguineous family with a history of excessive bleeding of unknown cause. METHODS A targeted gene panel of known bleeding and platelet genes was used to identify possible genetic variants. Platelet phenotyping, flow adhesion, flow cytometry, whole blood and platelet-rich plasma thrombin generation, and specialized extracellular vesicle measurements were performed. RESULTS We detected a novel homozygous frameshift variant, c.1943del (p.Arg648Hisfs∗23), in ANO6 encoding Anoctamin 6, in a patient with a bleeding history but interestingly with normal ANO6 expression. Phenotyping of the patient's platelets confirmed the absence of PS expression and procoagulant activity but also revealed other defects including reduced platelet δ granules, reduced ristocetin-mediated aggregation and secretion, and reduced P-selectin expression after stimulation. PS was absent on spread platelets, and thrombi formed over collagen at 1500/s. Reduced thrombin generation was observed in platelet-rich plasma and confirmed in whole blood using a new thrombin generation assay. CONCLUSION We present a comprehensive report of a patient with Scott syndrome with a novel frameshift variant in AN06, which is associated with no platelet PS exposure and markedly reduced thrombin generation in whole blood, explaining the significant bleeding phenotype observed.
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Affiliation(s)
- Samantha J Montague
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Joshua Price
- Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Katherine Pennycott
- Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Natasha J Pavey
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Eleyna M Martin
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Isaac Thirlwell
- Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Samuel Kemble
- Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Catarina Monteiro
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Lily Redmond-Motteram
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Natalie Lawson
- Haemophilia Unit, Birmingham Children's Hospital, Birmingham Women's and Children's NHS Foundation Trust, Birmingham, United Kingdom
| | - Katherine Reynolds
- Haemophilia Unit, Birmingham Children's Hospital, Birmingham Women's and Children's NHS Foundation Trust, Birmingham, United Kingdom
| | - Carl Fratter
- Oxford Genetics Laboratories, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Patricia Bignell
- Oxford Genetics Laboratories, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | | | - Dana Huskens
- Synapse Research Institute, Maastricht, the Netherlands
| | - Bas de Laat
- Synapse Research Institute, Maastricht, the Netherlands
| | - Jeremy A Pike
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom; Centre of Membrane Proteins and Receptors, Universities of Birmingham and Nottingham, the Midlands, United Kingdom
| | - Natalie S Poulter
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom; Centre of Membrane Proteins and Receptors, Universities of Birmingham and Nottingham, the Midlands, United Kingdom
| | - Steven G Thomas
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom; Centre of Membrane Proteins and Receptors, Universities of Birmingham and Nottingham, the Midlands, United Kingdom
| | - Gillian C Lowe
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom; Comprehensive Care Haemophilia Centre, University Hospital Birmingham NHS Foundation Trust, Birmingham, United Kingdom
| | - Jonathan Lancashire
- Haemophilia Unit, Birmingham Children's Hospital, Birmingham Women's and Children's NHS Foundation Trust, Birmingham, United Kingdom
| | - Paul Harrison
- Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Neil V Morgan
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom.
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13
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Song J, Luo N, Dong L, Peng J, Yi C. RNA base editors: The emerging approach of RNA therapeutics. WILEY INTERDISCIPLINARY REVIEWS. RNA 2024; 15:e1844. [PMID: 38576085 DOI: 10.1002/wrna.1844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 03/12/2024] [Accepted: 03/18/2024] [Indexed: 04/06/2024]
Abstract
RNA-based therapeutics offer a flexible and reversible approach for treating genetic disorders, such as antisense oligonucleotides, RNA interference, aptamers, mRNA vaccines, and RNA editing. In recent years, significant advancements have been made in RNA base editing to correct disease-relevant point mutations. These achievements have significantly influenced the fields of biotechnology, biomedical research and therapeutics development. In this article, we provide a comprehensive overview of the design and performance of contemporary RNA base editors, including A-to-I, C-to-U, A-to-m6A, and U-to-Ψ. We compare recent innovative developments and highlight their applications in disease-relevant contexts. Lastly, we discuss the limitations and future prospects of utilizing RNA base editing for therapeutic purposes. This article is categorized under: RNA Processing > RNA Editing and Modification RNA in Disease and Development > RNA in Development.
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Affiliation(s)
- Jinghui Song
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China
| | - Nan Luo
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China
| | - Liting Dong
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Jinying Peng
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China
| | - Chengqi Yi
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
- Department of Chemical Biology and Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
- Beijing Advanced Center of RNA Biology (BEACON), Peking University, Beijing, China
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14
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Song J, Zhuang Y, Yi C. Programmable RNA base editing via targeted modifications. Nat Chem Biol 2024; 20:277-290. [PMID: 38418907 DOI: 10.1038/s41589-023-01531-y] [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: 05/29/2023] [Accepted: 12/18/2023] [Indexed: 03/02/2024]
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR)-based genome editors are powerful tools in biology and hold great promise for the treatment of human diseases. Advanced DNA base editing tools, such as cytosine base editor and adenine base editor, have been developed to correct permanent mistakes in genetic material. However, undesired off-target edits would also be permanent, which poses a considerable risk for therapeutics. Alternatively, base editing at the RNA level is capable of correcting disease-causing mutations but does not lead to lasting genotoxic effects. RNA base editors offer temporary and reversible therapies and have been catching on in recent years. Here, we summarize some emerging RNA editors based on A-to-inosine, C-to-U and U-to-pseudouridine changes. We review the programmable RNA-targeting systems as well as modification enzyme-based effector proteins and highlight recent technological breakthroughs. Finally, we compare editing tools, discuss limitations and opportunities, and provide insights for the future directions of RNA base editing.
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Affiliation(s)
- Jinghui Song
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, People's Republic of China
| | - Yuan Zhuang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, People's Republic of China
| | - Chengqi Yi
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, People's Republic of China.
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, People's Republic of China.
- Department of Chemical Biology and Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular Engineering, Peking University, Beijing, People's Republic of China.
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15
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Zhang Y, Li H, Shen Y, Wang S, Tian L, Yin H, Shi J, Xing A, Zhang J, Ali U, Sami A, Chen X, Gao C, Zhao Y, Lyu Y, Wang X, Chen Y, Tian Z, Wu SB, Wu L. Readthrough events in plants reveal plasticity of stop codons. Cell Rep 2024; 43:113723. [PMID: 38300801 DOI: 10.1016/j.celrep.2024.113723] [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: 05/20/2023] [Revised: 10/02/2023] [Accepted: 01/15/2024] [Indexed: 02/03/2024] Open
Abstract
Stop codon readthrough (SCR) has important biological implications but remains largely uncharacterized. Here, we identify 1,009 SCR events in plants using a proteogenomic strategy. Plant SCR candidates tend to have shorter transcript lengths and fewer exons and splice variants than non-SCR transcripts. Mass spectrometry evidence shows that stop codons involved in SCR events can be recoded as 20 standard amino acids, some of which are also supported by suppressor tRNA analysis. We also observe multiple functional signals in 34 maize extended proteins and characterize the structural and subcellular localization changes in the extended protein of basic transcription factor 3. Furthermore, the SCR events exhibit non-conserved signature, and the extensions likely undergo protein-coding selection. Overall, our study not only characterizes that SCR events are commonly present in plants but also identifies the recoding plasticity of stop codons, which provides important insights into the flexibility of genetic decoding.
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Affiliation(s)
- Yuqian Zhang
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China; School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia
| | - Hehuan Li
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Yanting Shen
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Shunxi Wang
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Lei Tian
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Haoqiang Yin
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Jiawei Shi
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Anqi Xing
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC 29634, USA
| | - Jinghua Zhang
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Usman Ali
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Abdul Sami
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Xueyan Chen
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Chenxuan Gao
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Yangtao Zhao
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Yajing Lyu
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Xiaoxu Wang
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Yanhui Chen
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Zhixi Tian
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; College of Advanced Agriculture Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Shu-Biao Wu
- School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia.
| | - Liuji Wu
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China; School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia.
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16
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Takallou S, Hajikarimlou M, Al-Gafari M, Wang J, Kazmirchuk TDD, Said KB, Samanfar B, Golshani A. The Involvement of YNR069C in Protein Synthesis in the Baker's Yeast, Saccharomyces cerevisiae. BIOLOGY 2024; 13:138. [PMID: 38534408 DOI: 10.3390/biology13030138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 02/17/2024] [Accepted: 02/19/2024] [Indexed: 03/28/2024]
Abstract
Maintaining translation fidelity is a critical step within the process of gene expression. It requires the involvement of numerous regulatory elements to ensure the synthesis of functional proteins. The efficient termination of protein synthesis can play a crucial role in preserving this fidelity. Here, we report on investigating a protein of unknown function, YNR069C (also known as BSC5), for its activity in the process of translation. We observed a significant increase in the bypass of premature stop codons upon the deletion of YNR069C. Interestingly, the genomic arrangement of this ORF suggests a compatible mode of expression reliant on translational readthrough, incorporating the neighboring open reading frame. We also showed that the deletion of YNR069C results in an increase in the rate of translation. Based on our results, we propose that YNR069C may play a role in translation fidelity, impacting the overall quantity and quality of translation. Our genetic interaction analysis supports our hypothesis, associating the role of YNR069C to the regulation of protein synthesis.
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Affiliation(s)
- Sarah Takallou
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
- Department of Biology, Carleton University, Ottawa, ON K1S 5B6, Canada
| | - Maryam Hajikarimlou
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
- Department of Biology, Carleton University, Ottawa, ON K1S 5B6, Canada
| | - Mustafa Al-Gafari
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
- Department of Biology, Carleton University, Ottawa, ON K1S 5B6, Canada
| | - Jiashu Wang
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
- Department of Biology, Carleton University, Ottawa, ON K1S 5B6, Canada
| | - Thomas David Daniel Kazmirchuk
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
- Department of Biology, Carleton University, Ottawa, ON K1S 5B6, Canada
| | - Kamaledin B Said
- Department of Pathology and Microbiology, College of Medicine, University of Hail, Hail 55476, Saudi Arabia
| | - Bahram Samanfar
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
- Department of Biology, Carleton University, Ottawa, ON K1S 5B6, Canada
- Agriculture and Agri-Food Canada, Ottawa Research and Development Centre (ORDC), Ottawa, ON K1A 0C6, Canada
| | - Ashkan Golshani
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
- Department of Biology, Carleton University, Ottawa, ON K1S 5B6, Canada
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17
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Torices L, Nunes-Xavier CE, Mingo J, Luna S, Erramuzpe A, Cortés JM, Pulido R. Induction of Translational Readthrough on Protein Tyrosine Phosphatases Targeted by Premature Termination Codon Mutations in Human Disease. Methods Mol Biol 2024; 2743:1-19. [PMID: 38147205 DOI: 10.1007/978-1-0716-3569-8_1] [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] [Indexed: 12/27/2023]
Abstract
Nonsense mutations generating premature termination codons (PTCs) in various genes are frequently associated with somatic cancer and hereditary human diseases since PTCs commonly generate truncated proteins with defective or altered function. Induced translational readthrough during protein biosynthesis facilitates the incorporation of an amino acid at the position of a PTC, allowing the synthesis of a complete protein. This may evade the pathological effect of the PTC mutation and provide new therapeutic opportunities. Several protein tyrosine phosphatases (PTPs) genes are targeted by PTC in human disease, the tumor suppressor PTEN being the more prominent paradigm. Here, using PTEN and laforin as examples, two PTPs from the dual-specificity phosphatase subfamily, we describe methodologies to analyze in silico the distribution and frequency of pathogenic PTC in PTP genes. We also summarize laboratory protocols and technical notes to study the induced translational readthrough reconstitution of the synthesis of PTP targeted by PTC in association with disease in cellular models.
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Affiliation(s)
- Leire Torices
- Biobizkaia Health Research Institute, Barakaldo, Spain
| | - Caroline E Nunes-Xavier
- Biobizkaia Health Research Institute, Barakaldo, Spain
- Institute for Cancer Research, Oslo University Hospital, The Norwegian Radium Hospital, Oslo, Norway
| | - Janire Mingo
- Biobizkaia Health Research Institute, Barakaldo, Spain
| | - Sandra Luna
- Biobizkaia Health Research Institute, Barakaldo, Spain
| | - Asier Erramuzpe
- Biobizkaia Health Research Institute, Barakaldo, Spain
- Ikerbasque, The Basque Foundation for Science, Bilbao, Spain
| | - Jesús M Cortés
- Biobizkaia Health Research Institute, Barakaldo, Spain
- Ikerbasque, The Basque Foundation for Science, Bilbao, Spain
- Cell Biology and Histology Department, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Rafael Pulido
- Biobizkaia Health Research Institute, Barakaldo, Spain.
- Ikerbasque, The Basque Foundation for Science, Bilbao, Spain.
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18
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Patil MJ, Kim SH, Bahia PK, Nair SS, Darcey TS, Fiallo J, Zhu XX, Frisina RD, Hadley SH, Taylor-Clark TE. A Novel Flp Reporter Mouse Shows That TRPA1 Expression Is Largely Limited to Sensory Neuron Subsets. eNeuro 2023; 10:ENEURO.0350-23.2023. [PMID: 37989590 PMCID: PMC10698635 DOI: 10.1523/eneuro.0350-23.2023] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 11/09/2023] [Accepted: 11/11/2023] [Indexed: 11/23/2023] Open
Abstract
Transient receptor potential ankyrin 1 (TRPA1) is a polymodal cation channel that is activated by electrophilic irritants, oxidative stress, cold temperature, and GPCR signaling. TRPA1 expression has been primarily identified in subsets of nociceptive sensory afferents and is considered a target for future analgesics. Nevertheless, TRPA1 has been implicated in other cell types including keratinocytes, epithelium, enterochromaffin cells, endothelium, astrocytes, and CNS neurons. Here, we developed a knock-in mouse that expresses the recombinase FlpO in TRPA1-expressing cells. We crossed the TRPA1Flp mouse with the R26ai65f mouse that expresses tdTomato in a Flp-sensitive manner. We found tdTomato expression correlated well with TRPA1 mRNA expression and sensitivity to TRPA1 agonists in subsets of TRPV1 (transient receptor potential vanilloid receptor type 1)-expressing neurons in the vagal ganglia and dorsal root ganglia (DRGs), although tdTomato expression efficiency was limited in DRG. We observed tdTomato-expressing afferent fibers centrally (in the medulla and spinal cord) and peripherally in the esophagus, gut, airways, bladder, and skin. Furthermore, chemogenetic activation of TRPA1-expressing nerves in the paw evoked flinching behavior. tdTomato expression was very limited in other cell types. We found tdTomato in subepithelial cells in the gut mucosa but not in enterochromaffin cells. tdTomato was also observed in supporting cells within the cochlea, but not in hair cells. Lastly, tdTomato was occasionally observed in neurons in the somatomotor cortex and the piriform area, but not in astrocytes or vascular endothelium. Thus, this novel mouse strain may be useful for mapping and manipulating TRPA1-expressing cells and deciphering the role of TRPA1 in physiological and pathophysiological processes.
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Affiliation(s)
- Mayur J Patil
- Molecular Pharmacology & Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida 33612
| | - Seol-Hee Kim
- Molecular Pharmacology & Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida 33612
| | - Parmvir K Bahia
- Molecular Pharmacology & Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida 33612
| | - Sanjay S Nair
- Molecular Pharmacology & Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida 33612
| | - Teresa S Darcey
- Molecular Pharmacology & Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida 33612
| | - Jailene Fiallo
- Molecular Pharmacology & Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida 33612
| | - Xiao Xia Zhu
- Medical Engineering, College of Engineering, University of South Florida, Tampa, Florida 33620
| | - Robert D Frisina
- Medical Engineering, College of Engineering, University of South Florida, Tampa, Florida 33620
| | - Stephen H Hadley
- Molecular Pharmacology & Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida 33612
| | - Thomas E Taylor-Clark
- Molecular Pharmacology & Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida 33612
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19
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Palomar-Siles M, Yurevych V, Bykov VJN, Wiman KG. Pharmacological induction of translational readthrough of nonsense mutations in the retinoblastoma (RB1) gene. PLoS One 2023; 18:e0292468. [PMID: 37917619 PMCID: PMC10621805 DOI: 10.1371/journal.pone.0292468] [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: 01/23/2023] [Accepted: 09/21/2023] [Indexed: 11/04/2023] Open
Abstract
The retinoblastoma protein (Rb) is encoded by the RB1 tumor suppressor gene. Inactivation of RB1 by inherited or somatic mutation occurs in retinoblastoma and various other types of tumors. A significant fraction (25.9%) of somatic RB1 mutations are nonsense substitutions leading to a premature termination codon (PTC) in the RB1 coding sequence and expression of truncated inactive Rb protein. Here we show that aminoglycoside G418, a known translational readthrough inducer, can induce full-length Rb protein in SW1783 astrocytoma cells with endogenous R579X nonsense mutant RB1 as well as in MDA-MB-436 breast carcinoma cells transiently transfected with R251X, R320X, R579X or Q702X nonsense mutant RB1 cDNA. Readthrough was associated with increased RB1 mRNA levels in nonsense mutant RB1 cells. Induction of full-length Rb protein was potentiated by the cereblon E3 ligase modulator CC-90009. These results suggest that pharmacological induction of translational readthrough could be a feasible strategy for therapeutic targeting of tumors with nonsense mutant RB1.
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Affiliation(s)
- Mireia Palomar-Siles
- Department of Oncology-Pathology, BioClinicum, Karolinska Institutet, Stockholm, Sweden
| | - Viktor Yurevych
- Department of Oncology-Pathology, BioClinicum, Karolinska Institutet, Stockholm, Sweden
| | - Vladimir J. N. Bykov
- Department of Oncology-Pathology, BioClinicum, Karolinska Institutet, Stockholm, Sweden
| | - Klas G. Wiman
- Department of Oncology-Pathology, BioClinicum, Karolinska Institutet, Stockholm, Sweden
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20
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Liu Z, Wang J, Shi Y, Yee BA, Terrey M, Zhang Q, Lee JC, Lin KI, Wang AHJ, Ackerman S, Yeo G, Cui H, Yang XL. Seryl-tRNA synthetase promotes translational readthrough by mRNA binding and involvement of the selenocysteine incorporation machinery. Nucleic Acids Res 2023; 51:10768-10781. [PMID: 37739431 PMCID: PMC10602924 DOI: 10.1093/nar/gkad773] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 08/17/2023] [Accepted: 09/19/2023] [Indexed: 09/24/2023] Open
Abstract
Translational readthrough of UGA stop codons by selenocysteine-specific tRNA (tRNASec) enables the synthesis of selenoproteins. Seryl-tRNA synthetase (SerRS) charges tRNASec with serine, which is modified into selenocysteine and delivered to the ribosome by a designated elongation factor (eEFSec in eukaryotes). Here we found that components of the human selenocysteine incorporation machinery (SerRS, tRNASec, and eEFSec) also increased translational readthrough of non-selenocysteine genes, including VEGFA, to create C-terminally extended isoforms. SerRS recognizes target mRNAs through a stem-loop structure that resembles the variable loop of its cognate tRNAs. This function of SerRS depends on both its enzymatic activity and a vertebrate-specific domain. Through eCLIP-seq, we identified additional SerRS-interacting mRNAs as potential readthrough genes. Moreover, SerRS overexpression was sufficient to reverse premature termination caused by a pathogenic nonsense mutation. Our findings expand the repertoire of selenoprotein biosynthesis machinery and suggest an avenue for therapeutic targeting of nonsense mutations using endogenous factors.
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Affiliation(s)
- Ze Liu
- Department of Molecular Medicine, Scripps Research Institute, La Jolla, CA 92037, USA
| | - Justin Wang
- Department of Molecular Medicine, Scripps Research Institute, La Jolla, CA 92037, USA
| | - Yi Shi
- Department of Molecular Medicine, Scripps Research Institute, La Jolla, CA 92037, USA
- Department of Biochemistry, School of Medicine, Nankai University, Tianjin, China
| | - Brian A Yee
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Markus Terrey
- Howard Hughes Medical Institute, Department of Cellular and Molecular Medicine, School of Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Qian Zhang
- Department of Molecular Medicine, Scripps Research Institute, La Jolla, CA 92037, USA
| | - Jenq-Chang Lee
- Department of Surgery, National Cheng Kung University Medical College and Hospital, Taiwan
| | - Kuo-I Lin
- Genomics Research Center, Academia Sinica, Taiwan
| | - Andrew H-J Wang
- The Ph.D. Program for Translational Medicine, College of Medical Science and Technology, Taipei Medical University and Academia Sinica, Taipei 110, Taiwan
| | - Susan L Ackerman
- Howard Hughes Medical Institute, Department of Cellular and Molecular Medicine, School of Medicine, University of California San Diego, La Jolla, CA 92093, USA
- Department of Neurobiology, University of California San Diego, La Jolla, CA 92093, USA
| | - Gene W Yeo
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Haissi Cui
- Department of Molecular Medicine, Scripps Research Institute, La Jolla, CA 92037, USA
| | - Xiang-Lei Yang
- Department of Molecular Medicine, Scripps Research Institute, La Jolla, CA 92037, USA
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21
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Perriera R, Vitale E, Pibiri I, Carollo PS, Ricci D, Corrao F, Fiduccia I, Melfi R, Zizzo MG, Tutone M, Pace A, Lentini L. Readthrough Approach Using NV Translational Readthrough-Inducing Drugs (TRIDs): A Study of the Possible Off-Target Effects on Natural Termination Codons (NTCs) on TP53 and Housekeeping Gene Expression. Int J Mol Sci 2023; 24:15084. [PMID: 37894764 PMCID: PMC10606485 DOI: 10.3390/ijms242015084] [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: 08/11/2023] [Revised: 09/11/2023] [Accepted: 10/08/2023] [Indexed: 10/29/2023] Open
Abstract
Nonsense mutations cause several genetic diseases such as cystic fibrosis, Duchenne muscular dystrophy, β-thalassemia, and Shwachman-Diamond syndrome. These mutations induce the formation of a premature termination codon (PTC) inside the mRNA sequence, resulting in the synthesis of truncated polypeptides. Nonsense suppression therapy mediated by translational readthrough-inducing drugs (TRIDs) is a promising approach to correct these genetic defects. TRIDs generate a ribosome miscoding of the PTC named "translational readthrough" and restore the synthesis of full-length and potentially functional proteins. The new oxadiazole-core TRIDs NV848, NV914, and NV930 (NV) showed translational readthrough activity in nonsense-related in vitro systems. In this work, the possible off-target effect of NV molecules on natural termination codons (NTCs) was investigated. Two different in vitro approaches were used to assess if the NV molecule treatment induces NTC readthrough: (1) a study of the translational-induced p53 molecular weight and functionality; (2) the evaluation of two housekeeping proteins' (Cys-C and β2M) molecular weights. Our results showed that the treatment with NV848, NV914, or NV930 did not induce any translation alterations in both experimental systems. The data suggested that NV molecules have a specific action for the PTCs and an undetectable effect on the NTCs.
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Affiliation(s)
| | | | - Ivana Pibiri
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Università degli Studi di Palermo, Viale delle Scienze Ed. 16-17, 90128 Palermo, Italy; (R.P.); (E.V.); (P.S.C.); (D.R.); (F.C.); (I.F.); (R.M.); (M.G.Z.); (M.T.); (A.P.)
| | | | | | | | | | | | | | | | | | - Laura Lentini
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Università degli Studi di Palermo, Viale delle Scienze Ed. 16-17, 90128 Palermo, Italy; (R.P.); (E.V.); (P.S.C.); (D.R.); (F.C.); (I.F.); (R.M.); (M.G.Z.); (M.T.); (A.P.)
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22
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Anastassiadis T, Köhrer C. Ushering in the era of tRNA medicines. J Biol Chem 2023; 299:105246. [PMID: 37703991 PMCID: PMC10583094 DOI: 10.1016/j.jbc.2023.105246] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Revised: 09/03/2023] [Accepted: 09/06/2023] [Indexed: 09/15/2023] Open
Abstract
Long viewed as an intermediary in protein translation, there is a growing awareness that tRNAs are capable of myriad other biological functions linked to human health and disease. These emerging roles could be tapped to leverage tRNAs as diagnostic biomarkers, therapeutic targets, or even as novel medicines. Furthermore, the growing array of tRNA-derived fragments, which modulate an increasingly broad spectrum of cellular pathways, is expanding this opportunity. Together, these molecules offer drug developers the chance to modulate the impact of mutations and to alter cell homeostasis. Moreover, because a single therapeutic tRNA can facilitate readthrough of a genetic mutation shared across multiple genes, such medicines afford the opportunity to define patient populations not based on their clinical presentation or mutated gene but rather on the mutation itself. This approach could potentially transform the treatment of patients with rare and ultrarare diseases. In this review, we explore the diverse biology of tRNA and its fragments, examining the past and present challenges to provide a comprehensive understanding of the molecules and their therapeutic potential.
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23
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McGowan J, Kilias ES, Alacid E, Lipscombe J, Jenkins BH, Gharbi K, Kaithakottil GG, Macaulay IC, McTaggart S, Warring SD, Richards TA, Hall N, Swarbreck D. Identification of a non-canonical ciliate nuclear genetic code where UAA and UAG code for different amino acids. PLoS Genet 2023; 19:e1010913. [PMID: 37796765 PMCID: PMC10553269 DOI: 10.1371/journal.pgen.1010913] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 08/10/2023] [Indexed: 10/07/2023] Open
Abstract
The genetic code is one of the most highly conserved features across life. Only a few lineages have deviated from the "universal" genetic code. Amongst the few variants of the genetic code reported to date, the codons UAA and UAG virtually always have the same translation, suggesting that their evolution is coupled. Here, we report the genome and transcriptome sequencing of a novel uncultured ciliate, belonging to the Oligohymenophorea class, where the translation of the UAA and UAG stop codons have changed to specify different amino acids. Genomic and transcriptomic analyses revealed that UAA has been reassigned to encode lysine, while UAG has been reassigned to encode glutamic acid. We identified multiple suppressor tRNA genes with anticodons complementary to the reassigned codons. We show that the retained UGA stop codon is enriched in the 3'UTR immediately downstream of the coding region of genes, suggesting that there is functional drive to maintain tandem stop codons. Using a phylogenomics approach, we reconstructed the ciliate phylogeny and mapped genetic code changes, highlighting the remarkable number of independent genetic code changes within the Ciliophora group of protists. According to our knowledge, this is the first report of a genetic code variant where UAA and UAG encode different amino acids.
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Affiliation(s)
- Jamie McGowan
- Earlham Institute, Norwich Research Park, Norwich, United Kingdom
| | | | - Elisabet Alacid
- Department of Biology, University of Oxford, Oxford, United Kingdom
| | - James Lipscombe
- Earlham Institute, Norwich Research Park, Norwich, United Kingdom
| | | | - Karim Gharbi
- Earlham Institute, Norwich Research Park, Norwich, United Kingdom
| | | | - Iain C. Macaulay
- Earlham Institute, Norwich Research Park, Norwich, United Kingdom
| | - Seanna McTaggart
- Earlham Institute, Norwich Research Park, Norwich, United Kingdom
| | - Sally D. Warring
- Earlham Institute, Norwich Research Park, Norwich, United Kingdom
| | | | - Neil Hall
- Earlham Institute, Norwich Research Park, Norwich, United Kingdom
- School of Biological Sciences, University of East Anglia, Norwich, United Kingdom
| | - David Swarbreck
- Earlham Institute, Norwich Research Park, Norwich, United Kingdom
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24
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Valášek LS, Kučerová M, Zeman J, Beznosková P. Cysteine tRNA acts as a stop codon readthrough-inducing tRNA in the human HEK293T cell line. RNA (NEW YORK, N.Y.) 2023; 29:1379-1387. [PMID: 37221013 PMCID: PMC10573299 DOI: 10.1261/rna.079688.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 05/12/2023] [Indexed: 05/25/2023]
Abstract
Under certain circumstances, any of the three termination codons can be read through by a near-cognate tRNA; i.e., a tRNA whose two out of three anticodon nucleotides base pair with those of the stop codon. Unless programed to synthetize C-terminally extended protein variants with expanded physiological roles, readthrough represents an undesirable translational error. On the other side of a coin, a significant number of human genetic diseases is associated with the introduction of nonsense mutations (premature termination codons [PTCs]) into coding sequences, where stopping is not desirable. Here, the tRNA's ability to induce readthrough opens up the intriguing possibility of mitigating the deleterious effects of PTCs on human health. In yeast, the UGA and UAR stop codons were described to be read through by four readthrough-inducing rti-tRNAs-tRNATrp and tRNACys, and tRNATyr and tRNAGln, respectively. The readthrough-inducing potential of tRNATrp and tRNATyr was also observed in human cell lines. Here, we investigated the readthrough-inducing potential of human tRNACys in the HEK293T cell line. The tRNACys family consists of two isoacceptors, one with ACA and the other with GCA anticodons. We selected nine representative tRNACys isodecoders (differing in primary sequence and expression level) and tested them using dual luciferase reporter assays. We found that at least two tRNACys can significantly elevate UGA readthrough when overexpressed. This indicates a mechanistically conserved nature of rti-tRNAs between yeast and human, supporting the idea that they could be used in the PTC-associated RNA therapies.
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MESH Headings
- Humans
- Codon, Terminator/genetics
- Cysteine/genetics
- Cysteine/metabolism
- HEK293 Cells
- Saccharomyces cerevisiae/genetics
- RNA, Transfer, Cys/metabolism
- RNA, Transfer, Trp/metabolism
- RNA, Transfer, Tyr
- RNA, Transfer/genetics
- RNA, Transfer/metabolism
- Anticodon
- Codon, Nonsense/genetics
- Protein Biosynthesis
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Affiliation(s)
- Leoš Shivaya Valášek
- Laboratory of Regulation of Gene Expression, Institute of Microbiology ASCR, 142 20 Prague, the Czech Republic
| | - Michaela Kučerová
- Laboratory of Regulation of Gene Expression, Institute of Microbiology ASCR, 142 20 Prague, the Czech Republic
| | - Jakub Zeman
- Laboratory of Regulation of Gene Expression, Institute of Microbiology ASCR, 142 20 Prague, the Czech Republic
| | - Petra Beznosková
- Laboratory of Regulation of Gene Expression, Institute of Microbiology ASCR, 142 20 Prague, the Czech Republic
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25
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Hasenjäger S, Bologna A, Essen LO, Spadaccini R, Taxis C. C-terminal sequence stability profiling in Saccharomyces cerevisiae reveals protective protein quality control pathways. J Biol Chem 2023; 299:105166. [PMID: 37595870 PMCID: PMC10493509 DOI: 10.1016/j.jbc.2023.105166] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 07/22/2023] [Accepted: 08/09/2023] [Indexed: 08/20/2023] Open
Abstract
Protein quality control (PQC) mechanisms are essential for degradation of misfolded or dysfunctional proteins. An essential part of protein homeostasis is recognition of defective proteins by PQC components and their elimination by the ubiquitin-proteasome system, often concentrating on protein termini as indicators of protein integrity. Changes in amino acid composition of C-terminal ends arise through protein disintegration, alternative splicing, or during the translation step of protein synthesis from premature termination or translational stop-codon read-through. We characterized reporter protein stability using light-controlled exposure of the random C-terminal peptide collection (CtPC) in budding yeast revealing stabilizing and destabilizing features of amino acids at positions -5 to -1 of the C terminus. The (de)stabilization properties of CtPC-degrons depend on amino acid identity, position, as well as composition of the C-terminal sequence and are transferable. Evolutionary pressure toward stable proteins in yeast is evidenced by amino acid residues under-represented in cytosolic and nuclear proteins at corresponding C-terminal positions, but over-represented in unstable CtPC-degrons, and vice versa. Furthermore, analysis of translational stop-codon read-through peptides suggested that such extended proteins have destabilizing C termini. PQC pathways targeting CtPC-degrons involved the ubiquitin-protein ligase Doa10 and the cullin-RING E3 ligase SCFDas1 (Skp1-Cullin-F-box protein). Overall, our data suggest a proteome protection mechanism that targets proteins with unnatural C termini by recognizing a surprisingly large number of C-terminal sequence variants.
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Affiliation(s)
- Sophia Hasenjäger
- Department of Biology/Genetics, Philipps-University Marburg, Marburg, Germany
| | - Andrea Bologna
- Department of Science and Technology, Universita' Degli Studi Del Sannio, Benevento, Italy
| | - Lars-Oliver Essen
- Department of Chemistry/Biochemistry, Philipps-University Marburg, Marburg, Germany
| | - Roberta Spadaccini
- Department of Science and Technology, Universita' Degli Studi Del Sannio, Benevento, Italy; Department of Chemistry/Biochemistry, Philipps-University Marburg, Marburg, Germany
| | - Christof Taxis
- Department of Medicine, Health and Medical University, Erfurt, Germany.
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26
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Wong KM, Wegener E, Baradaran-Heravi A, Huppke B, Gärtner J, Huppke P. Evaluation of Novel Enhancer Compounds in Gentamicin-Mediated Readthrough of Nonsense Mutations in Rett Syndrome. Int J Mol Sci 2023; 24:11665. [PMID: 37511424 PMCID: PMC10380790 DOI: 10.3390/ijms241411665] [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] [Received: 06/21/2023] [Revised: 07/13/2023] [Accepted: 07/14/2023] [Indexed: 07/30/2023] Open
Abstract
Rett syndrome (RTT), a severe X-linked neurodevelopmental disorder, is primarily caused by mutations in the methyl CpG binding protein 2 gene (MECP2). Over 35% RTT patients carry nonsense mutation in MECP2, making it a suitable candidate disease for nonsense suppression therapy. In our previous study, gentamicin was found to induce readthrough of MECP2 nonsense mutations with modest efficiency. Given the recent discovery of readthrough enhancers, CDX compounds, we herein evaluated the potentiation effect of CDX5-1, CDX5-288, and CDX6-180 on gentamicin-mediated readthrough efficiency in transfected HeLa cell lines bearing the four most common MECP2 nonsense mutations. We showed that all three CDX compounds potentiated gentamicin-mediated readthrough and increased full-length MeCP2 protein levels in cells expressing the R168X, R255X, R270X, and R294X nonsense mutations. Among all three CDX compounds, CDX5-288 was the most potent enhancer and enabled the use of reduced doses of gentamicin, thus mitigating the toxicity. Furthermore, we successfully demonstrated the upregulation of full-length Mecp2 protein expression in fibroblasts derived from Mecp2R255X/Y mice through combinatorial treatment. Taken together, findings demonstrate the feasibility of this combinatorial approach to nonsense suppression therapy for a subset of RTT patients.
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Affiliation(s)
- Keit Men Wong
- Department of Neuropediatrics, Jena University Hospital, 07747 Jena, Germany
- Center for Rare Diseases, Jena University Hospital, 07747 Jena, Germany
| | - Eike Wegener
- Department of Pediatrics and Adolescent Medicine, Division of Neuropediatrics, Pediatric Neurology University Medical Center Göttingen, Georg August University Göttingen, 37075 Göttingen, Germany
| | - Alireza Baradaran-Heravi
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver BC V6T 1Z3, Canada
| | - Brenda Huppke
- Department of Neuropediatrics, Jena University Hospital, 07747 Jena, Germany
- Center for Rare Diseases, Jena University Hospital, 07747 Jena, Germany
| | - Jutta Gärtner
- Department of Pediatrics and Adolescent Medicine, Division of Neuropediatrics, Pediatric Neurology University Medical Center Göttingen, Georg August University Göttingen, 37075 Göttingen, Germany
| | - Peter Huppke
- Department of Neuropediatrics, Jena University Hospital, 07747 Jena, Germany
- Center for Rare Diseases, Jena University Hospital, 07747 Jena, Germany
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27
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Lahiri P, Martin MS, Lino BR, Scheck RA, Van Deventer JA. Dual Noncanonical Amino Acid Incorporation Enabling Chemoselective Protein Modification at Two Distinct Sites in Yeast. Biochemistry 2023; 62:2098-2114. [PMID: 37377426 PMCID: PMC11146674 DOI: 10.1021/acs.biochem.2c00711] [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] [Indexed: 06/29/2023]
Abstract
Incorporation of more than one noncanonical amino acid (ncAA) within a single protein endows the resulting construct with multiple useful features such as augmented molecular recognition or covalent cross-linking capabilities. Herein, for the first time, we demonstrate the incorporation of two chemically distinct ncAAs into proteins biosynthesized in Saccharomyces cerevisiae. To complement ncAA incorporation in response to the amber (TAG) stop codon in yeast, we evaluated opal (TGA) stop codon suppression using three distinct orthogonal translation systems. We observed selective TGA readthrough without detectable cross-reactivity from host translation components. Readthrough efficiency at TGA was modulated by factors including the local nucleotide environment, gene deletions related to the translation process, and the identity of the suppressor tRNA. These observations facilitated systematic investigation of dual ncAA incorporation in both intracellular and yeast-displayed protein constructs, where we observed efficiencies up to 6% of wild-type protein controls. The successful display of doubly substituted proteins enabled the exploration of two critical applications on the yeast surface─(A) antigen binding functionality and (B) chemoselective modification with two distinct chemical probes through sequential application of two bioorthogonal click chemistry reactions. Lastly, by utilizing a soluble form of a doubly substituted construct, we validated the dual incorporation system using mass spectrometry and demonstrated the feasibility of conducting selective labeling of the two ncAAs sequentially using a "single-pot" approach. Overall, our work facilitates the addition of a 22nd amino acid to the genetic code of yeast and expands the scope of applications of ncAAs for basic biological research and drug discovery.
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Affiliation(s)
- Priyanka Lahiri
- Chemical and Biological Engineering Department, Tufts University, Medford, MA 02155, USA
| | - Meghan S. Martin
- Chemistry Department, Tufts University, Medford, Massachusetts 02155, USA
| | - Briana R. Lino
- Chemical and Biological Engineering Department, Tufts University, Medford, MA 02155, USA
| | - Rebecca A. Scheck
- Chemistry Department, Tufts University, Medford, Massachusetts 02155, USA
| | - James A. Van Deventer
- Chemical and Biological Engineering Department, Tufts University, Medford, MA 02155, USA
- Biomedical Engineering Department, Tufts University, Medford, Massachusetts 02155, USA
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28
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Mangkalaphiban K, Ganesan R, Jacobson A. Direct and indirect consequences of PAB1 deletion in the regulation of translation initiation, translation termination, and mRNA decay. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.31.543082. [PMID: 37398227 PMCID: PMC10312514 DOI: 10.1101/2023.05.31.543082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Cytoplasmic poly(A)-binding protein (PABPC; Pab1 in yeast) is thought to be involved in multiple steps of post-transcriptional control, including translation initiation, translation termination, and mRNA decay. To understand these roles of PABPC in more detail for endogenous mRNAs, and to distinguish its direct effects from indirect effects, we have employed RNA-Seq and Ribo-Seq to analyze changes in the abundance and translation of the yeast transcriptome, as well as mass spectrometry to assess the abundance of the components of the yeast proteome, in cells lacking the PAB1 gene. We observed drastic changes in the transcriptome and proteome, as well as defects in translation initiation and termination, in pab1Δ cells. Defects in translation initiation and the stabilization of specific classes of mRNAs in pab1Δ cells appear to be partly indirect consequences of reduced levels of specific initiation factors, decapping activators, and components of the deadenylation complex in addition to the general loss of Pab1's direct role in these processes. Cells devoid of Pab1 also manifested a nonsense codon readthrough phenotype indicative of a defect in translation termination, but this defect may be a direct effect of the loss of Pab1 as it could not be attributed to significant reductions in the levels of release factors.
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Affiliation(s)
- Kotchaphorn Mangkalaphiban
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, 368 Plantation Street, Worcester, MA 01655
| | - Robin Ganesan
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, 368 Plantation Street, Worcester, MA 01655
| | - Allan Jacobson
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, 368 Plantation Street, Worcester, MA 01655
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29
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Zhang D, Zhu L, Wang F, Li P, Wang Y, Gao Y. Molecular mechanisms of eukaryotic translation fidelity and their associations with diseases. Int J Biol Macromol 2023; 242:124680. [PMID: 37141965 DOI: 10.1016/j.ijbiomac.2023.124680] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 04/27/2023] [Indexed: 05/06/2023]
Abstract
Converting genetic information into functional proteins is a complex, multi-step process, with each step being tightly regulated to ensure the accuracy of translation, which is critical to cellular health. In recent years, advances in modern biotechnology, especially the development of cryo-electron microscopy and single-molecule techniques, have enabled a clearer understanding of the mechanisms of protein translation fidelity. Although there are many studies on the regulation of protein translation in prokaryotes, and the basic elements of translation are highly conserved in prokaryotes and eukaryotes, there are still great differences in the specific regulatory mechanisms. This review describes how eukaryotic ribosomes and translation factors regulate protein translation and ensure translation accuracy. However, a certain frequency of translation errors does occur in translation, so we describe diseases that arise when the rate of translation errors reaches or exceeds a threshold of cellular tolerance.
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Affiliation(s)
- Dejiu Zhang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Lei Zhu
- College of Basic Medical, Qingdao Binhai University, Qingdao, China
| | - Fei Wang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Peifeng Li
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Yin Wang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China.
| | - Yanyan Gao
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China.
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30
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Rodríguez-García ME, Cotrina-Vinagre FJ, Sánchez-Calvin MT, de Aragón AM, de Las Heras RS, Dinman JD, de Vries BBA, Nabais Sá MJ, Quijada-Fraile P, Martínez-Azorín F. A novel de novo variant in CASK causes a severe neurodevelopmental disorder that masks the phenotype of a novel de novo variant in EEF2. J Hum Genet 2023:10.1038/s10038-023-01150-4. [PMID: 37072624 DOI: 10.1038/s10038-023-01150-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 03/10/2023] [Accepted: 04/01/2023] [Indexed: 04/20/2023]
Abstract
We report a 9-year-old Spanish boy with severe psychomotor developmental delay, short stature, microcephaly and abnormalities of the brain morphology, including cerebellar atrophy. Whole-exome sequencing (WES) uncovered two novel de novo variants, a hemizygous variant in CASK (Calcium/Calmodulin Dependent Serine Protein Kinase) and a heterozygous variant in EEF2 (Eukaryotic Translation Elongation Factor 2). CASK gene encodes the peripheral plasma membrane protein CASK that is a scaffold protein located at the synapses in the brain. The c.2506-6 A > G CASK variant induced two alternative splicing events that account for the 80% of the total transcripts, which are likely to be degraded by NMD. Pathogenic variants in CASK have been associated with severe neurological disorders such as mental retardation with or without nystagmus also called FG syndrome 4 (FGS4), and intellectual developmental disorder with microcephaly and pontine and cerebellar hypoplasia (MICPCH). Heterozygous variants in EEF2, which encodes the elongation factor 2 (eEF2), have been associated to Spinocerebellar ataxia 26 (SCA26) and more recently to a childhood-onset neurodevelopmental disorder with benign external hydrocephalus. The yeast model system used to investigate the functional consequences of the c.34 A > G EEF2 variant supported its pathogenicity by demonstrating it affects translational fidelity. In conclusion, the phenotype associated with the CASK variant is more severe and masks the milder phenotype of EEF2 variant.
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Affiliation(s)
- María Elena Rodríguez-García
- Grupo de Enfermedades Raras, Mitocondriales y Neuromusculares (ERMN). Instituto de Investigación Hospital 12 de Octubre (i + 12), E-28041, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), U723, E-28041, Madrid, Spain
| | - Francisco Javier Cotrina-Vinagre
- Grupo de Enfermedades Raras, Mitocondriales y Neuromusculares (ERMN). Instituto de Investigación Hospital 12 de Octubre (i + 12), E-28041, Madrid, Spain
| | | | | | | | - Jonathan D Dinman
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, 20742, USA
| | - Bert B A de Vries
- Department of Human Genetics, Radboud University Medical Center and Donders Institute for Brain, Cognition and Behavior, 6525 GA, Nijmegen, The Netherlands
| | - Maria João Nabais Sá
- Centre for Predictive and Preventive Genetics (CGPP) and UnIGENe, Institute for Molecular and Cell Biology (IBMC), i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Pilar Quijada-Fraile
- Unidad Pediátrica de Enfermedades Raras, Enfermedades Mitocondriales y Metabólicas Hereditarias, Hospital 12 de Octubre, E-28041, Madrid, Spain
| | - Francisco Martínez-Azorín
- Grupo de Enfermedades Raras, Mitocondriales y Neuromusculares (ERMN). Instituto de Investigación Hospital 12 de Octubre (i + 12), E-28041, Madrid, Spain.
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), U723, E-28041, Madrid, Spain.
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31
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Wagner RN, Wießner M, Friedrich A, Zandanell J, Breitenbach-Koller H, Bauer JW. Emerging Personalized Opportunities for Enhancing Translational Readthrough in Rare Genetic Diseases and Beyond. Int J Mol Sci 2023; 24:6101. [PMID: 37047074 PMCID: PMC10093890 DOI: 10.3390/ijms24076101] [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: 02/16/2023] [Revised: 03/17/2023] [Accepted: 03/21/2023] [Indexed: 04/14/2023] Open
Abstract
Nonsense mutations trigger premature translation termination and often give rise to prevalent and rare genetic diseases. Consequently, the pharmacological suppression of an unscheduled stop codon represents an attractive treatment option and is of high clinical relevance. At the molecular level, the ability of the ribosome to continue translation past a stop codon is designated stop codon readthrough (SCR). SCR of disease-causing premature termination codons (PTCs) is minimal but small molecule interventions, such as treatment with aminoglycoside antibiotics, can enhance its frequency. In this review, we summarize the current understanding of translation termination (both at PTCs and at cognate stop codons) and highlight recently discovered pathways that influence its fidelity. We describe the mechanisms involved in the recognition and readthrough of PTCs and report on SCR-inducing compounds currently explored in preclinical research and clinical trials. We conclude by reviewing the ongoing attempts of personalized nonsense suppression therapy in different disease contexts, including the genetic skin condition epidermolysis bullosa.
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Affiliation(s)
- Roland N. Wagner
- Department of Dermatology and Allergology, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria
| | - Michael Wießner
- Department of Dermatology and Allergology, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria
| | - Andreas Friedrich
- Department of Dermatology and Allergology, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria
- Department of Biosciences, University of Salzburg, 5020 Salzburg, Austria
| | - Johanna Zandanell
- Department of Dermatology and Allergology, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria
| | | | - Johann W. Bauer
- Department of Dermatology and Allergology, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria
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Kobayashi S, Kaji A, Kaji H. A novel function for eukaryotic elongation factor 3: Inhibition of stop codon readthrough in yeast. Arch Biochem Biophys 2023; 740:109580. [PMID: 36948349 DOI: 10.1016/j.abb.2023.109580] [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: 11/26/2022] [Revised: 03/16/2023] [Accepted: 03/18/2023] [Indexed: 03/24/2023]
Abstract
Eukaryotic elongation factor 3 (eEF3) is one of the essential yeast ribosome-associated ATP-binding cassette type F (ABCF) ATPases. Previously, we found that eEF3 stimulates release of mRNA from puromycin-treated polysomes. In this study, we used a cell-free cricket paralysis virus (CrPV) internal ribosome entry site (IRES)-mediated firefly luciferase bicistronic mRNA translation system with yeast S30 extract. When eEF3 was partially removed from the crude extract, the product from the downstream ORF was increased by the readthrough of a UAA stop codon in the upstream ORF. eEF3 enhanced the release of luciferase from the polysome by eukaryotic release factor (eRF)1 and eRF3. These results suggest that eEF3 is a factor that assists eRFs in performing normal protein synthesis termination in yeast.
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Affiliation(s)
- Soushi Kobayashi
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, 3610 Hamilton Walk, Philadelphia, PA, 19104, USA; Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA, 19107, USA.
| | - Akira Kaji
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, 3610 Hamilton Walk, Philadelphia, PA, 19104, USA.
| | - Hideko Kaji
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA, 19107, USA
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A High-Throughput Assay for In Vitro Determination of Release Factor-Dependent Peptide Release from a Pretermination Complex by Fluorescence Anisotropy-Application to Nonsense Suppressor Screening and Mechanistic Studies. Biomolecules 2023; 13:biom13020242. [PMID: 36830611 PMCID: PMC9953321 DOI: 10.3390/biom13020242] [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: 12/27/2022] [Revised: 01/23/2023] [Accepted: 01/25/2023] [Indexed: 02/03/2023] Open
Abstract
Premature termination codons (PTCs) account for ~12% of all human disease mutations. Translation readthrough-inducing drugs (TRIDs) are prominent among the several therapeutic approaches being used to overcome PTCs. Ataluren is the only TRID that has been approved for treating patients suffering from a PTC disease, Duchenne muscular dystrophy, but it gives variable readthrough results in cells isolated from patients suffering from other PTC diseases. We recently elucidated ataluren's mechanism of action as a competitive inhibitor of release factor complex (RFC) catalysis of premature termination and identified ataluren's binding sites on the ribosome responsible for such an inhibition. These results suggest the possibility of discovering new TRIDs, which would retain ataluren's low toxicity while displaying greater potency and generality in stimulating readthrough via the inhibition of termination. Here we present a detailed description of a new in vitro plate reader assay that we are using both to screen small compound libraries for the inhibition of RFC-dependent peptide release and to better understand the influence of termination codon identity and sequence context on RFC activity.
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Priante G, Ceol M, Gianesello L, Bizzotto D, Braghetta P, Calò LA, Del Prete D, Anglani F. Emerging Perspectives on the Rare Tubulopathy Dent Disease: Is Glomerular Damage a Direct Consequence of ClC-5 Dysfunction? Int J Mol Sci 2023; 24:1313. [PMID: 36674829 PMCID: PMC9864126 DOI: 10.3390/ijms24021313] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 12/22/2022] [Accepted: 12/24/2022] [Indexed: 01/12/2023] Open
Abstract
Dent disease (DD1) is a rare tubulopathy caused by mutations in the CLCN5 gene. Glomerulosclerosis was recently reported in DD1 patients and ClC-5 protein was shown to be expressed in human podocytes. Nephrin and actin cytoskeleton play a key role for podocyte functions and podocyte endocytosis seems to be crucial for slit diaphragm regulation. The aim of this study was to analyze whether ClC-5 loss in podocytes might be a direct consequence of the glomerular damage in DD1 patients. Three DD1 kidney biopsies presenting focal global glomerulosclerosis and four control biopsies were analyzed by immunofluorescence (IF) for nephrin and podocalyxin, and by immunohistochemistry (IHC) for ClC-5. ClC-5 resulted as down-regulated in DD1 vs. control (CTRL) biopsies in both tubular and glomerular compartments (p < 0.01). A significant down-regulation of nephrin (p < 0.01) in DD1 vs. CTRL was demonstrated. CRISPR/Cas9 (Clustered Regularly Interspaced Short Palindromic Repeats/Caspase9) gene editing of CLCN5 in conditionally immortalized human podocytes was used to obtain clones with the stop codon mutation p.(R34Efs*14). We showed that ClC-5 and nephrin expression, analyzed by quantitative Reverse Transcription/Polymerase Chain Reaction (qRT/PCR) and In-Cell Western (ICW), was significantly downregulated in mutant clones compared to the wild type ones. In addition, F-actin staining with fluorescent phalloidin revealed actin derangements. Our results indicate that ClC-5 loss might alter podocyte function either through cytoskeleton disorganization or through impairment of nephrin recycling.
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Affiliation(s)
- Giovanna Priante
- Kidney Histomorphology and Molecular Biology Laboratory, Nephrology Unit, Department of Medicine—DIMED, University of Padua, Via Giustiniani n° 2, 35128 Padua, Italy
| | - Monica Ceol
- Kidney Histomorphology and Molecular Biology Laboratory, Nephrology Unit, Department of Medicine—DIMED, University of Padua, Via Giustiniani n° 2, 35128 Padua, Italy
| | - Lisa Gianesello
- Kidney Histomorphology and Molecular Biology Laboratory, Nephrology Unit, Department of Medicine—DIMED, University of Padua, Via Giustiniani n° 2, 35128 Padua, Italy
| | - Dario Bizzotto
- Department of Molecular Medicine, University of Padua, 35121 Padua, Italy
| | - Paola Braghetta
- Department of Molecular Medicine, University of Padua, 35121 Padua, Italy
| | - Lorenzo Arcangelo Calò
- Kidney Histomorphology and Molecular Biology Laboratory, Nephrology Unit, Department of Medicine—DIMED, University of Padua, Via Giustiniani n° 2, 35128 Padua, Italy
| | - Dorella Del Prete
- Kidney Histomorphology and Molecular Biology Laboratory, Nephrology Unit, Department of Medicine—DIMED, University of Padua, Via Giustiniani n° 2, 35128 Padua, Italy
| | - Franca Anglani
- Kidney Histomorphology and Molecular Biology Laboratory, Nephrology Unit, Department of Medicine—DIMED, University of Padua, Via Giustiniani n° 2, 35128 Padua, Italy
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Song J, Dong L, Sun H, Luo N, Huang Q, Li K, Shen X, Jiang Z, Lv Z, Peng L, Zhang M, Wang K, Liu K, Hong J, Yi C. CRISPR-free, programmable RNA pseudouridylation to suppress premature termination codons. Mol Cell 2023; 83:139-155.e9. [PMID: 36521489 DOI: 10.1016/j.molcel.2022.11.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 10/03/2022] [Accepted: 11/14/2022] [Indexed: 12/15/2022]
Abstract
Nonsense mutations, accounting for >20% of disease-associated mutations, lead to premature translation termination. Replacing uridine with pseudouridine in stop codons suppresses translation termination, which could be harnessed to mediate readthrough of premature termination codons (PTCs). Here, we present RESTART, a programmable RNA base editor, to revert PTC-induced translation termination in mammalian cells. RESTART utilizes an engineered guide snoRNA (gsnoRNA) and the endogenous H/ACA box snoRNP machinery to achieve precise pseudouridylation. We also identified and optimized gsnoRNA scaffolds to increase the editing efficiency. Unexpectedly, we found that a minor isoform of pseudouridine synthase DKC1, lacking a C-terminal nuclear localization signal, greatly improved the PTC-readthrough efficiency. Although RESTART induced restricted off-target pseudouridylation, they did not change the coding information nor the expression level of off-targets. Finally, RESTART enables robust pseudouridylation in primary cells and achieves functional PTC readthrough in disease-relevant contexts. Collectively, RESTART is a promising RNA-editing tool for research and therapeutics.
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Affiliation(s)
- Jinghui Song
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, PRC
| | - Liting Dong
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, PRC; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, PRC
| | - Hanxiao Sun
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, PRC
| | - Nan Luo
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, PRC
| | - Qiang Huang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, PRC
| | - Kai Li
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, PRC; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, PRC; Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, PRC
| | - Xiaowen Shen
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, PRC
| | - Zhe Jiang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, PRC
| | - Zhicong Lv
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, PRC
| | - Luxin Peng
- College of Chemistry and Molecular Engineering, Peking University, Beijing, PRC
| | | | - Kun Wang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, PRC
| | - Ke Liu
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, PRC
| | - Jiaxu Hong
- Department of Ophthalmology, Eye and Ear, Nose, Throat Hospital of Fudan University, Shanghai, PRC
| | - Chengqi Yi
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, PRC; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, PRC; Department of Chemical Biology and Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular Engineering, Peking University, Beijing, PRC.
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36
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Beryozkin A, Nagel-Wolfum K, Banin E, Sharon D. Factors Affecting Readthrough of Natural Versus Premature Termination Codons. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1415:149-155. [PMID: 37440028 DOI: 10.1007/978-3-031-27681-1_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
Nonsense mutations occur within the open-reading frame of a gene resulting in a premature termination codon (PTC). PTC-containing mRNAs can either be degeraded or cause premature translation termination producing a truncated protein that can be either nonfunctional or toxic. Translational readthrough inducing drugs (TRIDs) are small molecules that are able to induce readthrough, resulting in the restoration of full-length protein expression. The re-expressed proteins usually harbor a missense change. The effciency of individual TRIDs is variable and varies between different genes and even different nonsense mutations in the same gene. This review summarizes factors, including the sequences located upstream and downstream the disease-causing mutation and the type of PTC, affecting the translational readthrough process by modulating the type of amino acid insertion and the efficiency of the process during readthrough following TRIDs treatments.
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Affiliation(s)
- Avigail Beryozkin
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Kerstin Nagel-Wolfum
- Institute of Molecular Physiology & Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Eyal Banin
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Dror Sharon
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel.
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37
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Heldin A, Cancer M, Palomar-Siles M, Öhlin S, Zhang M, Sun-Zhang A, Mariani A, Liu J, Bykov VJN, Wiman KG. Novel compounds that synergize with aminoglycoside G418 or eRF3 degraders for translational readthrough of nonsense mutant TP53 and PTEN. RNA Biol 2023; 20:368-383. [PMID: 37339263 DOI: 10.1080/15476286.2023.2222250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 05/12/2023] [Accepted: 05/18/2023] [Indexed: 06/22/2023] Open
Abstract
The TP53 and PTEN tumour suppressor genes are inactivated by nonsense mutations in a significant fraction of human tumours. TP53 nonsense mutatant tumours account for approximately one million new cancer cases per year worldwide. We have screened chemical libraries with the aim of identifying compounds that induce translational readthrough and expression of full-length p53 protein in cells with nonsense mutation in this gene. Here we describe two novel compounds with readthrough activity, either alone or in combination with other known readthrough-promoting substances. Both compounds induced levels of full-length p53 in cells carrying R213X nonsense mutant TP53. Compound C47 showed synergy with the aminoglycoside antibiotic and known readthrough inducer G418, whereas compound C61 synergized with eukaryotic release factor 3 (eRF3) degraders CC-885 and CC-90009. C47 alone showed potent induction of full-length PTEN protein in cells with different PTEN nonsense mutations. These results may facilitate further development of novel targeted cancer therapy by pharmacological induction of translational readthrough.
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Affiliation(s)
- Angelos Heldin
- Department of Oncology-Pathology, BioClinicum, Karolinska Institutet, Stockholm, Sweden
| | - Matko Cancer
- Department of Oncology-Pathology, BioClinicum, Karolinska Institutet, Stockholm, Sweden
| | - Mireia Palomar-Siles
- Department of Oncology-Pathology, BioClinicum, Karolinska Institutet, Stockholm, Sweden
| | - Susanne Öhlin
- Department of Oncology-Pathology, BioClinicum, Karolinska Institutet, Stockholm, Sweden
| | - Meiqiongzi Zhang
- Department of Oncology-Pathology, BioClinicum, Karolinska Institutet, Stockholm, Sweden
| | - Alexander Sun-Zhang
- Department of Oncology-Pathology, BioClinicum, Karolinska Institutet, Stockholm, Sweden
| | - Anna Mariani
- Department of Oncology-Pathology, BioClinicum, Karolinska Institutet, Stockholm, Sweden
| | - Jianping Liu
- Department of Medicine, Karolinska Institutet, Huddinge, Sweden
| | - Vladimir J N Bykov
- Department of Oncology-Pathology, BioClinicum, Karolinska Institutet, Stockholm, Sweden
| | - Klas G Wiman
- Department of Oncology-Pathology, BioClinicum, Karolinska Institutet, Stockholm, Sweden
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38
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Ngiwsara L, Sawangareetrakul P, Wattanasirichaigoon D, Tim-Aroon T, Dejkhamron P, Champattanachai V, Ketudat-Cairns JR, Svasti J. Effects of gentamicin inducing readthrough premature stop Codons: A study of alpha-L-iduronidase nonsense variants in COS-7 Cells. Biochem Biophys Res Commun 2022; 636:147-154. [DOI: 10.1016/j.bbrc.2022.10.081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 10/23/2022] [Indexed: 11/02/2022]
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39
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Palomar-Siles M, Heldin A, Zhang M, Strandgren C, Yurevych V, van Dinter JT, Engels SAG, Hofman DA, Öhlin S, Meineke B, Bykov VJN, van Heesch S, Wiman KG. Translational readthrough of nonsense mutant TP53 by mRNA incorporation of 5-Fluorouridine. Cell Death Dis 2022; 13:997. [PMID: 36433934 PMCID: PMC9700717 DOI: 10.1038/s41419-022-05431-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 11/08/2022] [Accepted: 11/10/2022] [Indexed: 11/27/2022]
Abstract
TP53 nonsense mutations in cancer produce truncated inactive p53 protein. We show that 5-FU metabolite 5-Fluorouridine (FUr) induces full-length p53 in human tumor cells carrying R213X nonsense mutant TP53. Ribosome profiling visualized translational readthrough at the R213X premature stop codon and demonstrated that FUr-induced readthrough is less permissive for canonical stop codon readthrough compared to aminoglycoside G418. FUr is incorporated into mRNA and can potentially base-pair with guanine, allowing insertion of Arg tRNA at the TP53 R213X UGA premature stop codon and translation of full-length wild-type p53. We confirmed that full-length p53 rescued by FUr triggers tumor cell death by apoptosis. FUr also restored full-length p53 in TP53 R213X mutant human tumor xenografts in vivo. Thus, we demonstrate a novel strategy for therapeutic rescue of nonsense mutant TP53 and suggest that FUr should be explored for treatment of patients with TP53 nonsense mutant tumors.
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Affiliation(s)
- Mireia Palomar-Siles
- grid.4714.60000 0004 1937 0626Department of Oncology-Pathology, Karolinska Institutet, Stockholm, Sweden
| | - Angelos Heldin
- grid.4714.60000 0004 1937 0626Department of Oncology-Pathology, Karolinska Institutet, Stockholm, Sweden
| | - Meiqiongzi Zhang
- grid.4714.60000 0004 1937 0626Department of Oncology-Pathology, Karolinska Institutet, Stockholm, Sweden
| | - Charlotte Strandgren
- grid.4714.60000 0004 1937 0626Department of Oncology-Pathology, Karolinska Institutet, Stockholm, Sweden
| | - Viktor Yurevych
- grid.487647.ePrincess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands
| | - Jip T. van Dinter
- grid.487647.ePrincess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands
| | - Sem A. G. Engels
- grid.487647.ePrincess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands
| | - Damon A. Hofman
- grid.487647.ePrincess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands
| | - Susanne Öhlin
- grid.4714.60000 0004 1937 0626Department of Oncology-Pathology, Karolinska Institutet, Stockholm, Sweden
| | - Birthe Meineke
- grid.4714.60000 0004 1937 0626Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Vladimir J. N. Bykov
- grid.4714.60000 0004 1937 0626Department of Oncology-Pathology, Karolinska Institutet, Stockholm, Sweden
| | - Sebastiaan van Heesch
- grid.487647.ePrincess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands
| | - Klas G. Wiman
- grid.4714.60000 0004 1937 0626Department of Oncology-Pathology, Karolinska Institutet, Stockholm, Sweden
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Egbert S, Hoffman JR, McMullin RT, Lendemer JC, Sorensen JL. Unraveling usnic acid: a comparison of biosynthetic gene clusters between two reindeer lichen (Cladonia rangiferina and C. uncialis). Fungal Biol 2022; 126:697-706. [PMID: 36517138 DOI: 10.1016/j.funbio.2022.08.007] [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: 03/31/2022] [Revised: 08/09/2022] [Accepted: 08/15/2022] [Indexed: 01/07/2023]
Abstract
Lichenized fungi are known for their production of a diversity of secondary metabolites, many of which have broad biological and pharmacological applications. By far the most well-studied of these metabolites is usnic acid. While this metabolite has been well-known and researched for decades, the gene cluster responsible for its production was only recently identified from the species Cladonia uncialis. Usnic acid production varies considerably in the genus Cladonia, even among closely related taxa, and many species, such as C. rangiferina, have been inferred to be incapable of producing the metabolite based on analysis by thin-layer chromatography (TLC). We sequenced and examined the usnic acid biosynthetic gene clusters, or lack thereof, from four closely related Cladonia species (C. oricola, C. rangiferina, C. stygia, and C. subtenuis), and compare them against those of C. uncialis. We complement this comparison with tiered chemical profile analyses to confirm the presence or absence of usnic acid in select samples, using both HPLC and LC-MS. Despite long-standing reporting that C. rangiferina lacks the ability to produce usnic acid, we observed functional gene clusters from the species and detected usnic acid when extracts were examined by LC-MS. By contrast, C. stygia and C. oricola, have been previously described as lacking the ability to produce usnic acid, lacked the gene cluster entirely, and no usnic acid could be detected in C. oricola extracts via HPLC or LC-MS. This work suggests that chemical profiles attained through inexpensive and low-sensitivity methods like TLC may fail to detect low abundance metabolites that can be taxonomically informative. This study also bolsters understanding of the usnic acid gene cluster in lichens, revealing differences among domains of the polyketide synthase which may explain observed differences in expression. These results reinforce the need for comprehensive characterization of lichen secondary metabolite profiles with sensitive LC-MS methods.
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Affiliation(s)
- Susan Egbert
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada
| | - Jordan R Hoffman
- Department of Biology, Graduate Center, City University of New York, The New York, USA; Botanical Garden, 2900 Southern Blvd, Bronx, NY, 10458-5126, USA
| | - R Troy McMullin
- Research and Collections, Canadian Museum of Nature, PO Box 3443, Station D, Ottawa, Ontario, K1P 6P4, Canada
| | - James C Lendemer
- Botanical Garden, 2900 Southern Blvd, Bronx, NY, 10458-5126, USA.
| | - John L Sorensen
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada.
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41
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Embree CM, Abu-Alhasan R, Singh G. Features and factors that dictate if terminating ribosomes cause or counteract nonsense-mediated mRNA decay. J Biol Chem 2022; 298:102592. [PMID: 36244451 PMCID: PMC9661723 DOI: 10.1016/j.jbc.2022.102592] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 10/07/2022] [Accepted: 10/10/2022] [Indexed: 11/13/2022] Open
Abstract
Nonsense-mediated mRNA decay (NMD) is a quality control pathway in eukaryotes that continuously monitors mRNA transcripts to ensure truncated polypeptides are not produced. The expression of many normal mRNAs that encode full-length polypeptides is also regulated by this pathway. Such transcript surveillance by NMD is intimately linked to translation termination. When a ribosome terminates translation at a normal termination codon, NMD is not activated, and mRNA can undergo repeated rounds of translation. On the other hand, when translation termination is deemed abnormal, such as that on a premature termination codon, it leads to a series of poorly understood events involving the NMD pathway, which destabilizes the transcript. In this review, we summarize our current understanding of how the NMD machinery interfaces with the translation termination factors to initiate NMD. We also discuss a variety of cis-acting sequence contexts and trans-acting factors that can cause readthrough, ribosome reinitiation, or ribosome frameshifting at stop codons predicted to induce NMD. These alternative outcomes can lead to the ribosome translating downstream of such stop codons and hence the transcript escaping NMD. NMD escape via these mechanisms can have wide-ranging implications on human health, from being exploited by viruses to hijack host cell systems to being harnessed as potential therapeutic possibilities to treat genetic diseases.
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Affiliation(s)
- Caleb M Embree
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, USA; Center for RNA Biology, The Ohio State University, Columbus, Ohio USA
| | - Rabab Abu-Alhasan
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, USA; Center for RNA Biology, The Ohio State University, Columbus, Ohio USA
| | - Guramrit Singh
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, USA; Center for RNA Biology, The Ohio State University, Columbus, Ohio USA.
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42
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Property based analysis: Optimality of RNY comma-free code versus circular code (X) after frameshift errors. GENE REPORTS 2022. [DOI: 10.1016/j.genrep.2022.101652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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43
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Bowling A, Eastman A, Merlo C, Lin G, West N, Patel S, Cutting G, Sharma N. Downstream Alternate Start Site Allows N-Terminal Nonsense Variants to Escape NMD and Results in Functional Recovery by Readthrough and Modulator Combination. J Pers Med 2022; 12:jpm12091448. [PMID: 36143233 PMCID: PMC9504986 DOI: 10.3390/jpm12091448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 08/26/2022] [Accepted: 08/31/2022] [Indexed: 11/23/2022] Open
Abstract
Genetic variants that introduce premature termination codons (PTCs) have remained difficult to therapeutically target due to lack of protein product. Nonsense mediated mRNA decay (NMD) targets PTC-bearing transcripts to reduce the potentially damaging effects of truncated proteins. Readthrough compounds have been tested on PTC-generating variants in attempt to permit translation through a premature stop. However, readthrough compounds have not proved efficacious in a clinical setting due to lack of stable mRNA. Here, we investigate N-terminal variants in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, which have been shown to escape NMD, potentially through a mechanism of alternative translation initiation at downstream AUG codons. We hypothesized that N-terminal variants in CFTR that evade NMD will produce stable transcript, allowing CFTR function to be restored by a combination of readthrough and protein modulator therapy. We investigate this using two cell line models expressing CFTR-expression minigenes (EMG; HEK293s and CFBEs) and primary human nasal epithelial (NE) cells, and we test readthrough compounds G418 and ELX-02 in combination with CFTR protein modulators. HEK293 cells expressing the variants E60X and L88X generate CFTR-specific core glycosylated products that are consistent with downstream translation initiation. Mutation of downstream methionines at codons 150 and 152 does not result in changes in CFTR protein processing in cells expressing L88X-CFTR-EMG. However, mutation of methionine at 265 results in loss of detectable CFTR protein in cells expressing E60X, L88X, and Y122X CFTR-EMGs, indicating that downstream translation initiation is occurring at the AUG codon at position M265. In HEK293 stable cells harboring L88X, treatment with readthrough compounds alone allows for formation of full-length, but misfolded CFTR protein. Upon addition of protein modulators in combination with readthrough, we observe formation of mature, complex-glycosylated CFTR. In CFBE and NE cells, addition of readthrough ELX-02 and modulator therapy results in substantial recovery of CFTR function. Our work indicates that N-terminal variants generate stable CFTR transcript due to translation initiation at a downstream AUG codon. Thus, individuals with CF bearing 5′ nonsense variants that evade NMD are ideal candidates for treatment with clinically safe readthrough compounds and modulator therapy.
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Affiliation(s)
- Alyssa Bowling
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Alice Eastman
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Christian Merlo
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD 21205, USA
| | - Gabrielle Lin
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Natalie West
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD 21205, USA
| | - Shivani Patel
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD 21205, USA
| | - Garry Cutting
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Neeraj Sharma
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Correspondence:
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Sellar RS, Sperling AS, Słabicki M, Gasser JA, McConkey ME, Donovan KA, Mageed N, Adams DN, Zou C, Miller PG, Dutta RK, Boettcher S, Lin AE, Sandoval B, Quevedo Barrios VA, Kovalcik V, Koeppel J, Henderson EK, Fink EC, Yang L, Chan A, Pokharel SP, Bergstrom EJ, Burt R, Udeshi ND, Carr SA, Fischer ES, Chen CW, Ebert BL. Degradation of GSPT1 causes TP53-independent cell death in leukemia while sparing normal hematopoietic stem cells. J Clin Invest 2022; 132:e153514. [PMID: 35763353 PMCID: PMC9374383 DOI: 10.1172/jci153514] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 06/24/2022] [Indexed: 11/17/2022] Open
Abstract
Targeted protein degradation is a rapidly advancing and expanding therapeutic approach. Drugs that degrade GSPT1 via the CRL4CRBN ubiquitin ligase are a new class of cancer therapy in active clinical development with evidence of activity against acute myeloid leukemia in early-phase trials. However, other than activation of the integrated stress response, the downstream effects of GSPT1 degradation leading to cell death are largely undefined, and no murine models are available to study these agents. We identified the domains of GSPT1 essential for cell survival and show that GSPT1 degradation leads to impaired translation termination, activation of the integrated stress response pathway, and TP53-independent cell death. CRISPR/Cas9 screens implicated decreased translation initiation as protective following GSPT1 degradation, suggesting that cells with higher levels of translation are more susceptible to the effects of GSPT1 degradation. We defined 2 Crbn amino acids that prevent Gspt1 degradation in mice, generated a knockin mouse with alteration of these residues, and demonstrated the efficacy of GSPT1-degrading drugs in vivo with relative sparing of numbers and function of long-term hematopoietic stem cells. Our results provide a mechanistic basis for the use of GSPT1 degraders for the treatment of cancer, including TP53-mutant acute myeloid leukemia.
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Affiliation(s)
- Rob S. Sellar
- Department of Haematology, UCL Cancer Institute, University College London, London, United Kingdom
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Adam S. Sperling
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Division of Hematology, Brigham and Women’s Hospital, Boston, Massachusetts, USA
| | - Mikołaj Słabicki
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Jessica A. Gasser
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Marie E. McConkey
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Katherine A. Donovan
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, USA
| | - Nada Mageed
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, USA
| | - Dylan N. Adams
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
| | - Charles Zou
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
| | - Peter G. Miller
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Ravi K. Dutta
- Division of Hematology, Brigham and Women’s Hospital, Boston, Massachusetts, USA
| | - Steffen Boettcher
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Medical Oncology and Hematology, University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | - Amy E. Lin
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women’s Hospital, Boston, Massachusetts, USA
| | - Brittany Sandoval
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
| | | | - Veronica Kovalcik
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
| | - Jonas Koeppel
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Elizabeth K. Henderson
- Department of Haematology, UCL Cancer Institute, University College London, London, United Kingdom
| | - Emma C. Fink
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Lu Yang
- Department of Systems Biology, City of Hope Comprehensive Cancer Center, Duarte, California, USA
| | - Anthony Chan
- Department of Systems Biology, City of Hope Comprehensive Cancer Center, Duarte, California, USA
| | - Sheela Pangeni Pokharel
- Department of Systems Biology, City of Hope Comprehensive Cancer Center, Duarte, California, USA
| | | | - Rajan Burt
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | | | - Steven A. Carr
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Eric S. Fischer
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, USA
| | - Chun-Wei Chen
- Department of Systems Biology, City of Hope Comprehensive Cancer Center, Duarte, California, USA
| | - Benjamin L. Ebert
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Howard Hughes Medical Institute, Boston, Massachusetts, USA
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45
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Baba H. [Introduction to Myelin Research]. YAKUGAKU ZASSHI 2022; 142:837-853. [PMID: 35908945 DOI: 10.1248/yakushi.21-00224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Myelin is a multilamellar membrane structure formed by oligodendrocytes in the central nervous system (CNS) and Schwann cells in the peripheral nervous system (PNS). It has been recognized as an insulator that is essential for the rapid and efficient propagation of action potentials by saltatory conduction. However, recently many studies have shown that myelin and myelin-forming cells interact with axons and regulate the nervous system far more actively than previously thought. For example, myelination changes axons dynamically and divides them into four distinct functional domains: node of Ranvier, paranode, juxtaparanode, and internode. Voltage-gated Na+ channels are clustered at the node, while K+ channels are at the juxtaparanode, and segregation of these channels by paranodal axoglial junction is necessary for proper axonal function. My research experience began at the neurology ward of the Niigata University Medical Hospital, where I saw a patient with peripheral neuropathy of unknown etiology more than 37 years ago. In the patient's serum, we found an autoantibody against a glycolipid enriched in the PNS. Since then, I have been interested in myelin because of its beautiful structure and unique roles in the nervous system. In this review, our recent studies related to CNS and PNS myelin are presented.
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Affiliation(s)
- Hiroko Baba
- Department of Molecular Neurobiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences
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Khani M, Nafissi S, Shamshiri H, Moazzeni H, Taheri H, Elahi E. Identification of RNF13 as cause of recessively inherited ALS in a multi-case pedigree. J Med Genet 2022; 60:jmedgenet-2022-108645. [PMID: 35879052 DOI: 10.1136/jmg-2022-108645] [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: 04/18/2022] [Accepted: 07/05/2022] [Indexed: 11/04/2022]
Abstract
BACKGROUND Amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease. The approximately 50 known ALS-associated genes do not fully explain its heritability, which suggests the existence of yet unidentified causative genes. We report results of studies aimed at identification of the genetic cause of ALS in a pedigree (three patients) without mutations in the common ALS-causative genes. METHODS Clinical investigations included thorough neurological and non-neurological examinations and testings. Genetic analysis was performed by exome sequencing. Functional studies included identification of altered splicing by PCR and sequencing, and mutated proteins by western blot analysis. Apoptosis in the presence and absence of tunicamycin was assessed in transfected HEK293T cells using an Annexin-PE-7AAD kit in conjunction with flow cytometry. RESULTS Clinical features are described in detail. Disease progression in the patients of the pedigree was relatively slow and survival was relatively long. An RNF13 mutation was identified as the cause of the recessively inherited ALS in the pedigree. The gene is highly conserved, and its encoded protein (RING finger protein 13) can potentially affect various neurodegenerative-relevant functions, including protein homeostasis. The RNF13 splice site mutation caused expression of two mis-spliced forms of RNF13 mRNA and an aberrant RNF13 protein, and affected apoptosis. CONCLUSION RNF13 was identified as a novel causative gene of recessively inherited ALS. The gene affects protein homeostasis, which is one of most important components of the pathology of neurodegeneration. The contribution of RNF13 to the aetiology of another neurodegenerative disease is discussed.
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Affiliation(s)
- Marzieh Khani
- School of Biology, College of Science, University of Tehran, Tehran, The Islamic Republic of Iran
| | - Shahriar Nafissi
- Department of Neurology, Tehran University of Medical Sciences, Tehran, The Islamic Republic of Iran
| | - Hosein Shamshiri
- Department of Neurology, Tehran University of Medical Sciences, Tehran, The Islamic Republic of Iran
| | - Hamidreza Moazzeni
- School of Biology, College of Science, University of Tehran, Tehran, The Islamic Republic of Iran
| | - Hanieh Taheri
- School of Biology, College of Science, University of Tehran, Tehran, The Islamic Republic of Iran
| | - Elahe Elahi
- School of Biology, College of Science, University of Tehran, Tehran, The Islamic Republic of Iran
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47
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Biziaev N, Sokolova E, Yanvarev DV, Toropygin IY, Shuvalov A, Egorova T, Alkalaeva E. Recognition of 3' nucleotide context and stop codon readthrough are determined during mRNA translation elongation. J Biol Chem 2022; 298:102133. [PMID: 35700825 PMCID: PMC9272376 DOI: 10.1016/j.jbc.2022.102133] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 06/06/2022] [Accepted: 06/08/2022] [Indexed: 11/16/2022] Open
Abstract
The nucleotide context surrounding stop codons significantly affects the efficiency of translation termination. In eukaryotes, various 3′ contexts that are unfavorable for translation termination have been described; however, the exact molecular mechanism that mediates their effects remains unknown. In this study, we used a reconstituted mammalian translation system to examine the efficiency of stop codons in different contexts, including several previously described weak 3′ stop codon contexts. We developed an approach to estimate the level of stop codon readthrough in the absence of eukaryotic release factors (eRFs). In this system, the stop codon is recognized by the suppressor or near-cognate tRNAs. We observed that in the absence of eRFs, readthrough occurs in a 3′ nucleotide context-dependent manner, and the main factors determining readthrough efficiency were the type of stop codon and the sequence of the 3′ nucleotides. Moreover, the efficiency of translation termination in weak 3′ contexts was almost equal to that in the tested standard context. Therefore, the ability of eRFs to recognize stop codons and induce peptide release is not affected by mRNA context. We propose that ribosomes or other participants of the elongation cycle can independently recognize certain contexts and increase the readthrough of stop codons. Thus, the efficiency of translation termination is regulated by the 3′ nucleotide context following the stop codon and depends on the concentrations of eRFs and suppressor/near-cognate tRNAs.
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Affiliation(s)
- Nikita Biziaev
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia.
| | - Elizaveta Sokolova
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia.
| | - Dmitry V Yanvarev
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia.
| | - Ilya Yu Toropygin
- Orekhovich Research Institute of Biomedical Chemistry, Moscow, 119992, Russia.
| | - Alexey Shuvalov
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia; Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia.
| | - Tatiana Egorova
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia; Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia; Pirogov Russian National Research Medical University, Moscow, 117997, Russia.
| | - Elena Alkalaeva
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia; Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia.
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48
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Wang X, Dong Q, Chen G, Zhang J, Liu Y, Cai Y. Frameshift and wild-type proteins are often highly similar because the genetic code and genomes were optimized for frameshift tolerance. BMC Genomics 2022; 23:416. [PMID: 35655139 PMCID: PMC9164415 DOI: 10.1186/s12864-022-08435-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 03/02/2022] [Indexed: 11/10/2022] Open
Abstract
Frameshift mutations have been considered of significant importance for the molecular evolution of proteins and their coding genes, while frameshift protein sequences encoded in the alternative reading frames of coding genes have been considered to be meaningless. However, functional frameshifts have been found widely existing. It was puzzling how a frameshift protein kept its structure and functionality while substantial changes occurred in its primary amino-acid sequence. This study shows that the similarities among frameshifts and wild types are higher than random similarities and are determined at different levels. Frameshift substitutions are more conservative than random substitutions in the standard genetic code (SGC). The frameshift substitutions score of SGC ranks in the top 2.0-3.5% of alternative genetic codes, showing that SGC is nearly optimal for frameshift tolerance. In many genes and certain genomes, frameshift-resistant codons and codon pairs appear more frequently than expected, suggesting that frameshift tolerance is achieved through not only the optimality of the genetic code but, more importantly, the further optimization of a specific gene or genome through the usages of codons/codon pairs, which sheds light on the role of frameshift mutations in molecular and genomic evolution.
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Inagaki N. Processing of D1 Protein: A Mysterious Process Carried Out in Thylakoid Lumen. Int J Mol Sci 2022; 23:ijms23052520. [PMID: 35269663 PMCID: PMC8909930 DOI: 10.3390/ijms23052520] [Citation(s) in RCA: 6] [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: 01/13/2022] [Revised: 02/16/2022] [Accepted: 02/21/2022] [Indexed: 11/16/2022] Open
Abstract
In oxygenic photosynthetic organisms, D1 protein, a core subunit of photosystem II (PSII), displays a rapid turnover in the light, in which D1 proteins are distinctively damaged and immediately removed from the PSII. In parallel, as a repair process, D1 proteins are synthesized and simultaneously assembled into the PSII. On this flow, the D1 protein is synthesized as a precursor with a carboxyl-terminal extension, and the D1 processing is defined as a step for proteolytic removal of the extension by a specific protease, CtpA. The D1 processing plays a crucial role in appearance of water-oxidizing capacity of PSII, because the main chain carboxyl group at carboxyl-terminus of the D1 protein, exposed by the D1 processing, ligates a manganese and a calcium atom in the Mn4CaO5-cluster, a special equipment for water-oxidizing chemistry of PSII. This review focuses on the D1 processing and discusses it from four angles: (i) Discovery of the D1 processing and recognition of its importance: (ii) Enzyme involved in the D1 processing: (iii) Efforts for understanding significance of the D1 processing: (iv) Remaining mysteries in the D1 processing. Through the review, I summarize the current status of our knowledge on and around the D1 processing.
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Affiliation(s)
- Noritoshi Inagaki
- Research Center for Advanced Analysis, National Agriculture and Food Research Organization (NARO), Tsukuba 305-8518, Japan
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50
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Preclinical Research in McArdle Disease: A Review of Research Models and Therapeutic Strategies. Genes (Basel) 2021; 13:genes13010074. [PMID: 35052414 PMCID: PMC8774685 DOI: 10.3390/genes13010074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 12/22/2021] [Accepted: 12/23/2021] [Indexed: 02/06/2023] Open
Abstract
McArdle disease is an autosomal recessive disorder of muscle glycogen metabolism caused by pathogenic mutations in the PYGM gene, which encodes the skeletal muscle-specific isoform of glycogen phosphorylase. Clinical symptoms are mainly characterized by transient acute “crises” of early fatigue, myalgia and contractures, which can be accompanied by rhabdomyolysis. Owing to the difficulty of performing mechanistic studies in patients that often rely on invasive techniques, preclinical models have been used for decades, thereby contributing to gain insight into the pathophysiology and pathobiology of human diseases. In the present work, we describe the existing in vitro and in vivo preclinical models for McArdle disease and review the insights these models have provided. In addition, despite presenting some differences with the typical patient’s phenotype, these models allow for a deep study of the different features of the disease while representing a necessary preclinical step to assess the efficacy and safety of possible treatments before they are tested in patients.
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