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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:S0022-3549(24)00047-9. [PMID: 38342339 DOI: 10.1016/j.xphs.2024.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 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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2
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Christie M, Friesen Westley J, Suresh B, Baiazitov Ramil Y, Wu D, Karloff Diane B, Chang-Sun L, Young-Choon M, Hongyu R, Jairo S, Yuki T, Priya V, Welch Ellen M, Xiaojiao X, Jin Z. Guanidino Quinazolines and Pyrimidines Promote Readthrough of Premature Termination Codons in Cells with Native Nonsense Mutations. Bioorg Med Chem Lett 2022; 76:128989. [PMID: 36150638 DOI: 10.1016/j.bmcl.2022.128989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 08/26/2022] [Accepted: 09/09/2022] [Indexed: 11/25/2022]
Abstract
Using small molecules to induce readthrough of premature termination codons is a promising therapeutic approach to treating genetic diseases and cancers caused by nonsense mutations, as evidenced by the widespread use of ataluren to treat nonsense mutation Duchene muscular dystrophy. Herein we describe a series of novel guanidino quinazoline and pyrimidine scaffolds that induce readthrough in both HDQ-P1 mammary carcinoma cells and mdx myotubes. Linkage of basic, tertiary amines with aliphatic, hydrophobic substituents to the terminal guanidine nitrogen of these scaffolds led to significant potency increases. Further potency gains were achieved by flanking the pyrimidine ring with hydrophobic substituents, inducing readthrough at concentrations as low as 120 nM and demonstrating the potential of these compounds to be used either in combination with ataluren or as stand-alone therapeutics.
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Affiliation(s)
- Morrill Christie
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ, 07080, USA
| | - J Friesen Westley
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ, 07080, USA
| | - Babu Suresh
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ, 07080, USA
| | - Y Baiazitov Ramil
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ, 07080, USA
| | - Du Wu
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ, 07080, USA
| | - B Karloff Diane
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ, 07080, USA
| | - Lee Chang-Sun
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ, 07080, USA
| | - Moon Young-Choon
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ, 07080, USA
| | - Ren Hongyu
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ, 07080, USA
| | - Sierra Jairo
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ, 07080, USA
| | - Tomizawa Yuki
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ, 07080, USA
| | - Vazirani Priya
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ, 07080, USA
| | - M Welch Ellen
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ, 07080, USA
| | - Xue Xiaojiao
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ, 07080, USA
| | - Zhuo Jin
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ, 07080, USA
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3
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Wang D, Xue X, Gunn G, Du M, Siddiqui A, Weetall M, Keeling KM. Ataluren suppresses a premature termination codon in an MPS I-H mouse. J Mol Med (Berl) 2022. [PMID: 35857082 DOI: 10.1007/s00109-022-02232-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 05/26/2022] [Accepted: 06/28/2022] [Indexed: 11/26/2022]
Abstract
Abstarct Suppressing translation termination at premature termination codons (PTCs), termed readthrough, is a potential therapy for genetic diseases caused by nonsense mutations. Ataluren is a compound that has shown promise for clinical use as a readthrough agent. However, some reports suggest that ataluren is ineffective at suppressing PTCs. To further evaluate the effectiveness of ataluren as a readthrough agent, we examined its ability to suppress PTCs in a variety of previously untested models. Using NanoLuc readthrough reporters expressed in two different cell types, we found that ataluren stimulated a significant level of readthrough. We also explored the ability of ataluren to suppress a nonsense mutation associated with Mucopolysaccharidosis I-Hurler (MPS I-H), a genetic disease that is caused by a deficiency of α-L-iduronidase that leads to lysosomal accumulation of glycosaminoglycans (GAGs). Using mouse embryonic fibroblasts (MEFs) derived from Idua-W402X mice, we found that ataluren partially rescued α-L-iduronidase function and significantly reduced GAG accumulation relative to controls. Two-week oral administration of ataluren to Idua-W402X mice led to significant GAG reductions in most tissues compared to controls. Together, these data reveal important details concerning the efficiency of ataluren as a readthrough agent and the mechanisms that govern its ability to suppress PTCs. Key messages Ataluren promotes readthrough of PTCs in a wide variety of contexts. Ataluren reduces glycosaminoglyan storage in MPS I-H cell and mouse models. Ataluren has a bell-shaped dose–response curve and a narrow effective range.
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Wang S, Yang Z, Liu Y, Zhao MT, Zhao J, Zhang H, Liu ZY, Wang XL, Ma L, Yang YH. Application of topical gentamicin-a new era in the treatment of genodermatosis. World J Pediatr 2021; 17:568-575. [PMID: 34787828 DOI: 10.1007/s12519-021-00469-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 09/17/2021] [Indexed: 11/26/2022]
Abstract
BACKGROUND The clinical use of gentamicin always lies in its antimicrobial activity in the past as an aminoglycoside antibiotic. However, in the past decade, there were considerable interests in therapeutic approaches in treating hereditary diseases. Some of the genodermatosis is caused by nonsense mutations that create premature termination codons and lead to the production of truncated or non-functional proteins. Gentamicin could induce readthrough of nonsense mutations and enable the synthesis of full-length proteins. We focus on previous publications on topical application of gentamicin and review its utility in genetic skin diseases. DATA SOURCES We search the MEDLINE through PubMed, EMBASE databases, and the Clinical Trials Registry Platform from January 1960 to July 2020 using the key search terms "gentamicin, topical gentamicin, genodermatosis, genetic skin diseases". RESULTS The application of gentamicin in genodermatosis yielded promising results, both in vivo and in vitro, including Nagashima-type palmoplantar keratosis, epidermolysis bullosa, Hailey-Hailey disease, hereditary hypotrichosis simplex of the scalp, etc. CONCLUSIONS: Topical gentamicin is a potential treatment option for genodermatosis caused by nonsense mutation.
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Affiliation(s)
- Shan Wang
- Department of Dermatology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, No. 56 South Li Shi Road, Xi Cheng District, Beijing, 100045, China
| | - Zhou Yang
- Department of Dermatology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, No. 56 South Li Shi Road, Xi Cheng District, Beijing, 100045, China
| | - Ying Liu
- Department of Dermatology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, No. 56 South Li Shi Road, Xi Cheng District, Beijing, 100045, China
| | - Mu-Tong Zhao
- Department of Dermatology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, No. 56 South Li Shi Road, Xi Cheng District, Beijing, 100045, China
| | - Juan Zhao
- Department of Dermatology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, No. 56 South Li Shi Road, Xi Cheng District, Beijing, 100045, China
| | - Huan Zhang
- Department of Pharmacy, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, No. 56 South Li Shi Road, Xi Cheng District, Beijing, 100045, China
| | - Zong-Yang Liu
- Department of Pharmacy, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, No. 56 South Li Shi Road, Xi Cheng District, Beijing, 100045, China
| | - Xiao-Ling Wang
- Department of Pharmacy, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, No. 56 South Li Shi Road, Xi Cheng District, Beijing, 100045, China
| | - Lin Ma
- Department of Dermatology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, No. 56 South Li Shi Road, Xi Cheng District, Beijing, 100045, China.
| | - Yong-Hong Yang
- China National Clinical Research Center for Respiratory Diseases, Department of Respiratory Medicine, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, No. 56 South Li Shi Road, Xi Cheng District, Beijing, 100045, China
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Jadav A, Truong K. Generation of stable cell lines using readthrough expression from lentiviral integration. Biotechnol Lett 2021; 43:2131-2136. [PMID: 34533680 DOI: 10.1007/s10529-021-03186-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 09/03/2021] [Indexed: 11/26/2022]
Abstract
Lentiviral infection is often used to integrate genetic material into cells to stably express transgenes of interest. Depending on the location of integration into the host genome, readthrough expression of the lentiviral cargo can occur via an upstream endogenous promoter, which is typically an unwanted phenomenon because it can result in dysfunctional expression. The purpose of this study was to demonstrate that readthrough expression can be a wanted phenomenon for expressing functional proteins while at the same time reducing the size of the lentiviral transfer plasmid. Readthrough expression was used to generate HEK293 cell lines stably expressing fluorescent reporter proteins, reporter protein-antibiotic resistance fusion proteins for selection, and the vascular endothelial growth factor receptor 2. The generated proteins were all functional, as demonstrated by their ability to fluoresce, confer antibiotic resistance, and participate in receptor-mediated signalling, respectively. Therefore, we suggest that the mechanism of readthrough expression may have further applications in the expression of larger genes or genetic circuits (e.g. cell-based therapeutics), where the lentiviral cargo limit is stretched to the maximum.
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Affiliation(s)
- Anish Jadav
- Institute of Biomedical Engineering, University of Toronto, 164 College Street, Toronto, ON, M5S 3G9, Canada
| | - Kevin Truong
- Institute of Biomedical Engineering, University of Toronto, 164 College Street, Toronto, ON, M5S 3G9, Canada.
- Edward S. Rogers, Sr. Department of Electrical and Computer Engineering, University of Toronto, 164 College Street Room 407, Rosebrugh Building, 10 King's College Circle, Toronto, ON, M5S 3G4, Canada.
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6
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Welponer T, Prodinger C, Pinon-Hofbauer J, Hintersteininger A, Breitenbach-Koller H, Bauer JW, Laimer M. Clinical Perspectives of Gene-Targeted Therapies for Epidermolysis Bullosa. Dermatol Ther (Heidelb) 2021; 11:1175-1197. [PMID: 34110606 PMCID: PMC8322229 DOI: 10.1007/s13555-021-00561-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Indexed: 02/06/2023] Open
Abstract
New insights into molecular genetics and pathomechanisms in epidermolysis bullosa (EB), methodological and technological advances in molecular biology as well as designated funding initiatives and facilitated approval procedures for orphan drugs have boosted translational research perspectives for this devastating disease. This is echoed by the increasing number of clinical trials assessing innovative molecular therapies in the field of EB. Despite remarkable progress, gene-corrective modalities, aimed at sustained or permanent restoration of functional protein expression, still await broad clinical availability. This also reflects the methodological and technological shortcomings of current strategies, including the translatability of certain methodologies beyond preclinical models as well as the safe, specific, efficient, feasible, sustained and cost-effective delivery of therapeutic/corrective information to target cells. This review gives an updated overview on status, prospects, challenges and limitations of current gene-targeted therapies.
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Affiliation(s)
- Tobias Welponer
- Department of Dermatology and Allergology and EB House Austria, University Hospital of the Paracelsus Medical University, Salzburg, Austria
| | - Christine Prodinger
- Department of Dermatology and Allergology and EB House Austria, University Hospital of the Paracelsus Medical University, Salzburg, Austria
| | - Josefina Pinon-Hofbauer
- Department of Dermatology and Allergology and EB House Austria, University Hospital of the Paracelsus Medical University, Salzburg, Austria
| | - Arno Hintersteininger
- Department of Dermatology and Allergology, University Hospital of the Paracelsus Medical University, Salzburg, Austria
| | | | - Johann W Bauer
- Department of Dermatology and Allergology and EB House Austria, University Hospital of the Paracelsus Medical University, Salzburg, Austria
- Department of Biosciences, Paris Lodron University of Salzburg, Salzburg, Austria
| | - Martin Laimer
- Department of Dermatology and Allergology and EB House Austria, University Hospital of the Paracelsus Medical University, Salzburg, Austria.
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7
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Younkin AD, Gregory ST, O'Connor M. Alterations in the ribosomal protein bL12 of E. coli affecting the initiation, elongation and termination of protein synthesis. Biochimie 2020; 175:173-180. [PMID: 32569619 DOI: 10.1016/j.biochi.2020.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 06/10/2020] [Accepted: 06/15/2020] [Indexed: 11/27/2022]
Abstract
In bacteria, ribosomal protein bL12 forms the prominent stalk structure on the ribosome and binds to multiple, distinct translational GTPase factors during the sequential steps of translation. Using a genetic selection in E. coli for altered readthrough of UGA stop codons, we have isolated seven different mutations affecting the C-terminal domain of the protein that forms the interaction surface with translation factors. Analysis of these altered proteins, along with four additional alterations previously shown to affect IF2-ribosome interactions, indicates that multiple steps of translation are affected, consistent with bL12's interaction with multiple factors. Surprisingly, deletion of the release factor GTPase, RF3, has relatively little effect on bL12-promoted stop codon readthrough, suggesting that other steps in termination are also influenced by bL12.
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Affiliation(s)
- Adam D Younkin
- School of Biological and Chemical Sciences, University of Missouri-Kansas City, Kansas City, MO, USA
| | - Steven T Gregory
- Department of Cell and Molecular Biology, The University of Rhode Island, Kingston, RI, 02881, USA
| | - Michael O'Connor
- School of Biological and Chemical Sciences, University of Missouri-Kansas City, Kansas City, MO, USA.
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8
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Frew J, Baradaran-Heravi A, Balgi AD, Wu X, Yan TD, Arns S, Shidmoossavee FS, Tan J, Jaquith JB, Jansen-West KR, Lynn FC, Gao FB, Petrucelli L, Feldman HH, Mackenzie IR, Roberge M, Nygaard HB. Premature termination codon readthrough upregulates progranulin expression and improves lysosomal function in preclinical models of GRN deficiency. Mol Neurodegener 2020; 15:21. [PMID: 32178712 PMCID: PMC7075020 DOI: 10.1186/s13024-020-00369-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 02/24/2020] [Indexed: 02/07/2023] Open
Abstract
Background Frontotemporal lobar degeneration (FTLD) is a devastating and progressive disorder, and a common cause of early onset dementia. Progranulin (PGRN) haploinsufficiency due to autosomal dominant mutations in the progranulin gene (GRN) is an important cause of FTLD (FTLD-GRN), and nearly a quarter of these genetic cases are due to a nonsense mutation. Premature termination codons (PTC) can be therapeutically targeted by compounds allowing readthrough, and aminoglycoside antibiotics are known to be potent PTC readthrough drugs. Restoring endogenous PGRN through PTC readthrough has not previously been explored as a therapeutic intervention in FTLD. Methods We studied whether the aminoglycoside G418 could increase PGRN expression in HEK293 and human induced pluripotent stem cell (hiPSC)-derived neurons bearing the heterozygous S116X, R418X, and R493X pathogenic GRN nonsense mutations. We further tested a novel substituted phthalimide PTC readthrough enhancer in combination with G418 in our cellular models. We next generated a homozygous R493X knock-in hiPSC isogenic line (R493X−/− KI), assessing whether combination treatment in hiPSC-derived neurons and astrocytes could increase PGRN and ameliorate lysosomal dysfunction relevant to FTLD-GRN. To provide in vivo proof-of-concept of our approach, we measured brain PGRN after intracerebroventricular administration of G418 in mice expressing the V5-tagged GRN nonsense mutation R493X. Results The R418X and R493X mutant GRN cell lines responded to PTC readthrough with G418, and treatments increased PGRN levels in R493X−/− KI hiPSC-derived neurons and astrocytes. Combining G418 with a PTC readthrough enhancer increased PGRN levels over G418 treatment alone in vitro. PGRN deficiency has been shown to impair lysosomal function, and the mature form of the lysosomal protease cathepsin D is overexpressed in R493X−/− KI neurons. Increasing PGRN through G418-mediated PTC readthrough normalized this abnormal lysosomal phenotype in R493X−/− KI neuronal cultures. A single intracerebroventricular injection of G418 induced GRN PTC readthrough in 6-week-old AAV-GRN-R493X-V5 mice. Conclusions Taken together, our findings suggest that PTC readthrough may be a potential therapeutic strategy for FTLD caused by GRN nonsense mutations.
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Affiliation(s)
- Jonathan Frew
- Division of Neurology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Alireza Baradaran-Heravi
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Aruna D Balgi
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Xiujuan Wu
- Division of Neurology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Tyler D Yan
- Division of Neurology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Steve Arns
- adMare BioInnovations, Vancouver, British Columbia, Canada
| | | | - Jason Tan
- adMare BioInnovations, Vancouver, British Columbia, Canada
| | | | | | - Francis C Lynn
- Department of Surgery, University of British Columbia, Faculty of Medicine, Vancouver, British Columbia, Canada
| | - Fen-Biao Gao
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, USA
| | | | - Howard H Feldman
- Division of Neurology, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Neurosciences, University of California, San Diego, San Diego, CA, USA
| | - Ian R Mackenzie
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Michel Roberge
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Haakon B Nygaard
- Division of Neurology, University of British Columbia, Vancouver, British Columbia, Canada.
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9
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Affiliation(s)
- Alessio Branchini
- Department of Life Sciences and Biotechnology, University of Ferrara, Italy..
| | - Mirko Pinotti
- Department of Life Sciences and Biotechnology, University of Ferrara, Italy
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10
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Midgley J. A breakthrough in readthrough? Could geneticin lead the way to effective treatment for cystinosis nonsense mutations? Pediatr Nephrol 2019; 34:917-920. [PMID: 30623245 DOI: 10.1007/s00467-018-4173-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 12/04/2018] [Accepted: 12/10/2018] [Indexed: 10/27/2022]
Affiliation(s)
- Julian Midgley
- Alberta Children's Hospital, Section of Paediatric Nephrology, Department of Paediatrics, Cumming School of Medicine, University of Calgary, Calgary, Canada.
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11
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Bukhari K, Mulley G, Gulyaeva AA, Zhao L, Shu G, Jiang J, Neuman BW. Description and initial characterization of metatranscriptomic nidovirus-like genomes from the proposed new family Abyssoviridae, and from a sister group to the Coronavirinae, the proposed genus Alphaletovirus. Virology 2018; 524:160-171. [PMID: 30199753 PMCID: PMC7112036 DOI: 10.1016/j.virol.2018.08.010] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 08/11/2018] [Accepted: 08/11/2018] [Indexed: 01/12/2023]
Abstract
Transcriptomics has the potential to discover new RNA virus genomes by sequencing total intracellular RNA pools. In this study, we have searched publicly available transcriptomes for sequences similar to viruses of the Nidovirales order. We report two potential nidovirus genomes, a highly divergent 35.9 kb likely complete genome from the California sea hare Aplysia californica, which we assign to a nidovirus named Aplysia abyssovirus 1 (AAbV), and a coronavirus-like 22.3 kb partial genome from the ornamented pygmy frog Microhyla fissipes, which we assign to a nidovirus named Microhyla alphaletovirus 1 (MLeV). AAbV was shown to encode a functional main proteinase, and a translational readthrough signal. Phylogenetic analysis suggested that AAbV represents a new family, proposed here as Abyssoviridae. MLeV represents a sister group to the other known coronaviruses. The importance of MLeV and AAbV for understanding nidovirus evolution, and the origin of terrestrial nidoviruses are discussed.
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Affiliation(s)
| | | | - Anastasia A Gulyaeva
- Dept. Medical Microbiology, Leiden University Medical Center, Leiden, the Netherlands
| | - Lanying Zhao
- Chengdu Institute of Biology, Chinese Academy of Science, Chengdu, China
| | - Guocheng Shu
- Chengdu Institute of Biology, Chinese Academy of Science, Chengdu, China
| | - Jianping Jiang
- Chengdu Institute of Biology, Chinese Academy of Science, Chengdu, China
| | - Benjamin W Neuman
- Texas A&M University-Texarkana, 7101 University Ave, Texarkana, TX 75503, United States.
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12
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Harada N, Hatakeyama A, Okuyama M, Miyatake Y, Nakagawa T, Kuroda M, Masumoto S, Tsutsumi R, Nakaya Y, Sakaue H. Readthrough of ACTN3 577X nonsense mutation produces full-length α-actinin-3 protein. Biochem Biophys Res Commun 2018; 502:422-428. [PMID: 29857001 DOI: 10.1016/j.bbrc.2018.05.193] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 05/28/2018] [Indexed: 01/21/2023]
Abstract
The ACTN3 gene encodes α-actinin-3 protein, which stabilizes the contractile apparatus at the Z-line in skeletal muscle cell fast fibers. A nonsense mutation of the arginine (R) at the codon for amino acid 577 of the ACTN3 gene generates a premature termination codon (PTC) and produces the R577X polymorphism in humans (X specifies translational termination). The ACTN3 577X genotype abolishes α-actinin-3 protein production due to targeted degradation of the mutant transcript by the cellular nonsense-mediated mRNA decay (NMD) system, which requires mRNA splicing. In humans, α-actinin-3 deficiency can decrease sprinting and power performance as well as skeletal muscle mass and strength. Here we investigated whether suppression of the in-frame PTC induced by treatment with the aminoglycosides gentamicin and G418 that promote termination codon readthrough could allow production of full-length α-actinin-3 protein from ACTN3 577X. We constructed expression plasmids encoding mature mRNA that lacks introns or pre-mRNA, which carries introns for the ACTN3 577X gene (X and Xpre, respectively) and transfected the constructs into HEK293 cells. Similar constructs for the ACTN3 577R gene were used as controls. HEK293 cells carrying the X gene, but not the Xpre gene, expressed exogenous truncated α-actinin-3 protein, indicating NMD-mediated suppression of exogenous Xpre expression. Cells treated with aminoglycosides produced exogenous full-length α-actinin-3 protein in X-transfected cells, but not in Xpre-transfected cells. The NMD inhibitor caffeine prevented suppression of Xpre expression and thereby induced production of full-length α-actinin-3 protein in the presence of aminoglycoside. Together these results indicate that the ACTN3 R577X polymorphism could be a novel target for readthrough therapy, which may affect athletic and muscle performance in humans.
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Affiliation(s)
- Nagakatsu Harada
- Department of Health and Nutrition, Faculty of Nursing and Nutrition, The University of Shimane, 151 Nishihayashigi, Izumo City, Shimane, 693-8550, Japan; Department of Nutrition and Metabolism, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15, Kuramoto-cho, Tokushima City, 770-8503, Japan.
| | - Adzumi Hatakeyama
- Department of Nutrition and Metabolism, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15, Kuramoto-cho, Tokushima City, 770-8503, Japan
| | - Maiko Okuyama
- Department of Nutrition and Metabolism, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15, Kuramoto-cho, Tokushima City, 770-8503, Japan
| | - Yumiko Miyatake
- Department of Nutrition and Metabolism, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15, Kuramoto-cho, Tokushima City, 770-8503, Japan
| | - Tadahiko Nakagawa
- Department of Health and Nutrition, Faculty of Nursing and Nutrition, The University of Shimane, 151 Nishihayashigi, Izumo City, Shimane, 693-8550, Japan
| | - Masashi Kuroda
- Department of Nutrition and Metabolism, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15, Kuramoto-cho, Tokushima City, 770-8503, Japan
| | - Saeko Masumoto
- Department of Nutrition and Metabolism, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15, Kuramoto-cho, Tokushima City, 770-8503, Japan
| | - Rie Tsutsumi
- Department of Nutrition and Metabolism, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15, Kuramoto-cho, Tokushima City, 770-8503, Japan
| | - Yutaka Nakaya
- Department of Nutrition and Metabolism, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15, Kuramoto-cho, Tokushima City, 770-8503, Japan
| | - Hiroshi Sakaue
- Department of Nutrition and Metabolism, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15, Kuramoto-cho, Tokushima City, 770-8503, Japan
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13
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Pallotti S, Pediconi D, Subramanian D, Molina MG, Antonini M, Morelli MB, Renieri C, La Terza A. Evidence of post-transcriptional readthrough regulation in FGF5 gene of alpaca. Gene 2018; 647:121-128. [PMID: 29307854 DOI: 10.1016/j.gene.2018.01.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 11/23/2017] [Accepted: 01/02/2018] [Indexed: 02/08/2023]
Abstract
Two different phenotypes are described in alpaca, identified as suri and huacaya, which differ in the type of fleece. The huacaya fleece is characterized by compact, soft and highly crimped fibers, while the suri fleece is longer, straight, less-crimped and lustrous. In our study, the Fibroblast growth factor 5 (FGF5) was investigated as a possible candidate gene for hair length in alpaca (Vicugna pacos). As previously identified in other mammals, our results show that the alpaca FGF5 gene gives rise to a short (FGF5S) and a long (FGF5) isoform. Interestingly, in the long isoform, we observed a point mutation (i.e., a transition C>T at position 499 downstream of the ATG codon) that is able to generate a premature termination codon (PTC). The highly conserved nucleotide and amino acid sequence after PTC suggested a readthrough event (RT) that was confirmed by western blot analysis. The analysis of cDNA sequence revealed motifs and structures of mRNA undergoing RT. In fact, the event is positively influenced by particular signals harbored by the transcript. To the best of our knowledge, this is the first case of a readthrough event on PTC reported for the FGF5 gene and the first case of this translational mechanism in alpaca.
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Affiliation(s)
- Stefano Pallotti
- School of Bioscience and Veterinary Medicine, University of Camerino, Via Gentile III da Varano, 62032 Camerino, (MC), Italy.
| | - Dario Pediconi
- School of Bioscience and Veterinary Medicine, University of Camerino, Via Gentile III da Varano, 62032 Camerino, (MC), Italy.
| | | | - María Gabriela Molina
- Facultad de Ciencias Agropecuarias, Universidad Nacional de Córdoba, Universidad Católica de Córdoba, Argentina
| | - Marco Antonini
- ENEA C.R. Casaccia Biotec-Agro, S.M. di Galeria, 00060 Roma, Italy
| | - Maria Beatrice Morelli
- School of Pharmacy, University of Camerino, Via Gentile III da Varano, 62032 Camerino, (MC), Italy
| | - Carlo Renieri
- School of Pharmacy, University of Camerino, Via Gentile III da Varano, 62032 Camerino, (MC), Italy
| | - Antonietta La Terza
- School of Bioscience and Veterinary Medicine, University of Camerino, Via Gentile III da Varano, 62032 Camerino, (MC), Italy.
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14
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Taguchi A, Hamada K, Shiozuka M, Kobayashi M, Murakami S, Takayama K, Taniguchi A, Usui T, Matsuda R, Hayashi Y. Structure-Activity Relationship Study of Leucyl-3- epi-deoxynegamycin for Potent Premature Termination Codon Readthrough. ACS Med Chem Lett 2017; 8:1060-1065. [PMID: 29057051 DOI: 10.1021/acsmedchemlett.7b00269] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 09/29/2017] [Indexed: 11/30/2022] Open
Abstract
(+)-Negamycin, isolated from Streptomyces purpeofuscus, shows antimicrobial activity against Gram-negative bacteria and readthrough activity against nonsense mutations. Previously, we reported that two natural negamycin analogues, 5-deoxy-3-epi-negamycin and its leucine adduct, have more potent readthrough activity in eukaryocytes (COS-7 cells) than negamycin but possess no antimicrobial activity and no in vitro readthrough activity in prokaryotic systems. In the present study, on leucyl-3-epi-deoxynegamycin, a structure-activity relationship study was performed to develop more potent readthrough agents. In a cell-based readthrough assay, the derivative 13b with an o-bromobenzyl ester functions as a prodrug and exhibits a higher readthrough activity against TGA-type PTC than the aminoglycoside G418. This ester (13b) shows an in vivo readthrough activity with low toxicity, suggesting that it has the potential for treatment of hereditary diseases caused by nonsense mutations.
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Affiliation(s)
- Akihiro Taguchi
- Department
of Medicinal Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji,
Tokyo 192-0392, Japan
| | - Keisuke Hamada
- Department
of Medicinal Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji,
Tokyo 192-0392, Japan
| | - Masataka Shiozuka
- Department
of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Tokyo 153-8902, Japan
| | - Misaki Kobayashi
- Department
of Medicinal Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji,
Tokyo 192-0392, Japan
| | - Saori Murakami
- Department
of Medicinal Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji,
Tokyo 192-0392, Japan
| | - Kentaro Takayama
- Department
of Medicinal Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji,
Tokyo 192-0392, Japan
| | - Atsuhiko Taniguchi
- Department
of Medicinal Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji,
Tokyo 192-0392, Japan
| | - Takeo Usui
- Faculty
of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8572, Japan
| | - Ryoichi Matsuda
- Department
of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Tokyo 153-8902, Japan
| | - Yoshio Hayashi
- Department
of Medicinal Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji,
Tokyo 192-0392, Japan
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15
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Gu Y, Chang X, Dai S, Song Q, Zhao H, Lei P. Identification of four novel XPC mutations in two xeroderma pigmentosum complementation group C patients and functional study of XPC Q320X mutant. Gene 2017; 628:162-169. [PMID: 28669926 DOI: 10.1016/j.gene.2017.06.057] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 06/24/2017] [Accepted: 06/28/2017] [Indexed: 11/12/2022]
Abstract
Xeroderma pigmentosum (XP) is a rare, recessive hereditary disease characterized by sunlight hypersensitivity and high incidence of skin cancer with clinical and genetic heterogeneity. We collected two unrelated Chinese patients showing typical symptoms of XPC without neurologic symptoms. Direct sequencing of XPC gene revealed that patient 1 carried IVS1+1G>A and c.958 C>T mutations, and patient 2 carried c.545_546delTA and c.2257_2258insC mutations. All these four mutations introduced premature terminal codons (PTCs) in XPC gene. The nonsense mutation c.958 C>T yielded truncated mutant Q320X, and we studied its function for global genome repair kinetics. Overexpressed Q320X mutant can localize to site of DNA damage, but it is defective in CPD and 6-4PP repair. Readthrough of PTCs is a new approach to treatment of genetic diseases. We found that aminoglycosides could significantly increase the full length protein expression of Q320X mutant, but NER defects were not rescued in vitro.
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Affiliation(s)
- Yajuan Gu
- Department of Medical Genetics, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Xiaodan Chang
- Department of Dermatology, Peking University Third Hospital, Beijing, China
| | - Shan Dai
- Department of Dermatology, Peking University Third Hospital, Beijing, China
| | - Qinghua Song
- Department of Dermatology, Peking University Third Hospital, Beijing, China.
| | - Hongshan Zhao
- Department of Medical Genetics, School of Basic Medical Sciences, Peking University, Beijing, China; Human Disease Genomics Center, Peking University, Beijing, China.
| | - Pengcheng Lei
- Department of Dermatology, Peking University Third Hospital, Beijing, China
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16
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Richardson R, Smart M, Tracey-White D, Webster AR, Moosajee M. Mechanism and evidence of nonsense suppression therapy for genetic eye disorders. Exp Eye Res 2017; 155:24-37. [PMID: 28065590 DOI: 10.1016/j.exer.2017.01.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 11/24/2016] [Accepted: 01/04/2017] [Indexed: 01/09/2023]
Abstract
Between 5 and 70% of genetic disease is caused by in-frame nonsense mutations, which introduce a premature termination codon (PTC) within the disease-causing gene. Consequently, during translation, non-functional or gain-of-function truncated proteins of pathological significance, are formed. Approximately 50% of all inherited retinal disorders have been associated with PTCs, highlighting the importance of novel pharmacological or gene correction therapies in ocular disease. Pharmacological nonsense suppression of PTCs could delineate a therapeutic strategy that treats the mutation in a gene- and disease-independent manner. This approach aims to suppress the fidelity of the ribosome during protein synthesis so that a near-cognate aminoacyl-tRNA, which shares two of the three nucleotides of the PTC, can be inserted into the peptide chain, allowing translation to continue, and a full-length functional protein to be produced. Here we discuss the mechanisms and evidence of nonsense suppression agents, including the small molecule drug ataluren (or PTC124) and next generation 'designer' aminoglycosides, for the treatment of genetic eye disease.
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Affiliation(s)
- Rose Richardson
- Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, UK
| | - Matthew Smart
- Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, UK
| | - Dhani Tracey-White
- Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, UK
| | - Andrew R Webster
- Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, UK; Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Mariya Moosajee
- Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, UK; Moorfields Eye Hospital NHS Foundation Trust, London, UK.
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17
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Mutyam V, Libby EF, Peng N, Hadjiliadis D, Bonk M, Solomon GM, Rowe SM. Therapeutic benefit observed with the CFTR potentiator, ivacaftor, in a CF patient homozygous for the W1282X CFTR nonsense mutation. J Cyst Fibros 2016; 16:24-29. [PMID: 27707539 DOI: 10.1016/j.jcf.2016.09.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 08/29/2016] [Accepted: 09/15/2016] [Indexed: 12/23/2022]
Abstract
Premature termination codons (PTCs) in cystic fibrosis transmembrane conductance regulator (CFTR) gene result in nonfunctional CFTR protein and are the proximate cause of ~11% of CF causing alleles. Aminoglycosides and other novel agents are known to induce translational readthrough of PTCs, a potential therapeutic approach. Among PTCs, W1282X CFTR is unique, as it is a C-terminal CFTR mutation that can exhibit partial activity, even in the truncated state. The potentiator ivacaftor (VX-770) is approved for treating CF patients with G551D and other gating mutations. Based on previous studies demonstrating the beneficial effect of ivacaftor for PTC mutations following readthrough in vitro, we hypothesized that ivacaftor may enhance CFTR activity in CF patients expressing W1282X CFTR, and could be further enhanced by readthrough. Ivacaftor significantly increased CFTR activity in W1282X-expressing cells compared to R1162X CFTR cells, and was further enhanced by readthrough with the aminoglycoside G418. Primary nasal epithelial cells from a W1282X homozygous patient showed improved CFTR function in the presence of ivacaftor. Upon ivacaftor administration to the same patient, there was significant improvement in pulmonary exacerbation frequency, BMI, and insulin requirement, whereas FEV1 remained stable over 3years. These studies suggest that ivacaftor may have moderate clinical benefit in patients with preserved expression of the W1282X CFTR mutation by stimulating residual activity of the truncated protein, suggesting the need for further studies including the addition of efficacious readthrough agents.
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Affiliation(s)
- Venkateshwar Mutyam
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Emily Falk Libby
- Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Ning Peng
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Denis Hadjiliadis
- Department of Medicine, University of Pennsylvania Medical Center, PA, USA
| | - Michael Bonk
- Department of Medicine, University of Pennsylvania Medical Center, PA, USA
| | - George M Solomon
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA; Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Steven M Rowe
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA; Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL, USA; Department of Cell Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA; Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, AL, USA.
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18
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Chkuaseli T, Newburn LR, Bakhshinyan D, White KA. Protein expression strategies in Tobacco necrosis virus-D. Virology 2015; 486:54-62. [PMID: 26402375 DOI: 10.1016/j.virol.2015.08.032] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 08/25/2015] [Accepted: 08/29/2015] [Indexed: 02/04/2023]
Abstract
Tobacco necrosis virus (TNV-D) has a plus-strand RNA genome that is neither 5' capped nor 3' poly-adenylated. Instead, it utilizes a 3' cap-independent translational enhancer (3'CITE) located in its 3' untranslated region (UTR) for translation of its proteins. We have examined the protein expression strategies used by TNV-D and our results indicate that: (i) a base pairing interaction between conserved ACCA and UGGU motifs in the genomic 5'UTR and 3'CITE, respectively, is not required for efficient plant cell infection, (ii) similar potential 5'UTR-3'CITE interactions in the two viral subgenomic mRNAs are not needed for efficient translation of viral proteins in vitro, (iii) a small amount of capsid protein is translated from the viral genome by a largely 3'CITE-independent mechanism, (iv) the larger of two possible forms of capsid protein is efficiently translated, and (v) p7b is translated from subgenomic mRNA1 by a leaky scanning mechanism.
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Affiliation(s)
- Tamari Chkuaseli
- Department of Biology, York University, Toronto, Ontario, Canada M3J 1P3
| | - Laura R Newburn
- Department of Biology, York University, Toronto, Ontario, Canada M3J 1P3
| | - David Bakhshinyan
- Department of Biology, York University, Toronto, Ontario, Canada M3J 1P3
| | - K Andrew White
- Department of Biology, York University, Toronto, Ontario, Canada M3J 1P3.
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19
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Gunn G, Dai Y, Du M, Belakhov V, Kandasamy J, Schoeb TR, Baasov T, Bedwell DM, Keeling KM. Long-term nonsense suppression therapy moderates MPS I-H disease progression. Mol Genet Metab 2014; 111:374-381. [PMID: 24411223 PMCID: PMC3943726 DOI: 10.1016/j.ymgme.2013.12.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 12/10/2013] [Accepted: 12/11/2013] [Indexed: 01/16/2023]
Abstract
Nonsense suppression therapy is a therapeutic approach aimed at treating genetic diseases caused by in-frame premature termination codons (PTCs; also commonly known as nonsense mutations). This approach utilizes compounds that suppress translation termination at PTCs, which allows translation to continue and partial levels of deficient protein function to be restored. We hypothesize that suppression therapy can attenuate the lysosomal storage disease mucopolysaccharidosis type I-Hurler (MPS I-H), the severe form of α-L-iduronidase deficiency. α-L-iduronidase participates in glycosaminoglycan (GAG) catabolism and its insufficiency causes progressive GAG accumulation and onset of the MPS I-H phenotype, which consists of multiple somatic and neurological defects. 60-80% of MPS I-H patients carry a nonsense mutation in the IDUA gene. We previously showed that 2-week treatment with the designer aminoglycoside NB84 restored enough α-L-iduronidase function via PTC suppression to reduce tissue GAG accumulation in the Idua(tm1Kmke) MPS I-H mouse model, which carries a PTC homologous to the human IDUA-W402X nonsense mutation. Here we report that long-term NB84 administration maintains α-L-iduronidase activity and GAG reduction in Idua(tm1Kmke) mice throughout a 28-week treatment period. An examination of more complex MPS I-H phenotypes in Idua(tm1Kmke) mice following 28-week NB84 treatment revealed significant moderation of the disease in multiple tissues, including the brain, heart and bone, that are resistant to current MPS I-H therapies. This study represents the first demonstration that long-term nonsense suppression therapy can moderate progression of a genetic disease.
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Affiliation(s)
- Gwen Gunn
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA.
| | - Yanying Dai
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA.
| | - Ming Du
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA.
| | - Valery Belakhov
- The Edith and Joseph Enzyme Inhibitors Laboratory, Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa, Israel.
| | - Jeyakumar Kandasamy
- The Edith and Joseph Enzyme Inhibitors Laboratory, Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa, Israel.
| | - Trenton R Schoeb
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL, USA.
| | - Timor Baasov
- The Edith and Joseph Enzyme Inhibitors Laboratory, Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa, Israel.
| | - David M Bedwell
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA.
| | - Kim M Keeling
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA.
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20
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Newburn LR, Nicholson BL, Yosefi M, Cimino PA, White KA. Translational readthrough in Tobacco necrosis virus-D. Virology 2014; 450-451:258-65. [PMID: 24503089 DOI: 10.1016/j.virol.2013.12.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 11/23/2013] [Accepted: 12/08/2013] [Indexed: 12/16/2022]
Abstract
The plus-strand RNA genome of Tobacco necrosis virus-D (TNV-D) expresses its polymerase via translational readthrough. The RNA signals involved in this readthrough process were characterized in vitro using a wheat germ extract translation system and in vivo via protoplast infections. The results indicate that (i) TNV-D requires a long-range RNA-RNA interaction between an extended stem-loop (SL) structure proximal to the readthrough site and a sequence in the 3'-untranslated region of its genome; (ii) stability of the extended SL structure is important for its function; (iii) TNV-D readthrough elements are compatible with UAG and UGA, but not UAA; (iv) a readthrough defect can be rescued by a heterologous readthrough element in vitro, but not in vivo; and (v) readthrough elements can also mediate translational frameshifting. These results provide new information on determinants of readthrough in TNV-D and further support the concept of a common general mechanism for readthrough in Tombusviridae.
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Affiliation(s)
- Laura R Newburn
- Department of Biology, York University, Toronto, ON, Canada M3J 1P3
| | - Beth L Nicholson
- Department of Biology, York University, Toronto, ON, Canada M3J 1P3
| | - Michael Yosefi
- Department of Biology, York University, Toronto, ON, Canada M3J 1P3
| | - Peter A Cimino
- Department of Biology, York University, Toronto, ON, Canada M3J 1P3
| | - K Andrew White
- Department of Biology, York University, Toronto, ON, Canada M3J 1P3.
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