1
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Palm SM, Horton CA, Zhang X, Collins K. Structure and sequence at an RNA template 5' end influence insertion of transgenes by an R2 retrotransposon protein. RNA (NEW YORK, N.Y.) 2024; 30:1227-1245. [PMID: 38960642 PMCID: PMC11331408 DOI: 10.1261/rna.080031.124] [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: 03/23/2024] [Accepted: 06/17/2024] [Indexed: 07/05/2024]
Abstract
R2 non-long terminal repeat retrotransposons insert site-specifically into ribosomal RNA genes (rDNA) in a broad range of multicellular eukaryotes. R2-encoded proteins can be leveraged to mediate transgene insertion at 28S rDNA loci in cultured human cells. This strategy, precise RNA-mediated insertion of transgenes (PRINT), relies on the codelivery of an mRNA encoding R2 protein and an RNA template encoding a transgene cassette of choice. Here, we demonstrate that the PRINT RNA template 5' module, which as a complementary DNA 3' end will generate the transgene 5' junction with rDNA, influences the efficiency and mechanism of gene insertion. Iterative design and testing identified optimal 5' modules consisting of a hepatitis delta virus-like ribozyme fold with high thermodynamic stability, suggesting that RNA template degradation from its 5' end may limit transgene insertion efficiency. We also demonstrate that transgene 5' junction formation can be either precise, formed by annealing the 3' end of first-strand complementary DNA with the upstream target site, or imprecise, by end-joining, but this difference in junction formation mechanism is not a major determinant of insertion efficiency. Sequence characterization of imprecise end-joining events indicates surprisingly minimal reliance on microhomology. Our findings expand the current understanding of the role of R2 retrotransposon transcript sequence and structure, and especially the 5' ribozyme fold, for retrotransposon mobility and RNA-templated gene synthesis in cells.
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Affiliation(s)
- Sarah M Palm
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720, USA
| | - Connor A Horton
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720, USA
| | - Xiaozhu Zhang
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720, USA
| | - Kathleen Collins
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720, USA
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2
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Chen CC, Han J, Chinn CA, Rounds JS, Li X, Nikan M, Myszka M, Tong L, Passalacqua LFM, Bredy T, Wood MA, Luptak A. Inhibition of Cpeb3 ribozyme elevates CPEB3 protein expression and polyadenylation of its target mRNAs and enhances object location memory. eLife 2024; 13:e90116. [PMID: 38319152 PMCID: PMC10919898 DOI: 10.7554/elife.90116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 02/05/2024] [Indexed: 02/07/2024] Open
Abstract
A self-cleaving ribozyme that maps to an intron of the cytoplasmic polyadenylation element-binding protein 3 (Cpeb3) gene is thought to play a role in human episodic memory, but the underlying mechanisms mediating this effect are not known. We tested the activity of the murine sequence and found that the ribozyme's self-scission half-life matches the time it takes an RNA polymerase to reach the immediate downstream exon, suggesting that the ribozyme-dependent intron cleavage is tuned to co-transcriptional splicing of the Cpeb3 mRNA. Our studies also reveal that the murine ribozyme modulates maturation of its harboring mRNA in both cultured cortical neurons and the hippocampus: inhibition of the ribozyme using an antisense oligonucleotide leads to increased CPEB3 protein expression, which enhances polyadenylation and translation of localized plasticity-related target mRNAs, and subsequently strengthens hippocampal-dependent long-term memory. These findings reveal a previously unknown role for self-cleaving ribozyme activity in regulating experience-induced co-transcriptional and local translational processes required for learning and memory.
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Affiliation(s)
- Claire C Chen
- Department of Pharmaceutical Sciences, University of California, IrvineIrvineUnited States
| | - Joseph Han
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California, IrvineIrvineUnited States
| | - Carlene A Chinn
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California, IrvineIrvineUnited States
| | - Jacob S Rounds
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California, IrvineIrvineUnited States
| | - Xiang Li
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California, IrvineIrvineUnited States
| | | | - Marie Myszka
- Department of Chemistry, University of California, IrvineIrvineUnited States
| | - Liqi Tong
- Institute for Memory Impairments and Neurological Disorders, University of California, IrvineIrvineUnited States
| | - Luiz FM Passalacqua
- Department of Pharmaceutical Sciences, University of California, IrvineIrvineUnited States
| | - Timothy Bredy
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California, IrvineIrvineUnited States
| | - Marcelo A Wood
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California, IrvineIrvineUnited States
| | - Andrej Luptak
- Department of Pharmaceutical Sciences, University of California, IrvineIrvineUnited States
- Department of Chemistry, University of California, IrvineIrvineUnited States
- Department of Molecular Biology and Biochemistry, University of California, IrvineIrvineUnited States
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3
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Ma X, Zhang Y, Huang K, Zhu L, Xu W. Multifunctional rolling circle transcription-based nanomaterials for advanced drug delivery. Biomaterials 2023; 301:122241. [PMID: 37451000 DOI: 10.1016/j.biomaterials.2023.122241] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 06/21/2023] [Accepted: 07/06/2023] [Indexed: 07/18/2023]
Abstract
As the up-and-comer in the development of RNA nanotechnology, RNA nanomaterials based on functionalized rolling circle transcription (RCT) have become promising carriers for drug production and delivery. This is due to RCT technology can self-produce polyvalent tandem nucleic acid prodrugs for intervention in intracellular gene expression and protein production. RNA component strands participating in de novo assembly enable RCT-based nanomaterials to exhibit good mechanical properties, biostability, and biocompatibility as delivery carriers. The biostability makes it to suitable for thermodynamically/kinetically favorable assembly, enzyme resistance and efficient expression in vivo. Controllable RCT system combined with polymers enables customizable and adjustable size, shape, structure, and stoichiometry of RNA building materials, which provide groundwork for the delivery of advanced drugs. Here, we review the assembly strategies and the dynamic regulation of RCT-based nanomaterials, summarize its functional properties referring to the bottom-up design philosophy, and describe its advancements in tumor gene therapy, synergistic chemotherapy, and immunotherapy. Last, we elaborate on the unique and practical value of RCT-based nanomaterials, namely "self-production and self-sale", and their potential challenges in nanotechnology, material science and biomedicine.
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Affiliation(s)
- Xuan Ma
- Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing, 100083, China; College of Food Science and Nutrition Engineering, China Agricultural University, Beijing, 100083, China
| | - Yangzi Zhang
- Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing, 100083, China; College of Food Science and Nutrition Engineering, China Agricultural University, Beijing, 100083, China
| | - Kunlun Huang
- College of Food Science and Nutrition Engineering, China Agricultural University, Beijing, 100083, China
| | - Longjiao Zhu
- Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing, 100083, China
| | - Wentao Xu
- Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing, 100083, China; College of Food Science and Nutrition Engineering, China Agricultural University, Beijing, 100083, China.
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4
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Chen CC, Han J, Chinn CA, Rounds JS, Li X, Nikan M, Myszka M, Tong L, Passalacqua LFM, Bredy TW, Wood MA, Lupták A. Inhibition of CPEB3 ribozyme elevates CPEB3 protein expression and polyadenylation of its target mRNAs, and enhances object location memory. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.07.543953. [PMID: 37333407 PMCID: PMC10274809 DOI: 10.1101/2023.06.07.543953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
A self-cleaving ribozyme that maps to an intron of the cytoplasmic polyadenylation element binding protein 3 (CPEB3) gene is thought to play a role in human episodic memory, but the underlying mechanisms mediating this effect are not known. We tested the activity of the murine sequence and found that the ribozyme's self-scission half-life matches the time it takes an RNA polymerase to reach the immediate downstream exon, suggesting that the ribozyme-dependent intron cleavage is tuned to co-transcriptional splicing of the CPEB3 mRNA. Our studies also reveal that the murine ribozyme modulates maturation of its harboring mRNA in both cultured cortical neurons and the hippocampus: inhibition of the ribozyme using an antisense oligonucleotide leads to increased CPEB3 protein expression, which enhances polyadenylation and translation of localized plasticity-related target mRNAs, and subsequently strengthens hippocampal-dependent long-term memory. These findings reveal a previously unknown role for self-cleaving ribozyme activity in regulating experience-induced co-transcriptional and local translational processes required for learning and memory.
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Affiliation(s)
- Claire C. Chen
- Department of Pharmaceutical Sciences, University of California–Irvine, Irvine, California 92697, United States
| | - Joseph Han
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California–Irvine, Irvine, California 92697, United States
| | - Carlene A. Chinn
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California–Irvine, Irvine, California 92697, United States
| | - Jacob S. Rounds
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California–Irvine, Irvine, California 92697, United States
| | - Xiang Li
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California–Irvine, Irvine, California 92697, United States
| | - Mehran Nikan
- Ionis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Marie Myszka
- Department of Chemistry, University of California–Irvine, Irvine, California 92697, United States
| | - Liqi Tong
- Institute for Memory Impairments and Neurological Disorders, University of California–Irvine, Irvine, California 92697, United States
| | - Luiz F. M. Passalacqua
- Department of Pharmaceutical Sciences, University of California–Irvine, Irvine, California 92697, United States
| | - Timothy W. Bredy
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California–Irvine, Irvine, California 92697, United States
| | - Marcelo A. Wood
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California–Irvine, Irvine, California 92697, United States
| | - Andrej Lupták
- Department of Pharmaceutical Sciences, University of California–Irvine, Irvine, California 92697, United States
- Department of Chemistry, University of California–Irvine, Irvine, California 92697, United States
- Department of Molecular Biology and Biochemistry, University of California–Irvine, Irvine, California 92697, United States
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5
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Climent-Catala A, Ouldridge TE, Stan GBV, Bae W. Building an RNA-Based Toggle Switch Using Inhibitory RNA Aptamers. ACS Synth Biol 2022; 11:562-569. [PMID: 35133150 PMCID: PMC9007568 DOI: 10.1021/acssynbio.1c00580] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
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Synthetic
RNA systems offer unique advantages such as faster response,
increased specificity, and programmability compared to conventional
protein-based networks. Here, we demonstrate an in vitro RNA-based toggle switch using RNA aptamers capable of inhibiting
the transcriptional activity of T7 or SP6 RNA polymerases. The activities
of both polymerases are monitored simultaneously by using Broccoli
and malachite green light-up aptamer systems. In our toggle switch,
a T7 promoter drives the expression of SP6 inhibitory aptamers, and
an SP6 promoter expresses T7 inhibitory aptamers. We show that the
two distinct states originating from the mutual inhibition of aptamers
can be toggled by adding DNA sequences to sequester the RNA inhibitory
aptamers. Finally, we assessed our RNA-based toggle switch in degrading
conditions by introducing controlled degradation of RNAs using a mix
of RNases. Our results demonstrate that the RNA-based toggle switch
could be used as a control element for nucleic acid networks in synthetic
biology applications.
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Affiliation(s)
- Alicia Climent-Catala
- Imperial College Centre for Synthetic Biology, London, SW7 2AZ, U.K
- Department of Chemistry, Imperial College London, London, SW7 2AZ, U.K
| | - Thomas E. Ouldridge
- Imperial College Centre for Synthetic Biology, London, SW7 2AZ, U.K
- Department of Bioengineering, Imperial College London, London, SW7 2AZ, U.K
| | - Guy-Bart V. Stan
- Imperial College Centre for Synthetic Biology, London, SW7 2AZ, U.K
- Department of Bioengineering, Imperial College London, London, SW7 2AZ, U.K
| | - Wooli Bae
- Imperial College Centre for Synthetic Biology, London, SW7 2AZ, U.K
- Department of Bioengineering, Imperial College London, London, SW7 2AZ, U.K
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6
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Pacin-Ruiz B, Cortese MF, Tabernero D, Sopena S, Gregori J, García-García S, Casillas R, Najarro A, Aldama U, Palom A, Rando-Segura A, Galán A, Vila M, Riveiro-Barciela M, Quer J, González-Aseguinolaza G, Buti M, Rodríguez-Frías F. Inspecting the Ribozyme Region of Hepatitis Delta Virus Genotype 1: Conservation and Variability. Viruses 2022; 14:v14020215. [PMID: 35215809 PMCID: PMC8877431 DOI: 10.3390/v14020215] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 01/18/2022] [Accepted: 01/19/2022] [Indexed: 02/07/2023] Open
Abstract
The hepatitis delta virus (HDV) genome has an autocatalytic region called the ribozyme, which is essential for viral replication. The aim of this study was to use next-generation sequencing (NGS) to analyze the ribozyme quasispecies (QS) in order to study its evolution and identify highly conserved regions potentially suitable for a gene-silencing strategy. HDV RNA was extracted from 2 longitudinal samples of chronic HDV patients and the ribozyme (nucleotide, nt 688-771) was analyzed using NGS. QS conservation, variability and genetic distance were analyzed. Mutations were identified by aligning sequences with their specific genotype consensus. The main relevant mutations were tested in vitro. The ribozyme was conserved overall, with a hyper-conserved region between nt 715-745. No difference in QS was observed over time. The most variable region was between nt 739-769. Thirteen mutations were observed, with three showing a higher frequency: T23C, T69C and C64 deletion. This last strongly reduced HDV replication by more than 1 log in vitro. HDV Ribozyme QS was generally highly conserved and was maintained during follow-up. The most conserved portion may be a valuable target for a gene-silencing strategy. The presence of the C64 deletion may strongly impair viral replication, as it is a potential mechanism of viral persistence.
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Affiliation(s)
- Beatriz Pacin-Ruiz
- Liver Pathology Unit, Departments of Biochemistry and Microbiology, Vall d’Hebron University Hospital, 08035 Barcelona, Spain; (B.P.-R.); (S.S.); (S.G.-G.); (R.C.); (A.N.); (U.A.); (A.G.); (M.V.); (F.R.-F.)
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, Instituto de Salud Carlos III, 28029 Madrid, Spain; (M.R.-B.); (M.B.)
| | - María Francesca Cortese
- Liver Pathology Unit, Departments of Biochemistry and Microbiology, Vall d’Hebron University Hospital, 08035 Barcelona, Spain; (B.P.-R.); (S.S.); (S.G.-G.); (R.C.); (A.N.); (U.A.); (A.G.); (M.V.); (F.R.-F.)
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, Instituto de Salud Carlos III, 28029 Madrid, Spain; (M.R.-B.); (M.B.)
- Correspondence: (M.F.C.); (D.T.)
| | - David Tabernero
- Liver Pathology Unit, Departments of Biochemistry and Microbiology, Vall d’Hebron University Hospital, 08035 Barcelona, Spain; (B.P.-R.); (S.S.); (S.G.-G.); (R.C.); (A.N.); (U.A.); (A.G.); (M.V.); (F.R.-F.)
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, Instituto de Salud Carlos III, 28029 Madrid, Spain; (M.R.-B.); (M.B.)
- Correspondence: (M.F.C.); (D.T.)
| | - Sara Sopena
- Liver Pathology Unit, Departments of Biochemistry and Microbiology, Vall d’Hebron University Hospital, 08035 Barcelona, Spain; (B.P.-R.); (S.S.); (S.G.-G.); (R.C.); (A.N.); (U.A.); (A.G.); (M.V.); (F.R.-F.)
| | - Josep Gregori
- Liver Unit, Liver Disease, Laboratory-Viral Hepatitis, Vall d’Hebron Institut Recerca-Vall d’Hebron University Hospital, 08035 Barcelona, Spain; (J.G.); (J.Q.)
| | - Selene García-García
- Liver Pathology Unit, Departments of Biochemistry and Microbiology, Vall d’Hebron University Hospital, 08035 Barcelona, Spain; (B.P.-R.); (S.S.); (S.G.-G.); (R.C.); (A.N.); (U.A.); (A.G.); (M.V.); (F.R.-F.)
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, Instituto de Salud Carlos III, 28029 Madrid, Spain; (M.R.-B.); (M.B.)
| | - Rosario Casillas
- Liver Pathology Unit, Departments of Biochemistry and Microbiology, Vall d’Hebron University Hospital, 08035 Barcelona, Spain; (B.P.-R.); (S.S.); (S.G.-G.); (R.C.); (A.N.); (U.A.); (A.G.); (M.V.); (F.R.-F.)
| | - Adrián Najarro
- Liver Pathology Unit, Departments of Biochemistry and Microbiology, Vall d’Hebron University Hospital, 08035 Barcelona, Spain; (B.P.-R.); (S.S.); (S.G.-G.); (R.C.); (A.N.); (U.A.); (A.G.); (M.V.); (F.R.-F.)
| | - Unai Aldama
- Liver Pathology Unit, Departments of Biochemistry and Microbiology, Vall d’Hebron University Hospital, 08035 Barcelona, Spain; (B.P.-R.); (S.S.); (S.G.-G.); (R.C.); (A.N.); (U.A.); (A.G.); (M.V.); (F.R.-F.)
| | - Adriana Palom
- Liver Unit, Department of Internal Medicine, Vall d’Hebron University Hospital, 08035 Barcelona, Spain;
| | - Ariadna Rando-Segura
- Department of Microbiology, Vall d’Hebron University Hospital, 08035 Barcelona, Spain;
| | - Anna Galán
- Liver Pathology Unit, Departments of Biochemistry and Microbiology, Vall d’Hebron University Hospital, 08035 Barcelona, Spain; (B.P.-R.); (S.S.); (S.G.-G.); (R.C.); (A.N.); (U.A.); (A.G.); (M.V.); (F.R.-F.)
| | - Marta Vila
- Liver Pathology Unit, Departments of Biochemistry and Microbiology, Vall d’Hebron University Hospital, 08035 Barcelona, Spain; (B.P.-R.); (S.S.); (S.G.-G.); (R.C.); (A.N.); (U.A.); (A.G.); (M.V.); (F.R.-F.)
| | - Mar Riveiro-Barciela
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, Instituto de Salud Carlos III, 28029 Madrid, Spain; (M.R.-B.); (M.B.)
- Liver Unit, Department of Internal Medicine, Vall d’Hebron University Hospital, 08035 Barcelona, Spain;
| | - Josep Quer
- Liver Unit, Liver Disease, Laboratory-Viral Hepatitis, Vall d’Hebron Institut Recerca-Vall d’Hebron University Hospital, 08035 Barcelona, Spain; (J.G.); (J.Q.)
| | | | - María Buti
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, Instituto de Salud Carlos III, 28029 Madrid, Spain; (M.R.-B.); (M.B.)
- Liver Unit, Department of Internal Medicine, Vall d’Hebron University Hospital, 08035 Barcelona, Spain;
| | - Francisco Rodríguez-Frías
- Liver Pathology Unit, Departments of Biochemistry and Microbiology, Vall d’Hebron University Hospital, 08035 Barcelona, Spain; (B.P.-R.); (S.S.); (S.G.-G.); (R.C.); (A.N.); (U.A.); (A.G.); (M.V.); (F.R.-F.)
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, Instituto de Salud Carlos III, 28029 Madrid, Spain; (M.R.-B.); (M.B.)
- Biochemistry and Molecular Biology Department, Universitat Autònoma de Barcelona (UAB), Plaça Cívica, 08193 Bellaterra, Spain
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7
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Sherlock ME, Higgs G, Yu D, Widner DL, White NA, Sudarsan N, Sadeeshkumar H, Perkins KR, Mirihana Arachchilage G, Malkowski SN, King CG, Harris KA, Gaffield G, Atilho RM, Breaker RR. Architectures and complex functions of tandem riboswitches. RNA Biol 2022; 19:1059-1076. [PMID: 36093908 PMCID: PMC9481103 DOI: 10.1080/15476286.2022.2119017] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 08/23/2022] [Indexed: 11/16/2022] Open
Abstract
Riboswitch architectures that involve the binding of a single ligand to a single RNA aptamer domain result in ordinary dose-response curves that require approximately a 100-fold change in ligand concentration to cover nearly the full dynamic range for gene regulation. However, by using multiple riboswitches or aptamer domains in tandem, these ligand-sensing structures can produce additional, complex gene control outcomes. In the current study, we have computationally searched for tandem riboswitch architectures in bacteria to provide a more complete understanding of the diverse biological and biochemical functions of gene control elements that are made exclusively of RNA. Numerous different arrangements of tandem homologous riboswitch architectures are exploited by bacteria to create more 'digital' gene control devices, which operate over a narrower ligand concentration range. Also, two heterologous riboswitch aptamers are sometimes employed to create two-input Boolean logic gates with various types of genetic outputs. These findings illustrate the sophisticated genetic decisions that can be made by using molecular sensors and switches based only on RNA.
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Affiliation(s)
- Madeline E. Sherlock
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
- Department of Biochemistry and Molecular Genetics, University of Colorado, Anschutz Medical Campus, Research-1S, Aurora, CO, USA
| | - Gadareth Higgs
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Diane Yu
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Danielle L. Widner
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Neil A. White
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | | | - Harini Sadeeshkumar
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Kevin R. Perkins
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Gayan Mirihana Arachchilage
- Howard Hughes Medical Institute, Yale University, New Haven, CT, USA
- PTC Therapeutics, Inc, South Plainfield, NJ, USA
| | | | - Christopher G. King
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | | | - Glenn Gaffield
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Ruben M. Atilho
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Ronald R. Breaker
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
- Howard Hughes Medical Institute, Yale University, New Haven, CT, USA
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8
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Olzog VJ, Gärtner C, Stadler PF, Fallmann J, Weinberg CE. cyPhyRNA-seq: a genome-scale RNA-seq method to detect active self-cleaving ribozymes by capturing RNAs with 2',3' cyclic phosphates and 5' hydroxyl ends. RNA Biol 2021; 18:818-831. [PMID: 34906034 PMCID: PMC8782182 DOI: 10.1080/15476286.2021.1999105] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Self-cleaving ribozymes are catalytically active RNAs that cleave themselves into a 5′-fragment with a 2′,3′-cyclic phosphate and a 3′-fragment with a 5′-hydroxyl. They are widely applied for the construction of synthetic RNA devices and RNA-based therapeutics. However, the targeted discovery of self-cleaving ribozymes remains a major challenge. We developed a transcriptome-wide method, called cyPhyRNA-seq, to screen for ribozyme cleavage fragments in total RNA extract. This approach employs the specific ligation-based capture of ribozyme 5′-fragments using a variant of the Arabidopsis thaliana tRNA ligase we engineered. To capture ribozyme 3′-fragments, they are enriched from total RNA by enzymatic treatments. We optimized and enhanced the individual steps of cyPhyRNA-seq in vitro and in spike-in experiments. Then, we applied cyPhyRNA-seq to total RNA isolated from the bacterium Desulfovibrio vulgaris and detected self-cleavage of the three predicted type II hammerhead ribozymes, whose activity had not been examined to date. cyPhyRNA-seq can be used for the global analysis of active self-cleaving ribozymes with the advantage to capture both ribozyme cleavage fragments from total RNA. Especially in organisms harbouring many self-cleaving RNAs, cyPhyRNA-seq facilitates the investigation of cleavage activity. Moreover, this method has the potential to be used to discover novel self-cleaving ribozymes in different organisms.
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Affiliation(s)
- V Janett Olzog
- Department of Life Science, Institute for Biochemistry, Leipzig, Germany
| | - Christiane Gärtner
- Bioinformatics Group, Department of Computer Science, and Interdisciplinary Center for Bioinformatics, Leipzig University, Leipzig, Germany
| | - Peter F Stadler
- Bioinformatics Group, Department of Computer Science, and Interdisciplinary Center for Bioinformatics, Leipzig University, Leipzig, Germany.,Max Planck Institute for Mathematics in the Sciences, Leipzig, Germany.,Department of Theoretical Chemistry, Vienna, Austria.,Facultad de Ciencias, Universidad National de Colombia, Sede Bogotá, Colombia.,Santa Fe Institute, University of Vienna, Santa Fe, New Mexico, USA
| | - Jörg Fallmann
- Bioinformatics Group, Department of Computer Science, and Interdisciplinary Center for Bioinformatics, Leipzig University, Leipzig, Germany
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9
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Gilmer O, Quignon E, Jousset AC, Paillart JC, Marquet R, Vivet-Boudou V. Chemical and Enzymatic Probing of Viral RNAs: From Infancy to Maturity and Beyond. Viruses 2021; 13:1894. [PMID: 34696322 PMCID: PMC8537439 DOI: 10.3390/v13101894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 09/13/2021] [Accepted: 09/16/2021] [Indexed: 11/17/2022] Open
Abstract
RNA molecules are key players in a variety of biological events, and this is particularly true for viral RNAs. To better understand the replication of those pathogens and try to block them, special attention has been paid to the structure of their RNAs. Methods to probe RNA structures have been developed since the 1960s; even if they have evolved over the years, they are still in use today and provide useful information on the folding of RNA molecules, including viral RNAs. The aim of this review is to offer a historical perspective on the structural probing methods used to decipher RNA structures before the development of the selective 2'-hydroxyl acylation analyzed by primer extension (SHAPE) methodology and to show how they have influenced the current probing techniques. Actually, these technological breakthroughs, which involved advanced detection methods, were made possible thanks to the development of next-generation sequencing (NGS) but also to the previous works accumulated in the field of structural RNA biology. Finally, we will also discuss how high-throughput SHAPE (hSHAPE) paved the way for the development of sophisticated RNA structural techniques.
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Affiliation(s)
| | | | | | | | - Roland Marquet
- Université de Strasbourg, CNRS, Architecture et Réactivité de l’ARN, UPR9002, F-67000 Strasbourg, France; (O.G.); (E.Q.); (A.-C.J.); (J.-C.P.)
| | - Valérie Vivet-Boudou
- Université de Strasbourg, CNRS, Architecture et Réactivité de l’ARN, UPR9002, F-67000 Strasbourg, France; (O.G.); (E.Q.); (A.-C.J.); (J.-C.P.)
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10
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Wang W, Lempp FA, Schlund F, Walter L, Decker CC, Zhang Z, Ni Y, Urban S. Assembly and infection efficacy of hepatitis B virus surface protein exchanges in 8 hepatitis D virus genotype isolates. J Hepatol 2021; 75:311-323. [PMID: 33845061 DOI: 10.1016/j.jhep.2021.03.025] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 03/04/2021] [Accepted: 03/24/2021] [Indexed: 02/06/2023]
Abstract
BACKGROUND & AIMS Chronic HDV infections cause the most severe form of viral hepatitis. HDV requires HBV envelope proteins for hepatocyte entry, particle assembly and release. Eight HDV and 8 HBV genotypes have been identified. However, there are limited data on the replication competence of different genotypes and the effect that different HBV envelopes have on virion assembly and infectivity. METHODS We subcloned complementary DNAs (cDNAs) of all HDV and HBV genotypes and systematically studied HDV replication, assembly and infectivity using northern blot, western blot, reverse-transcription quantitative PCR, and in-cell ELISA. RESULTS The 8 HDV cDNA clones initiated HDV replication with noticeable differences regarding replication efficacy. The 8 HBV-HBsAg-encoding constructs all supported secretion of subviral particles, however variations in envelope protein stoichiometry and secretion efficacy were observed. Co-transfection of all HDV/HBV combinations supported particle assembly, however, the respective pseudo-typed HDVs differed with respect to assembly kinetics. The most productive combinations did not correlate with the natural geographic distribution, arguing against an evolutionary adaptation of HDV ribonucleoprotein complexes to HBV envelopes. All HDVs elicited robust and comparable innate immune responses. HBV envelope-dependent differences in the activity of the EMA-approved entry inhibitor bulevirtide were observed, however efficient inhibition could be achieved at therapeutically applied doses. Lonafarnib also showed pan-genotypic activity. CONCLUSIONS HDVs from different genotypes replicate with variable efficacies. Variations in HDV genomes and HBV envelope proteins are both major determinants of HDV egress and entry efficacy, and consequently assembly inhibition by lonafarnib or entry inhibition by bulevirtide. These differences possibly influence HDV pathogenicity, immune responses and the efficacy of novel drug regimens. LAY SUMMARY HDV requires the envelope protein of HBV for assembly and to infect human cells. We investigated the ability of different HDV genotypes to infect cells and replicate. We also assessed the effect that envelope proteins from different HBV genotypes had on HDV infectivity and replication. Herein, we confirmed that genotypic differences in HDV and HBV envelope proteins are major determinants of HDV assembly, de novo cell entry and consequently the efficacy of novel antivirals.
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Affiliation(s)
- Wenshi Wang
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, Heidelberg, Germany.
| | - Florian A Lempp
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, Heidelberg, Germany; German Centre for Infection Research (DZIF), partner site Heidelberg, Heidelberg, Germany
| | - Franziska Schlund
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Lisa Walter
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Charlotte C Decker
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Zhenfeng Zhang
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Yi Ni
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, Heidelberg, Germany; German Centre for Infection Research (DZIF), partner site Heidelberg, Heidelberg, Germany
| | - Stephan Urban
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, Heidelberg, Germany; German Centre for Infection Research (DZIF), partner site Heidelberg, Heidelberg, Germany.
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11
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Chakraborty D, Ghosh S. Demonstration of a Ribozyme in Epsilon Domain of Hepatitis B Virus RNA. Methods Mol Biol 2021; 2167:45-59. [PMID: 32712914 DOI: 10.1007/978-1-0716-0716-9_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The epsilon domain of Hepatitis B virus plays a crucial role in encapsidation of viral pregenomic RNA and its partial NMR structure has been determined. However, we recently described a potassium-dependent ribonucleolytic activity associated with this region, so that a 53 nt long RNA containing the epsilon domain could release itself and cleaved other RNAs. We describe here the experimental methodologies for setting up the reactions and outline a general strategy for initial demonstration of this self-cleaving ribozyme activity.
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Affiliation(s)
| | - Sagarmoy Ghosh
- Department of Microbiology, University of Calcutta, University College of Science and Technology, Kolkata, India.
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12
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de la Peña M, Ceprián R, Casey JL, Cervera A. Hepatitis delta virus-like circular RNAs from diverse metazoans encode conserved hammerhead ribozymes. Virus Evol 2021; 7:veab016. [PMID: 33708415 PMCID: PMC7936874 DOI: 10.1093/ve/veab016] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Human hepatitis delta virus (HDV) is a unique infectious agent whose genome is composed of a small circular RNA. Recent data, however, have reported the existence of highly divergent HDV-like circRNAs in the transcriptomes of diverse vertebrate and invertebrate species. The HDV-like genomes described in amniotes such as birds and reptiles encode self-cleaving RNA motifs or ribozymes similar to the ones present in the human HDV, whereas no catalytic RNA domains have been reported for the HDV-like genomes detected in metagenomic data from some amphibians, fish, and invertebrates. Herein, we describe the self-cleaving motifs of the HDV-like genomes reported in newts and fish, which belong to the characteristic class of HDV ribozymes. Surprisingly, HDV-like genomes from a toad and a termite show conserved type III hammerhead ribozymes, which belong to an unrelated class of catalytic RNAs characteristic of plant genomes and plant subviral circRNAs, such as some viral satellites and viroids. Sequence analyses revealed the presence of similar HDV-like hammerhead ribozymes encoded in two termite genomes, but also in the genomes of several dipteran species. In vitro transcriptions confirmed the cleaving activity for these motifs, with moderate rates of self-cleavage. These data indicate that all described HDV-like agents contain self-cleaving motifs from either the HDV or the hammerhead class. Autocatalytic ribozymes in HDV-like genomes could be regarded as interchangeable domains and may have arisen from cellular transcriptomes, although we still cannot rule out some other evolutionary explanations.
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Affiliation(s)
- Marcos de la Peña
- IBMCP (CSIC-UPV), C/Ingeniero Fausto Elio s/n, Valencia 46022, Spain
| | - Raquel Ceprián
- IBMCP (CSIC-UPV), C/Ingeniero Fausto Elio s/n, Valencia 46022, Spain
| | - John L Casey
- Department of Microbiology and Immunology, Georgetown University Medical Center, Washington, DC, USA
| | - Amelia Cervera
- IBMCP (CSIC-UPV), C/Ingeniero Fausto Elio s/n, Valencia 46022, Spain
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13
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Abstract
Self-cleaving ribozymes are RNA molecules that catalyze a site-specific self-scission reaction. Analysis of self-cleavage is a crucial aspect of the biochemical study and understanding of these molecules. Here we describe a co-transcriptional assay that allows the analysis of self-cleaving ribozymes in different reaction conditions and in the presence of desired ligands and/or cofactors. Utilizing a standard T7 RNA polymerase in vitro transcription system under limiting Mg2+ concentration, followed by a 25-fold dilution of the reaction in desired conditions of self-cleavage (buffer, ions, ligands, pH, temperature, etc.) to halt the synthesis of new RNA molecules, allows the study of self-scission of these molecules without the need for purification or additional preparation steps, such as refolding procedures. Furthermore, because the transcripts are not denatured, this assay likely yields RNAs in conformations relevant to co-transcriptionally folded species in vivo.
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14
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Kruse RL, Legras X, Barzi M. Cre/LoxP-HBV plasmids generating recombinant covalently closed circular DNA genome upon transfection. Virus Res 2020; 292:198224. [PMID: 33166564 DOI: 10.1016/j.virusres.2020.198224] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 09/18/2020] [Accepted: 11/03/2020] [Indexed: 02/08/2023]
Abstract
New therapies against hepatitis B virus (HBV) require the elimination of covalently closed circular DNA (cccDNA), the episomal HBV genome. HBV plasmids containing an overlength 1.3-mer genome and bacterial backbone (pHBV1.3) are used in many different models, but do not replicate the unique features of cccDNA. Since the stable cccDNA pool is a barrier to HBV eradication in patients, we developed a recombinant circular HBV genome (rcccDNA) to mimic the cccDNA using Cre/LoxP technology. We validated four LoxP insertion sites into the HBV genome using hydrodynamic tail vein injection into murine liver, demonstrating high levels of HBV surface antigen (HBsAg) and HBV DNA expression with rcccDNA formation. HBsAg expression from rcccDNA was >30,000 ng/mL over 78 days, while HBsAg-expression from pHBV1.3 plasmid DNA declined from 2753 ng/mL to 131 ng/mL over that time in immunodeficient mice (P < 0.001), reflective of plasmid DNA silencing. We then cloned Cre-recombinase in cis on the LoxP-HBV plasmids, achieving plasmid stability in bacteria with intron insertion into Cre and demonstrating rcccDNA formation after transfection in vitro and in vivo. These cis-Cre/LoxP-HBV plasmids were then used to create HBx-mutant and GFP reporter plasmids to further probe cccDNA biology and antiviral strategies against cccDNA. Overall, we believe these auto-generating rcccDNA plasmids will be of great value to model cccDNA for testing new therapies against HBV infection.
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Affiliation(s)
- Robert L Kruse
- Center for Cell and Gene Therapy, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX, 77030, USA.
| | - Xavier Legras
- Center for Cell and Gene Therapy, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX, 77030, USA
| | - Mercedes Barzi
- Center for Cell and Gene Therapy, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX, 77030, USA
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15
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Li J, Mohammed-Elsabagh M, Paczkowski F, Li Y. Circular Nucleic Acids: Discovery, Functions and Applications. Chembiochem 2020; 21:1547-1566. [PMID: 32176816 DOI: 10.1002/cbic.202000003] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 02/13/2020] [Indexed: 12/14/2022]
Abstract
Circular nucleic acids (CNAs) are nucleic acid molecules with a closed-loop structure. This feature comes with a number of advantages including complete resistance to exonuclease degradation, much better thermodynamic stability, and the capability of being replicated by a DNA polymerase in a rolling circle manner. Circular functional nucleic acids, CNAs containing at least a ribozyme/DNAzyme or a DNA/RNA aptamer, not only inherit the advantages of CNAs but also offer some unique application opportunities, such as the design of topology-controlled or enabled molecular devices. This article will begin by summarizing the discovery, biogenesis, and applications of naturally occurring CNAs, followed by discussing the methods for constructing artificial CNAs. The exploitation of circular functional nucleic acids for applications in nanodevice engineering, biosensing, and drug delivery will be reviewed next. Finally, the efforts to couple functional nucleic acids with rolling circle amplification for ultra-sensitive biosensing and for synthesizing multivalent molecular scaffolds for unique applications in biosensing and drug delivery will be recapitulated.
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Affiliation(s)
- Jiuxing Li
- M.G. DeGroote Institute for Infectious Disease Research Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, L8S 4K1, Canada
| | - Mostafa Mohammed-Elsabagh
- M.G. DeGroote Institute for Infectious Disease Research Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, L8S 4K1, Canada
| | - Freeman Paczkowski
- M.G. DeGroote Institute for Infectious Disease Research Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, L8S 4K1, Canada
| | - Yingfu Li
- M.G. DeGroote Institute for Infectious Disease Research Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, L8S 4K1, Canada
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16
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Hsu CW, Juang HH, Kuo CY, Li HP, Iang SB, Lin SH, Yeh CT, Chao M. Structural Pattern Differences in Unbranched Rod-like RNA of Hepatitis Delta Virus affect RNA Editing. Viruses 2019; 11:v11100934. [PMID: 31614652 PMCID: PMC6832723 DOI: 10.3390/v11100934] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 10/08/2019] [Accepted: 10/08/2019] [Indexed: 12/18/2022] Open
Abstract
Hepatitis delta virus (HDV) RNA forms an unbranched rod-like structure and complexes with the delta antigen (HDAg). Host ADAR1-catalyzed RNA editing at the amber/W site of the small HDAg leads to the production of the large HDAg, which inhibits replication and is required for virion assembly. For HDV genotype 1, amber/W editing is controlled by HDAg and the RNA structure immediate vicinity and downstream of the editing site. Here, the effects of 20 mutants carrying an increased length of consecutive base-pairing at various sites in HDV RNA on amber/W site editing were examined. All nine mutants carrying genomic regions that formed up to 15 consecutive base pairs, which is also the maximum length observed in 41 naturally occurring HDV genomes, showed normal editing rate. However, mutants carrying a 16 or 17 consecutive base-paired antigenomic segment located as far as 114 nt upstream could increase editing efficiency, possibly by interfering with HDAg binding. These data show for the first time that extended base-pairing upstream of the amber/W site could increase HDV RNA editing efficiency. Furthermore, it appears that the naturally occurring HDV RNA structures have been selected for suboptimal amber/W RNA editing, which favors the HDV replication cycle.
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Affiliation(s)
- Chao-Wei Hsu
- Liver Research Center, Department of Hepato-Gastroenterology, Chang Gung Memorial Hospital, Guishan, Taoyang 33302, Taiwan; (C.-W.H.); (C.-T.Y.)
| | - Horng-Heng Juang
- Department of Anatomy, Chang Gung University, Guishan, Taoyang 33302, Taiwan;
| | - Chien-Yi Kuo
- Department of Microbiology and Immunology, Chang Gung University, Guishan, Taoyang 33302, Taiwan; (C.-Y.K.); (H.-P.L.); (S.-B.I.); (S.-H.L.)
| | - Hsin-Pai Li
- Department of Microbiology and Immunology, Chang Gung University, Guishan, Taoyang 33302, Taiwan; (C.-Y.K.); (H.-P.L.); (S.-B.I.); (S.-H.L.)
- Division of Microbiology, Graduate Institute of Biomedical Sciences, Chang Gung University, Guishan, Taoyang 33302, Taiwan
| | - Shan-Bei Iang
- Department of Microbiology and Immunology, Chang Gung University, Guishan, Taoyang 33302, Taiwan; (C.-Y.K.); (H.-P.L.); (S.-B.I.); (S.-H.L.)
| | - Siao-Han Lin
- Department of Microbiology and Immunology, Chang Gung University, Guishan, Taoyang 33302, Taiwan; (C.-Y.K.); (H.-P.L.); (S.-B.I.); (S.-H.L.)
| | - Chau-Ting Yeh
- Liver Research Center, Department of Hepato-Gastroenterology, Chang Gung Memorial Hospital, Guishan, Taoyang 33302, Taiwan; (C.-W.H.); (C.-T.Y.)
| | - Mei Chao
- Liver Research Center, Department of Hepato-Gastroenterology, Chang Gung Memorial Hospital, Guishan, Taoyang 33302, Taiwan; (C.-W.H.); (C.-T.Y.)
- Department of Microbiology and Immunology, Chang Gung University, Guishan, Taoyang 33302, Taiwan; (C.-Y.K.); (H.-P.L.); (S.-B.I.); (S.-H.L.)
- Division of Microbiology, Graduate Institute of Biomedical Sciences, Chang Gung University, Guishan, Taoyang 33302, Taiwan
- Correspondence:
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17
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Hepatitis Delta Antigen Regulates mRNA and Antigenome RNA Levels during Hepatitis Delta Virus Replication. J Virol 2019; 93:JVI.01989-18. [PMID: 30728256 DOI: 10.1128/jvi.01989-18] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 01/18/2019] [Indexed: 01/17/2023] Open
Abstract
Hepatitis delta virus (HDV) is a satellite of hepatitis B virus that increases the severity of acute and chronic liver disease. HDV produces three processed RNAs that accumulate in infected cells: the circular genome; the circular antigenome, which serves as a replication intermediate; and lesser amounts of the mRNA, which encodes the sole viral protein, hepatitis delta antigen (HDAg). The HDV genome and antigenome RNAs form ribonucleoprotein complexes with HDAg. Although HDAg is required for HDV replication, it is not known how the relative amounts of HDAg and HDV RNA affect replication, or whether HDAg synthesis is regulated by the virus. Using a novel transfection system in which HDV replication is initiated using in vitro-synthesized circular HDV RNAs, HDV replication was found to depend strongly on the relative amounts of HDV RNA and HDAg. HDV controls these relative amounts via differential effects of HDAg on the production of HDV mRNA and antigenome RNA, both of which are synthesized from the genome RNA template. mRNA synthesis is favored at low HDAg levels but becomes saturated at high HDAg concentrations. Antigenome RNA accumulation increases linearly with HDAg and dominates at high HDAg levels. These results provide a conceptual model for how HDV antigenome RNA production and mRNA transcription are controlled from the earliest stage of infection onward and also demonstrate that, in this control, HDV behaves similarly to other negative-strand RNA viruses, even though there is no genetic similarity between them.IMPORTANCE Hepatitis delta virus (HDV) is a satellite of hepatitis B virus that increases the severity of liver disease; approximately 15 million people are chronically infected worldwide. There are no licensed therapies available. HDV is not related to any known virus, and few details regarding its replication cycle are known. One key question is whether and how HDV regulates the relative amounts of viral RNA and protein in infected cells. Such regulation might be important because the HDV RNA and protein form complexes that are essential for HDV replication, and the proper stoichiometry of these complexes could be critical for their function. Our results show that the relative amounts of HDV RNA and protein in cells are indeed important for HDV replication and that the virus does control them. These observations indicate that further study of these regulatory mechanisms is required to better understand replication of this serious human pathogen.
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18
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Webb CHT, Lupták A. Kinetic Parameters of trans Scission by Extended HDV-like Ribozymes and the Prospect for the Discovery of Genomic trans-Cleaving RNAs. Biochemistry 2018; 57:1440-1450. [PMID: 29388767 DOI: 10.1021/acs.biochem.7b00789] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Hepatitis delta virus (HDV)-like ribozymes are self-cleaving catalytic RNAs with a widespread distribution in nature and biological roles ranging from self-scission during rolling-circle replication in viroids to co-transcriptional processing of eukaryotic retrotransposons, among others. The ribozymes fold into a double pseudoknot with a common catalytic core motif and highly variable peripheral domains. Like other self-cleaving ribozymes, HDV-like ribozymes can be converted into trans-acting catalytic RNAs by bisecting the self-cleaving variants at non-essential loops. Here we explore the trans-cleaving activity of ribozymes derived from the largest examples of the ribozymes (drz-Agam-2 family), which contain an extended domain between the substrate strand and the rest of the RNA. When this peripheral domain is bisected at its distal end, the substrate strand is recognized through two helices, rather than just one 7 bp helix common among the HDV ribozymes, resulting in stronger binding and increased sequence specificity. Kinetic characterization of the extended trans-cleaving ribozyme revealed an efficient trans-cleaving system with a surprisingly high KM', supporting a model that includes a recently proposed activation barrier related to the assembly of the catalytically competent ribozyme. The ribozymes also exhibit a very long koff for the products (∼2 weeks), resulting in a trade-off between sequence specificity and turnover. Finally, structure-based searches for the catalytic cores of these ribozymes in the genome of the mosquito Anopheles gambiae, combined with sequence searches for their putative substrates, revealed two potential ribozyme-substrate pairs that may represent examples of natural trans-cleaving ribozymes.
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Affiliation(s)
- Chiu-Ho T Webb
- Department of Molecular Biology and Biochemistry , University of California-Irvine , Irvine , California 92697 , United States
| | - Andrej Lupták
- Department of Molecular Biology and Biochemistry , University of California-Irvine , Irvine , California 92697 , United States.,Department of Pharmaceutical Sciences , University of California-Irvine , Irvine , California 92697 , United States.,Department of Chemistry , University of California-Irvine , Irvine , California 92697 , United States
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19
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Studying Parasite Gene Function and Interaction Through Ribozymes and Riboswitches Design Mechanism. Synth Biol (Oxf) 2018. [DOI: 10.1007/978-981-10-8693-9_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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20
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Passalacqua LFM, Jimenez RM, Fong JY, Lupták A. Allosteric Modulation of the Faecalibacterium prausnitzii Hepatitis Delta Virus-like Ribozyme by Glucosamine 6-Phosphate: The Substrate of the Adjacent Gene Product. Biochemistry 2017; 56:6006-6014. [PMID: 29045794 DOI: 10.1021/acs.biochem.7b00879] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Self-cleaving ribozymes were discovered 30 years ago and have been found throughout nature, from bacteria to animals, but little is known about their biological functions and regulation, particularly how cofactors and metabolites alter their activity. A hepatitis delta virus-like self-cleaving ribozyme maps upstream of a phosphoglucosamine mutase (glmM) open reading frame in the genome of the human gut bacterium Faecalibacterium prausnitzii. The presence of a ribozyme in the untranslated region of glmM suggests a regulation mechanism of gene expression. In the bacterial hexosamine biosynthesis pathway, the enzyme glmM catalyzes the isomerization of glucosamine 6-phosphate into glucosamine 1-phosphate. In this study, we investigated the effect of these metabolites on the co-transcriptional self-cleavage rate of the ribozyme. Our results suggest that glucosamine 6-phosphate, but not glucosamine 1-phosphate, is an allosteric ligand that increases the self-cleavage rate of drz-Fpra-1, providing the first known example of allosteric modulation of a self-cleaving ribozyme by the substrate of the adjacent gene product. Given that the ribozyme is activated by the glmM substrate, but not the product, this allosteric modulation may represent a potential feed-forward mechanism of gene expression regulation in bacteria.
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Affiliation(s)
- Luiz F M Passalacqua
- Department of Pharmaceutical Sciences, University of California , Irvine, California 92697, United States
| | - Randi M Jimenez
- Department of Molecular Biology and Biochemistry, University of California , Irvine, California 92697, United States
| | - Jennifer Y Fong
- Department of Pharmaceutical Sciences, University of California , Irvine, California 92697, United States
| | - Andrej Lupták
- Department of Pharmaceutical Sciences, University of California , Irvine, California 92697, United States.,Department of Molecular Biology and Biochemistry, University of California , Irvine, California 92697, United States.,Department of Chemistry, University of California , Irvine, California 92697, United States
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21
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Botelho-Souza LF, Vasconcelos MPA, Dos Santos ADO, Salcedo JMV, Vieira DS. Hepatitis delta: virological and clinical aspects. Virol J 2017; 14:177. [PMID: 28903779 PMCID: PMC5597996 DOI: 10.1186/s12985-017-0845-y] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 09/05/2017] [Indexed: 02/06/2023] Open
Abstract
There are an estimated 400 million chronic carriers of HBV worldwide; between 15 and 20 million have serological evidence of exposure to HDV. Traditionally, regions with high rates of endemicity are central and northern Africa, the Amazon Basin, eastern Europe and the Mediterranean, the Middle East and parts of Asia. There are two types of HDV/HBV infection which are differentiated by the previous status infection by HBV for the individual. Individuals with acute HBV infection contaminated by HDV is an HDV/HBV co-infection, while individuals with chronic HBV infection contaminated by HDV represent an HDV/HBV super-infection. The appropriate treatment for chronic hepatitis delta is still widely discussed since it does not have an effective drug. Alpha interferon is currently the only licensed therapy for the treatment of chronic hepatitis D. The most widely used drug is pegylated interferon but only approximately 25% of patients maintain a sustained viral response after 1 year of treatment. The best marker of therapeutic success would be the clearance of HBsAg, but this data is rare in clinical practice. Therefore, the best way to predict a sustained virologic response is the maintenance of undetectable HDV RNA levels.
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Affiliation(s)
- Luan Felipo Botelho-Souza
- Laboratório de Virologia Molecular - FIOCRUZ - RONDÔNIA, Rua da Beira, 7671 - BR 364, Km 3,5 Bairro Lagoa, CEP: 76812, Porto Velho, RO, CEP: 76812-329, Brazil.
- Ambulatório de Hepatites Virais, Fundação Oswaldo Cruz Rondônia e Centro de Pesquisa em Medicina Tropical - CEPEM, Avenida Guaporé, 215, anexo Hospital CEMETRON, Agenor M de Carvalho, Porto Velho, RO, CEP: 76812-329, Brazil.
- Programa de Pós-Graduação em Biologia Experimental - PGBioExp, Rodovia Br-364, KM 9, CAMPUS UNIR, Porto Velho, RO, CEP: 76801-974, Brazil.
| | | | - Alcione de Oliveira Dos Santos
- Laboratório de Virologia Molecular - FIOCRUZ - RONDÔNIA, Rua da Beira, 7671 - BR 364, Km 3,5 Bairro Lagoa, CEP: 76812, Porto Velho, RO, CEP: 76812-329, Brazil
- Ambulatório de Hepatites Virais, Fundação Oswaldo Cruz Rondônia e Centro de Pesquisa em Medicina Tropical - CEPEM, Avenida Guaporé, 215, anexo Hospital CEMETRON, Agenor M de Carvalho, Porto Velho, RO, CEP: 76812-329, Brazil
- Programa de Pós-Graduação em Biologia Experimental - PGBioExp, Rodovia Br-364, KM 9, CAMPUS UNIR, Porto Velho, RO, CEP: 76801-974, Brazil
| | - Juan Miguel Villalobos Salcedo
- Laboratório de Virologia Molecular - FIOCRUZ - RONDÔNIA, Rua da Beira, 7671 - BR 364, Km 3,5 Bairro Lagoa, CEP: 76812, Porto Velho, RO, CEP: 76812-329, Brazil
- Ambulatório de Hepatites Virais, Fundação Oswaldo Cruz Rondônia e Centro de Pesquisa em Medicina Tropical - CEPEM, Avenida Guaporé, 215, anexo Hospital CEMETRON, Agenor M de Carvalho, Porto Velho, RO, CEP: 76812-329, Brazil
- Programa de Pós-Graduação em Biologia Experimental - PGBioExp, Rodovia Br-364, KM 9, CAMPUS UNIR, Porto Velho, RO, CEP: 76801-974, Brazil
| | - Deusilene Souza Vieira
- Laboratório de Virologia Molecular - FIOCRUZ - RONDÔNIA, Rua da Beira, 7671 - BR 364, Km 3,5 Bairro Lagoa, CEP: 76812, Porto Velho, RO, CEP: 76812-329, Brazil
- Ambulatório de Hepatites Virais, Fundação Oswaldo Cruz Rondônia e Centro de Pesquisa em Medicina Tropical - CEPEM, Avenida Guaporé, 215, anexo Hospital CEMETRON, Agenor M de Carvalho, Porto Velho, RO, CEP: 76812-329, Brazil
- Programa de Pós-Graduação em Biologia Experimental - PGBioExp, Rodovia Br-364, KM 9, CAMPUS UNIR, Porto Velho, RO, CEP: 76801-974, Brazil
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22
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Lempp FA, Urban S. Hepatitis Delta Virus: Replication Strategy and Upcoming Therapeutic Options for a Neglected Human Pathogen. Viruses 2017; 9:E172. [PMID: 28677645 PMCID: PMC5537664 DOI: 10.3390/v9070172] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 06/28/2017] [Accepted: 06/29/2017] [Indexed: 12/15/2022] Open
Abstract
The human Hepatitis Delta Virus (HDV) is unique among all viral pathogens. Encoding only one protein (Hepatitis Delta Antigen; HDAg) within its viroid-like self-complementary RNA, HDV constitutes the smallest known virus in the animal kingdom. To disseminate in its host, HDV depends on a helper virus, the human Hepatitis B virus (HBV), which provides the envelope proteins required for HDV assembly. HDV affects an estimated 15-20 million out of the 240 million chronic HBV-carriers and disperses unequally in disparate geographical regions of the world. The disease it causes (chronic Hepatitis D) presents as the most severe form of viral hepatitis, leading to accelerated progression of liver dysfunction including cirrhosis and hepatocellular carcinoma and a high mortality rate. The lack of approved drugs interfering with specific steps of HDV replication poses a high burden for gaining insights into the molecular biology of the virus and, consequently, the development of specific novel medications that resiliently control HDV replication or, in the best case, functionally cure HDV infection or HBV/HDV co-infection. This review summarizes our current knowledge of HBV molecular biology, presents an update on novel cell culture and animal models to study the virus and provides updates on the clinical development of the three developmental drugs Lonafarnib, REP2139-Ca and Myrcludex B.
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Affiliation(s)
- Florian A Lempp
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Im Neuenheimer Feld 345, 69120 Heidelberg, Germany.
- German Centre for Infection Research (DZIF), Partner Site Heidelberg, 69120 Heidelberg, Germany.
| | - Stephan Urban
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Im Neuenheimer Feld 345, 69120 Heidelberg, Germany.
- German Centre for Infection Research (DZIF), Partner Site Heidelberg, 69120 Heidelberg, Germany.
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23
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Lilley DMJ. How RNA acts as a nuclease: some mechanistic comparisons in the nucleolytic ribozymes. Biochem Soc Trans 2017; 45:683-691. [PMID: 28620029 DOI: 10.1042/bst20160158] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 02/28/2017] [Accepted: 03/02/2017] [Indexed: 02/11/2024]
Abstract
Recent structural and mechanistic studies have shed considerable light on the catalytic mechanisms of nucleolytic ribozymes. The discovery of several new ribozymes in this class has now allowed comparisons to be made, and the beginnings of mechanistic groupings to emerge.
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Affiliation(s)
- David M J Lilley
- Cancer Research UK Nucleic Acid Structure Research Group, MSI/WTB Complex, The University of Dundee, Dow Street, Dundee DD1 5EH, U.K.
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24
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Chao M, Wang TC, Lin CC, Yung-Liang Wang R, Lin WB, Lee SE, Cheng YY, Yeh CT, Iang SB. Analyses of a whole-genome inter-clade recombination map of hepatitis delta virus suggest a host polymerase-driven and viral RNA structure-promoted template-switching mechanism for viral RNA recombination. Oncotarget 2017; 8:60841-60859. [PMID: 28977829 PMCID: PMC5617389 DOI: 10.18632/oncotarget.18339] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 05/22/2017] [Indexed: 01/05/2023] Open
Abstract
The genome of hepatitis delta virus (HDV) is a 1.7-kb single-stranded circular RNA that folds into an unbranched rod-like structure and has ribozyme activity. HDV redirects host RNA polymerase(s) (RNAP) to perform viral RNA-directed RNA transcription. RNA recombination is known to contribute to the genetic heterogeneity of HDV, but its molecular mechanism is poorly understood. Here, we established a whole-genome HDV-1/HDV-4 recombination map using two cloned sequences coexisting in cultured cells. Our functional analyses of the resulting chimeric delta antigens (the only viral-encoded protein) and recombinant genomes provide insights into how recombination promotes the genotypic and phenotypic diversity of HDV. Our examination of crossover distribution and subsequent mutagenesis analyses demonstrated that ribozyme activity on HDV genome, which is required for viral replication, also contributes to the generation of an inter-clade junction. These data provide circumstantial evidence supporting our contention that HDV RNA recombination occurs via a replication-dependent mechanism. Furthermore, we identify an intrinsic asymmetric bulge on the HDV genome, which appears to promote recombination events in the vicinity. We therefore propose a mammalian RNAP-driven and viral-RNA-structure-promoted template-switching mechanism for HDV genetic recombination. The present findings improve our understanding of the capacities of the host RNAP beyond typical DNA-directed transcription.
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Affiliation(s)
- Mei Chao
- Department of Microbiology and Immunology, Chang Gung University, Guishan, Taoyang, Taiwan.,Division of Microbiology, Graduate Institute of Biomedical Sciences, Chang Gung University, Guishan, Taoyang, Taiwan.,Department of Hepato-Gastroenterology, Liver Research Center, Chang Gung Memorial Hospital, Guishan, Taoyang, Taiwan
| | - Tzu-Chi Wang
- Division of Microbiology, Graduate Institute of Biomedical Sciences, Chang Gung University, Guishan, Taoyang, Taiwan
| | - Chia-Chi Lin
- Division of Microbiology, Graduate Institute of Biomedical Sciences, Chang Gung University, Guishan, Taoyang, Taiwan
| | - Robert Yung-Liang Wang
- Division of Microbiology, Graduate Institute of Biomedical Sciences, Chang Gung University, Guishan, Taoyang, Taiwan.,Department of Biomedical Sciences, Chang Gung University, Guishan, Taoyang, Taiwan
| | - Wen-Bin Lin
- Division of Microbiology, Graduate Institute of Biomedical Sciences, Chang Gung University, Guishan, Taoyang, Taiwan
| | - Shang-En Lee
- Division of Microbiology, Graduate Institute of Biomedical Sciences, Chang Gung University, Guishan, Taoyang, Taiwan
| | - Ying-Yu Cheng
- Division of Microbiology, Graduate Institute of Biomedical Sciences, Chang Gung University, Guishan, Taoyang, Taiwan
| | - Chau-Ting Yeh
- Department of Hepato-Gastroenterology, Liver Research Center, Chang Gung Memorial Hospital, Guishan, Taoyang, Taiwan
| | - Shan-Bei Iang
- Division of Microbiology, Graduate Institute of Biomedical Sciences, Chang Gung University, Guishan, Taoyang, Taiwan
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25
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A screening assay for the identification of host cell requirements and antiviral targets for hepatitis D virus infection. Antiviral Res 2017; 141:116-123. [PMID: 28223128 DOI: 10.1016/j.antiviral.2017.02.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 02/15/2017] [Accepted: 02/17/2017] [Indexed: 01/10/2023]
Abstract
Hepatitis delta virus (HDV) is a minimalistic satellite virus of hepatitis B virus (HBV). HBV/HDV co-infection, i.e. "hepatitis D", is the most severe form of viral hepatitis. No effective therapy for HDV infection is available partly due to the fact that HDV is a highly host-dependent virus devoid of any potentially drugable enzyme encoded in its small genome. In this study we present a semi-automated method to evaluate HDV infection and replication under the influence of different drugs. We utilized a Huh-7/hNTCP cell culture based system in a 96-well plate format, an automated microscope and image acquisition as well as analysis with the CellProfiler software to quantify the impact of these drugs on HDV infection. For validation, three groups of potential anti-HDV agents were evaluated: To target ribozyme activity of HDV RNA, we screened ribozyme inhibitors but only observed marked toxicity. Testing innate antiviral mediators showed that interferons alpha-2a and beta-1a had a specific inhibitory effect on HDV infection. Finally, we screened a library of 160 human kinase inhibitors covering all parts of the human kinome. Overall, only inhibitors targeting the tyrosine kinase-like group had significant average anti-HDV activity. Looking at individual substances, kenpaullone, a GSK-3β and Cdk inhibitor, had the highest selective index of 3.44. Thus, we provide a potentially useful tool to screen for substances with anti-HDV activity and novel insights into interactions between HDV replication and the human kinome.
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26
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Lempp FA, Ni Y, Urban S. Hepatitis delta virus: insights into a peculiar pathogen and novel treatment options. Nat Rev Gastroenterol Hepatol 2016; 13:580-9. [PMID: 27534692 DOI: 10.1038/nrgastro.2016.126] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Chronic hepatitis D is the most severe form of viral hepatitis, affecting ∼20 million HBV-infected people worldwide. The causative agent, hepatitis delta virus (HDV), is a unique human pathogen: it is the smallest known virus; it depends on HBV to disseminate its viroid-like RNA; it encodes only one protein (HDAg), which has both structural and regulatory functions; and it replicates using predominantly host proteins. The failure of HBV-specific nucleoside analogues to suppress the HBV helper function, and the limitations of experimental systems to study the HDV life cycle, have impeded the development of HDV-specific drugs. Thus, the only clinical regimen for HDV is IFNα, which shows some efficacy but long-term virological responses are rare. Insights into the receptor-mediated entry of HDV, and the observation that HDV assembly requires farnesyltransferase, have enabled novel therapeutic strategies to be developed. Interference with entry, for example through blockade of the HBV-HDV-specific receptor sodium/taurocholate cotransporting polypeptide NTCP by Myrcludex B, and inhibition of assembly by blockade of farnesyltransferase using lonafarnib or nucleic acid polymers such as REP 2139-Ca, have shown promising results in phase II studies. In this Review, we summarize our knowledge of HDV epidemiology, pathogenesis and molecular biology, with a particular emphasis on possible future developments.
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Affiliation(s)
- Florian A Lempp
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, Im Neuenheimer Feld 345, 69120 Heidelberg, Germany
| | - Yi Ni
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, Im Neuenheimer Feld 345, 69120 Heidelberg, Germany.,German Center for Infection Research (DZIF), Heidelberg Partner Site, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
| | - Stephan Urban
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, Im Neuenheimer Feld 345, 69120 Heidelberg, Germany.,German Center for Infection Research (DZIF), Heidelberg Partner Site, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
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27
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James W. Towards Gene-Inhibition Therapy: A Review of Progress and Prospects in the Field of Antiviral Antisense Nucleic Acids and Ribozymes. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/095632029100200401] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Antisense RNA and its derivatives may provide the basis for highly selective gene inhibition therapies of virus infections. In this review, I concentrate on advances made in the study of antisense RNA and ribozymes during the last five years and their implications for the development of such therapies. It appears that antisense RNAs synthesized at realistic levels within the cell can be much more effective inhibitors than originally supposed. Looking at those experiments that enable comparisons to be made, it seems that inhibitory antisense RNAs are not those that are complementary to particular sites within mRNAs but those that are able to make stable duplexes with their targets, perhaps by virtue of their secondary structure and length. The inclusion of ribozyme sequences within antisense RNAs confers RNA-cleaving activity upon them in vitro and possibly in cells, thereby offering the possibility of markedly increasing their therapeutic potential. The varieties of natural ribozyme and their adaptation as artificial catalysts are reviewed. The implications of these developments for antiviral therapy are discussed.
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Affiliation(s)
- W. James
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, U.K
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28
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Chao M, Lin CC, Lin FM, Li HP, Iang SB. Whole-genome analysis of genetic recombination of hepatitis delta virus: molecular domain in delta antigen determining trans-activating efficiency. J Gen Virol 2016; 96:3460-3469. [PMID: 26407543 DOI: 10.1099/jgv.0.000297] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Hepatitis delta virus (HDV) is the only animal RNA virus that has an unbranched rod-like genome with ribozyme activity and is replicated by host RNA polymerase. HDV RNA recombination was previously demonstrated in patients and in cultured cells by analysis of a region corresponding to the C terminus of the delta antigen (HDAg), the only viral-encoded protein. Here, a whole-genome recombination map of HDV was constructed using an experimental system in which two HDV-1 sequences were co-transfected into cultured cells and the recombinants were analysed by sequencing of cloned reverse transcription-PCR products. Fifty homologous recombinants with 60 crossovers mapping to 22 junctions were identified from 200 analysed clones. Small HDAg chimeras harbouring a junction newly detected in the recombination map were then constructed. The results further indicated that the genome-replication level of HDV was sensitive to the sixth amino acid within the N-terminal 22 aa of HDAg. Therefore, the recombination map established in this study provided a tool for not only understanding HDV RNA recombination, but also elucidating the related mechanisms, such as molecular elements responsible for the trans-activation levels of the small HDAg.
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Affiliation(s)
- Mei Chao
- Division of Microbiology, Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Guishan, Taoyuan 33302, Taiwan
- Department of Microbiology and Immunology, Chang Gung University, Guishan, Taoyuan 33302, Taiwan
| | - Chia-Chi Lin
- Division of Microbiology, Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Guishan, Taoyuan 33302, Taiwan
| | - Feng-Ming Lin
- Division of Microbiology, Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Guishan, Taoyuan 33302, Taiwan
| | - Hsin-Pai Li
- Division of Microbiology, Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Guishan, Taoyuan 33302, Taiwan
- Department of Microbiology and Immunology, Chang Gung University, Guishan, Taoyuan 33302, Taiwan
- Molecular Medicine Research Center, Chang Gung University, Guishan, Taoyuan 33302, Taiwan
| | - Shan-Bei Iang
- Molecular Medicine Research Center, Chang Gung University, Guishan, Taoyuan 33302, Taiwan
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29
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Sureau C, Negro F. The hepatitis delta virus: Replication and pathogenesis. J Hepatol 2016; 64:S102-S116. [PMID: 27084031 DOI: 10.1016/j.jhep.2016.02.013] [Citation(s) in RCA: 184] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 02/01/2016] [Accepted: 02/10/2016] [Indexed: 02/06/2023]
Abstract
Hepatitis delta virus (HDV) is a defective virus and a satellite of the hepatitis B virus (HBV). Its RNA genome is unique among animal viruses, but it shares common features with some plant viroids, including a replication mechanism that uses a host RNA polymerase. In infected cells, HDV genome replication and formation of a nucleocapsid-like ribonucleoprotein (RNP) are independent of HBV. But the RNP cannot exit, and therefore propagate, in the absence of HBV, as the latter supplies the propagation mechanism, from coating the HDV RNP with the HBV envelope proteins for cell egress to delivery of the HDV virions to the human hepatocyte target. HDV is therefore an obligate satellite of HBV; it infects humans either concomitantly with HBV or after HBV infection. HDV affects an estimated 15 to 20 million individuals worldwide, and the clinical significance of HDV infection is more severe forms of viral hepatitis--acute or chronic--, and a higher risk of developing cirrhosis and hepatocellular carcinoma in comparison to HBV monoinfection. This review covers molecular aspects of HDV replication cycle, including its interaction with the helper HBV and the pathogenesis of infection in humans.
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Affiliation(s)
- Camille Sureau
- Molecular Virology laboratory, Institut National de la Transfusion Sanguine (INTS), CNRS INSERM U1134, Paris, France.
| | - Francesco Negro
- Division of Gastroenterology and Hepatology, University Hospitals, Geneva, Switzerland; Division of Clinical Pathology, University Hospitals, Geneva, Switzerland.
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30
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Lee TS, Radak BK, Harris ME, York DM. A Two-Metal-Ion-Mediated Conformational Switching Pathway for HDV Ribozyme Activation. ACS Catal 2016; 6:1853-1869. [PMID: 27774349 DOI: 10.1021/acscatal.5b02158] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
RNA enzymes serve as a potentially powerful platform from which to design catalysts and engineer new biotechnology. A fundamental understanding of these systems provides insight to guide design. The hepatitis delta virus ribozyme (HDVr) is a small, self-cleaving RNA motif widely distributed in nature, that has served as a paradigm for understanding basic principles of RNA catalysis. Nevertheless, questions remain regarding the precise roles of divalent metal ions and key nucleotides in catalysis. In an effort to establish a reaction mechanism model consistent with available experimental data, we utilize molecular dynamics simulations to explore different conformations and metal ion binding modes along the HDVr reaction path. Building upon recent crystallographic data, our results provide a dynamic model of the HDVr reaction mechanism involving a conformational switch between multiple non-canonical G25:U20 base pair conformations in the active site. These local nucleobase dynamics play an important role in catalysis by modulating the metal binding environments of two Mg2+ ions that support catalysis at different steps of the reaction pathway. The first ion plays a structural role by inducing a base pair flip necessary to obtain the catalytic fold in which C75 moves towards to the scissile phosphate in the active site. Ejection of this ion then permits a second ion to bind elsewhere in the active site and facilitate nucleophile activation. The simulations collectively describe a mechanistic scenario that is consistent with currently available experimental data from crystallography, phosphorothioate substitutions, and chemical probing studies. Avenues for further experimental verification are suggested.
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Affiliation(s)
- Tai-Sung Lee
- Center for Integrative Proteomics Research and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, United States
| | - Brian K. Radak
- Center for Integrative Proteomics Research and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, United States
- Argonne National Laboratory, Argonne, Illinois 60439, United State
| | - Michael E. Harris
- Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, United States
| | - Darrin M. York
- Center for Integrative Proteomics Research and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, United States
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31
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Lee CH, Han SR, Lee SW. Therapeutic Applications of Aptamer-Based Riboswitches. Nucleic Acid Ther 2015; 26:44-51. [PMID: 26539634 DOI: 10.1089/nat.2015.0570] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Aptamers bind to their targets with high affinity and specificity through structure-based complementarity, instead of sequence complementarity that is used by most of the oligonucleotide-based therapeutics. This property has been exploited in using aptamers as multifunctional therapeutic units, by attaching them to therapeutic drugs, nanoparticles, or imaging agents, or as direct molecular decoys for inducing loss-of-function or gain-of-function of targets. One of the most interesting fields of aptamer application is their development as molecular sensors to regulate artificial riboswitches. Naturally, the riboswitches sense small-molecule metabolites and respond by regulating the expression of the corresponding metabolic genes. Riboswitches are cis-acting RNA structures that consist of the sensing (aptamer) and the regulating (expression platform) domains. In principle, diverse riboswitches can be engineered and applied to control different steps of gene expression in bacterial species as well as eukaryotes, by simply replacing aptamers against various endogenous and/or exogenous targets. Although these engineered aptamer-based riboswitches are recently gaining attention, it is clear that aptamer-based riboswitches have a potential for next-generation therapeutics against various diseases because of their controllability, specificity, and modularity in regulating gene expression through various cellular processes, including transcription, splicing, stability, RNA interference, and translation. In this review, we provide a summary of the recently developed and engineered aptamer-based riboswitches focusing on their therapeutic availability and further discuss their clinical potential.
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Affiliation(s)
- Chang Ho Lee
- Department of Molecular Biology, Institute of Nanosensor and Biotechnology, and Research Institute of Advanced Omics, Dankook University , Yongin, Republic of Korea
| | - Seung Ryul Han
- Department of Molecular Biology, Institute of Nanosensor and Biotechnology, and Research Institute of Advanced Omics, Dankook University , Yongin, Republic of Korea
| | - Seong-Wook Lee
- Department of Molecular Biology, Institute of Nanosensor and Biotechnology, and Research Institute of Advanced Omics, Dankook University , Yongin, Republic of Korea
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32
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Jimenez RM, Polanco JA, Lupták A. Chemistry and Biology of Self-Cleaving Ribozymes. Trends Biochem Sci 2015; 40:648-661. [PMID: 26481500 DOI: 10.1016/j.tibs.2015.09.001] [Citation(s) in RCA: 130] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 08/28/2015] [Accepted: 09/01/2015] [Indexed: 11/26/2022]
Abstract
Self-cleaving ribozymes were discovered 30 years ago, but their biological distribution and catalytic mechanisms are only beginning to be defined. Each ribozyme family is defined by a distinct structure, with unique active sites accelerating the same transesterification reaction across the families. Biochemical studies show that general acid-base catalysis is the most common mechanism of self-cleavage, but metal ions and metabolites can be used as cofactors. Ribozymes have been discovered in highly diverse genomic contexts throughout nature, from viroids to vertebrates. Their biological roles include self-scission during rolling-circle replication of RNA genomes, co-transcriptional processing of retrotransposons, and metabolite-dependent gene expression regulation in bacteria. Other examples, including highly conserved mammalian ribozymes, suggest that many new biological roles are yet to be discovered.
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Affiliation(s)
- Randi M Jimenez
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, USA
| | - Julio A Polanco
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, USA
| | - Andrej Lupták
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, USA; Department of Pharmaceutical Sciences, University of California, Irvine, CA, USA; Department of Chemistry, University of California, Irvine, CA, USA.
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33
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Shang R, Zhang F, Xu B, Xi H, Zhang X, Wang W, Wu L. Ribozyme-enhanced single-stranded Ago2-processed interfering RNA triggers efficient gene silencing with fewer off-target effects. Nat Commun 2015; 6:8430. [PMID: 26455506 PMCID: PMC4633630 DOI: 10.1038/ncomms9430] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 08/21/2015] [Indexed: 02/06/2023] Open
Abstract
Short-hairpin RNAs (shRNAs) are widely used to produce small-interfering RNAs (siRNAs) for gene silencing. Here we design an alternative siRNA precursor, named single-stranded, Argonaute 2 (Ago2)-processed interfering RNA (saiRNA), containing a 16-18 bp stem and a loop complementary to the target transcript. The introduction of a self-cleaving ribozyme derived from hepatitis delta virus to the 3' end of the transcribed saiRNA dramatically improves its silencing activity by generating a short 3' overhang that facilitates the efficient binding of saiRNA to Ago2. The same ribozyme also enhances the activity of Dicer-dependent shRNAs. Unlike a classical shRNA, the strand-specific cleavage of saiRNA by Ago2 during processing eliminates the passenger strand and prevents the association of siRNA with non-nucleolytic Ago proteins. As a result, off-target effects are reduced. In addition, saiRNA exhibits less competition with the biogenesis of endogenous miRNAs. Therefore, ribozyme-enhanced saiRNA provides a reliable tool for RNA interference applications.
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Affiliation(s)
- Renfu Shang
- National Center for Protein Science Shanghai, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.,Shanghai Science Research Center, Chinese Academy of Sciences, Shanghai 201204, China.,Shanghai Key Laboratory of Molecular Andrology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Fengjuan Zhang
- National Center for Protein Science Shanghai, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.,Shanghai Science Research Center, Chinese Academy of Sciences, Shanghai 201204, China.,Shanghai Key Laboratory of Molecular Andrology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Beiying Xu
- National Center for Protein Science Shanghai, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.,Shanghai Science Research Center, Chinese Academy of Sciences, Shanghai 201204, China.,Shanghai Key Laboratory of Molecular Andrology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Hairui Xi
- School of Life Sciences, Shanghai University, Shanghai 200444, China
| | - Xue Zhang
- National Center for Protein Science Shanghai, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.,Shanghai Science Research Center, Chinese Academy of Sciences, Shanghai 201204, China.,Shanghai Key Laboratory of Molecular Andrology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Weihua Wang
- National Center for Protein Science Shanghai, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.,Shanghai Science Research Center, Chinese Academy of Sciences, Shanghai 201204, China.,Shanghai Key Laboratory of Molecular Andrology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Ligang Wu
- National Center for Protein Science Shanghai, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.,Shanghai Science Research Center, Chinese Academy of Sciences, Shanghai 201204, China.,Shanghai Key Laboratory of Molecular Andrology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
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34
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Alfaiate D, Dény P, Durantel D. Hepatitis delta virus: From biological and medical aspects to current and investigational therapeutic options. Antiviral Res 2015; 122:112-29. [DOI: 10.1016/j.antiviral.2015.08.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 08/10/2015] [Accepted: 08/11/2015] [Indexed: 12/14/2022]
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35
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Radak BK, Lee TS, Harris ME, York DM. Assessment of metal-assisted nucleophile activation in the hepatitis delta virus ribozyme from molecular simulation and 3D-RISM. RNA (NEW YORK, N.Y.) 2015; 21:1566-1577. [PMID: 26170378 PMCID: PMC4536318 DOI: 10.1261/rna.051466.115] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Accepted: 05/26/2015] [Indexed: 06/04/2023]
Abstract
The hepatitis delta virus ribozyme is an efficient catalyst of RNA 2'-O-transphosphorylation and has emerged as a key experimental system for identifying and characterizing fundamental features of RNA catalysis. Recent structural and biochemical data have led to a proposed mechanistic model whereby an active site Mg(2+) ion facilitates deprotonation of the O2' nucleophile, and a protonated cytosine residue (C75) acts as an acid to donate a proton to the O5' leaving group as noted in a previous study. This model assumes that the active site Mg(2+) ion forms an inner-sphere coordination with the O2' nucleophile and a nonbridging oxygen of the scissile phosphate. These contacts, however, are not fully resolved in the crystal structure, and biochemical data are not able to unambiguously exclude other mechanistic models. In order to explore the feasibility of this model, we exhaustively mapped the free energy surfaces with different active site ion occupancies via quantum mechanical/molecular mechanical (QM/MM) simulations. We further incorporate a three-dimensional reference interaction site model for the solvated ion atmosphere that allows these calculations to consider not only the rate associated with the chemical steps, but also the probability of observing the system in the presumed active state with the Mg(2+) ion bound. The QM/MM results predict that a pathway involving metal-assisted nucleophile activation is feasible based on the rate-controlling transition state barrier departing from the presumed metal-bound active state. However, QM/MM results for a similar pathway in the absence of Mg(2+) are not consistent with experimental data, suggesting that a structural model in which the crystallographically determined Mg(2+) is simply replaced with Na(+) is likely incorrect. It should be emphasized, however, that these results hinge upon the assumption of the validity of the presumed Mg(2+)-bound starting state, which has not yet been definitively verified experimentally, nor explored in depth computationally. Thus, further experimental and theoretical study is needed such that a consensus view of the catalytic mechanism emerges.
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Affiliation(s)
- Brian K Radak
- Center for Integrative Proteomics Research and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854-8076, USA Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455-0431, USA
| | - Tai-Sung Lee
- Center for Integrative Proteomics Research and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854-8076, USA
| | - Michael E Harris
- Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA
| | - Darrin M York
- Center for Integrative Proteomics Research and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854-8076, USA
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36
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Strobel B, Klauser B, Hartig JS, Lamla T, Gantner F, Kreuz S. Riboswitch-mediated Attenuation of Transgene Cytotoxicity Increases Adeno-associated Virus Vector Yields in HEK-293 Cells. Mol Ther 2015; 23:1582-91. [PMID: 26137851 DOI: 10.1038/mt.2015.123] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 06/21/2015] [Indexed: 01/24/2023] Open
Abstract
Cytotoxicity of transgenes carried by adeno-associated virus (AAV) vectors might be desired, for instance, in oncolytic virotherapy or occur unexpectedly in exploratory research when studying sparsely characterized genes. To date, most AAV-based studies use constitutively active promoters (e.g., the CMV promoter) to drive transgene expression, which often hampers efficient AAV production due to cytotoxic, antiproliferative, or unknown transgene effects interfering with producer cell performance. Therefore, we explored artificial riboswitches as novel tools to control transgene expression during AAV production in mammalian cells. Our results demonstrate that the guanine-responsive GuaM8HDV aptazyme efficiently attenuates transgene expression and associated detrimental effects, thereby boosting AAV vector yields up to 23-fold after a single addition of guanine. Importantly, riboswitch-harboring vectors preserved their ability to express functional transgene at high levels in the absence of ligand, as demonstrated in a mouse model of AAV-TGFβ1-induced pulmonary fibrosis. Thus, our study provides the first application-ready biotechnological system-based on aptazymes, which should enable high viral vector yields largely independent of the transgene used. Moreover, the RNA-intrinsic, small-molecule regulatable mode of action of riboswitches provides key advantages over conventional transcription factor-based regulatory systems. Therefore, such riboswitch vectors might be ultimately applied to temporally control therapeutic transgene expression in vivo.
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Affiliation(s)
- Benjamin Strobel
- Target Discovery Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Benedikt Klauser
- Department of Chemistry, University of Konstanz, Konstanz, Germany
| | - Jörg S Hartig
- Department of Chemistry, University of Konstanz, Konstanz, Germany
| | - Thorsten Lamla
- Target Discovery Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Florian Gantner
- Translational Medicine and Clinical Pharmacology, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Sebastian Kreuz
- Respiratory Diseases Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
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Kapral GJ, Jain S, Noeske J, Doudna JA, Richardson DC, Richardson JS. New tools provide a second look at HDV ribozyme structure, dynamics and cleavage. Nucleic Acids Res 2014; 42:12833-46. [PMID: 25326328 PMCID: PMC4227795 DOI: 10.1093/nar/gku992] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The hepatitis delta virus (HDV) ribozyme is a self-cleaving RNA enzyme essential for processing viral transcripts during rolling circle viral replication. The first crystal structure of the cleaved ribozyme was solved in 1998, followed by structures of uncleaved, mutant-inhibited and ion-complexed forms. Recently, methods have been developed that make the task of modeling RNA structure and dynamics significantly easier and more reliable. We have used ERRASER and PHENIX to rebuild and re-refine the cleaved and cis-acting C75U-inhibited structures of the HDV ribozyme. The results correct local conformations and identify alternates for RNA residues, many in functionally important regions, leading to improved R values and model validation statistics for both structures. We compare the rebuilt structures to a higher resolution, trans-acting deoxy-inhibited structure of the ribozyme, and conclude that although both inhibited structures are consistent with the currently accepted hammerhead-like mechanism of cleavage, they do not add direct structural evidence to the biochemical and modeling data. However, the rebuilt structures (PDBs: 4PR6, 4PRF) provide a more robust starting point for research on the dynamics and catalytic mechanism of the HDV ribozyme and demonstrate the power of new techniques to make significant improvements in RNA structures that impact biologically relevant conclusions.
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Affiliation(s)
- Gary J Kapral
- Department of Biochemistry, Duke University, Durham, NC 27710, USA
| | - Swati Jain
- Department of Biochemistry, Duke University, Durham, NC 27710, USA Program in Computational Biology and Bioinformatics, Duke University, Durham, NC 27710, USA
| | - Jonas Noeske
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720, USA
| | - Jennifer A Doudna
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720, USA
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Chung SH, Baek C, Cong VT, Min J. The microfluidic chip module for the detection of murine norovirus in oysters using charge switchable micro-bead beating. Biosens Bioelectron 2014; 67:625-33. [PMID: 25449875 DOI: 10.1016/j.bios.2014.09.083] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 08/28/2014] [Accepted: 09/22/2014] [Indexed: 01/01/2023]
Abstract
Sample preparation has recently been an issue in the detection of food poisoning pathogens, particularly viruses such as norovirus (NoV), in food because of the complexity of foods and raw fresh materials. Here, we demonstrate a total analytical microfluidic chip module to automatically perform a series of essential processes (cell concentration, lysis (RNA extraction), nucleic acid amplification, and detection) for the fast but sensitive detection of norovirus in oysters. The murine NoV spiked oyster was stomached using a standard method. The supernatant was first loaded into a shape switchable sample preparation chamber consisting of charge switchable micro-beads. Murine NoV, which was adsorbed on microbeads by electrostatic physisorption, was lysed using bead beating. The extracted RNA was transferred to the detection chamber to be amplified using Nucleic Acid Sequence Based Amplification (NASBA). The optimal surface functionality, size, and number of microbeads were achieved for the virus concentration and the stable RNA extraction in the shape-switchable micro-channel. As a result, murine NoV in a single oyster was successfully detected within 4h by the microfluidic chip developed here, and could be directly applied to the large volume environmental sample as well as the food sample.
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Affiliation(s)
- Sung Hee Chung
- School of Integrative Engineering, Chung-Ang University, Heuksuk-dong, Dongjak-gu, Seoul 156-756, Republic of Korea
| | - Changyoon Baek
- School of Integrative Engineering, Chung-Ang University, Heuksuk-dong, Dongjak-gu, Seoul 156-756, Republic of Korea
| | - Vu Tan Cong
- School of Integrative Engineering, Chung-Ang University, Heuksuk-dong, Dongjak-gu, Seoul 156-756, Republic of Korea
| | - Junhong Min
- School of Integrative Engineering, Chung-Ang University, Heuksuk-dong, Dongjak-gu, Seoul 156-756, Republic of Korea.
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39
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Riccitelli N, Lupták A. HDV family of self-cleaving ribozymes. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2014; 120:123-71. [PMID: 24156943 DOI: 10.1016/b978-0-12-381286-5.00004-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The hepatitis delta virus (HDV) ribozymes are catalytic RNAs capable of cleaving their own sugar-phosphate backbone. The HDV virus possesses the ribozymes in both sense and antisense genomic transcripts, where they are essential for processing during replication. These ribozymes have been the subject of intense biochemical scrutiny and have yielded a wealth of mechanistic insights. In recent years, many HDV-like ribozymes have been identified in nearly all branches of life. The ribozymes are implicated in a variety of biological events, including episodic memory in mammals and retrotransposition in many eukaryotes. Detailed analysis of additional HDV-like ribozyme isolates will likely reveal many more biological functions and provide information about the evolution of this unique RNA.
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Affiliation(s)
- Nathan Riccitelli
- Department of Chemistry, University of California, Irvine, California, USA
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40
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Kodani M, Martin A, Mixson-Hayden T, Drobeniuc J, Gish RR, Kamili S. One-step real-time PCR assay for detection and quantitation of hepatitis D virus RNA. J Virol Methods 2013; 193:531-5. [PMID: 23896020 DOI: 10.1016/j.jviromet.2013.07.033] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 07/11/2013] [Accepted: 07/18/2013] [Indexed: 12/28/2022]
Abstract
Hepatitis D virus (HDV) is a defective virus which requires hepatitis B virus (HBV) surface antigen (HBsAg) for its assembly. Hepatitis B infected individuals co-infected or superinfected with HDV often present with more severe hepatitis, progress faster to liver disease, and have a higher mortality rate than individuals infected with HBV alone. Currently, there are no commercially available clinical tests for the detection and quantitation of HDV RNA in the United States. A one-step TaqMan quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assay was developed for detection of HDV RNA, designing primers located in the region just downstream from the HDV antigen gene. The assay has the potential to detect all eight HDV genotypes. A quantifiable synthetic RNA control was also developed for use in the determination of HDV RNA titers in clinical samples. The limit of detection of this assay is 7.5×10(2) HDV RNA copies/ml with a dynamic range of six logs. Most clinical specimens tested (40/41) fell within the linear range of the assay. The median HDV RNA titer of the tested specimens was 6.24×10(6) copies/ml, with a range of 8.52×10(3)-1.79×10(9) copies/ml. Out of 132 anti-HDV-positive specimens 41 (31.1%) were positive for HDV RNA.
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Affiliation(s)
- Maja Kodani
- Division of Viral Hepatitis, National Center for HIV, Hepatitis, STD and Tuberculosis Prevention, Centers for Disease Control and Prevention, Atlanta, GA 30333, United States
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41
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Karayiannis P. Direct acting antivirals for the treatment of chronic viral hepatitis. SCIENTIFICA 2012; 2012:478631. [PMID: 24278700 PMCID: PMC3820491 DOI: 10.6064/2012/478631] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Accepted: 10/08/2012] [Indexed: 06/02/2023]
Abstract
The development and evaluation of antiviral agents through carefully designed clinical trials over the last 25 years have heralded a new dawn in the treatment of patients chronically infected with the hepatitis B and C viruses, but not so for the D virus (HBV, HCV, and HDV). The introduction of direct acting antivirals (DDAs) for the treatment of HBV carriers has permitted the long-term use of these compounds for the continuous suppression of viral replication, whilst in the case of HCV in combination with the standard of care [SOC, pegylated interferon (PegIFN), and ribavirin] sustained virological responses (SVRs) have been achieved with increasing frequency. Progress in the case of HDV has been slow and lacking in significant breakthroughs.This paper aims to summarise the current state of play in treatment approaches for chonic viral hepatitis patients and future perspectives.
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Affiliation(s)
- Peter Karayiannis
- Section of Hepatology and Gastroenterology, Department of Medicine, Imperial College, St Mary's Campus, London W2 1PG, UK
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42
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Fürtig B, Buck J, Richter C, Schwalbe H. Functional dynamics of RNA ribozymes studied by NMR spectroscopy. Methods Mol Biol 2012; 848:185-199. [PMID: 22315070 DOI: 10.1007/978-1-61779-545-9_12] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Catalytic RNA motifs (ribozymes) are involved in various cellular processes. Although functional cleavage of the RNA phosphodiester backbone for self-cleaving ribozymes strongly differs with respect to sequence specificity, the structural context, and the underlying mechanism, these ribozyme motifs constitute evolved RNA molecules that carry out identical chemical functionality. Therefore, they represent ideal systems for detailed studies of the underlying structure-function relationship, illustrating the diversity of RNA's functional role in biology. Nuclear magnetic resonance (NMR) spectroscopic methods in solution allow investigation of structure and dynamics of functional RNA motifs at atomic resolution. In addition, characterization of RNA conformational transitions initiated either through addition of specific cofactors, as e.g. ions or small molecules, or by photo-chemical triggering of essential RNA functional groups provides insights into the reaction mechanism. Here, we discuss applications of static and time-resolved NMR spectroscopy connected with the design of suitable NMR probes that have been applied to characterize global and local RNA functional dynamics together with cleavage-induced conformational transitions of two RNA ribozyme motifs: a minimal hammerhead ribozyme and an adenine-dependent hairpin ribozyme.
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Affiliation(s)
- Boris Fürtig
- Institute of Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe-University, Frankfurt am Main, Germany
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43
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Grimpe B. Deoxyribozymes and bioinformatics: complementary tools to investigate axon regeneration. Cell Tissue Res 2011; 349:181-200. [PMID: 22190188 PMCID: PMC7087747 DOI: 10.1007/s00441-011-1291-6] [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: 09/08/2011] [Accepted: 11/17/2011] [Indexed: 11/28/2022]
Abstract
For over 100 years, scientists have tried to understand the mechanisms that lead to the axonal growth seen during development or the lack thereof during regeneration failure after spinal cord injury (SCI). Deoxyribozyme technology as a potential therapeutic to treat SCIs or other insults to the brain, combined with a bioinformatics approach to comprehend the complex protein-protein interactions that occur after such trauma, is the focus of this review. The reader will be provided with information on the selection process of deoxyribozymes and their catalytic sequences, on the mechanism of target digestion, on modifications, on cellular uptake and on therapeutic applications and deoxyribozymes are compared with ribozymes, siRNAs and antisense technology. This gives the reader the necessary knowledge to decide which technology is adequate for the problem at hand and to design a relevant agent. Bioinformatics helps to identify not only key players in the complex processes that occur after SCI but also novel or less-well investigated molecules against which new knockdown agents can be generated. These two tools used synergistically should facilitate the pursuit of a treatment for insults to the central nervous system.
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Affiliation(s)
- Barbara Grimpe
- Applied Neurobiology, Department of Neurology, Heinrich Heine University Düsseldorf, Moorenstrasse 5, 40225 Düsseldorf, Germany.
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44
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Lee TS, Giambaşu G, Harris ME, York DM. Characterization of the Structure and Dynamics of the HDV Ribozyme at Different Stages Along the Reaction Path. J Phys Chem Lett 2011; 2:2538-2543. [PMID: 22200005 PMCID: PMC3244300 DOI: 10.1021/jz201106y] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The structure and dynamics of the hepatitis delta virus ribozyme (HDVr) are studies using molecular dynamics simulations at several stages along its catalytic reaction path, including reactant, activated precursor, transition state mimic and product states, departing from an initial structure based on the C75U mutant crystal structure (PDB: 1VC7). Results of five 350 ns molecular dynamics simulations reveal a spontaneous rotation of U-1 that leads to an in-line conformation and support the role of protonated C75 as the general acid in the transition state. Our results provide rationale for the interpretation of several important experimental results, and make experimentally testable predictions regarding the roles of key active site residues that are not obvious from any available crystal structures.
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45
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Abstract
HDV ribozymes catalyze their own scission from the transcript during rolling circle replication of the hepatitis delta virus. In vitro selection of self-cleaving ribozymes from a human genomic library revealed an HDV-like ribozyme in the second intron of the human CPEB3 gene and recent results suggest that this RNA affects episodic memory performance. Bioinformatic searches based on the secondary structure of the HDV/CPEB3 fold yielded numerous functional ribozymes in a wide variety of organisms. Genomic mapping of these RNAs suggested several biological roles, one of which is the 5' processing of non-LTR retrotransposons. The family of HDV-like ribozymes thus continues to grow in numbers and biological importance.
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Affiliation(s)
- Chiu-Ho T Webb
- Department of Molecular Biology, University of California, Irvine, CA, USA
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46
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Abstract
Hepatitis delta virus (HDV) is a small, defective RNA virus that can infect only individuals who have hepatitis B virus (HBV); worldwide more than 15 million people are co-infected. There are eight reported genotypes of HDV with unexplained variations in their geographical distribution and pathogenicity. The hepatitis D virion is composed of a coat of HBV envelope proteins surrounding the nucleocapsid, which consists of a single-stranded, circular RNA genome complexed with delta antigen, the viral protein. HDV is clinically important because although it suppresses HBV replication, it causes severe liver disease with rapid progression to cirrhosis and hepatic decompensation. The range of clinical presentation is wide, varying from mild disease to fulminant liver failure. The prevalence of HDV is declining in some endemic areas but increasing in northern and central Europe because of immigration. Treatment of HDV is with pegylated interferon alfa; however, response rates are poor. Increased understanding of the molecular virology of HDV will identify novel therapeutic targets for this most severe form of chronic viral hepatitis.
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Affiliation(s)
- Sarah A Hughes
- Institute of Liver Studies, King's College Hospital, London, UK
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47
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Jimenez RM, Delwart E, Lupták A. Structure-based search reveals hammerhead ribozymes in the human microbiome. J Biol Chem 2011; 286:7737-7743. [PMID: 21257745 DOI: 10.1074/jbc.c110.209288] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Deep sequencing of viral or bacterial nucleic acids monitors the presence and diversity of microbes in select populations and locations. Metagenomic study of mammalian viromes can help trace paths of viral transmissions within or between species. High throughput sequencing of patient and untreated sewage microbiomes showed many sequences with no similarity to genomic sequences of known function or origin. To estimate the distribution of functional RNAs in these microbiomes, we used the hammerhead ribozyme (HHR) motif to search for sequences capable of assuming its three-way junction fold. Although only two of the three possible natural HHR topologies had been known, our analysis revealed highly active ribozymes that terminated in any of the three stems. The most abundant of these are type II HHRs, one of which is the fastest natural cis-acting HHR yet discovered. Altogether, 13 ribozymes were confirmed in vitro, but only one showed sequence similarity to previously described HHRs. Sequences surrounding the ribozymes do not generally show similarity to known genes, except in one case, where a ribozyme is immediately preceded by a bacterial RadC gene. We demonstrate that a structure-based search for a known functional RNA is a powerful tool for analysis of metagenomic datasets, complementing sequence alignments.
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Affiliation(s)
| | - Eric Delwart
- the Blood Systems Research Institute and; Department of Laboratory Medicine, University of California, San Francisco, California 94118
| | - Andrej Lupták
- From the Departments of Pharmaceutical Sciences,; Chemistry, and; Molecular Biology and Biochemistry, University of California, Irvine, California 92697 and.
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48
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Johnson-Buck AE, McDowell SE, Walter NG. Metal ions: supporting actors in the playbook of small ribozymes. Met Ions Life Sci 2011; 9:175-96. [PMID: 22010272 DOI: 10.1039/9781849732512-00175] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Since the 1980s, several small RNA motifs capable of chemical catalysis have been discovered. These small ribozymes, composed of between approximately 40 and 200 nucleotides, have been found to play vital roles in the replication of subviral and viral pathogens, as well as in gene regulation in prokaryotes, and have recently been discovered in noncoding eukaryotic RNAs. All of the known natural small ribozymes - the hairpin, hammerhead, hepatitis delta virus, Varkud satellite, and glmS ribozymes--catalyze the same self-cleavage reaction as RNase A, resulting in two products, one bearing a 2'-3' cyclic phosphate and the other a 5'-hydroxyl group. Although originally thought to be obligate metalloenzymes like the group I and II self-splicing introns, the small ribozymes are now known to support catalysis in a wide variety of cations that appear to be only indirectly involved in catalysis. Nevertheless, under physiologic conditions, metal ions are essential for the proper folding and function of the small ribozymes, the most effective of these being magnesium. Metal ions contribute to catalysis in the small ribozymes primarily by stabilizing the catalytically active conformation, but in some cases also by activating RNA functional groups for catalysis, directly participating in catalytic acid-base chemistry, and perhaps by neutralizing the developing negative charge of the transition state. Although interactions between the small ribozymes and cations are relatively nonspecific, ribozyme activity is quite sensitive to the types and concentrations of metal ions present in solution, suggesting a close evolutionary relationship between cellular metal ion homeostasis and cation requirements of catalytic RNAs, and perhaps RNA in general.
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Affiliation(s)
- Alexander E Johnson-Buck
- Department of Chemistry, University of Michigan, 930 N. University, Ann Arbor, MI 48109-1055, USA.
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49
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Seehafer C, Kalweit A, Steger G, Gräf S, Hammann C. From alpaca to zebrafish: hammerhead ribozymes wherever you look. RNA (NEW YORK, N.Y.) 2011; 17:21-6. [PMID: 21081661 PMCID: PMC3004062 DOI: 10.1261/rna.2429911] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The hammerhead ribozyme was originally discovered in subviral plant pathogens and was subsequently also found in a few other genomic locations. Using a secondary structure-based descriptor, we have searched publicly accessible sequence databases for new examples of type III hammerhead ribozymes. The more than 60,000 entries fulfilling the descriptor were filtered with respect to folding and stability parameters that were experimentally validated. This resulted in a set of 284 unique motifs, of which 124 represent database entries of known hammerhead ribozymes from subviral plant pathogens and A. thaliana. The remainder are 160 novel ribozyme candidates in 50 different eukaryotic genomes. With a few exceptions, the ribozymes were found either in repetitive DNA sequences or in introns of protein coding genes. Our data, which is complementary to a study by De la Peña and García-Robles in 2010, indicate that the hammerhead is the most abundant small endonucleolytic ribozyme, which, in view of no sequence conservation beyond the essential nucleotides, likely has evolved independently in different organisms.
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50
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Chadalavada DM, Gratton EA, Bevilacqua PC. The human HDV-like CPEB3 ribozyme is intrinsically fast-reacting. Biochemistry 2010; 49:5321-30. [PMID: 20524672 DOI: 10.1021/bi100434c] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Self-cleaving RNAs have recently been identified in mammalian genomes. A small ribozyme related in structure to the hepatitis delta virus (HDV) ribozyme occurs in a number of mammals, including chimpanzees and humans, within an intron of the CPEB3 gene. The catalytic mechanisms for the CPEB3 and HDV ribozymes appear to be similar, generating cleavage products with 5'-hydroxyl and 2',3'-cyclic phosphate termini; nonetheless, the cleavage rate reported for the CPEB3 ribozyme is more than 6000-fold slower than for the fastest HDV ribozyme. Herein, we use full-length RNA and cotranscriptional self-cleavage assays to compare reaction rates among human CPEB3, chimp CPEB3, and HDV ribozymes. Our data reveal that a single base change of the upstream flanking sequence, which sequesters an intrinsically weak P1.1 pairing in a misfold, increases the rate of the wild-type human CPEB3 ribozyme by approximately 250-fold; thus, the human ribozyme is intrinsically fast-reacting. Secondary structure determination and native gel analyses reveal that the cleaved population of the CPEB3 ribozyme has a single, secondary structure that closely resembles the HDV ribozyme. In contrast, the precleavage population of the CPEB3 ribozyme appears to have a more diverse secondary structure, possibly reflecting misfolding with the upstream sequence and dynamics intrinsic to the ribozyme. Prior identification of expressed sequence tags (ESTs) in human cells indicated that cleavage activity of the human ribozyme is tissue-specific. It is therefore possible that cellular factors interact with regions upstream of the CPEB3 ribozyme to unmask its high intrinsic reactivity.
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Affiliation(s)
- Durga M Chadalavada
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
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