1
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Mathez G, Cagno V. Small Molecules Targeting Viral RNA. Int J Mol Sci 2023; 24:13500. [PMID: 37686306 PMCID: PMC10487773 DOI: 10.3390/ijms241713500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 08/25/2023] [Accepted: 08/28/2023] [Indexed: 09/10/2023] Open
Abstract
The majority of antivirals available target viral proteins; however, RNA is emerging as a new and promising antiviral target due to the presence of highly structured RNA in viral genomes fundamental for their replication cycle. Here, we discuss methods for the identification of RNA-targeting compounds, starting from the determination of RNA structures either from purified RNA or in living cells, followed by in silico screening on RNA and phenotypic assays to evaluate viral inhibition. Moreover, we review the small molecules known to target the programmed ribosomal frameshifting element of SARS-CoV-2, the internal ribosomal entry site of different viruses, and RNA elements of HIV.
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Affiliation(s)
| | - Valeria Cagno
- Institute of Microbiology, University Hospital of Lausanne, University of Lausanne, 1011 Lausanne, Switzerland
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2
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Sekar RV, Oliva PJ, Woodside MT. Modelling the structures of frameshift-stimulatory pseudoknots from representative bat coronaviruses. PLoS Comput Biol 2023; 19:e1011124. [PMID: 37205708 DOI: 10.1371/journal.pcbi.1011124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 04/24/2023] [Indexed: 05/21/2023] Open
Abstract
Coronaviruses (CoVs) use -1 programmed ribosomal frameshifting stimulated by RNA pseudoknots in the viral genome to control expression of enzymes essential for replication, making CoV pseudoknots a promising target for anti-coronaviral drugs. Bats represent one of the largest reservoirs of CoVs and are the ultimate source of most CoVs infecting humans, including those causing SARS, MERS, and COVID-19. However, the structures of bat-CoV frameshift-stimulatory pseudoknots remain largely unexplored. Here we use a combination of blind structure prediction followed by all-atom molecular dynamics simulations to model the structures of eight pseudoknots that, together with the SARS-CoV-2 pseudoknot, are representative of the range of pseudoknot sequences in bat CoVs. We find that they all share some key qualitative features with the pseudoknot from SARS-CoV-2, notably the presence of conformers with two distinct fold topologies differing in whether or not the 5' end of the RNA is threaded through a junction, and similar conformations for stem 1. However, they differed in the number of helices present, with half sharing the 3-helix architecture of the SARS-CoV-2 pseudoknot but two containing 4 helices and two others only 2. These structure models should be helpful for future work studying bat-CoV pseudoknots as potential therapeutic targets.
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Affiliation(s)
| | | | - Michael T Woodside
- Department of Physics, University of Alberta, Edmonton, Canada
- Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Canada
- Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Canada
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3
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Wu MC, Li MZ, Chen YX, Liu F, Xiao JA, Chen K, Xiang HY, Yang H. Photoredox-Catalyzed C–H Trideuteromethylation of Quinoxalin-2(1 H)-ones with CDCl 3 as the “CD 3” source. Org Lett 2022; 24:6412-6416. [DOI: 10.1021/acs.orglett.2c02439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Mei-Chun Wu
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China
- College of Chemistry and Chemical Engineering, Huaihua University, Huaihua 418008, P. R. China
| | - Ming-Zhi Li
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China
| | - Yi-Xuan Chen
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China
| | - Fang Liu
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China
| | - Jun-An Xiao
- College of Chemistry and Materials Science, Nanning Normal University, Nanning 530001, P. R. China
| | - Kai Chen
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China
| | - Hao-Yue Xiang
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China
- School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, P. R. China
| | - Hua Yang
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China
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4
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Benner BE, Bruce JW, Kentala JR, Murray M, Becker JT, Garcia-Miranda P, Ahlquist P, Butcher SE, Sherer NM. Perturbing HIV-1 Ribosomal Frameshifting Frequency Reveals a cis Preference for Gag-Pol Incorporation into Assembling Virions. J Virol 2022; 96:e0134921. [PMID: 34643428 PMCID: PMC8754204 DOI: 10.1128/jvi.01349-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 09/30/2021] [Indexed: 12/29/2022] Open
Abstract
HIV-1 virion production is driven by Gag and Gag-Pol (GP) proteins, with Gag forming the bulk of the capsid and driving budding, while GP binds Gag to deliver the essential virion enzymes protease, reverse transcriptase, and integrase. Virion GP levels are traditionally thought to reflect the relative abundances of GP and Gag in cells (∼1:20), dictated by the frequency of a -1 programmed ribosomal frameshifting (PRF) event occurring in gag-pol mRNAs. Here, we exploited a panel of PRF mutant viruses to show that mechanisms in addition to PRF regulate GP incorporation into virions. First, we show that GP is enriched ∼3-fold in virions relative to cells, with viral infectivity being better maintained at subphysiological levels of GP than when GP levels are too high. Second, we report that GP is more efficiently incorporated into virions when Gag and GP are synthesized in cis (i.e., from the same gag-pol mRNA) than in trans, suggesting that Gag/GP translation and assembly are spatially coupled processes. Third, we show that, surprisingly, virions exhibit a strong upper limit to trans-delivered GP incorporation; an adaptation that appears to allow the virus to temper defects to GP/Gag cleavage that may negatively impact reverse transcription. Taking these results together, we propose a "weighted Goldilocks" scenario for HIV-1 GP incorporation, wherein combined mechanisms of GP enrichment and exclusion buffer virion infectivity over a broad range of local GP concentrations. These results provide new insights into the HIV-1 virion assembly pathway relevant to the anticipated efficacy of PRF-targeted antiviral strategies. IMPORTANCE HIV-1 infectivity requires incorporation of the Gag-Pol (GP) precursor polyprotein into virions during the process of virus particle assembly. Mechanisms dictating GP incorporation into assembling virions are poorly defined, with GP levels in virions traditionally thought to solely reflect relative levels of Gag and GP expressed in cells, dictated by the frequency of a -1 programmed ribosomal frameshifting (PRF) event that occurs in gag-pol mRNAs. Herein, we provide experimental support for a "weighted Goldilocks" scenario for GP incorporation, wherein the virus exploits both random and nonrandom mechanisms to buffer infectivity over a wide range of GP expression levels. These mechanistic data are relevant to ongoing efforts to develop antiviral strategies targeting PRF frequency and/or HIV-1 virion maturation.
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Affiliation(s)
- Bayleigh E. Benner
- Department of Oncology (McArdle Laboratory for Cancer Research), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin—Madison, Madison, Wisconsin, USA
- UW—Madison Microbiology Doctoral Training Program, Madison, Wisconsin, USA
| | - James W. Bruce
- Department of Oncology (McArdle Laboratory for Cancer Research), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin—Madison, Madison, Wisconsin, USA
- John and Jeanne Rowe Center for Research in Virology, Morgridge Institute for Research, Madison, Wisconsin, USA
| | - Jacob R. Kentala
- Department of Oncology (McArdle Laboratory for Cancer Research), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin—Madison, Madison, Wisconsin, USA
| | - Magdalena Murray
- Department of Oncology (McArdle Laboratory for Cancer Research), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin—Madison, Madison, Wisconsin, USA
| | - Jordan T. Becker
- Department of Oncology (McArdle Laboratory for Cancer Research), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin—Madison, Madison, Wisconsin, USA
| | - Pablo Garcia-Miranda
- Department of Oncology (McArdle Laboratory for Cancer Research), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin—Madison, Madison, Wisconsin, USA
- Department of Biochemistry, University of Wisconsin—Madison, Madison, Wisconsin, USA
| | - Paul Ahlquist
- Department of Oncology (McArdle Laboratory for Cancer Research), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin—Madison, Madison, Wisconsin, USA
- John and Jeanne Rowe Center for Research in Virology, Morgridge Institute for Research, Madison, Wisconsin, USA
| | - Samuel E. Butcher
- Department of Biochemistry, University of Wisconsin—Madison, Madison, Wisconsin, USA
| | - Nathan M. Sherer
- Department of Oncology (McArdle Laboratory for Cancer Research), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin—Madison, Madison, Wisconsin, USA
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5
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Anokhina VS, Miller BL. Targeting Ribosomal Frameshifting as an Antiviral Strategy: From HIV-1 to SARS-CoV-2. Acc Chem Res 2021; 54:3349-3361. [PMID: 34403258 DOI: 10.1021/acs.accounts.1c00316] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Treatment of HIV-1 has largely involved targeting viral enzymes using a cocktail of inhibitors. However, resistance to these inhibitors and toxicity in the long term have pushed the field to identify new therapeutic targets. To that end, -1 programmed ribosomal frameshifting (-1 PRF) has gained attention as a potential node for therapeutic intervention. In this process, a ribosome moves one nucleotide backward in the course of translating a mRNA, revealing a new reading frame for protein synthesis. In HIV-1, -1 PRF allows the virus to regulate the ratios of enzymatic and structural proteins as needed for correct viral particle assembly. Two RNA structural elements are central to -1 PRF in HIV: a slippery sequence and a highly conserved stable hairpin called the HIV-1 frameshifting stimulatory signal (FSS). Dysregulation of -1 PRF is deleterious for the virus. Thus, -1 PRF is an attractive target for new antiviral development. It is important to note that HIV-1 is not the only virus exploiting -1 PRF for regulating production of its proteins. Coronaviruses, including the COVID-19 pandemic virus SARS-CoV-2, also rely on -1 PRF. In SARS-CoV-2 and other coronaviruses, -1 PRF is required for synthesis of RNA-dependent RNA polymerase and several other nonstructural proteins. Coronaviruses employ a more complex RNA structural element for regulating -1 PRF called a pseudoknot. The purpose of this Account is primarily to review the development of molecules targeting HIV-1 -1 PRF. These approaches are case studies illustrating how the entire pipeline from screening to the generation of high-affinity leads might be implemented. We consider both target-based and function-based screening, with a particular focus on our group's approach beginning with a resin-bound dynamic combinatorial library (RBDCL) screen. We then used rational design approaches to optimize binding affinity, selectivity, and cellular bioavailability. Our tactic is, to the best of our knowledge, the only study resulting in compounds that bind specifically to the HIV-1 FSS RNA and reduce infectivity of laboratory and drug-resistant strains of HIV-1 in human cells. Lessons learned from strategies targeting -1 PRF HIV-1 might provide solutions in the development of antivirals in areas of unmet medical need. This includes the development of new frameshift-altering therapies for SARS-CoV-2, approaches to which are very recently beginning to appear.
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Affiliation(s)
- Viktoriya S. Anokhina
- Department of Biochemistry and Biophysics, University of Rochester, Rochester, New York 14642, United States
| | - Benjamin L. Miller
- Department of Biochemistry and Biophysics, University of Rochester, Rochester, New York 14642, United States
- Department of Dermatology, University of Rochester, Rochester, New York 14642, United States
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6
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Steverlynck J, Sitdikov R, Rueping M. The Deuterated "Magic Methyl" Group: A Guide to Site-Selective Trideuteromethyl Incorporation and Labeling by Using CD 3 Reagents. Chemistry 2021; 27:11751-11772. [PMID: 34076925 PMCID: PMC8457246 DOI: 10.1002/chem.202101179] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Indexed: 12/12/2022]
Abstract
In the field of medicinal chemistry, the precise installation of a trideuteromethyl group is gaining ever-increasing attention. Site-selective incorporation of the deuterated "magic methyl" group can provide profound pharmacological benefits and can be considered an important tool for drug optimization and development. This review provides a structured overview, according to trideuteromethylation reagent, of currently established methods for site-selective trideuteromethylation of carbon atoms. In addition to CD3 , the selective introduction of CD2 H and CDH2 groups is also considered. For all methods, the corresponding mechanism and scope are discussed whenever reported. As such, this review can be a starting point for synthetic chemists to further advance trideuteromethylation methodologies. At the same time, this review aims to be a guide for medicinal chemists, offering them the available C-CD3 formation strategies for the preparation of new or modified drugs.
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Affiliation(s)
- Joost Steverlynck
- Kaust Catalysis Center (KCC)King Abdullah University Science and Technology (KAUST)Thuwal23955-6900Saudi Arabia
| | - Ruzal Sitdikov
- Kaust Catalysis Center (KCC)King Abdullah University Science and Technology (KAUST)Thuwal23955-6900Saudi Arabia
| | - Magnus Rueping
- Kaust Catalysis Center (KCC)King Abdullah University Science and Technology (KAUST)Thuwal23955-6900Saudi Arabia
- Institute for Experimental Molecular ImagingRWTH Aachen UniversityForckenbeckstrasse 5552074Aachen
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7
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Neupane K, Munshi S, Zhao M, Ritchie DB, Ileperuma SM, Woodside MT. Anti-Frameshifting Ligand Active against SARS Coronavirus-2 Is Resistant to Natural Mutations of the Frameshift-Stimulatory Pseudoknot. J Mol Biol 2020; 432:5843-5847. [PMID: 32920049 PMCID: PMC7483078 DOI: 10.1016/j.jmb.2020.09.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 09/03/2020] [Accepted: 09/05/2020] [Indexed: 01/23/2023]
Abstract
SARS-CoV-2 uses −1 programmed ribosomal frameshifting (−1 PRF) to control expression of key viral proteins. Because modulating −1 PRF can attenuate the virus, ligands binding to the RNA pseudoknot that stimulates −1 PRF may have therapeutic potential. Mutations in the pseudoknot have occurred during the pandemic, but how they affect −1 PRF efficiency and ligand activity is unknown. Studying a panel of six mutations in key regions of the pseudoknot, we found that most did not change −1 PRF levels, even when base-pairing was disrupted, but one led to a striking 3-fold decrease, suggesting SARS-CoV-2 may be less sensitive to −1 PRF modulation than expected. Examining the effects of a small-molecule −1 PRF inhibitor active against SARS-CoV-2, it had a similar effect on all mutants tested, regardless of basal −1 PRF efficiency, indicating that anti-frameshifting activity can be resistant to natural pseudoknot mutations. These results have important implications for therapeutic strategies targeting SARS-CoV-2 through modulation of −1 PRF.
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Affiliation(s)
- Krishna Neupane
- Department of Physics, University of Alberta, Edmonton, AB T6G 2E1, Canada
| | - Sneha Munshi
- Department of Physics, University of Alberta, Edmonton, AB T6G 2E1, Canada
| | - Meng Zhao
- Department of Physics, University of Alberta, Edmonton, AB T6G 2E1, Canada
| | - Dustin B Ritchie
- Department of Physics, University of Alberta, Edmonton, AB T6G 2E1, Canada
| | | | - Michael T Woodside
- Department of Physics, University of Alberta, Edmonton, AB T6G 2E1, Canada.
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8
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Chen Y. Advances in the Synthesis of Methylated Products through Indirect Approaches. Adv Synth Catal 2019. [DOI: 10.1002/adsc.201901240] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Yantao Chen
- Medicinal Chemistry, Research and Early DevelopmentCardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca 43183 Gothenburg Sweden
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9
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Desterro J, Bak-Gordon P, Carmo-Fonseca M. Targeting mRNA processing as an anticancer strategy. Nat Rev Drug Discov 2019; 19:112-129. [PMID: 31554928 DOI: 10.1038/s41573-019-0042-3] [Citation(s) in RCA: 110] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/08/2019] [Indexed: 12/19/2022]
Abstract
Discoveries in the past decade have highlighted the potential of mRNA as a therapeutic target for cancer. Specifically, RNA sequencing revealed that, in addition to gene mutations, alterations in mRNA can contribute to the initiation and progression of cancer. Indeed, precursor mRNA processing, which includes the removal of introns by splicing and the formation of 3' ends by cleavage and polyadenylation, is frequently altered in tumours. These alterations result in numerous cancer-specific mRNAs that generate altered levels of normal proteins or proteins with new functions, leading to the activation of oncogenes or the inactivation of tumour-suppressor genes. Abnormally spliced and polyadenylated mRNAs are also associated with resistance to cancer treatment and, unexpectedly, certain cancers are highly sensitive to the pharmacological inhibition of splicing. This Review summarizes recent progress in our understanding of how splicing and polyadenylation are altered in cancer and highlights how this knowledge has been translated for drug discovery, resulting in the production of small molecules and oligonucleotides that modulate the spliceosome and are in clinical trials for the treatment of cancer.
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Affiliation(s)
- Joana Desterro
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.,Instituto Português de Oncologia de Lisboa, Serviço de Hematologia, Lisboa, Portugal
| | - Pedro Bak-Gordon
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Maria Carmo-Fonseca
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.
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10
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Morgan BS, Forte JE, Hargrove AE. Insights into the development of chemical probes for RNA. Nucleic Acids Res 2019; 46:8025-8037. [PMID: 30102391 PMCID: PMC6144806 DOI: 10.1093/nar/gky718] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 07/27/2018] [Indexed: 12/18/2022] Open
Abstract
Over the past decade, the RNA revolution has revealed thousands of non-coding RNAs that are essential for cellular regulation and are misregulated in disease. While the development of methods and tools to study these RNAs has been challenging, the power and promise of small molecule chemical probes is increasingly recognized. To harness existing knowledge, we compiled a list of 116 ligands with reported activity against RNA targets in biological systems (R-BIND). In this survey, we examine the RNA targets, design and discovery strategies, and chemical probe characterization techniques of these ligands. We discuss the applicability of current tools to identify and evaluate RNA-targeted chemical probes, suggest criteria to assess the quality of RNA chemical probes and targets, and propose areas where new tools are particularly needed. We anticipate that this knowledge will expedite the discovery of RNA-targeted ligands and the next phase of the RNA revolution.
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Affiliation(s)
| | - Jordan E Forte
- Department of Chemistry, Duke University, Durham, NC 27708, USA
| | - Amanda E Hargrove
- Department of Chemistry, Duke University, Durham, NC 27708, USA.,Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
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11
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Saavedra CJ, Carro C, Hernández D, Boto A. Conversion of “Customizable Units” into N-Alkyl Amino Acids and Generation of N-Alkyl Peptides. J Org Chem 2019; 84:8392-8410. [DOI: 10.1021/acs.joc.9b00114] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Carlos J. Saavedra
- Instituto de Productos Naturales y Agrobiología del CSIC, Avda. Astrofísico Francisco Sánchez 3, 38206 La Laguna, Tenerife, Spain
- BIOSIGMA, Antonio Domı́nguez Alfonso 16, 38003-Sta. Cruz de Tenerife, Tenerife, Spain
| | - Carmen Carro
- Instituto de Productos Naturales y Agrobiología del CSIC, Avda. Astrofísico Francisco Sánchez 3, 38206 La Laguna, Tenerife, Spain
- BIOSIGMA, Antonio Domı́nguez Alfonso 16, 38003-Sta. Cruz de Tenerife, Tenerife, Spain
| | - Dácil Hernández
- Instituto de Productos Naturales y Agrobiología del CSIC, Avda. Astrofísico Francisco Sánchez 3, 38206 La Laguna, Tenerife, Spain
| | - Alicia Boto
- Instituto de Productos Naturales y Agrobiología del CSIC, Avda. Astrofísico Francisco Sánchez 3, 38206 La Laguna, Tenerife, Spain
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12
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Umuhire Juru A, Patwardhan NN, Hargrove AE. Understanding the Contributions of Conformational Changes, Thermodynamics, and Kinetics of RNA-Small Molecule Interactions. ACS Chem Biol 2019; 14:824-838. [PMID: 31042354 DOI: 10.1021/acschembio.8b00945] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The implication of RNA in multiple cellular processes beyond protein coding has revitalized interest in the development of small molecules for therapeutically targeting RNA and for further probing its cellular biology. However, the process of rationally designing such small molecule probes is hampered by the paucity of information about fundamental molecular recognition principles of RNA. In this Review, we summarize two important and often underappreciated aspects of RNA-small molecule recognition: RNA conformational dynamics and the biophysical properties of interactions of small molecules with RNA, specifically thermodynamics and kinetics. While conformational flexibility is often said to impede RNA ligand development, the ability of small molecules to influence the RNA conformational landscape can have a significant effect on the cellular functions of RNA. An analysis of the conformational landscape of RNA and the interactions of individual conformations with ligands can thus guide the development of new small molecule probes, which needs to be investigated further. Additionally, while it is common practice to quantify the binding affinities ( Ka or Kd) of small molecules for biomacromolecules as a measure of their activity, further biophysical characterization of their interaction can provide a deeper understanding. Studies that focus on the thermodynamic and kinetic parameters for interaction between RNA and ligands are next discussed. Finally, this Review provides the reader with a perspective on how such in-depth analysis of biophysical characteristics of the interaction of RNA and small molecules can impact our understanding of these interactions and how they will benefit the future design of small molecule probes.
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Affiliation(s)
- Aline Umuhire Juru
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Neeraj N. Patwardhan
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Amanda E. Hargrove
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
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13
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Anokhina VS, McAnany JD, Ciesla JH, Hilimire TA, Santoso N, Miao H, Miller BL. Enhancing the ligand efficiency of anti-HIV compounds targeting frameshift-stimulating RNA. Bioorg Med Chem 2019; 27:2972-2977. [PMID: 31101492 DOI: 10.1016/j.bmc.2019.05.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 04/22/2019] [Accepted: 05/07/2019] [Indexed: 11/29/2022]
Abstract
Ribosomal frameshifting, a process whereby a translating ribosome is diverted from one reading frame to another on a contiguous mRNA, is an important regulatory mechanism in biology and an opportunity for therapeutic intervention in several human diseases. In HIV, ribosomal frameshifting controls the ratio of Gag and Gag-Pol, two polyproteins critical to the HIV life cycle. We have previously reported compounds able to selectively bind an RNA stemloop within the Gag-Pol mRNA; these compounds alter the production of Gag-Pol in a manner consistent with increased frameshifting. Importantly, they also display antiretroviral activity in human T-cells. Here, we describe new compounds with significantly reduced molecular weight, but with substantially maintained affinity and anti-HIV activity. These results suggest that development of more "ligand efficient" enhancers of ribosomal frameshifting is an achievable goal.
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Affiliation(s)
- Viktoriya S Anokhina
- Department of Biochemistry and Biophysics, University of Rochester, Rochester, NY 14642, United States
| | - John D McAnany
- Department of Chemistry, University of Rochester, Rochester, NY 14642, United States
| | - Jessica H Ciesla
- Department of Biochemistry and Biophysics, University of Rochester, Rochester, NY 14642, United States
| | - Thomas A Hilimire
- Department of Biochemistry and Biophysics, University of Rochester, Rochester, NY 14642, United States
| | - Netty Santoso
- Department of Biostatistics, University of Rochester, Rochester, NY 14642, United States
| | - Hongyu Miao
- Department of Biostatistics and Data Science, School of Public Health, University of Texas Health Science Center at Houston, Houston, TX 77030, United States
| | - Benjamin L Miller
- Department of Biochemistry and Biophysics, University of Rochester, Rochester, NY 14642, United States; Department of Dermatology, University of Rochester, Rochester, NY 14642, United States.
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14
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Chen Y. Recent Advances in Methylation: A Guide for Selecting Methylation Reagents. Chemistry 2018; 25:3405-3439. [DOI: 10.1002/chem.201803642] [Citation(s) in RCA: 119] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Indexed: 11/10/2022]
Affiliation(s)
- Yantao Chen
- Medicinal Chemistry, Cardiovascular, Renal and Metabolism, IMED Biotech UnitAstraZeneca Gothenburg Sweden
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15
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Eubanks CS, Hargrove AE. RNA Structural Differentiation: Opportunities with Pattern Recognition. Biochemistry 2018; 58:199-213. [PMID: 30513196 DOI: 10.1021/acs.biochem.8b01090] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Our awareness and appreciation of the many regulatory roles of RNA have dramatically increased in the past decade. This understanding, in addition to the impact of RNA in many disease states, has renewed interest in developing selective RNA-targeted small molecule probes. However, the fundamental guiding principles in RNA molecular recognition that could accelerate these efforts remain elusive. While high-resolution structural characterization can provide invaluable insight, examples of well-characterized RNA structures, not to mention small molecule:RNA complexes, remain limited. This Perspective provides an overview of the current techniques used to understand RNA molecular recognition when high-resolution structural information is unavailable. We will place particular emphasis on a new method, pattern recognition of RNA with small molecules (PRRSM), that provides rapid insight into critical components of RNA recognition and differentiation by small molecules as well as into RNA structural features.
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Affiliation(s)
- Christopher S Eubanks
- Department of Chemistry , Duke University , Durham , North Carolina 27708-0354 , United States
| | - Amanda E Hargrove
- Department of Chemistry , Duke University , Durham , North Carolina 27708-0354 , United States
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16
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Patil KM, Toh DFK, Yuan Z, Meng Z, Shu Z, Zhang H, Ong A, Krishna MS, Lu L, Lu Y, Chen G. Incorporating uracil and 5-halouracils into short peptide nucleic acids for enhanced recognition of A-U pairs in dsRNAs. Nucleic Acids Res 2018; 46:7506-7521. [PMID: 30011039 PMCID: PMC6125629 DOI: 10.1093/nar/gky631] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 06/09/2018] [Accepted: 07/03/2018] [Indexed: 01/16/2023] Open
Abstract
Double-stranded RNA (dsRNA) structures form triplexes and RNA-protein complexes through binding to single-stranded RNA (ssRNA) regions and proteins, respectively, for diverse biological functions. Hence, targeting dsRNAs through major-groove triplex formation is a promising strategy for the development of chemical probes and potential therapeutics. Short (e.g., 6-10 mer) chemically-modified Peptide Nucleic Acids (PNAs) have been developed that bind to dsRNAs sequence specifically at physiological conditions. For example, a PNA incorporating a modified base thio-pseudoisocytosine (L) has an enhanced recognition of a G-C pair in an RNA duplex through major-groove L·G-C base triple formation at physiological pH, with reduced pH dependence as observed for C+·G-C base triple formation. Currently, an unmodified T base is often incorporated into PNAs to recognize a Watson-Crick A-U pair through major-groove T·A-U base triple formation. A substitution of the 5-methyl group in T by hydrogen and halogen atoms (F, Cl, Br, and I) causes a decrease of the pKa of N3 nitrogen atom, which may result in improved hydrogen bonding in addition to enhanced base stacking interactions. Here, we synthesized a series of PNAs incorporating uracil and halouracils, followed by binding studies by non-denaturing polyacrylamide gel electrophoresis, circular dichroism, and thermal melting. Our results suggest that replacing T with uracil and halouracils may enhance the recognition of an A-U pair by PNA·RNA2 triplex formation in a sequence-dependent manner, underscoring the importance of local stacking interactions. Incorporating bromouracils and chlorouracils into a PNA results in a significantly reduced pH dependence of triplex formation even for PNAs containing C bases, likely due to an upshift of the apparent pKa of N3 atoms of C bases. Thus, halogenation and other chemical modifications may be utilized to enhance hydrogen bonding of the adjacent base triples and thus triplex formation. Furthermore, our experimental and computational modelling data suggest that PNA·RNA2 triplexes may be stabilized by incorporating a BrUL step but not an LBrU step, in dsRNA-binding PNAs.
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Affiliation(s)
- Kiran M Patil
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| | - Desiree-Faye Kaixin Toh
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| | - Zhen Yuan
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| | - Zhenyu Meng
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| | - Zhiyu Shu
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| | - Haiping Zhang
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551
| | - Alan Ann Lerk Ong
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| | - Manchugondanahalli S Krishna
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| | - Lanyuan Lu
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551
| | - Yunpeng Lu
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| | - Gang Chen
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
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17
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Dever TE, Dinman JD, Green R. Translation Elongation and Recoding in Eukaryotes. Cold Spring Harb Perspect Biol 2018; 10:cshperspect.a032649. [PMID: 29610120 DOI: 10.1101/cshperspect.a032649] [Citation(s) in RCA: 127] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
In this review, we highlight the current understanding of translation elongation and recoding in eukaryotes. In addition to providing an overview of the process, recent advances in our understanding of the role of the factor eIF5A in both translation elongation and termination are discussed. We also highlight mechanisms of translation recoding with a focus on ribosomal frameshifting during elongation. We see that the balance between the basic steps in elongation and the less common recoding events is determined by the kinetics of the different processes as well as by specific sequence determinants.
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Affiliation(s)
- Thomas E Dever
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892
| | - Jonathan D Dinman
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742
| | - Rachel Green
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
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18
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Das D, Khan HPA, Shivahare R, Gupta S, Sarkar J, Siddiqui MI, Ampapathi RS, Chakraborty TK. Synthesis, SAR and biological studies of sugar amino acid-based almiramide analogues: N-methylation leads the way. Org Biomol Chem 2018; 15:3337-3352. [PMID: 28368065 DOI: 10.1039/c6ob02610a] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Leishmaniasis, caused by the protozoan parasites of the genus Leishmania, is one of the most neglected diseases endemic in many continents posing enormous global health threats and therefore the discovery of new antileishmanial compounds is of utmost urgency. The antileishmanial activities of a library of sugar amino acid-based linear lipopeptide analogues were examined with the aim to identify potential drug candidates to treat visceral leishmaniasis. It was found that among the synthesized analogues, most of the permethylated compounds exhibited more activity in in vitro studies against intra-macrophagic amastigotes than the non-methylated analogues. SAR and NMR studies revealed that introduction of the N-methyl groups inhibited the formation of any turn structure in these molecules, which led to their improved activities.
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Affiliation(s)
- Dipendu Das
- Medicinal & Process Chemistry Division, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, India
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19
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Targeting Virulence in Staphylococcus aureus by Chemical Inhibition of the Accessory Gene Regulator System In Vivo. mSphere 2018; 3:mSphere00500-17. [PMID: 29359191 PMCID: PMC5770542 DOI: 10.1128/msphere.00500-17] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) presents one of the most serious health concerns worldwide. The WHO labeled it as a “high-priority” pathogen in 2017, also citing the more recently emerged vancomycin-intermediate and -resistant strains. Methicillin-resistant Staphylococcus aureus (MRSA) presents one of the most serious health concerns worldwide. The WHO labeled it as a “high-priority” pathogen in 2017, also citing the more recently emerged vancomycin-intermediate and -resistant strains. With the spread of antibiotic resistance due in large part to the selective pressure exerted by conventional antibiotics, the use of antivirulence strategies has been recurrently proposed as a promising therapeutic approach. In MRSA, virulence is chiefly controlled by quorum sensing (QS); inhibitors of QS are called quorum quenchers (QQ). In S. aureus, the majority of QS components are coded for by the accessory gene regulator (Agr) system. Although much work has been done to develop QQs against MRSA, only a few studies have progressed to in vivo models. Those studies include both prophylactic and curative models of infection as well as combination treatments with antibiotic. For most, high efficacy is seen at attenuating MRSA virulence and pathogenicity, with some studies showing effects such as synergy with antibiotics and antibiotic resensitization. This minireview aims to summarize and derive conclusions from the literature on the in vivo efficacy of QQ agents in MRSA infection models. In vitro data are also summarized to provide sufficient background on the hits discussed. On the whole, the reported in vivo effects of the reviewed QQs against MRSA represent positive progress at this early stage in drug development. Follow-up studies that thoroughly examine in vitro and in vivo activity are needed to propel the field forward and set the stage for lead optimization.
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20
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Li W, Hu K, Zhang Q, Wang D, Ma Y, Hou Z, Yin F, Li Z. N terminal N-methylation modulates chiral centre induced helical (CIH) peptides’ biophysical properties. Chem Commun (Camb) 2018; 54:1865-1868. [DOI: 10.1039/c7cc09201f] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The effects of N-methylation on CIH peptides’ biophysical properties were systematically studied.
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Affiliation(s)
- Wenjun Li
- The Key Laboratory of Chemical Genomics School of Chemical Biology and Biotechnology
- Peking University Shenzhen Graduate School
- Shenzhen
- China
| | - Kuan Hu
- Beijing Institute of Nanoenergy and Nanosystems
- National Center for Nanoscience and Technology (NCNST)
- Chinese Academy of Sciences
- Beijing 100083
- China
| | - Qingzhou Zhang
- The Key Laboratory of Chemical Genomics School of Chemical Biology and Biotechnology
- Peking University Shenzhen Graduate School
- Shenzhen
- China
| | - Dongyuan Wang
- The Key Laboratory of Chemical Genomics School of Chemical Biology and Biotechnology
- Peking University Shenzhen Graduate School
- Shenzhen
- China
| | - Yue Ma
- The Key Laboratory of Chemical Genomics School of Chemical Biology and Biotechnology
- Peking University Shenzhen Graduate School
- Shenzhen
- China
| | - Zhanfeng Hou
- The Key Laboratory of Chemical Genomics School of Chemical Biology and Biotechnology
- Peking University Shenzhen Graduate School
- Shenzhen
- China
| | - Feng Yin
- The Key Laboratory of Chemical Genomics School of Chemical Biology and Biotechnology
- Peking University Shenzhen Graduate School
- Shenzhen
- China
| | - Zigang Li
- The Key Laboratory of Chemical Genomics School of Chemical Biology and Biotechnology
- Peking University Shenzhen Graduate School
- Shenzhen
- China
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21
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Bunteang S, Chanakul W, Hongthong S, Kuhakarn C, Chintakovid W, Sungchawek N, Akkarawongsapat R, Limthongkul J, Nantasaen N, Reutrakul V, Jaipetch T. Anti-HIV Activity of Alkaloids from Dasymaschalon echinatum. Nat Prod Commun 2018. [DOI: 10.1177/1934578x1801300110] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Bioassay-guided fractionation of the aerial parts of Dasymaschalon echinatum led to the isolation of five known aristolactams; aristolactam AII (1), aristolactam BII (2), piperolactam A (3), piperolactam C (4), and goniopedaline (5), together with two aphorphine alkaloids; duguevalline (6) and noraristolodione (7) and two amide derivatives; asperphenamate (8), and N -benzoyl-L-phenylalaninol (9). Alkaloids 2 and 7 were isolated for the first time from the Dasymaschalon genus. The anti-HIV 1 reverse transcriptase (RT) activity of all isolated compounds was determined. Except for aristolactam BII (2), this is the first report of the anti-HIV 1-RT activity of compounds 1 and 3-9. Compounds 1, 3, 5, 6 and 8 showed weak anti-HIV 1-RT inhibitory activity with IC50 ranging from 112.74 to 225.55μM.
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Affiliation(s)
- Samreang Bunteang
- Department of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Mahidol University, Rama 6 Road, Bangkok 10400, Thailand
| | - Waraporn Chanakul
- Faculty of Science, Energy and Environment, KMUTNB, Rayong Campus, Ban-Kai, Rayong 21120, Thailand
| | - Sakchai Hongthong
- Department of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Mahidol University, Rama 6 Road, Bangkok 10400, Thailand
| | - Chutima Kuhakarn
- Department of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Mahidol University, Rama 6 Road, Bangkok 10400, Thailand
| | - Watcharra Chintakovid
- Mahidol University and Center of Excellence for Innovation in Chemistry (PERCH-CIC), Kanchanaburi Campus, Saiyok, Kanchanaburi 71150, Thailand
| | - Natthapat Sungchawek
- Department of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Mahidol University, Rama 6 Road, Bangkok 10400, Thailand
| | - Radeekorn Akkarawongsapat
- Department of Microbiology, Faculty of Science, Mahidol University, Rama 6 Road, Bangkok 10400, Thailand
| | - Jitra Limthongkul
- Department of Microbiology, Faculty of Science, Mahidol University, Rama 6 Road, Bangkok 10400, Thailand
| | - Narong Nantasaen
- The Forest Herbarium National Park, Wildlife and Plant Conservation Department, Ministry of Natural Resources and Environment, Thailand
| | - Vichai Reutrakul
- Department of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Mahidol University, Rama 6 Road, Bangkok 10400, Thailand
| | - Thaworn Jaipetch
- Mahidol University and Center of Excellence for Innovation in Chemistry (PERCH-CIC), Kanchanaburi Campus, Saiyok, Kanchanaburi 71150, Thailand
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22
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Penno C, Kumari R, Baranov PV, van Sinderen D, Atkins JF. Specific reverse transcriptase slippage at the HIV ribosomal frameshift sequence: potential implications for modulation of GagPol synthesis. Nucleic Acids Res 2017; 45:10156-10167. [PMID: 28973470 PMCID: PMC5737442 DOI: 10.1093/nar/gkx690] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 07/24/2017] [Indexed: 12/28/2022] Open
Abstract
Synthesis of HIV GagPol involves a proportion of ribosomes translating a U6A shift site at the distal end of the gag gene performing a programmed -1 ribosomal frameshift event to enter the overlapping pol gene. In vitro studies here show that at the same shift motif HIV reverse transcriptase generates -1 and +1 indels with their ratio being sensitive to the relative concentration ratio of dNTPs specified by the RNA template slippage-prone sequence and its 5' adjacent base. The GGG sequence 3' adjacent to the U6A shift/slippage site, which is important for ribosomal frameshifting, is shown here to limit reverse transcriptase base substitution and indel 'errors' in the run of A's in the product. The indels characterized here have either 1 more or less A, than the corresponding number of template U's. cDNA with 5 A's may yield novel Gag product(s), while cDNA with an extra base, 7 A's, may only be a minor contributor to GagPol polyprotein. Synthesis of a proportion of non-ribosomal frameshift derived GagPol would be relevant in efforts to identify therapeutically useful compounds that perturb the ratio of GagPol to Gag, and pertinent to the extent in which specific polymerase slippage is utilized in gene expression.
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Affiliation(s)
- Christophe Penno
- School of Biochemistry, University College Cork, Cork, Ireland.,School of Microbiology, University College Cork, Cork, Ireland.,Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
| | - Romika Kumari
- School of Biochemistry, University College Cork, Cork, Ireland
| | - Pavel V Baranov
- School of Biochemistry, University College Cork, Cork, Ireland
| | - Douwe van Sinderen
- School of Microbiology, University College Cork, Cork, Ireland.,Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
| | - John F Atkins
- School of Biochemistry, University College Cork, Cork, Ireland.,School of Microbiology, University College Cork, Cork, Ireland.,Department of Human Genetics, University of Utah, Salt Lake City, UT 84112-5330, USA
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23
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Puah RY, Jia H, Maraswami M, Toh DFK, Ero R, Yang L, Patil KM, Ong AAL, Krishna MS, Sun R, Tong C, Huang M, Chen X, Loh TP, Gao YG, Liu DX, Chen G. Selective Binding to mRNA Duplex Regions by Chemically Modified Peptide Nucleic Acids Stimulates Ribosomal Frameshifting. Biochemistry 2017; 57:149-159. [PMID: 29116759 DOI: 10.1021/acs.biochem.7b00744] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Minus-one programmed ribosomal frameshifting (-1 PRF) allows the precise maintenance of the ratio between viral proteins and is involved in the regulation of the half-lives of cellular mRNAs. Minus-one ribosomal frameshifting is activated by several stimulatory elements such as a heptameric slippery sequence (X XXY YYZ) and an mRNA secondary structure (hairpin or pseudoknot) that is positioned 2-8 nucleotides downstream from the slippery site. Upon -1 RF, the ribosomal reading frame is shifted from the normal zero frame to the -1 frame with the heptameric slippery sequence decoded as XXX YYY Z instead of X XXY YYZ. Our research group has developed chemically modified peptide nucleic acid (PNA) L and Q monomers to recognize G-C and C-G Watson-Crick base pairs, respectively, through major-groove parallel PNA·RNA-RNA triplex formation. L- and Q-incorporated PNAs show selective binding to double-stranded RNAs (dsRNAs) over single-stranded RNAs (ssRNAs). The sequence specificity and structural selectivity of L- and Q-modified PNAs may allow the precise targeting of desired viral and cellular RNA structures, and thus may serve as valuable biological tools for mechanistic studies and potential therapeutics for fighting diseases. Here, for the first time, we demonstrate by cell-free in vitro translation assays using rabbit reticulocyte lysate that the dsRNA-specific chemically modified PNAs targeting model mRNA hairpins stimulate -1 RF (from 2% to 32%). An unmodified control PNA, however, shows nonspecific inhibition of translation. Our results suggest that the modified dsRNA-binding PNAs may be advantageous for targeting structured RNAs.
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Affiliation(s)
| | | | | | | | - Rya Ero
- School of Biological Sciences, Nanyang Technological University , 60 Nanyang Drive, Singapore 637551
| | | | | | | | | | | | | | - Mei Huang
- School of Biological Sciences, Nanyang Technological University , 60 Nanyang Drive, Singapore 637551
| | | | | | - Yong-Gui Gao
- School of Biological Sciences, Nanyang Technological University , 60 Nanyang Drive, Singapore 637551
| | - Ding Xiang Liu
- School of Biological Sciences, Nanyang Technological University , 60 Nanyang Drive, Singapore 637551.,Guangdong Province Key Laboratory Microbial Signals & Disease Co, and Integrative Microbiology Research Centre, South China Agricultural University , Guangzhou 510642, Guangdong, People's Republic of China
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24
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Hilimire TA, Chamberlain JM, Anokhina V, Bennett RP, Swart O, Myers JR, Ashton JM, Stewart RA, Featherston AL, Gates K, Helms ED, Smith HC, Dewhurst S, Miller BL. HIV-1 Frameshift RNA-Targeted Triazoles Inhibit Propagation of Replication-Competent and Multi-Drug-Resistant HIV in Human Cells. ACS Chem Biol 2017; 12:1674-1682. [PMID: 28448121 PMCID: PMC5477779 DOI: 10.1021/acschembio.7b00052] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
![]()
The
HIV-1 frameshift-stimulating (FSS) RNA, a regulatory RNA of
critical importance in the virus’ life cycle, has been posited
as a novel target for anti-HIV drug development. We report the synthesis
and evaluation of triazole-containing compounds able to bind the FSS
with high affinity and selectivity. Readily accessible synthetically,
these compounds are less toxic than previously reported olefin congeners.
We show for the first time that FSS-targeting compounds have antiviral
activity against replication-competent HIV in human cells, including
a highly cytopathic, multidrug-resistant strain. These results support
the viability of the HIV-1 FSS RNA as a therapeutic target and more
generally highlight opportunities for synthetic molecule-mediated
interference with protein recoding in a wide range of organisms.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Eric D. Helms
- Department of Chemistry, SUNY Geneseo, Geneseo, New York 14454, United States
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25
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Naoum JN, Chandra K, Shemesh D, Gerber RB, Gilon C, Hurevich M. DMAP-assisted sulfonylation as an efficient step for the methylation of primary amine motifs on solid support. Beilstein J Org Chem 2017; 13:806-816. [PMID: 28546838 PMCID: PMC5433225 DOI: 10.3762/bjoc.13.81] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 04/11/2017] [Indexed: 11/23/2022] Open
Abstract
Several multistep strategies were developed to ensure single methylation of amines on solid support. These strategies rely on the introduction of the o-NBS protecting/activating group as a key step. We found that the state-of-the-art strategies fail for the methylation of several primary amine motifs, largely due to inefficient sulfonylation. Here we show that using the superior nucleophilic base DMAP instead of the commonly used base collidine as a sulfonylation additive is essential for the introduction of the o-NBS group to these amine motifs. DFT calculations provide an explanation by showing that the energy barrier of the DMAP intermediate is significantly lower than the one of the collidine. We demonstrate that using DMAP as a sole additive in the sulfonylation step results in an overall effective and regioselective N-methylation. The method presented herein proved highly efficient in solid-phase synthesis of a somatostatin analogue bearing three Nα-methylation sites that could not be synthesized using the previously described state-of-the-art methods.
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Affiliation(s)
- Johnny N Naoum
- Institute of Chemistry, The Hebrew University of Jerusalem, Edmond Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Koushik Chandra
- Institute of Chemistry, The Hebrew University of Jerusalem, Edmond Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Dorit Shemesh
- Institute of Chemistry, The Hebrew University of Jerusalem, Edmond Safra Campus, Givat Ram, Jerusalem, 91904, Israel
- Fritz Haber Research Center, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - R Benny Gerber
- Institute of Chemistry, The Hebrew University of Jerusalem, Edmond Safra Campus, Givat Ram, Jerusalem, 91904, Israel
- Fritz Haber Research Center, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Chaim Gilon
- Institute of Chemistry, The Hebrew University of Jerusalem, Edmond Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Mattan Hurevich
- Institute of Chemistry, The Hebrew University of Jerusalem, Edmond Safra Campus, Givat Ram, Jerusalem, 91904, Israel
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26
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Shi S, Nguyen PK, Cabral HJ, Diez-Barroso R, Derry PJ, Kanahara SM, Kumar VA. Development of peptide inhibitors of HIV transmission. Bioact Mater 2016; 1:109-121. [PMID: 29744399 PMCID: PMC5883972 DOI: 10.1016/j.bioactmat.2016.09.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 08/18/2016] [Accepted: 09/07/2016] [Indexed: 12/26/2022] Open
Abstract
Treatment of HIV has long faced the challenge of high mutation rates leading to rapid development of resistance, with ongoing need to develop new methods to effectively fight the infection. Traditionally, early HIV medications were designed to inhibit RNA replication and protein production through small molecular drugs. Peptide based therapeutics are a versatile, promising field in HIV therapy, which continues to develop as we expand our understanding of key protein-protein interactions that occur in HIV replication and infection. This review begins with an introduction to HIV, followed by the biological basis of disease, current clinical management of the disease, therapeutics on the market, and finally potential avenues for improved drug development.
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Key Words
- AIDS, acquired immunodeficiency syndrome
- ART, antiretroviral therapy
- CDC, Centers for Disease Control and Prevention
- Drug development
- FDA, US Food and Drug Administration
- FY, fiscal year
- HAART, highly active antiretroviral therapy
- HCV, hepatitis C Virus
- HIV
- HIV treatment
- HIV, human immunodeficiency virus
- INSTI, Integrase strand transfer inhibitors
- LEDGF, lens epithelium-derived growth factor
- NNRTI, Non-nucleoside reverse transcriptase inhibitors
- NRTI, Nucleoside/Nucleotide Reverse Transcriptase Inhibitors
- Peptide inhibitor
- Peptide therapeutic
- R&D, research and development
- RT, reverse transcriptase
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Affiliation(s)
- Siyu Shi
- Department of Chemistry, Rice University, Houston, TX 77030, USA
| | - Peter K. Nguyen
- Department of Biomedical Engineering, New Jersey Institute of Technology, University Heights, Newark, NJ 07102, USA
- Department of Chemical, Biological and Pharmaceutical Engineering, New Jersey Institute of Technology, University Heights, Newark, NJ 07102, USA
| | - Henry J. Cabral
- Department of Biomedical Engineering, New Jersey Institute of Technology, University Heights, Newark, NJ 07102, USA
- Department of Chemical, Biological and Pharmaceutical Engineering, New Jersey Institute of Technology, University Heights, Newark, NJ 07102, USA
| | | | - Paul J. Derry
- Department of Chemistry, Rice University, Houston, TX 77030, USA
| | | | - Vivek A. Kumar
- Department of Biomedical Engineering, New Jersey Institute of Technology, University Heights, Newark, NJ 07102, USA
- Department of Chemical, Biological and Pharmaceutical Engineering, New Jersey Institute of Technology, University Heights, Newark, NJ 07102, USA
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27
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Ngambenjawong C, Pineda JMB, Pun SH. Engineering an Affinity-Enhanced Peptide through Optimization of Cyclization Chemistry. Bioconjug Chem 2016; 27:2854-2862. [PMID: 27779387 DOI: 10.1021/acs.bioconjchem.6b00502] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Peptide cyclization is a strategy used to improve stability and activity of peptides. The most commonly used cyclization method is disulfide bridge formation of cysteine-containing peptides, as is typically found in nature. Over the years, an increasing number of alternative chemistries for peptide cyclization with improved efficiency, kinetics, orthogonality, and stability have been reported. However, there has been less appreciation for the opportunity to fine-tune peptide activity via the diverse chemical entities introduced at the site of linkage by different cyclization strategies. Here, we demonstrate how cyclization optimization of an M2 "anti-inflammatory" macrophage-binding peptide (M2pep) resulted in a significant increase in binding affinity of the optimized analog to M2 macrophages while maintaining binding selectivity compared to M1 "pro-inflammatory" macrophages. In this study, we report synthesis and evaluation of four cyclic M2pep(RY) analogs with diverse cyclization strategies: (1) Asp-[amide]-Lys, (2) azido-Lys-[triazole(copper(I)-catalyzed alkyne-azide cycloaddition (CuAAC))]-propargyl-Gly, (3) Cys-[decafluorobiphenyl (DFBP)]-Cys, and (4) Cys-[decafluorobiphenyl sulfone (DFS)]-Cys, whereby the chemical entity or linker at the linkage site is shown in the square bracket and is between the residues involved in cyclization. These peptides are compared to a disulfide-cyclized M2pep(RY) that we previously reported as a serum-stable, affinity-enhanced analog to the original linear M2pep. DFBP-cyclized M2pep(RY) exhibits the highest binding activity to M2 macrophages with apparent dissociation constant (KD) about 2.03 μM compared to 36.3 μM for the original disulfide-cyclized M2pep(RY) and 220 μM for the original linear peptide. DFS-cyclized M2pep(RY) also binds more strongly than the original cyclized analog, whereas amide- and triazole-cyclized M2pep(RY) analogs bind less strongly. We verified that DFBP alone has negligible binding to M2 macrophages and the incorporation of diphenylalanine to the original sequence improves binding activity at the expense of solubility and increased toxicity. In conclusion, we report development of cyclic M2pep(RY) analogs with diverse cyclization strategies leading to the discovery of DFBP-cyclized M2pep(RY) with enhanced M2 macrophage-binding activity.
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Affiliation(s)
- Chayanon Ngambenjawong
- Department of Bioengineering and Molecular Engineering and Sciences Institute, University of Washington , Seattle, Washington 98195, United States
| | - Julio Marco B Pineda
- Department of Bioengineering and Molecular Engineering and Sciences Institute, University of Washington , Seattle, Washington 98195, United States
| | - Suzie H Pun
- Department of Bioengineering and Molecular Engineering and Sciences Institute, University of Washington , Seattle, Washington 98195, United States
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Connelly CM, Moon MH, Schneekloth JS. The Emerging Role of RNA as a Therapeutic Target for Small Molecules. Cell Chem Biol 2016; 23:1077-1090. [PMID: 27593111 PMCID: PMC5064864 DOI: 10.1016/j.chembiol.2016.05.021] [Citation(s) in RCA: 211] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 05/07/2016] [Accepted: 05/18/2016] [Indexed: 01/09/2023]
Abstract
Recent advances in understanding different RNAs and unique features of their biology have revealed a wealth of information. However, approaches to identify small molecules that target these newly discovered regulatory elements have been lacking. The application of new biochemical screening and design-based technologies, coupled with a resurgence of interest in phenotypic screening, has resulted in several compelling successes in targeting RNA. A number of recent advances suggest that achieving the long-standing goal of developing drug-like, biologically active small molecules that target RNA is possible. This review highlights advances and successes in approaches to targeting RNA with diverse small molecules, and the potential for these technologies to pave the way to new types of RNA-targeted therapeutics.
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Affiliation(s)
- Colleen M Connelly
- Chemical Biology Laboratory, National Cancer Institute, Frederick, MD 21702, USA
| | - Michelle H Moon
- Chemical Biology Laboratory, National Cancer Institute, Frederick, MD 21702, USA
| | - John S Schneekloth
- Chemical Biology Laboratory, National Cancer Institute, Frederick, MD 21702, USA.
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Atkins JF, Loughran G, Bhatt PR, Firth AE, Baranov PV. Ribosomal frameshifting and transcriptional slippage: From genetic steganography and cryptography to adventitious use. Nucleic Acids Res 2016; 44:7007-78. [PMID: 27436286 PMCID: PMC5009743 DOI: 10.1093/nar/gkw530] [Citation(s) in RCA: 161] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 05/26/2016] [Indexed: 12/15/2022] Open
Abstract
Genetic decoding is not ‘frozen’ as was earlier thought, but dynamic. One facet of this is frameshifting that often results in synthesis of a C-terminal region encoded by a new frame. Ribosomal frameshifting is utilized for the synthesis of additional products, for regulatory purposes and for translational ‘correction’ of problem or ‘savior’ indels. Utilization for synthesis of additional products occurs prominently in the decoding of mobile chromosomal element and viral genomes. One class of regulatory frameshifting of stable chromosomal genes governs cellular polyamine levels from yeasts to humans. In many cases of productively utilized frameshifting, the proportion of ribosomes that frameshift at a shift-prone site is enhanced by specific nascent peptide or mRNA context features. Such mRNA signals, which can be 5′ or 3′ of the shift site or both, can act by pairing with ribosomal RNA or as stem loops or pseudoknots even with one component being 4 kb 3′ from the shift site. Transcriptional realignment at slippage-prone sequences also generates productively utilized products encoded trans-frame with respect to the genomic sequence. This too can be enhanced by nucleic acid structure. Together with dynamic codon redefinition, frameshifting is one of the forms of recoding that enriches gene expression.
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Affiliation(s)
- John F Atkins
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland School of Microbiology, University College Cork, Cork, Ireland Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA
| | - Gary Loughran
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Pramod R Bhatt
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Andrew E Firth
- Division of Virology, Department of Pathology, University of Cambridge, Hills Road, Cambridge CB2 0QQ, UK
| | - Pavel V Baranov
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
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Stability of HIV Frameshift Site RNA Correlates with Frameshift Efficiency and Decreased Virus Infectivity. J Virol 2016; 90:6906-6917. [PMID: 27194769 DOI: 10.1128/jvi.00149-16] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 05/13/2016] [Indexed: 12/18/2022] Open
Abstract
UNLABELLED Human immunodeficiency virus (HIV) replication is strongly dependent upon a programmed ribosomal frameshift. Here we investigate the relationships between the thermodynamic stability of the HIV type 1 (HIV-1) RNA frameshift site stem-loop, frameshift efficiency, and infectivity, using pseudotyped HIV-1 and HEK293T cells. The data reveal a strong correlation between frameshift efficiency and local, but not overall, RNA thermodynamic stability. Mutations that modestly increase the local stability of the frameshift site RNA stem-loop structure increase frameshift efficiency 2-fold to 3-fold in cells. Thus, frameshift efficiency is determined by the strength of the thermodynamic barrier encountered by the ribosome. These data agree with previous in vitro measurements, suggesting that there are no virus- or host-specific factors that modulate frameshifting. The data also indicate that there are no sequence-specific requirements for the frameshift site stem-loop. A linear correlation between Gag-polymerase (Gag-Pol) levels in cells and levels in virions supports the idea of a stochastic virion assembly mechanism. We further demonstrate that the surrounding genomic RNA secondary structure influences frameshift efficiency and that a mutation that commonly arises in response to protease inhibitor therapy creates a functional but inefficient secondary slippery site. Finally, HIV-1 mutants with enhanced frameshift efficiencies are significantly less infectious, suggesting that compounds that increase frameshift efficiency by as little as 2-fold may be effective at suppressing HIV-1 replication. IMPORTANCE HIV, like many retroviruses, utilizes a -1 programmed ribosomal frameshift to generate viral enzymes in the form of a Gag-Pol polyprotein precursor. Thus, frameshifting is essential for viral replication. Here, we utilized a panel of mutant HIV strains to demonstrate that in cells, frameshifting efficiency is correlated with the stability of the local thermodynamic barrier to ribosomal translocation. Increasing the stability of the frameshift site RNA increases the frameshift efficiency 2-fold to 3-fold. Mutant viruses with increased frameshift efficiencies have significantly reduced infectivity. These data suggest that this effect might be exploited in the development of novel antiviral strategies.
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Eustache S, Leprince J, Tufféry P. Progress with peptide scanning to study structure-activity relationships: the implications for drug discovery. Expert Opin Drug Discov 2016; 11:771-84. [PMID: 27310575 DOI: 10.1080/17460441.2016.1201058] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
INTRODUCTION Peptides have gained renewed interest as candidate therapeutics. However, to bring them to a broader clinical use, challenges such as the rational optimization of their pharmacological properties remain. Peptide scanning techniques offer a systematic framework to gain information on the functional role of individual amino acids of a peptide. Due to progress in mastering new chemical synthesis routes targeting amino acid backbone, they are currently diversified. Structure-activity relationship (SAR) analyses such as alanine- or enantioneric- scanning can now be supplemented by N-substitution, lactam cyclisation- or aza-amino scanning procedures addressing not only SAR considerations but also the peptide pharmacological properties. AREAS COVERED This review highlights the different scanning techniques currently available and illustrates how they can impact drug discovery. EXPERT OPINION Progress in peptide scanning techniques opens new perspectives for peptide drug development. It comes with the promise of a paradigm change in peptide drug design in which peptide drugs will be closer to the parent peptides. However, scanning still remains assimilable to a trial and error strategy that could benefit from being combined with specific in silico approaches that start reaching maturity.
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Affiliation(s)
- Stéphanie Eustache
- a INSERM UMR-S 973 , University Paris-Diderot, Sorbonne Paris Cité , Paris , France
| | - Jérôme Leprince
- b INSERM U982 , Regional Platform for Cell Imaging of Normandy (PRIMACEN), University Rouen-Normandy , Mont-Saint-Aignan, France
| | - Pierre Tufféry
- a INSERM UMR-S 973 , University Paris-Diderot, Sorbonne Paris Cité , Paris , France
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McAnany JD, Reichert JP, Miller BL. Probing the geometric constraints of RNA binding via dynamic covalent chemistry. Bioorg Med Chem 2016; 24:3940-3946. [PMID: 26935941 DOI: 10.1016/j.bmc.2016.02.029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Accepted: 02/23/2016] [Indexed: 12/31/2022]
Abstract
Dynamic Combinatorial Chemistry (DCC) has proven to be a reliable method for identifying hit compounds for target nucleic acid (DNA and RNA) sequences. Typically, these hit compounds are subjected to a lengthy process of optimization via traditional medicinal chemistry. Here, we examine the potential of DCC to also generate and test variations on a hit compound as a method for probing the binding site of an RNA-targeted compound. Specifically, we demonstrate that addition of linker dithiols to a disulfide library containing a known binder to the HIV-1 frameshift-stimulatory RNA (a critical regulator of the HIV life cycle) can yield a mixture of new bridged structures incorporating the dithiol, depending on dithiol structure. Equilibration of this library with the HIV FSS RNA resulted in selection of the original disulfide in preference to bridged structures, suggesting incorporation of the bridge is not compatible with this particular binding site. Application of this strategy to other RNA targets should allow for rapidly profiling the affinity of modified compounds.
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Affiliation(s)
- John D McAnany
- Department of Chemistry, University of Rochester, Rochester, NY 14642, United States
| | - John P Reichert
- Department of Biochemistry and Biophysics, University of Rochester, Rochester, NY 14642, United States
| | - Benjamin L Miller
- Department of Chemistry, University of Rochester, Rochester, NY 14642, United States; Department of Biochemistry and Biophysics, University of Rochester, Rochester, NY 14642, United States; Department of Dermatology, University of Rochester, Rochester, NY 14642, United States.
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