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Gruenke PR, Mayer MD, Aneja R, Schulze WJ, Song Z, Burke DH, Heng X, Lange MJ. A Branched SELEX Approach Identifies RNA Aptamers That Bind Distinct HIV-1 Capsid Structural Components. ACS Infect Dis 2024. [PMID: 39016538 DOI: 10.1021/acsinfecdis.3c00708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2024]
Abstract
The HIV-1 capsid protein (CA) assumes distinct structural forms during replication, each presenting unique, solvent-accessible surfaces that facilitate multifaceted functions and host factor interactions. However, functional contributions of individual CA structures remain unclear, as evaluation of CA presents several technical challenges. To address this knowledge gap, we identified CA-targeting aptamers with different structural specificities, which emerged through a branched SELEX approach using an aptamer library previously selected to bind the CA hexamer lattice. Subsets were either highly specific for the CA lattice or bound both the CA lattice and CA hexamer. We then evaluated four representatives to reveal aptamer regions required for binding, highlighting interesting structural features and challenges in aptamer structure determination. Further, we demonstrate binding to biologically relevant CA structural forms and aptamer-mediated affinity purification of CA from cell lysates without virus or host modification, supporting the development of structural form-specific aptamers as exciting new tools for the study of CA.
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Affiliation(s)
- Paige R Gruenke
- Department of Molecular Microbiology and Immunology, University of Missouri, Columbia, Missouri 65212, United States
- Department of Biochemistry, University of Missouri, Columbia, Missouri 65211, United States
- Bond Life Sciences Center, University of Missouri, Columbia, Missouri 65211, United States
| | - Miles D Mayer
- Department of Biochemistry, University of Missouri, Columbia, Missouri 65211, United States
| | - Rachna Aneja
- Department of Molecular Microbiology and Immunology, University of Missouri, Columbia, Missouri 65212, United States
| | - William J Schulze
- Department of Molecular Microbiology and Immunology, University of Missouri, Columbia, Missouri 65212, United States
| | - Zhenwei Song
- Department of Biochemistry, University of Missouri, Columbia, Missouri 65211, United States
| | - Donald H Burke
- Department of Molecular Microbiology and Immunology, University of Missouri, Columbia, Missouri 65212, United States
- Department of Biochemistry, University of Missouri, Columbia, Missouri 65211, United States
- Bond Life Sciences Center, University of Missouri, Columbia, Missouri 65211, United States
| | - Xiao Heng
- Department of Biochemistry, University of Missouri, Columbia, Missouri 65211, United States
| | - Margaret J Lange
- Department of Molecular Microbiology and Immunology, University of Missouri, Columbia, Missouri 65212, United States
- Department of Biochemistry, University of Missouri, Columbia, Missouri 65211, United States
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2
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Sapkota K, Lucas JK, Faulkner JW, Lichte MF, Guo YL, Burke DH, Huang F. Post-transcriptional capping generates coenzyme A-linked RNA. RNA Biol 2024; 21:1-12. [PMID: 38032240 PMCID: PMC10761072 DOI: 10.1080/15476286.2023.2288740] [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] [Accepted: 11/21/2023] [Indexed: 12/01/2023] Open
Abstract
NAD can be inserted co-transcriptionally via non-canonical initiation to form NAD-RNA. However, that mechanism is unlikely for CoA-linked RNAs due to low intracellular concentration of the required initiator nucleotide, 3'-dephospho-CoA (dpCoA). We report here that phosphopantetheine adenylyltransferase (PPAT), an enzyme of CoA biosynthetic pathway, accepts RNA transcripts as its acceptor substrate and transfers 4'-phosphopantetheine to yield CoA-RNA post-transcriptionally. Synthetic natural (RNAI) and small artificial RNAs were used to identify the features of RNA that are needed for it to serve as PPAT substrate. RNAs with 4-10 unpaired nucleotides at the 5' terminus served as PPAT substrates, but RNAs having <4 unpaired nucleotides did not undergo capping. No capping was observed when the +1A was changed to G or when 5' triphosphate was removed by RNA pyrophosphohydrolase (RppH), suggesting the enzyme recognizes pppA-RNA as an ATP analog. PPAT binding affinities were equivalent for transcripts with +1A, +1 G, or 5'OH (+1A), indicating that productive enzymatic recognition is driven more by local positioning effects than by overall binding affinity. Capping rates were independent of the number of unpaired nucleotides in the range of 4-10 nucleotides. Capping was strongly inhibited by ATP, reducing CoA-RNA production ~70% when equimolar ATP and substrate RNA were present. Dual bacterial expression of candidate RNAs with different 5' structures followed by CoA-RNA CaptureSeq revealed 12-fold enrichment of the better PPAT substrate, consistent with in vivo CoA-capping of RNA transcripts by PPAT. These results suggest post-transcriptional RNA capping as a possible mechanism for the biogenesis of CoA-RNAs in bacteria.
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Affiliation(s)
- Krishna Sapkota
- Department of Chemistry and Biochemistry, University of Southern Mississippi, Hattiesburg, MS, USA
| | - Jordyn K. Lucas
- Department of Biochemistry, University of Missouri, Columbia, MO, USA
- Bond Life Sciences Center, University of Missouri, Columbia, MO, USA
| | - Jarrett W. Faulkner
- Department of Chemistry and Biochemistry, University of Southern Mississippi, Hattiesburg, MS, USA
| | - Matt F. Lichte
- Department of Biochemistry, University of Missouri, Columbia, MO, USA
- Bond Life Sciences Center, University of Missouri, Columbia, MO, USA
| | - Yan-Lin Guo
- Department of Cell and Molecular Biology, University of Southern Mississippi, Hattiesburg, MS, USA
| | - Donald H. Burke
- Department of Biochemistry, University of Missouri, Columbia, MO, USA
- Bond Life Sciences Center, University of Missouri, Columbia, MO, USA
- Department of Molecular Microbiology & Immunology, University of Missouri, Columbia, MO, USA
| | - Faqing Huang
- Department of Chemistry and Biochemistry, University of Southern Mississippi, Hattiesburg, MS, USA
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3
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Gruenke PR, Mayer MD, Aneja R, Song Z, Burke DH, Heng X, Lange MJ. Differentiation SELEX approach identifies RNA aptamers with different specificities for HIV-1 capsid assembly forms. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.11.571135. [PMID: 38168417 PMCID: PMC10760009 DOI: 10.1101/2023.12.11.571135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
The HIV-1 capsid protein (CA) assumes distinct assembly forms during replication, each presenting unique, solvent-accessible surfaces that facilitate multifaceted functions and host factor interactions. However, contributions of individual CA assemblies remain unclear, as the evaluation of CA in cells presents several technical challenges. To address this need, we sought to identify CA assembly form-specific aptamers. Aptamer subsets with different specificities emerged from within a highly converged, pre-enriched aptamer library previously selected to bind the CA hexamer lattice. Subsets were either highly specific for CA lattice or bound both CA lattice and CA hexamer. We further evaluated four representatives to reveal aptamer structural features required for binding, highlighting interesting features and challenges in aptamer structure determination. Importantly, our aptamers bind biologically relevant forms of CA and we demonstrate aptamer-mediated affinity purification of CA from cell lysates without virus or host modification. Thus, we have identified CA assembly form-specific aptamers that represent exciting new tools for the study of CA.
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4
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Cutts ZW, Hong JM, Shao S, Tran A, Dimon M, Berndl M, Wu D, Pawlosky A. Target-switch SELEX: Screening with alternating targets to generate aptamers to conserved terminal dipeptides. STAR Protoc 2022; 3:101724. [PMID: 36208449 PMCID: PMC9557731 DOI: 10.1016/j.xpro.2022.101724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 07/04/2022] [Accepted: 08/31/2022] [Indexed: 11/05/2022] Open
Abstract
Systematic evolution of ligands by exponential enrichment (SELEX) encompasses a wide variety of high-throughput screening techniques for producing nucleic acid binders to molecular targets through directed evolution. We describe here the design and selection steps for discovery of DNA aptamers with specificity for the two consecutive N-terminal amino acids (AAs) of a small peptide (8-10 amino acids). This bead-based method may be adapted for applications requiring binders which recognize a specific portion of the desired target. For complete details on the use and execution of this protocol, please refer to Hong et al. (2022).
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Affiliation(s)
| | | | | | | | | | | | - Diana Wu
- Google, LLC, Mountain View, CA 94043, USA.
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5
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Kramer ST, Gruenke PR, Alam KK, Xu D, Burke DH. FASTAptameR 2.0: A web tool for combinatorial sequence selections. MOLECULAR THERAPY - NUCLEIC ACIDS 2022; 29:862-870. [PMID: 36159593 PMCID: PMC9464650 DOI: 10.1016/j.omtn.2022.08.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 08/18/2022] [Indexed: 11/12/2022]
Abstract
Combinatorial selections are powerful strategies for identifying biopolymers with specific biological, biomedical, or chemical characteristics. Unfortunately, most available software tools for high-throughput sequencing analysis have high entrance barriers for many users because they require extensive programming expertise. FASTAptameR 2.0 is an R-based reimplementation of FASTAptamer designed to minimize this barrier while maintaining the ability to answer complex sequence-level and population-level questions. This open-source toolkit features a user-friendly web tool, interactive graphics, up to 100 times faster clustering, an expanded module set, and an extensive user guide. FASTAptameR 2.0 accepts diverse input polymer types and can be applied to any sequence-encoded selection.
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6
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Liu S, Xu Y, Jiang X, Tan H, Ying B. Translation of aptamers toward clinical diagnosis and commercialization. Biosens Bioelectron 2022; 208:114168. [PMID: 35364525 DOI: 10.1016/j.bios.2022.114168] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Revised: 02/28/2022] [Accepted: 03/07/2022] [Indexed: 02/08/2023]
Abstract
The dominance of antibodies in diagnostics has gradually changed following the discovery of aptamers in the early 1990s. Aptamers offer inherent advantages over traditional antibodies, including higher specificity, higher affinity, smaller size, greater stability, ease of manufacture, and low immunogenicity, rendering them the best candidates for point-of-care testing (POCT). In the past 20 years, the research community and pharmaceutical companies have made great efforts to promote the development of aptamer technology. Macugen® (pegaptanib) was the first aptamer drug approved by the US Food and Drug Administration (FDA), and various aptamer-based diagnostics show great promise in preclinical research and clinical trials. In this review, we introduce recent literature, ongoing clinical trials, commercial reagents of aptamer-based diagnostics, discuss the FDA regulatory mechanisms, and highlight the prospects and challenges in translating these studies into viable clinical diagnostic tools.
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Affiliation(s)
- Shan Liu
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Department of Medical Genetics, Department of Laboratory Medicine, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology, Chengdu, 610072, China
| | - Yixin Xu
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, 610041, China; Med+ Molecular Diagnostics Institute of West China Hospital/West China School of Medicine, Chengdu, 610041, China
| | - Xin Jiang
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, 610041, China; Med+ Molecular Diagnostics Institute of West China Hospital/West China School of Medicine, Chengdu, 610041, China
| | - Hong Tan
- Department of General Surgery, Chengdu Integrated TCM&Western Medicine Hospital (Chengdu First People's Hospital), Chengdu, 610041, China.
| | - Binwu Ying
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, 610041, China; Med+ Molecular Diagnostics Institute of West China Hospital/West China School of Medicine, Chengdu, 610041, China.
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7
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Xu Y, Jiang X, Zhou Y, Ma M, Wang M, Ying B. Systematic Evolution of Ligands by Exponential Enrichment Technologies and Aptamer-Based Applications: Recent Progress and Challenges in Precision Medicine of Infectious Diseases. Front Bioeng Biotechnol 2021; 9:704077. [PMID: 34447741 PMCID: PMC8383106 DOI: 10.3389/fbioe.2021.704077] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Accepted: 07/26/2021] [Indexed: 02/05/2023] Open
Abstract
Infectious diseases are considered as a pressing challenge to global public health. Accurate and rapid diagnostics tools for early recognition of the pathogen, as well as individualized precision therapy are essential for controlling the spread of infectious diseases. Aptamers, which were screened by systematic evolution of ligands by exponential enrichment (SELEX), can bind to targets with high affinity and specificity so that have exciting potential in both diagnosis and treatment of infectious diseases. In this review, we provide a comprehensive overview of the latest development of SELEX technology and focus on the applications of aptamer-based technologies in infectious diseases, such as targeted drug-delivery, treatments and biosensors for diagnosing. The challenges and the future development in this field of clinical application will also be discussed.
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Affiliation(s)
- Yixin Xu
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, China
| | - Xin Jiang
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, China
| | - Yanhong Zhou
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, China
| | - Ming Ma
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, China.,The First People's Hospital of Shuangliu District, Chengdu/West China (Airport)Hospital Sichuan University, Chengdu, China
| | - Minjin Wang
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, China
| | - Binwu Ying
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, China
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8
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Jiang L, Wang M, Zhang Y, Chen H, Su Y, Wang Y, Lin JS. Preparation and characterization of DNA aptamers against roxithromycin. Anal Chim Acta 2021; 1164:338509. [PMID: 33992220 DOI: 10.1016/j.aca.2021.338509] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 04/03/2021] [Accepted: 04/05/2021] [Indexed: 11/18/2022]
Abstract
Roxithromycin is a broad-spectrum antibiotic widely used in human and livestock. It is continually released and accumulated in our natural environment. It exhibited an extreme resistance to microbial biodegradation and has a serious impact on ecosystem and human health. It is in urgent need of establishing a rapid and efficient method for the detection of environmental roxithromycin. This study was based on capture-SELEX to select aptamers against roxithromycin from an initial library containing randomized ssDNA sequences. Candidate aptamers were obtained by 16 rounds of capture-SELEX process. Competent clones were prepared for sequencing. Clone Ap01 was chosen for further characterization. SYBR Green I fluorescence assays showed high affinity with roxithromycin. The dissociation constant of Ap01 was 0.46 ± 0.08 μM. Ap01 bound specifically to roxithromycin with capable of distinguish from non-roxithromycin macrolides. There was no cross reaction with the detected non-macrolide compounds. Accordingly, a colorimetric aptasensor has been developed. It has been demonstrated that the detection limit achieved 0.077 μM. To proof the concept, detections of roxithromycin contained in tap water and lake water were evaluated. It laid a foundation for further study on the detection of roxithromycin in actual aquatic environments.
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Affiliation(s)
- Lingli Jiang
- School of Medicine, Huaqiao University, Quanzhou, 362021, Fujian, China; Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, 400030, China
| | - Min Wang
- University Hospital, Huaqiao University, Quanzhou, 362021, Fujian, China
| | - Yi Zhang
- Guangzhou Tengwei Technology Application Co. Ltd, Guangzhou, 510200, Guangdong, China
| | - Haihua Chen
- School of Medicine, Huaqiao University, Quanzhou, 362021, Fujian, China
| | - Yi Su
- School of Medicine, Huaqiao University, Quanzhou, 362021, Fujian, China
| | - Yiyi Wang
- School of Medicine, Huaqiao University, Quanzhou, 362021, Fujian, China
| | - Jun Sheng Lin
- School of Medicine, Huaqiao University, Quanzhou, 362021, Fujian, China.
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9
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Ning Y, Hu J, Lu F. Aptamers used for biosensors and targeted therapy. Biomed Pharmacother 2020; 132:110902. [PMID: 33096353 PMCID: PMC7574901 DOI: 10.1016/j.biopha.2020.110902] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 10/12/2020] [Accepted: 10/14/2020] [Indexed: 01/07/2023] Open
Abstract
Aptamers are single-stranded nucleic acid sequences that can bind to target molecules with high selectivity and affinity. Most aptamers are screened in vitro by a combinatorial biology technique called systematic evolution of ligands by exponential enrichment (SELEX). Since aptamers were discovered in the 1990s, they have attracted considerable attention and have been widely used in many fields owing to their unique advantages. In this review, we present an overview of the advancements made in aptamers used for biosensors and targeted therapy. For the former, we will discuss multiple aptamer-based biosensors with different principles detected by various signaling methods. For the latter, we will focus on aptamer-based targeted therapy using aptamers as both biotechnological tools for targeted drug delivery and as targeted therapeutic agents. Finally, challenges and new perspectives associated with these two regions were further discussed. We hope that this review will help researchers interested in aptamer-related biosensing and targeted therapy research.
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Affiliation(s)
- Yi Ning
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan, 410208, PR China
| | - Jue Hu
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan, 410208, PR China
| | - Fangguo Lu
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan, 410208, PR China.
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10
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Komarova N, Barkova D, Kuznetsov A. Implementation of High-Throughput Sequencing (HTS) in Aptamer Selection Technology. Int J Mol Sci 2020; 21:E8774. [PMID: 33233573 PMCID: PMC7699794 DOI: 10.3390/ijms21228774] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 11/18/2020] [Accepted: 11/19/2020] [Indexed: 12/18/2022] Open
Abstract
Aptamers are nucleic acid ligands that bind specifically to a target of interest. Aptamers have gained in popularity due to their high potential for different applications in analysis, diagnostics, and therapeutics. The procedure called systematic evolution of ligands by exponential enrichment (SELEX) is used for aptamer isolation from large nucleic acid combinatorial libraries. The huge number of unique sequences implemented in the in vitro evolution in the SELEX process imposes the necessity of performing extensive sequencing of the selected nucleic acid pools. High-throughput sequencing (HTS) meets this demand of SELEX. Analysis of the data obtained from sequencing of the libraries produced during and after aptamer isolation provides an informative basis for precise aptamer identification and for examining the structure and function of nucleic acid ligands. This review discusses the technical aspects and the potential of the integration of HTS with SELEX.
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Affiliation(s)
- Natalia Komarova
- Scientific-Manufacturing Complex Technological Centre, 1–7 Shokin Square, Zelenograd, 124498 Moscow, Russia; (D.B.); (A.K.)
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11
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Gruenke PR, Alam KK, Singh K, Burke DH. 2'-fluoro-modified pyrimidines enhance affinity of RNA oligonucleotides to HIV-1 reverse transcriptase. RNA (NEW YORK, N.Y.) 2020; 26:1667-1679. [PMID: 32732393 PMCID: PMC7566575 DOI: 10.1261/rna.077008.120] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 07/24/2020] [Indexed: 06/01/2023]
Abstract
Nucleic acid aptamers can be chemically modified to enhance function, but modifying previously selected aptamers can have nontrivial structural and functional consequences. We present a reselection strategy to evaluate the impact of several modifications on preexisting aptamer pools. RNA aptamer libraries with affinity to HIV-1 reverse transcriptase (RT) were retranscribed with 2'-F, 2'-OMe, or 2'-NH2 pyrimidines and subjected to three additional selection cycles. RT inhibition was observed for representative aptamers from several structural families identified by high-throughput sequencing when transcribed with their corresponding modifications. Thus, reselection identified specialized subsets of aptamers that tolerated chemical modifications from unmodified preenriched libraries. Inhibition was the strongest with the 2'-F-pyrimidine (2'-FY) RNAs, as compared to inhibition by the 2'-OMeY and 2'-NH2Y RNAs. Unexpectedly, a diverse panel of retroviral RTs were strongly inhibited by all 2'-FY-modified transcripts, including sequences that do not inhibit those RTs as unmodified RNA. The magnitude of promiscuous RT inhibition was proportional to mole fraction 2'-FY in the transcript. RT binding affinity by 2'-FY transcripts was more sensitive to salt concentration than binding by unmodified transcripts, indicating that interaction with retroviral RTs is more ionic in character for 2'-FY RNA than for unmodified 2'-OH RNA. These surprising features of 2'-FY-modified RNA may have general implications for applied aptamer technologies.
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Affiliation(s)
- Paige R Gruenke
- Department of Biochemistry, University of Missouri, Columbia, Missouri 65211, USA
- Bond Life Sciences Center, University of Missouri, Columbia, Missouri 65211, USA
| | - Khalid K Alam
- Department of Biochemistry, University of Missouri, Columbia, Missouri 65211, USA
- Bond Life Sciences Center, University of Missouri, Columbia, Missouri 65211, USA
| | - Kamal Singh
- Bond Life Sciences Center, University of Missouri, Columbia, Missouri 65211, USA
- Department of Veterinary Pathobiology, University of Missouri, Columbia, Missouri 65211, USA
| | - Donald H Burke
- Department of Biochemistry, University of Missouri, Columbia, Missouri 65211, USA
- Bond Life Sciences Center, University of Missouri, Columbia, Missouri 65211, USA
- Department of Molecular Microbiology and Immunology, University of Missouri, Columbia, Missouri 65211, USA
- Department of Biological Engineering, University of Missouri, Columbia, Missouri 65211, USA
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12
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Shieh KR, Kratschmer C, Maier KE, Greally JM, Levy M, Golden A. AptCompare: optimized de novo motif discovery of RNA aptamers via HTS-SELEX. Bioinformatics 2020; 36:2905-2906. [PMID: 31999328 DOI: 10.1093/bioinformatics/btaa054] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 12/20/2019] [Accepted: 01/22/2020] [Indexed: 11/14/2022] Open
Abstract
SUMMARY High-throughput sequencing can enhance the analysis of aptamer libraries generated by the Systematic Evolution of Ligands by EXponential enrichment. Robust analysis of the resulting sequenced rounds is best implemented by determining a ranked consensus of reads following the processing by multiple aptamer detection algorithms. While several such approaches have been developed to this end, their installation and implementation is problematic. We developed AptCompare, a cross-platform program that combines six of the most widely used analytical approaches for the identification of RNA aptamer motifs and uses a simple weighted ranking to order the candidate aptamers, all driven within the same GUI-enabled environment. We demonstrate AptCompare's performance by identifying the top-ranked candidate aptamers from a previously published selection experiment in our laboratory, with follow-up bench assays demonstrating good correspondence between the sequences' rankings and their binding affinities. AVAILABILITY AND IMPLEMENTATION The source code and pre-built virtual machine images are freely available at https://bitbucket.org/shiehk/aptcompare. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Kevin R Shieh
- Department of Medicine, Maimonides Medical Center, Brooklyn, NY, USA
| | - Christina Kratschmer
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | | | - John M Greally
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY, USA
| | | | - Aaron Golden
- School of Mathematics, Statistics and Applied Mathematics, National University of Ireland, Galway, Galway, Ireland
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13
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Nguyen PDM, Zheng J, Gremminger TJ, Qiu L, Zhang D, Tuske S, Lange MJ, Griffin PR, Arnold E, Chen SJ, Zou X, Heng X, Burke DH. Binding interface and impact on protease cleavage for an RNA aptamer to HIV-1 reverse transcriptase. Nucleic Acids Res 2020; 48:2709-2722. [PMID: 31943114 PMCID: PMC7049723 DOI: 10.1093/nar/gkz1224] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 12/17/2019] [Accepted: 01/03/2020] [Indexed: 12/31/2022] Open
Abstract
RNA aptamers that bind HIV-1 reverse transcriptase (RT) inhibit RT in enzymatic and viral replication assays. Some aptamers inhibit RT from only a few viral clades, while others show broad-spectrum inhibition. Biophysical determinants of recognition specificity are poorly understood. We investigated the interface between HIV-1 RT and a broad–spectrum UCAA-family aptamer. SAR and hydroxyl radical probing identified aptamer structural elements critical for inhibition and established the role of signature UCAA bulge motif in RT-aptamer interaction. HDX footprinting on RT ± aptamer shows strong contacts with both subunits, especially near the C-terminus of p51. Alanine scanning revealed decreased inhibition by the aptamer for mutants P420A, L422A and K424A. 2D proton nuclear magnetic resonance and SAXS data provided constraints on the solution structure of the aptamer and enable computational modeling of the docked complex with RT. Surprisingly, the aptamer enhanced proteolytic cleavage of precursor p66/p66 by HIV-1 protease, suggesting that it stabilizes the productive conformation to allow maturation. These results illuminate features at the RT-aptamer interface that govern recognition specificity by a broad-spectrum antiviral aptamer, and they open new possibilities for accelerating RT maturation and interfering with viral replication.
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Affiliation(s)
- Phuong D M Nguyen
- Department of Biochemistry, University of Missouri, Columbia, MO 65211, USA.,Bond Life Sciences Center, University Missouri, Columbia, MO 65211, USA
| | - Jie Zheng
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL 33458, USA
| | | | - Liming Qiu
- Dalton Cardiovascular Research Center, University Missouri, Columbia, MO 65211, USA
| | - Dong Zhang
- Department of Physics and Astronomy, University Missouri, Columbia, MO 65211, USA
| | - Steve Tuske
- Center for Advanced Biotechnology & Medicine, and Department of Chemistry & Chemical Biology, Rutgers University, Piscataway, NJ 08854, USA
| | - Margaret J Lange
- Department of Molecular Microbiology & Immunology, University Missouri, Columbia, MO 65211, USA
| | - Patrick R Griffin
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Eddy Arnold
- Center for Advanced Biotechnology & Medicine, and Department of Chemistry & Chemical Biology, Rutgers University, Piscataway, NJ 08854, USA
| | - Shi-Jie Chen
- Department of Biochemistry, University of Missouri, Columbia, MO 65211, USA.,Department of Physics and Astronomy, University Missouri, Columbia, MO 65211, USA.,MU Institute for Data Science and Informatics, University Missouri, Columbia, MO 65211, USA
| | - Xiaoqin Zou
- Department of Biochemistry, University of Missouri, Columbia, MO 65211, USA.,Dalton Cardiovascular Research Center, University Missouri, Columbia, MO 65211, USA.,Department of Physics and Astronomy, University Missouri, Columbia, MO 65211, USA.,MU Institute for Data Science and Informatics, University Missouri, Columbia, MO 65211, USA
| | - Xiao Heng
- Department of Biochemistry, University of Missouri, Columbia, MO 65211, USA
| | - Donald H Burke
- Department of Biochemistry, University of Missouri, Columbia, MO 65211, USA.,Bond Life Sciences Center, University Missouri, Columbia, MO 65211, USA.,Department of Molecular Microbiology & Immunology, University Missouri, Columbia, MO 65211, USA
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14
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Liu Q, Zhang W, Chen S, Zhuang Z, Zhang Y, Jiang L, LIN JS. SELEX tool: a novel and convenient gel-based diffusion method for monitoring of aptamer-target binding. J Biol Eng 2020; 14:1. [PMID: 31956340 PMCID: PMC6956507 DOI: 10.1186/s13036-019-0223-y] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 12/29/2019] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Aptamers, single-stranded DNAs or RNAs, can be selected from a library containing random sequences using a method called Systematic Evolution of Ligands by EXponential Enrichment (SELEX). In SELEX, monitoring the enriching statuses of aptamer candidates during the process is a key step until today. Conformational change of an aptamer caused by target-binding in gel can be used to indicate its statuses of binding. RESULTS In this study, an easy-to-implement gel-based diffusion method (GBDM) was developed to monitor the interaction between enriched aptamer candidates and their targets. In order to prove the concept, characterization of aptamers targeting their targets including protein (thrombin) and non-protein molecules (acetamiprid, ATP, atrazine, profenofos and roxithromycin), respectively, were performed using mini gels. Our method has advantages over the common methods including easy performed with labor- and time- saving in experimental operation. The concept has been proven by monitoring enrichment of dynamic aptamer candidate libraries targeting a small molecule 2,2-bis(4-chlorophenyl) acetic acid (DDA) during SELEX process. A mini gel cassette was designed and fabricated by our laboratory to make mini agarose gels for diffusion with different directions. CONCLUSIONS These results indicate that GBDM, in particular, chasing diffusion is suitable for monitoring the interaction between enriched aptamer candidates and their targets. These pioneering efforts are helpful for novel aptamer selection by breaking through the technical bottleneck of aptamer development and helpful for development of novel aptasensors.
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Affiliation(s)
- Qingxiu Liu
- School of Medicine, Huaqiao University, 269 Chenghua Rd, Fengze, Quanzhou, 362021 Fujian China
| | - Wei Zhang
- School of Medicine, Huaqiao University, 269 Chenghua Rd, Fengze, Quanzhou, 362021 Fujian China
| | - Siying Chen
- School of Medicine, Huaqiao University, 269 Chenghua Rd, Fengze, Quanzhou, 362021 Fujian China
| | - Zhenjing Zhuang
- School of Medicine, Huaqiao University, 269 Chenghua Rd, Fengze, Quanzhou, 362021 Fujian China
| | - Yi Zhang
- School of Medicine, Huaqiao University, 269 Chenghua Rd, Fengze, Quanzhou, 362021 Fujian China
| | - Lingli Jiang
- School of Medicine, Huaqiao University, 269 Chenghua Rd, Fengze, Quanzhou, 362021 Fujian China
| | - Jun Sheng LIN
- School of Medicine, Huaqiao University, 269 Chenghua Rd, Fengze, Quanzhou, 362021 Fujian China
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Jeong S, Yang D, Beyene AG, Del Bonis-O’Donnell JT, Gest AMM, Navarro N, Sun X, Landry MP. High-throughput evolution of near-infrared serotonin nanosensors. SCIENCE ADVANCES 2019; 5:eaay3771. [PMID: 31897432 PMCID: PMC6920020 DOI: 10.1126/sciadv.aay3771] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 10/30/2019] [Indexed: 05/11/2023]
Abstract
Imaging neuromodulation with synthetic probes is an emerging technology for studying neurotransmission. However, most synthetic probes are developed through conjugation of fluorescent signal transducers to preexisting recognition moieties such as antibodies or receptors. We introduce a generic platform to evolve synthetic molecular recognition on the surface of near-infrared fluorescent single-wall carbon nanotube (SWCNT) signal transducers. We demonstrate evolution of molecular recognition toward neuromodulator serotonin generated from large libraries of ~6.9 × 1010 unique ssDNA sequences conjugated to SWCNTs. This probe is reversible and produces a ~200% fluorescence enhancement upon exposure to serotonin with a K d = 6.3 μM, and shows selective responsivity over serotonin analogs, metabolites, and receptor-targeting drugs. Furthermore, this probe remains responsive and reversible upon repeat exposure to exogenous serotonin in the extracellular space of acute brain slices. Our results suggest that evolution of nanosensors could be generically implemented to develop other neuromodulator probes with synthetic molecular recognition.
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Affiliation(s)
- Sanghwa Jeong
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Darwin Yang
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Abraham G. Beyene
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, CA 94720, USA
| | | | - Anneliese M. M. Gest
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Nicole Navarro
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Xiaoqi Sun
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Markita P. Landry
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, CA 94720, USA
- Innovative Genomics Institute (IGI), Berkeley, CA 94720, USA
- California Institute for Quantitative Biosciences, QB3, University of California, Berkeley, Berkeley, CA 94720, USA
- Chan Zuckerberg Biohub, San Francisco, CA 94158, USA
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Yan J, Xiong H, Cai S, Wen N, He Q, Liu Y, Peng D, Liu Z. Advances in aptamer screening technologies. Talanta 2019; 200:124-144. [DOI: 10.1016/j.talanta.2019.03.015] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 02/20/2019] [Accepted: 03/02/2019] [Indexed: 02/07/2023]
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17
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Wakui K, Yoshitomi T, Yamaguchi A, Tsuchida M, Saito S, Shibukawa M, Furusho H, Yoshimoto K. Rapidly Neutralizable and Highly Anticoagulant Thrombin-Binding DNA Aptamer Discovered by MACE SELEX. MOLECULAR THERAPY-NUCLEIC ACIDS 2019; 16:348-359. [PMID: 30986696 PMCID: PMC6462803 DOI: 10.1016/j.omtn.2019.03.002] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 03/08/2019] [Accepted: 03/08/2019] [Indexed: 02/07/2023]
Abstract
We present a rapidly neutralizable and highly anticoagulant thrombin-binding aptamer with a short toehold sequence, originally discovered by systematic evolution of ligands by exponential enrichment (SELEX) with microbead-assisted capillary electrophoresis (MACE). MACE is a novel CE-partitioning method for SELEX and able to separate aptamers from a library of unbound nucleic acids, where the aptamer and target complexes can be detected reliably and partitioned with high purity even in the first selection cycle. Three selection rounds of MACE-SELEX discovered several TBAs with a nanomolar affinity (Kd = 4.5-8.2 nM) that surpasses previously reported TBAs such as HD1, HD22, and NU172 (Kd = 118, 13, and 12 nM, respectively). One of the obtained aptamers, M08, showed a 10- to 20-fold longer prolonged clotting time than other anticoagulant TBAs, such as HD1, NU172, RE31, and RA36. Analyses of the aptamer and thrombin complexes using both bare and coated capillaries suggested that a large number of efficient aptamers are missed in conventional CE-SELEX because of increased interaction between the complex and the capillary. In addition, the toehold-mediated rapid antidote was designed for safe administration. The efficient aptamer and antidote system developed in the present study could serve as a new candidate for anticoagulant therapy.
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Affiliation(s)
- Koji Wakui
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan
| | - Toru Yoshitomi
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan
| | - Akane Yamaguchi
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan
| | - Maho Tsuchida
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570, Japan
| | - Shingo Saito
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570, Japan
| | - Masami Shibukawa
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570, Japan
| | - Hitoshi Furusho
- Chemical General Division, Nissan Chemical Industries, Ltd., 2-10-2 Tsuboi-nishi, Funabashi, Chiba 274-8507, Japan
| | - Keitaro Yoshimoto
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan; JST, PRESTO, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan.
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18
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Cole KH, Lupták A. High-throughput methods in aptamer discovery and analysis. Methods Enzymol 2019; 621:329-346. [PMID: 31128787 DOI: 10.1016/bs.mie.2019.02.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Aptamers are small, functional nucleic acids that bind a variety of targets, often with high specificity and affinity. Genomic aptamers constitute the ligand-binding domains of riboswitches, whereas synthetic aptamers find applications as diagnostic and therapeutic tools, and as ligand-binding domains of regulatory RNAs in synthetic biology. Discovery and characterization of aptamers has been limited by a lack of high-throughput approaches that uncover the target-binding domains and the biochemical properties of individual sequences. With the advent of high-throughput sequencing, large-scale analysis of in vitro selected populations of aptamers (and catalytic nucleic acids, such as ribozymes and DNAzmes) became possible. In recent years the development of new experimental approaches and software tools has led to significant streamlining of the selection-pool analysis. This article provides an overview of post-selection data analysis and describes high-throughput methods that facilitate rapid discovery and biochemical characterization of aptamers.
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Affiliation(s)
- Kyle H Cole
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, United States
| | - Andrej Lupták
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, United States; Department of Pharmaceutical Sciences, University of California, Irvine, CA, United States; Department of Chemistry, University of California, Irvine, CA, United States.
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19
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Poly-Target Selection Identifies Broad-Spectrum RNA Aptamers. MOLECULAR THERAPY. NUCLEIC ACIDS 2018; 13:605-619. [PMID: 30472639 PMCID: PMC6251793 DOI: 10.1016/j.omtn.2018.10.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 10/18/2018] [Accepted: 10/19/2018] [Indexed: 12/18/2022]
Abstract
Aptamer selections often yield distinct subpopulations, each with unique phenotypes that can be leveraged for specialized applications. Although most selections aim to attain ever higher specificity, we sought to identify aptamers that recognize increasingly divergent primate lentiviral reverse transcriptases (RTs). We hypothesized that aptamer subpopulations in libraries pre-enriched against a single RT may exhibit broad-spectrum binding and inhibition, and we devised a multiplexed poly-target selection to elicit those phenotypes against a panel of primate lentiviral RTs. High-throughput sequencing and coenrichment/codepletion analysis of parallel and duplicate selection trajectories rapidly narrowed the list of candidate aptamers by orders of magnitude and identified dozens of priority candidates for further screening. Biochemical characterization validated a novel aptamer motif and several rare and unobserved variants of previously known motifs that inhibited recombinant RTs to varying degrees. These broad-spectrum aptamers also suppressed replication of viral constructs carrying phylogenetically diverse RTs. The poly-target selection and coenrichment/codepletion approach described herein is a generalizable strategy for identifying cross-reactivity among related targets from combinatorial libraries.
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20
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Nguyen Quang N, Bouvier C, Henriques A, Lelandais B, Ducongé F. Time-lapse imaging of molecular evolution by high-throughput sequencing. Nucleic Acids Res 2018; 46:7480-7494. [PMID: 29982617 PMCID: PMC6125620 DOI: 10.1093/nar/gky583] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 06/12/2018] [Accepted: 06/15/2018] [Indexed: 12/19/2022] Open
Abstract
High-throughput sequencing of in vitro selection could artificially provide large quantities of relic sequences from known times of molecular evolution. Here, we demonstrate how it can be used to reconstruct an empirical genealogical evolutionary (EGE) tree of an aptamer family. In contrast to classical phylogenetic trees, this tree-diagram represents proliferation and extinction of sequences within a population during rounds of selection. Such information, which corresponds to their evolutionary fitness, is used to infer which sequences may have been mutated through the selection process that led to the appearance and spreading of new sequences. This approach was validated by the re-analysis of an in vitro selection that had previously identified an aptamer against Annexin A2. It revealed that this aptamer might be the descendant of a sequence that was more highly amplified in early rounds. It also succeeded in predicting improved variants of this aptamer and providing a means to understand the influence of selection pressure on evolution. This is the first demonstration that HTS can provide time-lapse imaging of the evolutionary pathway that is taken by a macromolecule during in vitro selection to evolve by successive mutations through better fitness.
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Affiliation(s)
- Nam Nguyen Quang
- CEA, Fundamental Research Division (DRF), Institut of Biology François Jacob (Jacob), Molecular Imaging Research Center (MIRCen), Fontenay-aux-Roses, France
- Neurodegenerative Diseases Laboratory, CNRS CEA UMR 9199, Fontenay-aux-Roses, France
- Université Paris-Saclay, Université Paris-Sud, Orsay, France
| | - Clément Bouvier
- CEA, Fundamental Research Division (DRF), Institut of Biology François Jacob (Jacob), Molecular Imaging Research Center (MIRCen), Fontenay-aux-Roses, France
- Neurodegenerative Diseases Laboratory, CNRS CEA UMR 9199, Fontenay-aux-Roses, France
- Université Pierre et Marie Curie, Paris, France
| | - Adrien Henriques
- CEA, Fundamental Research Division (DRF), Institut of Biology François Jacob (Jacob), Molecular Imaging Research Center (MIRCen), Fontenay-aux-Roses, France
- Neurodegenerative Diseases Laboratory, CNRS CEA UMR 9199, Fontenay-aux-Roses, France
- Université Paris-Saclay, Université Paris-Sud, Orsay, France
| | - Benoit Lelandais
- CEA, Fundamental Research Division (DRF), Institut of Biology François Jacob (Jacob), Molecular Imaging Research Center (MIRCen), Fontenay-aux-Roses, France
- Neurodegenerative Diseases Laboratory, CNRS CEA UMR 9199, Fontenay-aux-Roses, France
- Université Paris-Saclay, Université Paris-Sud, Orsay, France
| | - Frédéric Ducongé
- CEA, Fundamental Research Division (DRF), Institut of Biology François Jacob (Jacob), Molecular Imaging Research Center (MIRCen), Fontenay-aux-Roses, France
- Neurodegenerative Diseases Laboratory, CNRS CEA UMR 9199, Fontenay-aux-Roses, France
- Université Paris-Saclay, Université Paris-Sud, Orsay, France
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21
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Kinghorn AB, Fraser LA, Liang S, Shiu SCC, Tanner JA. Aptamer Bioinformatics. Int J Mol Sci 2017; 18:E2516. [PMID: 29186809 PMCID: PMC5751119 DOI: 10.3390/ijms18122516] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 11/17/2017] [Accepted: 11/20/2017] [Indexed: 02/07/2023] Open
Abstract
Aptamers are short nucleic acid sequences capable of specific, high-affinity molecular binding. They are isolated via SELEX (Systematic Evolution of Ligands by Exponential Enrichment), an evolutionary process that involves iterative rounds of selection and amplification before sequencing and aptamer characterization. As aptamers are genetic in nature, bioinformatic approaches have been used to improve both aptamers and their selection. This review will discuss the advancements made in several enclaves of aptamer bioinformatics, including simulation of aptamer selection, fragment-based aptamer design, patterning of libraries, identification of lead aptamers from high-throughput sequencing (HTS) data and in silico aptamer optimization.
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Affiliation(s)
| | | | | | | | - Julian A. Tanner
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR China; (A.B.K.); (L.A.F.); (S.L.); (S.C.-C.S.)
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22
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Lange MJ, Nguyen PDM, Callaway MK, Johnson MC, Burke DH. RNA-protein interactions govern antiviral specificity and encapsidation of broad spectrum anti-HIV reverse transcriptase aptamers. Nucleic Acids Res 2017; 45:6087-6097. [PMID: 28334941 PMCID: PMC5449596 DOI: 10.1093/nar/gkx155] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Accepted: 03/02/2017] [Indexed: 11/29/2022] Open
Abstract
RNA aptamers that bind HIV-1 reverse transcriptase (RT) inhibit HIV-1 replication, but little is known about potential aptamer-specific viral resistance. During replication, RT interacts with diverse nucleic acids. Thus, the genetic threshold for eliciting resistance may be high for aptamers that make numerous contacts with RT. To evaluate the impact of RT–aptamer binding specificity on replication, we engineered proviral plasmids encoding diverse RTs within the backbone of HIV-1 strain NL4-3. Viruses inhibited by pseudoknot aptamers were rendered insensitive by a naturally occurring R277K variant, providing the first demonstration of aptamer-specific resistance in cell culture. Naturally occurring, pseudoknot-insensitive viruses were rendered sensitive by the inverse K277R mutation, establishing RT as the genetic locus for aptamer-mediated HIV-1 inhibition. Non-pseudoknot RNA aptamers exhibited broad-spectrum inhibition. Inhibition was observed only when virus was produced in aptamer-expressing cells, indicating that encapsidation is required. HIV-1 suppression magnitude correlated with the number of encapsidated aptamer transcripts per virion, with saturation occurring around 1:1 stoichiometry with packaged RT. Encapsidation specificity suggests that aptamers may encounter dimerized GagPol in the cytosol during viral assembly. This study provides new insights into HIV-1's capacity to escape aptamer-mediated inhibition, the potential utility of broad-spectrum aptamers to overcome resistance, and molecular interactions that occur during viral assembly.
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Affiliation(s)
- Margaret J Lange
- Department of Molecular Microbiology & Immunology, University of Missouri, Columbia, MO 65211, USA.,Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
| | - Phuong D M Nguyen
- Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA.,Department of Biochemistry, University of Missouri, Columbia, MO 65211, USA
| | - Mackenzie K Callaway
- Department of Biological Engineering, University of Missouri, Columbia, MO 65211, USA
| | - Marc C Johnson
- Department of Molecular Microbiology & Immunology, University of Missouri, Columbia, MO 65211, USA.,Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
| | - Donald H Burke
- Department of Molecular Microbiology & Immunology, University of Missouri, Columbia, MO 65211, USA.,Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA.,Department of Biochemistry, University of Missouri, Columbia, MO 65211, USA.,Department of Biological Engineering, University of Missouri, Columbia, MO 65211, USA
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23
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Pei S, Slinger BL, Meyer MM. Recognizing RNA structural motifs in HT-SELEX data for ribosomal protein S15. BMC Bioinformatics 2017; 18:298. [PMID: 28587636 PMCID: PMC5461778 DOI: 10.1186/s12859-017-1704-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 05/22/2017] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND Proteins recognize many different aspects of RNA ranging from single stranded regions to discrete secondary or tertiary structures. High-throughput sequencing (HTS) of in vitro selected populations offers a large scale method to study RNA-proteins interactions. However, most existing analysis methods require that the binding motifs are enriched in the population relative to earlier rounds, and that motifs are found in a loop or single stranded region of the potential RNA secondary structure. Such methods do not generalize to all RNA-protein interaction as some RNA binding proteins specifically recognize more complex structures such as double stranded RNA. RESULTS In this study, we use HT-SELEX derived populations to study the landscape of RNAs that interact with Geobacillus kaustophilus ribosomal protein S15. Our data show high sequence and structure diversity and proved intractable to existing methods. Conventional programs identified some sequence motifs, but these are found in less than 5-10% of the total sequence pool. Therefore, we developed a novel framework to analyze HT-SELEX data. Our process accounts for both sequence and structure components by abstracting the overall secondary structure into smaller substructures composed of a single base-pair stack, which allows us to leverage existing approaches already used in k-mer analysis to identify enriched motifs. By focusing on secondary structure motifs composed of specific two base-pair stacks, we identified significantly enriched or depleted structure motifs relative to earlier rounds. CONCLUSIONS Discrete substructures are likely to be important to RNA-protein interactions, but they are difficult to elucidate. Substructures can help make highly diverse sequence data more tractable. The structure motifs provide limited accuracy in predicting enrichment suggesting that G. kaustophilus S15 can either recognize many different secondary structure motifs or some aspects of the interaction are not captured by the analysis. This highlights the importance of considering secondary and tertiary structure elements and their role in RNA-protein interactions.
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Affiliation(s)
- Shermin Pei
- Boston College, 140 Commonwealth Ave., 02467, Chestnut Hill, USA
| | - Betty L Slinger
- Boston College, 140 Commonwealth Ave., 02467, Chestnut Hill, USA
| | - Michelle M Meyer
- Boston College, 140 Commonwealth Ave., 02467, Chestnut Hill, USA.
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24
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Amano R, Aoki K, Miyakawa S, Nakamura Y, Kozu T, Kawai G, Sakamoto T. NMR monitoring of the SELEX process to confirm enrichment of structured RNA. Sci Rep 2017; 7:283. [PMID: 28325909 PMCID: PMC5428055 DOI: 10.1038/s41598-017-00273-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 02/15/2017] [Indexed: 01/20/2023] Open
Abstract
RNA aptamers are RNA molecules that bind to a target molecule with high affinity and specificity using uniquely-folded tertiary structures. RNA aptamers are selected from an RNA pool typically comprising up to 1015 different sequences generated by iterative steps of selection and amplification known as Systematic Evolution of Ligands by EXponential enrichment (SELEX). Over several rounds of SELEX, the diversity of the RNA pool decreases and the aptamers are enriched. Hence, monitoring of the enrichment of these RNA pools is critical for the successful selection of aptamers, and several methods for monitoring them have been developed. In this study, we measured one-dimensional imino proton NMR spectra of RNA pools during SELEX. The spectrum of the initial RNA pool indicates that the RNAs adopt tertiary structures. The structural diversity of the RNA pools was shown to depend highly on the design of the primer-binding sequence. Furthermore, we demonstrate that enrichment of RNA aptamers can be monitored using NMR. The RNA pools can be recovered from the NMR tube after measurement of NMR spectra. We also can monitor target binding in the NMR tubes. Thus, we propose using NMR to monitor the enrichment of structured aptamers during the SELEX process.
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Affiliation(s)
- Ryo Amano
- Department of Life and Environmental Sciences, Faculty of Engineering, Chiba Institute of Technology, 2-17-1 Tsudanuma, Narashino, Chiba, 275-0016, Japan
| | - Kazuteru Aoki
- Ribomic Inc., 3-16-13 Shirokanedai, Minato-ku, Tokyo, 108-0071, Japan
| | - Shin Miyakawa
- Ribomic Inc., 3-16-13 Shirokanedai, Minato-ku, Tokyo, 108-0071, Japan
| | - Yoshikazu Nakamura
- Ribomic Inc., 3-16-13 Shirokanedai, Minato-ku, Tokyo, 108-0071, Japan
- Department of Basic Medical Sciences, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo, 108-8639, Japan
| | - Tomoko Kozu
- Research Institute for Clinical Oncology, Saitama Cancer Center, 818 Komuro, Ina, Kitaadachi-gun, Saitama, 362-0806, Japan
| | - Gota Kawai
- Department of Life and Environmental Sciences, Faculty of Engineering, Chiba Institute of Technology, 2-17-1 Tsudanuma, Narashino, Chiba, 275-0016, Japan
| | - Taiichi Sakamoto
- Department of Life and Environmental Sciences, Faculty of Engineering, Chiba Institute of Technology, 2-17-1 Tsudanuma, Narashino, Chiba, 275-0016, Japan.
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25
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Recurrent RNA motifs as scaffolds for genetically encodable small-molecule biosensors. Nat Chem Biol 2017; 13:295-301. [PMID: 28092358 PMCID: PMC5310984 DOI: 10.1038/nchembio.2278] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 11/21/2016] [Indexed: 12/05/2022]
Abstract
Allosteric RNA devices are increasingly viewed as important tools capable of monitoring enzyme evolution, optimizing engineered metabolic pathways, facilitating gene discovery and regulators of nucleic acid-based therapeutics. A key bottleneck in the development of these platforms is the availability of small molecule binding RNA aptamers that robustly function in the cellular environment. While aptamers can be raised against nearly any desired target by in vitro selection, many cannot be easily integrated into devices or do not reliably function in a cellular context. Here, we describe a new approach using secondary and tertiary structural scaffolds derived from biologically active riboswitches and small ribozymes. Applied to neurotransmitter precursors 5-hydroxytryptophan and 3,4-dihydroxyphenylalanine, this approach yields easily identifiable and characterizable aptamers predisposed for coupling to readout domains to engineer nucleic acid sensory devices that function in vitro and in the cellular context.
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26
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Nguyen Quang N, Perret G, Ducongé F. Applications of High-Throughput Sequencing for In Vitro Selection and Characterization of Aptamers. Pharmaceuticals (Basel) 2016; 9:ph9040076. [PMID: 27973417 PMCID: PMC5198051 DOI: 10.3390/ph9040076] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 12/06/2016] [Accepted: 12/07/2016] [Indexed: 12/21/2022] Open
Abstract
Aptamers are identified through an iterative process of evolutionary selection starting from a random pool containing billions of sequences. Simultaneously to the amplification of high-affinity candidates, the diversity in the pool is exponentially reduced after several rounds of in vitro selection. Until now, cloning and Sanger sequencing of about 100 sequences was usually used to identify the enriched candidates. However, High-Throughput Sequencing (HTS) is now extensively used to replace such low throughput sequencing approaches. Providing a deeper analysis of the library, HTS is expected to accelerate the identification of aptamers as well as to identify aptamers with higher affinity. It is also expected that it can provide important information on the binding site of the aptamers. Nevertheless, HTS requires handling a large amount of data that is only possible through the development of new in silico methods. Here, this review presents these different strategies that have been recently developed to improve the identification and characterization of aptamers using HTS.
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Affiliation(s)
- Nam Nguyen Quang
- CEA, DSV, I²BM, Molecular Imaging Research Center (MIRCen), 18 route du panorama, 92260 Fontenay-aux-Roses, France.
- Neurodegenerative Diseases Laboratory, Centre National de la Recherche Scientifique (CNRS), Université Paris-Saclay, Université Paris-Sud, UMR 9199, 92260 Fontenay-aux-Roses, France.
| | - Gérald Perret
- LFB Biotechnologies, 3 avenue des Tropiques, 91958 Courtaboeuf CEDEX, France.
| | - Frédéric Ducongé
- CEA, DSV, I²BM, Molecular Imaging Research Center (MIRCen), 18 route du panorama, 92260 Fontenay-aux-Roses, France.
- Neurodegenerative Diseases Laboratory, Centre National de la Recherche Scientifique (CNRS), Université Paris-Saclay, Université Paris-Sud, UMR 9199, 92260 Fontenay-aux-Roses, France.
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Aptamer Selection Technology and Recent Advances. MOLECULAR THERAPY. NUCLEIC ACIDS 2016; 4:e223. [PMID: 28110747 PMCID: PMC4345306 DOI: 10.1038/mtna.2014.74] [Citation(s) in RCA: 219] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 12/04/2014] [Indexed: 02/07/2023]
Abstract
Over the last decade, aptamers have begun to find their way from basic research to diverse commercial applications. The development of diagnostics is even more widespread than clinical applications because aptamers do not have to be extensively modified to enhance their in vivo stability and pharmacokinetics in diagnostic assays. The increasing attention has propelled the technical progress of the in vitro selection technology (SELEX) to enhance the efficiency of developing aptamers for commercially interesting targets. This review highlights recent progress in the technical steps of a SELEX experiment with a focus on high-throughput next-generation sequencing and bioinformatics. Achievements have been made in the optimization of aptamer libraries, separation schemes, amplification of the selected libraries and the identification of aptamer sequences from enriched libraries.
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Blank M. Next-Generation Analysis of Deep Sequencing Data: Bringing Light into the Black Box of SELEX Experiments. Methods Mol Biol 2016; 1380:85-95. [PMID: 26552818 DOI: 10.1007/978-1-4939-3197-2_7] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In silico analysis of next-generation sequencing data (NGS; also termed deep sequencing) derived from in vitro selection experiments enables the analysis of the SELEX procedure (Systematic Evolution of Ligands by EXponential enrichment) in an unprecedented depth and improves the identification of aptamers. Besides quality control and optimization of starting libraries, advanced screening strategies for difficult targets or early identification of rare but high quality aptamers which are otherwise lost in the in vitro selection experiments become possible. The high information content of sequence data obtained from selection experiments is furthermore useful for subsequent lead optimization.
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Jijakli K, Khraiwesh B, Fu W, Luo L, Alzahmi A, Koussa J, Chaiboonchoe A, Kirmizialtin S, Yen L, Salehi-Ashtiani K. The in vitro selection world. Methods 2016; 106:3-13. [PMID: 27312879 DOI: 10.1016/j.ymeth.2016.06.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 05/23/2016] [Accepted: 06/07/2016] [Indexed: 12/20/2022] Open
Abstract
Through iterative cycles of selection, amplification, and mutagenesis, in vitro selection provides the ability to isolate molecules of desired properties and function from large pools (libraries) of random molecules with as many as 10(16) distinct species. This review, in recognition of a quarter of century of scientific discoveries made through in vitro selection, starts with a brief overview of the method and its history. It further covers recent developments in in vitro selection with a focus on tools that enhance the capabilities of in vitro selection and its expansion from being purely a nucleic acids selection to that of polypeptides and proteins. In addition, we cover how next generation sequencing and modern biological computational tools are being used to complement in vitro selection experiments. On the very least, sequencing and computational tools can translate the large volume of information associated with in vitro selection experiments to manageable, analyzable, and exploitable information. Finally, in vivo selection is briefly compared and contrasted to in vitro selection to highlight the unique capabilities of each method.
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Affiliation(s)
- Kenan Jijakli
- Laboratory of Algal, Systems, and Synthetic Biology, Division of Science and Math, and Center for Genomics and Systems Biology (CGSB), New York University Abu Dhabi, P.O. Box 129188, Abu Dhabi, United Arab Emirates
| | - Basel Khraiwesh
- Laboratory of Algal, Systems, and Synthetic Biology, Division of Science and Math, and Center for Genomics and Systems Biology (CGSB), New York University Abu Dhabi, P.O. Box 129188, Abu Dhabi, United Arab Emirates
| | - Weiqi Fu
- Laboratory of Algal, Systems, and Synthetic Biology, Division of Science and Math, and Center for Genomics and Systems Biology (CGSB), New York University Abu Dhabi, P.O. Box 129188, Abu Dhabi, United Arab Emirates
| | - Liming Luo
- Department of Pathology & Immunology, Department of Molecular and Cellular Biology, Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Amnah Alzahmi
- Laboratory of Algal, Systems, and Synthetic Biology, Division of Science and Math, and Center for Genomics and Systems Biology (CGSB), New York University Abu Dhabi, P.O. Box 129188, Abu Dhabi, United Arab Emirates
| | - Joseph Koussa
- Laboratory of Algal, Systems, and Synthetic Biology, Division of Science and Math, and Center for Genomics and Systems Biology (CGSB), New York University Abu Dhabi, P.O. Box 129188, Abu Dhabi, United Arab Emirates
| | - Amphun Chaiboonchoe
- Laboratory of Algal, Systems, and Synthetic Biology, Division of Science and Math, and Center for Genomics and Systems Biology (CGSB), New York University Abu Dhabi, P.O. Box 129188, Abu Dhabi, United Arab Emirates
| | - Serdal Kirmizialtin
- Chemistry Program, Division of Science and Math, New York University Abu Dhabi, P.O. Box 129188, Abu Dhabi, United Arab Emirates
| | - Laising Yen
- Department of Pathology & Immunology, Department of Molecular and Cellular Biology, Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Kourosh Salehi-Ashtiani
- Laboratory of Algal, Systems, and Synthetic Biology, Division of Science and Math, and Center for Genomics and Systems Biology (CGSB), New York University Abu Dhabi, P.O. Box 129188, Abu Dhabi, United Arab Emirates.
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Bjerregaard N, Andreasen PA, Dupont DM. Expected and unexpected features of protein-binding RNA aptamers. WILEY INTERDISCIPLINARY REVIEWS-RNA 2016; 7:744-757. [PMID: 27173731 DOI: 10.1002/wrna.1360] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 04/03/2016] [Accepted: 04/04/2016] [Indexed: 12/28/2022]
Abstract
RNA molecules with high affinity to specific proteins can be isolated from libraries of up to 1016 different RNA sequences by systematic evolution of ligands by exponential enrichment (SELEX). These so-called protein-binding RNA aptamers are often interesting, e.g., as modulators of protein function for therapeutic use, for probing the conformations of proteins, for studies of basic aspects of nucleic acid-protein interactions, etc. Studies on the interactions between RNA aptamers and proteins display a number of expected and unexpected features, including the chemical nature of the interacting RNA-protein surfaces, the conformation of protein-bound aptamer versus free aptamer, the conformation of aptamer-bound protein versus free protein, and the effects of aptamers on protein function. Here, we review current insights into the details of RNA aptamer-protein interactions. WIREs RNA 2016, 7:744-757. doi: 10.1002/wrna.1360 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Nils Bjerregaard
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Peter A Andreasen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Daniel M Dupont
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark.
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Abstract
Nucleic acid aptamers are promising alternatives to antibodies in analytics. They are generally obtained through an iterative SELEX protocol that enriches a population of synthetic oligonucleotides to a subset that can recognize the chosen target molecule specifically and avidly. A wide range of targets is recognized by aptamers. Once identified and optimized for performance, aptamers can be reproducibly synthesized and offer other key features, like small size, low cost, sensitivity, specificity, rapid response, stability, and reusability. This makes them excellent options for sensory units in a variety of analytical platforms including those with electrochemical, optical, and mass sensitive transduction detection. Many novel sensing strategies have been developed by rational design to take advantage of the tendency of aptamers to undergo conformational changes upon target/analyte binding and employing the principles of base complementarity that can drive the nucleic acid structure. Despite their many advantages over antibodies, surprisingly few aptamers have yet been integrated into commercially available analytical devices. In this review, we discuss how to select and engineer aptamers for their identified application(s), some of the challenges faced in developing aptamers for analytics and many examples of their reported successful performance as sensors in a variety of analytical platforms.
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Affiliation(s)
- Muslum Ilgu
- Roy J Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames IA 50011, USA. and Aptalogic Inc., Ames IA 50014, USA
| | - Marit Nilsen-Hamilton
- Roy J Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames IA 50011, USA. and Aptalogic Inc., Ames IA 50014, USA and Ames Laboratory, US DOE, Ames IA 50011, USA
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Ligation of RNA Oligomers by the Schistosoma mansoni Hammerhead Ribozyme in Frozen Solution. J Mol Evol 2016; 82:81-92. [PMID: 26897022 DOI: 10.1007/s00239-016-9729-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Accepted: 02/10/2016] [Indexed: 01/29/2023]
Abstract
The interstitial liquid phase within frozen aqueous solutions is an environment that minimizes RNA degradation and facilitates reactions that may have relevance to the RNA World hypothesis. Previous work has shown that frozen solutions support condensation of activated nucleotides into RNA oligomers, RNA ligation by the hairpin ribozyme, and RNA synthesis by a RNA polymerase ribozyme. In the current study, we examined the activity of a hammerhead ribozyme (HHR) in frozen solution. The Schistosoma mansoni hammerhead ribozyme, which predominantly cleaves RNA, can ligate its cleaved products (P1 and P2) with yields up to ~23 % in single turnover experiments at 25 °C in the presence of Mg(2+). Our studies show that this HHR ligates RNA oligomers in frozen solution in the absence of divalent cations. Citrate and other anions that exhibit strong ion-water affinity enhanced ligation. Yields up to 43 % were observed in one freeze-thaw cycle and a maximum of 60 % was obtained after several freeze-thaw cycles using wild-type P1 and P2. Truncated and mutated P1 substrates were ligated to P2 with yields of 14-24 % in one freeze-thaw cycle. A pool of P2 substrates with mixtures of all four bases at five positions were ligated with P1 in frozen solution. High-throughput sequencing indicated that 70 of the 1024 possible P2 sequences were represented in ligated products at 1000 or more read counts per million reads. The results indicate that the HHR can ligate a range of short RNA oligomers into an ensemble of diverse sequences in ice.
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Alves Ferreira-Bravo I, Cozens C, Holliger P, DeStefano JJ. Selection of 2'-deoxy-2'-fluoroarabinonucleotide (FANA) aptamers that bind HIV-1 reverse transcriptase with picomolar affinity. Nucleic Acids Res 2015; 43:9587-99. [PMID: 26476448 PMCID: PMC4751925 DOI: 10.1093/nar/gkv1057] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 10/02/2015] [Indexed: 11/17/2022] Open
Abstract
Using a Systematic Evolution of Ligands by Exponential Enrichment (SELEX) protocol capable of selecting xeno-nucleic acid (XNA) aptamers, a 2′-deoxy-2′-fluoroarabinonucleotide (FANA) aptamer (referred to as FA1) to HIV-1 reverse transcriptase (HIV-1 RT) was selected. FA1 bound HIV-1 RT with KD,app values in the low pM range under different ionic conditions. Comparisons to published HIV-1 RT RNA and DNA aptamers indicated that FA1 bound at least as well as these aptamers. FA1 contained a 20 nucleotide 5′ DNA sequence followed by a 57 nucleotide region of FANA nucleotides. Removal of the fourteen 5′ DNA nucleotides did not affect binding. FA1's predicted structure was composed of four stems and four loops. All stem nucleotides could be modified to G-C base pairs (14 total changes) with a small effect on binding. Eliminating or altering most loop sequences reduced or abolished tight binding. Overall, results suggested that the structure and the sequence of FA1 were important for binding. FA1 showed strong inhibition of HIV-1 RT in extension assays while no specific binding to avian myeloblastosis or Moloney murine leukemia RTs was detected. A complete DNA version of FA1 showed low binding to HIV-1 RT, emphasizing the unique properties of FANA in HIV-1 RT binding.
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Affiliation(s)
- Irani Alves Ferreira-Bravo
- Cell Biology and Molecular Genetics, Bioscience Research Building, University of Maryland, College Park, MD 20742, USA Maryland Pathogen Research Institute, College Park, MD 20742, USA
| | - Christopher Cozens
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, UK
| | - Philipp Holliger
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, UK
| | - Jeffrey J DeStefano
- Cell Biology and Molecular Genetics, Bioscience Research Building, University of Maryland, College Park, MD 20742, USA Maryland Pathogen Research Institute, College Park, MD 20742, USA
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Caroli J, Taccioli C, De La Fuente A, Serafini P, Bicciato S. APTANI: a computational tool to select aptamers through sequence-structure motif analysis of HT-SELEX data. Bioinformatics 2015; 32:161-4. [PMID: 26395772 DOI: 10.1093/bioinformatics/btv545] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 09/09/2015] [Indexed: 11/14/2022] Open
Abstract
MOTIVATION Aptamers are synthetic nucleic acid molecules that can bind biological targets in virtue of both their sequence and three-dimensional structure. Aptamers are selected using SELEX, Systematic Evolution of Ligands by EXponential enrichment, a technique that exploits aptamer-target binding affinity. The SELEX procedure, coupled with high-throughput sequencing (HT-SELEX), creates billions of random sequences capable of binding different epitopes on specific targets. Since this technique produces enormous amounts of data, computational analysis represents a critical step to screen and select the most biologically relevant sequences. RESULTS Here, we present APTANI, a computational tool to identify target-specific aptamers from HT-SELEX data and secondary structure information. APTANI builds on AptaMotif algorithm, originally implemented to analyze SELEX data; extends the applicability of AptaMotif to HT-SELEX data and introduces new functionalities, as the possibility to identify binding motifs, to cluster aptamer families or to compare output results from different HT-SELEX cycles. Tabular and graphical representations facilitate the downstream biological interpretation of results. AVAILABILITY AND IMPLEMENTATION APTANI is available at http://aptani.unimore.it. CONTACT silvio.bicciato@unimore.it SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- J Caroli
- Center for Genome Research, Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy and
| | - C Taccioli
- Center for Genome Research, Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy and
| | - A De La Fuente
- Department of Microbiology & Immunology, UM/Sylvester Comprehensive Cancer Center, Leonard M. Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - P Serafini
- Department of Microbiology & Immunology, UM/Sylvester Comprehensive Cancer Center, Leonard M. Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - S Bicciato
- Center for Genome Research, Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy and
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Kun Á, Szathmáry E. Fitness Landscapes of Functional RNAs. Life (Basel) 2015; 5:1497-517. [PMID: 26308059 PMCID: PMC4598650 DOI: 10.3390/life5031497] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Revised: 07/26/2015] [Accepted: 08/03/2015] [Indexed: 11/16/2022] Open
Abstract
The notion of fitness landscapes, a map between genotype and fitness, was proposed more than 80 years ago. For most of this time data was only available for a few alleles, and thus we had only a restricted view of the whole fitness landscape. Recently, advances in genetics and molecular biology allow a more detailed view of them. Here we review experimental and theoretical studies of fitness landscapes of functional RNAs, especially aptamers and ribozymes. We find that RNA structures can be divided into critical structures, connecting structures, neutral structures and forbidden structures. Such characterisation, coupled with theoretical sequence-to-structure predictions, allows us to construct the whole fitness landscape. Fitness landscapes then can be used to study evolution, and in our case the development of the RNA world.
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Affiliation(s)
- Ádám Kun
- Parmenides Center for the Conceptual Foundations of Science, Kirchplatz 1, 82049 Munich/Pullach, Germany.
- MTA-ELTE-MTMT Ecology Research Group, Pázmány Péter sétány 1/C, 1117 Budapest, Hungary.
- Department of Plant Systematics, Ecology and Theoretical Biology, Institute of Biology, Eötvös University, Pázmány Péter sétány 1/C, 1117 Budapest, Hungary.
| | - Eörs Szathmáry
- Parmenides Center for the Conceptual Foundations of Science, Kirchplatz 1, 82049 Munich/Pullach, Germany.
- Department of Plant Systematics, Ecology and Theoretical Biology, Institute of Biology, Eötvös University, Pázmány Péter sétány 1/C, 1117 Budapest, Hungary.
- MTA-ELTE Theoretical Biology and Evolutionary Ecology Research Group, Pázmány Péter sétány 1/C, 1117 Budapest, Hungary.
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36
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Dupont DM, Larsen N, Jensen JK, Andreasen PA, Kjems J. Characterisation of aptamer-target interactions by branched selection and high-throughput sequencing of SELEX pools. Nucleic Acids Res 2015; 43:e139. [PMID: 26163061 PMCID: PMC4666376 DOI: 10.1093/nar/gkv700] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 06/30/2015] [Indexed: 01/05/2023] Open
Abstract
Nucleic acid aptamer selection by systematic evolution of ligands by exponential enrichment (SELEX) has shown great promise for use in the development of research tools, therapeutics and diagnostics. Typically, aptamers are identified from libraries containing up to 1016 different RNA or DNA sequences by 5–10 rounds of affinity selection towards a target of interest. Such library screenings can result in complex pools of many target-binding aptamers. New high-throughput sequencing techniques may potentially revolutionise aptamer selection by allowing quantitative assessment of the dynamic changes in the pool composition during the SELEX process and by facilitating large-scale post-SELEX characterisation. In the present study, we demonstrate how high-throughput sequencing of SELEX pools, before and after a single round of branched selection for binding to different target variants, can provide detailed information about aptamer binding sites, preferences for specific target conformations, and functional effects of the aptamers. The procedure was applied on a diverse pool of 2′-fluoropyrimidine-modified RNA enriched for aptamers specific for the serpin plasminogen activator inhibitor-1 (PAI-1) through five rounds of standard selection. The results demonstrate that it is possible to perform large-scale detailed characterisation of aptamer sequences directly in the complex pools obtained from library selection methods, thus without the need to produce individual aptamers.
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Affiliation(s)
- Daniel M Dupont
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark Danish-Chinese Centre for Proteases and Cancer, Aarhus University, 8000 Aarhus C, Denmark
| | - Niels Larsen
- iNANO Interdisciplinary Nanoscience Center, Aarhus University, 8000 Aarhus C, Denmark
| | - Jan K Jensen
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark Danish-Chinese Centre for Proteases and Cancer, Aarhus University, 8000 Aarhus C, Denmark
| | - Peter A Andreasen
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark Danish-Chinese Centre for Proteases and Cancer, Aarhus University, 8000 Aarhus C, Denmark
| | - Jørgen Kjems
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark iNANO Interdisciplinary Nanoscience Center, Aarhus University, 8000 Aarhus C, Denmark
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37
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Popović M, Fliss PS, Ditzler MA. In vitro evolution of distinct self-cleaving ribozymes in diverse environments. Nucleic Acids Res 2015; 43:7070-82. [PMID: 26130717 PMCID: PMC4538833 DOI: 10.1093/nar/gkv648] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 06/11/2015] [Indexed: 01/08/2023] Open
Abstract
In vitro evolution experiments have long been used to evaluate the roles of RNA in both modern and ancient biology, and as a tool for biotechnology applications. The conditions under which these experiments have been conducted, however, do not reflect the range of cellular environments in modern biology or our understanding of chemical environments on the early earth, when the atmosphere and oceans were largely anoxic and soluble Fe2+ was abundant. To test the impact of environmental factors relevant to RNA's potential role in the earliest forms of life, we evolved populations of self-cleaving ribozymes in an anoxic atmosphere with varying pH in the presence of either Fe2+ or Mg2+. Populations evolved under these different conditions are dominated by different sequences and secondary structures, demonstrating global differences in the underlying fitness landscapes. Comparisons between evolutionary outcomes and catalytic activities also indicate that Mg2+ can readily take the place of Fe2+ in supporting the catalysis of RNA cleavage at neutral pH, but not at lower pH. These results highlight the importance of considering the specific environments in which functional biopolymers evolve when evaluating their potential roles in the origin of life, extant biology, or biotechnology.
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Affiliation(s)
- Milena Popović
- NASA Postdoctoral Program, NASA Ames Research Center, Moffett Field, CA 94035, USA Space Science and Astrobiology Division, Exobiology Branch, NASA Ames Research Center, Moffett Field, CA 94035, USA Blue Marble Space Institute of Science, Seattle, WA 98145, USA
| | - Palmer S Fliss
- Blue Marble Space Institute of Science, Seattle, WA 98145, USA
| | - Mark A Ditzler
- Space Science and Astrobiology Division, Exobiology Branch, NASA Ames Research Center, Moffett Field, CA 94035, USA
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Hoinka J, Berezhnoy A, Dao P, Sauna ZE, Gilboa E, Przytycka TM. Large scale analysis of the mutational landscape in HT-SELEX improves aptamer discovery. Nucleic Acids Res 2015; 43:5699-707. [PMID: 25870409 PMCID: PMC4499121 DOI: 10.1093/nar/gkv308] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 03/27/2015] [Indexed: 12/12/2022] Open
Abstract
High-Throughput (HT) SELEX combines SELEX (Systematic Evolution of Ligands by EXponential Enrichment), a method for aptamer discovery, with massively parallel sequencing technologies. This emerging technology provides data for a global analysis of the selection process and for simultaneous discovery of a large number of candidates but currently lacks dedicated computational approaches for their analysis. To close this gap, we developed novel in-silico methods to analyze HT-SELEX data and utilized them to study the emergence of polymerase errors during HT-SELEX. Rather than considering these errors as a nuisance, we demonstrated their utility for guiding aptamer discovery. Our approach builds on two main advancements in aptamer analysis: AptaMut—a novel technique allowing for the identification of polymerase errors conferring an improved binding affinity relative to the ‘parent’ sequence and AptaCluster—an aptamer clustering algorithm which is to our best knowledge, the only currently available tool capable of efficiently clustering entire aptamer pools. We applied these methods to an HT-SELEX experiment developing aptamers against Interleukin 10 receptor alpha chain (IL-10RA) and experimentally confirmed our predictions thus validating our computational methods.
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Affiliation(s)
- Jan Hoinka
- National Center of Biotechnology Information, National Library of Medicine, NIH, Bethesda, MD 20894, USA
| | - Alexey Berezhnoy
- Department of Microbiology & Immunology, University of Miami Miller School of Medicine, Miami, FL 33101, USA
| | - Phuong Dao
- National Center of Biotechnology Information, National Library of Medicine, NIH, Bethesda, MD 20894, USA
| | - Zuben E Sauna
- Laboratory of Hemostasis, Division of Hematology, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993, USA
| | - Eli Gilboa
- Department of Microbiology & Immunology, University of Miami Miller School of Medicine, Miami, FL 33101, USA
| | - Teresa M Przytycka
- National Center of Biotechnology Information, National Library of Medicine, NIH, Bethesda, MD 20894, USA
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Kobori S, Nomura Y, Miu A, Yokobayashi Y. High-throughput assay and engineering of self-cleaving ribozymes by sequencing. Nucleic Acids Res 2015; 43:e85. [PMID: 25829176 PMCID: PMC4513843 DOI: 10.1093/nar/gkv265] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 03/17/2015] [Indexed: 01/20/2023] Open
Abstract
Self-cleaving ribozymes are found in all domains of life and are believed to play important roles in biology. Additionally, self-cleaving ribozymes have been the subject of extensive engineering efforts for applications in synthetic biology. These studies often involve laborious assays of multiple individual variants that are either designed rationally or discovered through selection or screening. However, these assays provide only a limited view of the large sequence space relevant to the ribozyme function. Here, we report a strategy that allows quantitative characterization of greater than 1000 ribozyme variants in a single experiment. We generated a library of predefined ribozyme variants that were converted to DNA and analyzed by high-throughput sequencing. By counting the number of cleaved and uncleaved reads of every variant in the library, we obtained a complete activity profile of the ribozyme pool which was used to both analyze and engineer allosteric ribozymes.
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Affiliation(s)
- Shungo Kobori
- Department of Biomedical Engineering, University of California, Davis, CA 95616, USA
| | - Yoko Nomura
- Department of Biomedical Engineering, University of California, Davis, CA 95616, USA
| | - Anh Miu
- Department of Biomedical Engineering, University of California, Davis, CA 95616, USA
| | - Yohei Yokobayashi
- Department of Biomedical Engineering, University of California, Davis, CA 95616, USA Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904 0495, Japan
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40
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Alam KK, Chang JL, Burke DH. FASTAptamer: A Bioinformatic Toolkit for High-throughput Sequence Analysis of Combinatorial Selections. MOLECULAR THERAPY-NUCLEIC ACIDS 2015; 4:e230. [PMID: 25734917 PMCID: PMC4354339 DOI: 10.1038/mtna.2015.4] [Citation(s) in RCA: 159] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2014] [Accepted: 01/08/2015] [Indexed: 12/22/2022]
Abstract
High-throughput sequence (HTS) analysis of combinatorial selection populations accelerates lead discovery and optimization and offers dynamic insight into selection processes. An underlying principle is that selection enriches high-fitness sequences as a fraction of the population, whereas low-fitness sequences are depleted. HTS analysis readily provides the requisite numerical information by tracking the evolutionary trajectory of individual sequences in response to selection pressures. Unlike genomic data, for which a number of software solutions exist, user-friendly tools are not readily available for the combinatorial selections field, leading many users to create custom software. FASTAptamer was designed to address the sequence-level analysis needs of the field. The open source FASTAptamer toolkit counts, normalizes and ranks read counts in a FASTQ file, compares populations for sequence distribution, generates clusters of sequence families, calculates fold-enrichment of sequences throughout the course of a selection and searches for degenerate sequence motifs. While originally designed for aptamer selections, FASTAptamer can be applied to any selection strategy that can utilize next-generation DNA sequencing, such as ribozyme or deoxyribozyme selections, in vivo mutagenesis and various surface display technologies (peptide, antibody fragment, mRNA, etc.). FASTAptamer software, sample data and a user's guide are available for download at http://burkelab.missouri.edu/fastaptamer.html.
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Affiliation(s)
- Khalid K Alam
- Department of Biochemistry, University of Missouri, Columbia, Missouri, USA
| | - Jonathan L Chang
- 1] Department of Molecular Microbiology and Immunology, University of Missouri, Columbia, Missouri, USA [2] Current Address: School of Medicine, University of Missouri, Columbia, Missouri, USA
| | - Donald H Burke
- 1] Department of Biochemistry, University of Missouri, Columbia, Missouri, USA [2] Department of Molecular Microbiology and Immunology, University of Missouri, Columbia, Missouri, USA
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Darmostuk M, Rimpelova S, Gbelcova H, Ruml T. Current approaches in SELEX: An update to aptamer selection technology. Biotechnol Adv 2015; 33:1141-61. [PMID: 25708387 DOI: 10.1016/j.biotechadv.2015.02.008] [Citation(s) in RCA: 406] [Impact Index Per Article: 45.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 01/26/2015] [Accepted: 02/13/2015] [Indexed: 12/21/2022]
Abstract
Systematic evolution of ligands by exponential enrichment (SELEX) is a well-established and efficient technology for the generation of oligonucleotides with a high target affinity. These SELEX-derived single stranded DNA and RNA molecules, called aptamers, were selected against various targets, such as proteins, cells, microorganisms, chemical compounds etc. They have a great potential in the use as novel antibodies, in cancer theragnostics and in biomedical research. Vast interest in aptamers stimulated continuous development of SELEX, which underwent numerous modifications since its first application in 1990. Novel modifications made the selection process more efficient, cost-effective and significantly less time-consuming. This article brings a comprehensive and up-to-date review of recent advances in SELEX methods and pinpoints advantages, main obstacles and limitations. The post-SELEX strategies and examples of application are also briefly outlined in this review.
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Affiliation(s)
- Mariia Darmostuk
- Department of Biochemistry and Microbiology, University of Chemistry and Technology Prague, Technická 5, Prague 6 166 28, Czech Republic.
| | - Silvie Rimpelova
- Department of Biochemistry and Microbiology, University of Chemistry and Technology Prague, Technická 5, Prague 6 166 28, Czech Republic.
| | - Helena Gbelcova
- Department of Biochemistry and Microbiology, University of Chemistry and Technology Prague, Technická 5, Prague 6 166 28, Czech Republic; Institute of Medical Biology, Genetics and Clinical Genetics, Faculty of Medicine, Comenius University in Bratislava, Sasinkova 4, Bratislava 811 08, Slovak Republic.
| | - Tomas Ruml
- Department of Biochemistry and Microbiology, University of Chemistry and Technology Prague, Technická 5, Prague 6 166 28, Czech Republic.
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Takahashi M, Burnett JC, Rossi JJ. Aptamer–siRNA Chimeras for HIV. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 848:211-34. [DOI: 10.1007/978-1-4939-2432-5_11] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Identification and Characterization of an eIF4e DNA Aptamer That Inhibits Proliferation With High Throughput Sequencing. MOLECULAR THERAPY-NUCLEIC ACIDS 2014; 3:e217. [PMID: 25514650 PMCID: PMC4272410 DOI: 10.1038/mtna.2014.70] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 11/06/2014] [Indexed: 12/19/2022]
Abstract
Development of DNA aptamer screens that are both simple and informative can increase the success rate of DNA aptamer selection and induce greater adoption. High eIF4e levels contribute to malignancies, thus eIF4e presents itself as a valuable target for DNA aptamer-based inhibition screen. Here, we demonstrate a method for the rapid selection of looped DNA aptamers against eIF4e by combining negative selection and purification in a single step, followed by characterization with high throughput sequencing. The resulting aptamers show functional binding to eIF4e and inhibit translation initiation in biochemical assays. When transfected into cells, eIF4e aptamers cause a dramatic loss of cell proliferation in tumor cells as seen with eIF4e knockdown with antisense oligonucleotides, shRNAs, and siRNAs, hinting at therapeutic possibilities. With the large data set provided by high throughput sequencing, we demonstrate that selection happens in waves and that sequencing data can be used to infer aptamer structure. Lastly, we show that ligation of looped aptamers can enhance their functional effects. These results demonstrate a rapid protocol to screen and optimize aptamers against macromolecules of interest.
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Experimental fitness landscapes to understand the molecular evolution of RNA-based life. Curr Opin Chem Biol 2014; 22:35-9. [PMID: 25270912 DOI: 10.1016/j.cbpa.2014.09.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 09/10/2014] [Indexed: 01/11/2023]
Abstract
In evolutionary biology, the relationship between genotype and Darwinian fitness is known as a fitness landscape. These landscapes underlie natural selection, so understanding them would greatly improve quantitative prediction of evolutionary outcomes, guiding the development of synthetic living systems. However, the structure of fitness landscapes is essentially unknown. Our ability to experimentally probe these landscapes is physically limited by the number of different sequences that can be identified. This number has increased dramatically in the last several years, leading to qualitatively new investigations. Several approaches to illuminate fitness landscapes are possible, ranging from tight focus on a single peak to random speckling or even comprehensive coverage of an entire landscape. We discuss recent experimental studies of fitness landscapes, with a special focus on functional RNA, an important system for both synthetic cells and the origin of life.
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Sánchez-Luque FJ, Stich M, Manrubia S, Briones C, Berzal-Herranz A. Efficient HIV-1 inhibition by a 16 nt-long RNA aptamer designed by combining in vitro selection and in silico optimisation strategies. Sci Rep 2014; 4:6242. [PMID: 25175101 PMCID: PMC4150108 DOI: 10.1038/srep06242] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 08/04/2014] [Indexed: 02/08/2023] Open
Abstract
The human immunodeficiency virus type-1 (HIV-1) genome contains multiple, highly conserved structural RNA domains that play key roles in essential viral processes. Interference with the function of these RNA domains either by disrupting their structures or by blocking their interaction with viral or cellular factors may seriously compromise HIV-1 viability. RNA aptamers are amongst the most promising synthetic molecules able to interact with structural domains of viral genomes. However, aptamer shortening up to their minimal active domain is usually necessary for scaling up production, what requires very time-consuming, trial-and-error approaches. Here we report on the in vitro selection of 64 nt-long specific aptamers against the complete 5′-untranslated region of HIV-1 genome, which inhibit more than 75% of HIV-1 production in a human cell line. The analysis of the selected sequences and structures allowed for the identification of a highly conserved 16 nt-long stem-loop motif containing a common 8 nt-long apical loop. Based on this result, an in silico designed 16 nt-long RNA aptamer, termed RNApt16, was synthesized, with sequence 5′-CCCCGGCAAGGAGGGG-3′. The HIV-1 inhibition efficiency of such an aptamer was close to 85%, thus constituting the shortest RNA molecule so far described that efficiently interferes with HIV-1 replication.
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Affiliation(s)
- Francisco J Sánchez-Luque
- 1] Department of Molecular Biology. Instituto de Parasitología y Biomedicina "López-Neyra" (IPBLN-CSIC), PTS Granada. Avda. del Conocimiento s/n, Armilla (Granada 18016, Spain) [2]
| | - Michael Stich
- 1] Department of Molecular Evolution. Centro de Astrobiología (CAB-CSIC/INTA). Carretera Torrejón a Ajalvir km 4, Torrejón de Ardoz (Madrid 28850, Spain) [2]
| | - Susanna Manrubia
- Department of Molecular Evolution. Centro de Astrobiología (CAB-CSIC/INTA). Carretera Torrejón a Ajalvir km 4, Torrejón de Ardoz (Madrid 28850, Spain)
| | - Carlos Briones
- 1] Department of Molecular Evolution. Centro de Astrobiología (CAB-CSIC/INTA). Carretera Torrejón a Ajalvir km 4, Torrejón de Ardoz (Madrid 28850, Spain) [2] Centro de Investigación Biomédica en Red de enfermedades hepáticas y digestivas (CIBERehd), Spain
| | - Alfredo Berzal-Herranz
- Department of Molecular Biology. Instituto de Parasitología y Biomedicina "López-Neyra" (IPBLN-CSIC), PTS Granada. Avda. del Conocimiento s/n, Armilla (Granada 18016, Spain)
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New Technologies Provide Quantum Changes in the Scale, Speed, and Success of SELEX Methods and Aptamer Characterization. MOLECULAR THERAPY. NUCLEIC ACIDS 2014; 3:e183. [PMID: 25093707 PMCID: PMC4221594 DOI: 10.1038/mtna.2014.34] [Citation(s) in RCA: 120] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Accepted: 06/10/2014] [Indexed: 12/24/2022]
Abstract
Single-stranded oligonucleotide aptamers have attracted great attention in the past decade because of their diagnostic and therapeutic potential. These versatile, high affinity and specificity reagents are selected by an iterative in vitro process called SELEX, Systematic Evolution of Ligands by Exponential Enrichment. Numerous SELEX methods have been developed for aptamer selections; some that are simple and straightforward, and some that are specialized and complicated. The method of SELEX is crucial for selection of an aptamer with desired properties; however, success also depends on the starting aptamer library, the target molecule, aptamer enrichment monitoring assays, and finally, the analysis and characterization of selected aptamers. Here, we summarize key recent developments in aptamer selection methods, as well as other aspects of aptamer selection that have significant impact on the outcome. We discuss potential pitfalls and limitations in the selection process with an eye to aid researchers in the choice of a proper SELEX strategy, and we highlight areas where further developments and improvements are desired. We believe carefully designed multiplexed selection methods, when complemented with high-throughput downstream analysis and characterization assays, will yield numerous high-affinity aptamers to protein and small molecule targets, and thereby generate a vast array of reagents for probing basic biological mechanisms and implementing new diagnostic and therapeutic applications in the near future.
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The use of hairpin DNA duplexes as HIV-1 fusion inhibitors: synthesis, characterization, and activity evaluation. Eur J Med Chem 2014; 82:341-6. [PMID: 24927054 DOI: 10.1016/j.ejmech.2014.05.068] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Revised: 04/26/2014] [Accepted: 05/28/2014] [Indexed: 12/21/2022]
Abstract
Discovery of new drugs for the treatment of AIDS that possess unique structures associated with novel mechanisms of action are of great importance due the rapidity with which drug-resistant HIV-1 strains evolve. Recently we reported on a novel class of DNA duplex-based HIV-1 fusion inhibitors modified with hydrophobic groups. The present study describes a new category of hairpin fusion inhibitor DNA duplexes bearing a 3 nucleotide loop located at either the hydrophobic or hydrophilic end. The new loop structures were designed to link 2 separate duplex-forming oligodeoxynucleotides (ODNs) to make helix-assembly easier and more thermally stable resulting in a more compact form of DNA duplex based HIV-1 fusion inhibitors. A series of new hairpin duplexes were tested for anti-HIV-1 cell-cell membrane fusion activity. In addition, Tm, CD, fluorescent resonance energy transfer assays, and molecular modeling analyses were carried out to define their structural activity relationships and possible mechanisms of action.
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Abstract
Enzymatic probing is a rapid, straightforward method for determining which regions of a folded RNA are structurally constrained. It can be carried out using very small amounts of material, and is especially suitable for short RNAs. Here we report a protocol that we have found to be useful and readily adaptable to the evaluation of RNAs up to 150-200 nucleotides in length. Considerations for optimization are also included. In brief, the method includes folding end-labeled RNA into its native conformation, partial digestion with structure-sensitive nucleases, and identification of the cleavage sites by electrophoretic separation of the cleavage fragments.
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Affiliation(s)
- Elisa Biondi
- Department of Molecular Microbiology and Immunology, University of Missouri, Columbia, MO, USA
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Szeto K, Latulippe DR, Ozer A, Pagano JM, White BS, Shalloway D, Lis JT, Craighead HG. RAPID-SELEX for RNA aptamers. PLoS One 2013; 8:e82667. [PMID: 24376564 PMCID: PMC3869713 DOI: 10.1371/journal.pone.0082667] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 10/26/2013] [Indexed: 01/11/2023] Open
Abstract
Aptamers are high-affinity ligands selected from DNA or RNA libraries via SELEX, a repetitive in vitro process of sequential selection and amplification steps. RNA SELEX is more complicated than DNA SELEX because of the additional transcription and reverse transcription steps. Here, we report a new selection scheme, RAPID-SELEX (RNA Aptamer Isolation via Dual-cycles SELEX), that simplifies this process by systematically skipping unnecessary amplification steps. Using affinity microcolumns, we were able to complete a multiplex selection for protein targets, CHK2 and UBLCP1, in a third of the time required for analogous selections using a conventional SELEX approach. High-throughput sequencing of the enriched pools from both RAPID and SELEX revealed many identical candidate aptamers from the starting pool of 5×1015 sequences. For CHK2, the same sequence was preferentially enriched in both selections as the top candidate and was found to bind to its respective target. These results demonstrate the efficiency and, most importantly, the robustness of our selection scheme. RAPID provides a generalized approach that can be used with any selection technology to accelerate the rate of aptamer discovery, without compromising selection performance.
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Affiliation(s)
- Kylan Szeto
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York, United States of America
| | - David R Latulippe
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York, United States of America
| | - Abdullah Ozer
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
| | - John M Pagano
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
| | - Brian S White
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
| | - David Shalloway
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
| | - John T Lis
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
| | - Harold G Craighead
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York, United States of America
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Aptamer-based therapeutics: new approaches to combat human viral diseases. Pharmaceuticals (Basel) 2013; 6:1507-42. [PMID: 24287493 PMCID: PMC3873675 DOI: 10.3390/ph6121507] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 11/12/2013] [Accepted: 11/15/2013] [Indexed: 12/18/2022] Open
Abstract
Viruses replicate inside the cells of an organism and continuously evolve to contend with an ever-changing environment. Many life-threatening diseases, such as AIDS, SARS, hepatitis and some cancers, are caused by viruses. Because viruses have small genome sizes and high mutability, there is currently a lack of and an urgent need for effective treatment for many viral pathogens. One approach that has recently received much attention is aptamer-based therapeutics. Aptamer technology has high target specificity and versatility, i.e., any viral proteins could potentially be targeted. Consequently, new aptamer-based therapeutics have the potential to lead a revolution in the development of anti-infective drugs. Additionally, aptamers can potentially bind any targets and any pathogen that is theoretically amenable to rapid targeting, making aptamers invaluable tools for treating a wide range of diseases. This review will provide a broad, comprehensive overview of viral therapies that use aptamers. The aptamer selection process will be described, followed by an explanation of the potential for treating virus infection by aptamers. Recent progress and prospective use of aptamers against a large variety of human viruses, such as HIV-1, HCV, HBV, SCoV, Rabies virus, HPV, HSV and influenza virus, with particular focus on clinical development of aptamers will also be described. Finally, we will discuss the challenges of advancing antiviral aptamer therapeutics and prospects for future success.
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