1
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Liu P, Lin Y, Zhuo X, Zeng J, Chen B, Zou Z, Liu G, Xiong E, Yang R. Universal crRNA Acylation Strategy for Robust Photo-Initiated One-Pot CRISPR-Cas12a Nucleic Acid Diagnostics. Angew Chem Int Ed Engl 2024; 63:e202401486. [PMID: 38563640 DOI: 10.1002/anie.202401486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 03/26/2024] [Accepted: 04/02/2024] [Indexed: 04/04/2024]
Abstract
Spatiotemporal regulation of clustered regularly interspaced short palindromic repeats (CRISPR) system is attractive for precise gene editing and accurate molecular diagnosis. Although many efforts have been made, versatile and efficient strategies to control CRISPR system are still desirable. Here, we proposed a universal and accessible acylation strategy to regulate the CRISPR-Cas12a system by efficient acylation of 2'-hydroxyls (2'-OH) on crRNA strand with photolabile agents (PLGs). The introduction of PLGs confers efficient suppression of crRNA function and rapid restoration of CRISPR-Cas12a reaction upon short light exposure regardless of crRNA sequences. Based on this strategy, we constructed a universal PhotO-Initiated CRISPR-Cas12a system for Robust One-pot Testing (POIROT) platform integrated with recombinase polymerase amplification (RPA), which showed two orders of magnitude more sensitive than the conventional one-step assay and comparable to the two-step assay. For clinical sample testing, POIROT achieved high-efficiency detection performance comparable to the gold-standard quantitative PCR (qPCR) in sensitivity and specificity, but faster than the qPCR method. Overall, we believe the proposed strategy will promote the development of many other universal photo-controlled CRISPR technologies for one-pot assay, and even expand applications in the fields of controllable CRISPR-based genomic editing, disease therapy, and cell imaging.
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Affiliation(s)
- Pengfei Liu
- Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research, Ministry of Education, College of Chemistry and Chemical Engineering, Hunan Normal University, 410081, Changsha, P. R. China
| | - Yating Lin
- Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research, Ministry of Education, College of Chemistry and Chemical Engineering, Hunan Normal University, 410081, Changsha, P. R. China
| | - Xiaohua Zhuo
- Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research, Ministry of Education, College of Chemistry and Chemical Engineering, Hunan Normal University, 410081, Changsha, P. R. China
| | - Jiayu Zeng
- Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research, Ministry of Education, College of Chemistry and Chemical Engineering, Hunan Normal University, 410081, Changsha, P. R. China
| | - Bolin Chen
- The Second Department of Thoracic Oncology, Hunan Cancer Hospital & The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, 410013, Changsha, P. R. China
| | - Zhen Zou
- Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research, Ministry of Education, College of Chemistry and Chemical Engineering, Hunan Normal University, 410081, Changsha, P. R. China
| | - Guhuan Liu
- Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research, Ministry of Education, College of Chemistry and Chemical Engineering, Hunan Normal University, 410081, Changsha, P. R. China
| | - Erhu Xiong
- Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research, Ministry of Education, College of Chemistry and Chemical Engineering, Hunan Normal University, 410081, Changsha, P. R. China
| | - Ronghua Yang
- Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research, Ministry of Education, College of Chemistry and Chemical Engineering, Hunan Normal University, 410081, Changsha, P. R. China
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2
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Pani S, Qiu T, Kentala K, Azizi SA, Dickinson BC. Bioorthogonal masked acylating agents for proximity-dependent RNA labelling. Nat Chem 2024; 16:717-726. [PMID: 38594368 DOI: 10.1038/s41557-024-01493-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 02/28/2024] [Indexed: 04/11/2024]
Abstract
RNA localization is highly regulated, with subcellular organization driving context-dependent cell physiology. Although proximity-based labelling technologies that use highly reactive radicals or carbenes provide a powerful method for unbiased mapping of protein organization within a cell, methods for unbiased RNA mapping are scarce and comparably less robust. Here we develop α-alkoxy thioenol and chloroenol esters that function as potent acylating agents upon controlled ester unmasking. We pair these probes with subcellular-localized expression of a bioorthogonal esterase to establish a platform for spatial analysis of RNA: bioorthogonal acylating agents for proximity labelling and sequencing (BAP-seq). We demonstrate that, by selectively unmasking the enol probe in a locale of interest, we can map RNA distribution in membrane-bound and membrane-less organelles. The controlled-release acylating agent chemistry and corresponding BAP-seq method expand the scope of proximity labelling technologies and provide a powerful approach to interrogate the cellular organization of RNAs.
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Affiliation(s)
- Shubhashree Pani
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
| | - Tian Qiu
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
| | - Kaitlin Kentala
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
| | - Saara-Anne Azizi
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
- Medical Scientist Training Program, Pritzker School of Medicine, The University of Chicago, Chicago, IL, USA
| | - Bryan C Dickinson
- Department of Chemistry, The University of Chicago, Chicago, IL, USA.
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3
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Wang H, Xiong X, Zhang J, Wu M, Gu Y, Chen Y, Gu Y, Wang P. Near-Infrared Light-Driven Nanoparticles for Cancer Photoimmunotherapy by Synergizing Immune Cell Death and Epigenetic Regulation. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2309202. [PMID: 38100237 DOI: 10.1002/smll.202309202] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 12/01/2023] [Indexed: 05/25/2024]
Abstract
Histone deacetylases (HDACs) are a class of epigenetic enzymes that are closely related to tumorigenesis and suppress the expression of tumor suppressor genes. Whereas the HDACs inhibitors can release DNA into the cytoplasm and trigger innate immunity. However, the high density of chromatin limits DNA damage and release. In this study, suitable nanosized CycNHOH NPs (150 nm) and CypNHOH NPs (85 nm) efficiently accumulate at the tumor site due to the enhanced permeability and retention (EPR) effect. In addition, robust single-linear oxygen generation and good photothermal conversion efficiency under NIR laser irradiation accelerated the DNA damage process. By effectively initiating immune cell death, CypNHOH NPs activated both innate and adaptive immunity by maturing dendritic cells, infiltrating tumors with natural killer cells, and activating cytotoxic T lymphocytes, which offer a fresh perspective for the development of photo-immunotherapy.
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Affiliation(s)
- Huizhe Wang
- Department of Biomedical Engineering, School of Engineering, China Pharmaceutical University, Nanjing, 210009, China
| | - Xiaohui Xiong
- Department of Biomedical Engineering, School of Engineering, China Pharmaceutical University, Nanjing, 210009, China
| | - Jiaqi Zhang
- Department of Biomedical Engineering, School of Engineering, China Pharmaceutical University, Nanjing, 210009, China
| | - Meicen Wu
- Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, 999077, China
| | - Yinhui Gu
- Department of Biomedical Engineering, School of Engineering, China Pharmaceutical University, Nanjing, 210009, China
| | - Yanli Chen
- Department of Biomedical Engineering, School of Engineering, China Pharmaceutical University, Nanjing, 210009, China
| | - YueQing Gu
- Department of Biomedical Engineering, School of Engineering, China Pharmaceutical University, Nanjing, 210009, China
| | - Peng Wang
- Department of Biomedical Engineering, School of Engineering, China Pharmaceutical University, Nanjing, 210009, China
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4
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Bardhan A, Brown W, Albright S, Tsang M, Davidson LA, Deiters A. Direct Activation of Nucleobases with Small Molecules for the Conditional Control of Antisense Function. Angew Chem Int Ed Engl 2024; 63:e202318773. [PMID: 38411401 DOI: 10.1002/anie.202318773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 02/22/2024] [Accepted: 02/26/2024] [Indexed: 02/28/2024]
Abstract
Conditionally controlled antisense oligonucleotides provide precise interrogation of gene function at different developmental stages in animal models. Only one example of small molecule-induced activation of antisense function exist. This has been restricted to cyclic caged morpholinos that, based on sequence, can have significant background activity in the absence of the trigger. Here, we provide a new approach using azido-caged nucleobases that are site-specifically introduced into antisense morpholinos. The caging group design is a simple azidomethylene (Azm) group that, despite its very small size, efficiently blocks Watson-Crick base pairing in a programmable fashion. Furthermore, it undergoes facile decaging via Staudinger reduction when exposed to a small molecule phosphine, generating the native antisense oligonucleotide under conditions compatible with biological environments. We demonstrated small molecule-induced gene knockdown in mammalian cells, zebrafish embryos, and frog embryos. We validated the general applicability of this approach by targeting three different genes.
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Affiliation(s)
- Anirban Bardhan
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, United States
| | - Wes Brown
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, United States
| | - Savannah Albright
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, United States
| | - Michael Tsang
- Department of Cell Biology, Center for Integrative Organ Systems., University of Pittsburgh, Pittsburgh, PA 15260, United States
| | - Lance A Davidson
- Department of Bioengineering, Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, PA 15260, United States
| | - Alexander Deiters
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, United States
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5
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Xiao L, Fang L, Kool ET. 2'-OH as a universal handle for studying intracellular RNAs. Cell Chem Biol 2024; 31:110-124. [PMID: 37992716 PMCID: PMC10841764 DOI: 10.1016/j.chembiol.2023.10.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 09/28/2023] [Accepted: 10/29/2023] [Indexed: 11/24/2023]
Abstract
RNA plays pivotal roles in most cellular processes, serving as both the traditional carrier of genetic information and as a key regulator of cellular functions. The advent of chemical technologies has contributed critically to the analysis of cellular RNA structures, functions, and interactions. Many of these methods and molecules involve the utilization of chemically reactive handles in RNAs, either introduced externally or inherent within the polymer itself. Among these handles, the 2'-hydroxyl (2'-OH) group has emerged as an exceptionally well-suited and general chemical moiety for the modification and profiling of RNAs in intracellular studies. In this review, we provide an overview of the recent advancements in intracellular applications of acylation at the 2'-OH group of RNA. We outline progress made in probing RNA structure and interactomes, controlling RNA function, RNA imaging, and analyzing RNA-small molecule interactions, all achieved in living cells through this simple chemical handle on the biopolymer.
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Affiliation(s)
- Lu Xiao
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA
| | - Linglan Fang
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA
| | - Eric T Kool
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA; Sarafan ChEM-H, Stanford University, Stanford, CA 94305, USA.
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6
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Shioi R, Xiao L, Kool ET. Aqueous Activation of RNA 2'-OH for Conjugation with Amines and Thiols. Bioconjug Chem 2024; 35:43-50. [PMID: 38150592 DOI: 10.1021/acs.bioconjchem.3c00370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2023]
Abstract
Strategies for covalent modification of RNA are important for enabling biological studies of the biopolymer and for enhancing properties of therapeutic RNAs. While a number of electrophiles have been observed to react with RNA, few methods exist for reaction with nucleophiles. Here, we describe new reagents that enable efficient conjugation of amines and other nucleophiles to unmodified RNA postsynthetically via transient activation of 2'-OH groups. Reaction of single-stranded RNA in aqueous solution with phenolic imidazolecarbamates at room temperature results in stoichiometric and superstoichiometric yields of imidazolecarbonyl group adducts, and control experiments with DNA confirm the site of reaction in RNA as 2'-OH. Subsequent incubation of imidazolecarbonyl-activated RNAs with primary or selected secondary amines results in rapid, high-yield conversion to carbamate conjugates. The activation and subsequent nucleophile reaction can be carried out either stepwise or in a one-pot reaction. Thiols and phenol species react to yield (thio)carbonate adducts, and amino acid sidechains also react, suggesting possible future utility for protein conjugates and analysis of protein-RNA interactions. The activation method is found to be selective to unpaired regions of RNA, and can be directed to a specific location in a strand by use of a loop-inducing helper DNA. The results establish novel and efficient reagents and methods for modifying RNA postsynthetically with nucleophiles.
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Affiliation(s)
- Ryuta Shioi
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Lu Xiao
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Eric T Kool
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
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7
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Shioi R, Xiao L, Fang L, Kool ET. Efficient post-synthesis incorporation and conjugation of reactive ketones in RNA via 2'-acylation. Chem Commun (Camb) 2023; 60:232-235. [PMID: 38054242 PMCID: PMC10745195 DOI: 10.1039/d3cc05123d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2023]
Abstract
Despite the broad utility of ketones in bioconjugation, few methods exist to introduce them into RNA. Here we develop highly reactive 2'-OH acylating reagents containing strained-ring ketones, and employ them as versatile labeling handles for RNA.
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Affiliation(s)
- Ryuta Shioi
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA.
| | - Lu Xiao
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA.
| | - Linglan Fang
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA.
| | - Eric T Kool
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA.
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8
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Shioi R, Xiao L, Chatterjee S, Kool ET. Stereoselective RNA reaction with chiral 2'-OH acylating agents. Chem Sci 2023; 14:13235-13243. [PMID: 38023505 PMCID: PMC10664579 DOI: 10.1039/d3sc03067a] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 10/29/2023] [Indexed: 11/24/2023] Open
Abstract
The reactivity of RNA 2'-OH groups with acylating agents has recently been investigated for high-yield conjugation of RNA strands. To date, only achiral molecules have been studied for this reaction, despite the complex chiral structure of RNA. Here we prepare a set of chiral acylimidazoles and study their stereoselectivity in RNA reactions. Reactions performed with unfolded and folded RNAs reveal that positional selectivity and reactivity vary widely with local RNA macro-chirality. We further document remarkable effects of chirality on reagent reactivity, identifying an asymmetric reagent with 1000-fold greater reactivity than prior achiral reagents. In addition, we identify a chiral compound with higher RNA structural selectivity than any previously reported RNA-mapping species. Further, azide-containing homologs of a chiral dimethylalanine reagent were synthesized and applied to local RNA labeling, displaying 92% yield and 16 : 1 diastereoselectivity. The results establish that reagent stereochemistry and chiral RNA structure are critical elements of small molecule-RNA reactions, and demonstrate new chemical strategies for selective RNA modification and probing.
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Affiliation(s)
- Ryuta Shioi
- Department of Chemistry, Stanford University Stanford CA 94305 USA
| | - Lu Xiao
- Department of Chemistry, Stanford University Stanford CA 94305 USA
| | | | - Eric T Kool
- Department of Chemistry, Stanford University Stanford CA 94305 USA
- Sarafan ChEM-H, Stanford University Stanford CA 94305 USA
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9
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Fang L, Xiao L, Jun YW, Onishi Y, Kool ET. Reversible 2'-OH acylation enhances RNA stability. Nat Chem 2023; 15:1296-1305. [PMID: 37365334 DOI: 10.1038/s41557-023-01246-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 05/19/2023] [Indexed: 06/28/2023]
Abstract
The presence of a hydroxyl group at the 2'-position in its ribose makes RNA susceptible to hydrolysis. Stabilization of RNAs for storage, transport and biological application thus remains a serious challenge, particularly for larger RNAs that are not accessible by chemical synthesis. Here we present reversible 2'-OH acylation as a general strategy to preserve RNA of any length or origin. High-yield polyacylation of 2'-hydroxyls ('cloaking') by readily accessible acylimidazole reagents effectively shields RNAs from both thermal and enzymatic degradation. Subsequent treatment with water-soluble nucleophilic reagents removes acylation adducts quantitatively ('uncloaking') and recovers a remarkably broad range of RNA functions, including reverse transcription, translation and gene editing. Furthermore, we show that certain α-dimethylamino- and α-alkoxy- acyl adducts are spontaneously removed in human cells, restoring messenger RNA translation with extended functional half-lives. These findings support the potential of reversible 2'-acylation as a simple and general molecular solution for enhancing RNA stability and provide mechanistic insights for stabilizing RNA regardless of length or origin.
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Affiliation(s)
- Linglan Fang
- Department of Chemistry, Stanford University, Stanford, CA, USA
| | - Lu Xiao
- Department of Chemistry, Stanford University, Stanford, CA, USA
| | - Yong Woong Jun
- Department of Chemistry, Stanford University, Stanford, CA, USA
| | | | - Eric T Kool
- Department of Chemistry, Stanford University, Stanford, CA, USA.
- Sarafan ChEM-H Institute, Stanford University, Stanford, CA, USA.
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10
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Huang K, Fang X. A review on recent advances in methods for site-directed spin labeling of long RNAs. Int J Biol Macromol 2023; 239:124244. [PMID: 37001783 DOI: 10.1016/j.ijbiomac.2023.124244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 01/12/2023] [Accepted: 03/15/2023] [Indexed: 03/31/2023]
Abstract
RNAs are important biomolecules that play essential roles in various cellular processes and are crucially linked with many human diseases. The key to elucidate the mechanisms underlying their biological functions and develop RNA-based therapeutics is to investigate RNA structure and dynamics and their connections to function in detail using a variety of approaches. Magnetic resonance techniques including paramagnetic nuclear magnetic resonance (NMR) and electron magnetic resonance (EPR) spectroscopies have proved to be powerful tools to gain insights into such properties. The prerequisites for paramagnetic NMR and EPR studies on RNAs are to achieve site-specific spin labeling of the intrinsically diamagnetic RNAs, which however is not trivial, especially for long ones. In this review, we present some covalent labeling strategies that allow site-specific introduction of electron spins to long RNAs. Generally, these strategies include assembly of long RNAs via enzymatic ligation of short oligonucleotides, co- and post-transcriptional site-specific labeling empowered with the unnatural base pair system, and direct enzymatic functionalization of natural RNAs. We introduce a few case studies to discuss the advantages and limitations of each strategy, and to provide a vision for the future development.
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11
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Xiao L, Fang L, Chatterjee S, Kool ET. Diverse Reagent Scaffolds Provide Differential Selectivity of 2'-OH Acylation in RNA. J Am Chem Soc 2023; 145:143-151. [PMID: 36542611 DOI: 10.1021/jacs.2c09040] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
RNA 2'-OH acylation is widely used both for mapping structure and for conjugating RNA, generally relying on selective reactions with unpaired nucleotides over paired ones. Common reagents for this acylation have been chiefly restricted to two similar aryl scaffolds, leaving open the question of how more broadly varied reagent structure might affect selectivity. Here, we prepared a set of 10 structurally diverse acylimidazole reagents and employed deep sequencing to profile their reactivity and selectivity in an RNA library of systematically varied structure. We show that structure-directed reactivity profiles vary significantly with the reagent scaffold, and we document new acylating agents that have altered selectivity profiles, including reagents that show elevated selectivity within loops, as well as compounds with reduced off-target reactivity in loop closing base pairs. Interestingly, we also show that the simplest reagent (acetylimidazole) is cell permeable and is small enough to map RNA structure in the presence of protein contacts that block other reagents. Finally, we describe reagents that show elevated selectivity within small loops, with applications in site-selective labeling. The results provide new tools for improved conjugation and mapping of RNA.
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Affiliation(s)
- Lu Xiao
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Linglan Fang
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Sayantan Chatterjee
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Eric T Kool
- Department of Chemistry and Sarafan ChEM-H, Stanford University, Stanford, California 94305, United States
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12
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Efficient DNA fluorescence labeling via base excision trapping. Nat Commun 2022; 13:5043. [PMID: 36028479 PMCID: PMC9418136 DOI: 10.1038/s41467-022-32494-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 08/03/2022] [Indexed: 01/19/2023] Open
Abstract
Fluorescence labeling of DNAs is broadly useful, but methods for labeling are expensive and labor-intensive. Here we describe a general method for fluorescence labeling of oligonucleotides readily and cost-efficiently via base excision trapping (BETr), employing deaminated DNA bases to mark label positions, which are excised by base excision repair enzymes generating AP sites. Specially designed aminooxy-substituted rotor dyes trap the AP sites, yielding high emission intensities. BETr is orthogonal to DNA synthesis by polymerases, enabling multi-uracil incorporation into an amplicon and in situ BETr labeling without washing. BETr also enables labeling of dsDNA such as genomic DNA at a high labeling density in a single tube by use of nick translation. Use of two different deaminated bases facilitates two-color site-specific labeling. Use of a multi-labeled DNA construct as a bright fluorescence tag is demonstrated through the conjugation to an antibody for imaging proteins. Finally, double-strand selectivity of a repair enzyme is harnessed in sensitive reporting on the presence of a target DNA or RNA in a mixture with isothermal turnover and single nucleotide specificity. Overall, the results document a convenient and versatile method for general fluorescence labeling of DNAs.
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13
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Xiao L, Fang L, Kool ET. Acylation probing of "generic" RNA libraries reveals critical influence of loop constraints on reactivity. Cell Chem Biol 2022; 29:1341-1352.e8. [PMID: 35662395 PMCID: PMC9391288 DOI: 10.1016/j.chembiol.2022.05.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 03/16/2022] [Accepted: 05/12/2022] [Indexed: 01/08/2023]
Abstract
The reactivity of RNA 2'-OH acylation is broadly useful both in probing structure and in preparing conjugates. To date, this reactivity has been analyzed in limited sets of biological RNA sequences, leaving open questions of how reactivity varies inherently without regard to sequence in structured contexts. We constructed and probed "generic" structured RNA libraries using homogeneous loop sequences, employing deep sequencing to carry out a systematic survey of reactivity. We find a wide range of RNA reactivities among single-stranded sequences, with nearest neighbors playing substantial roles. Remarkably, certain small loops are found to be far more reactive on average (up to 4,000-fold) than single-stranded RNAs, due to conformational constraints that enhance reactivity. Among loops, we observe large variations in reactivity based on size, type, and position. The results lend insights into RNA designs for achieving high-efficiency local conjugation and provide new opportunities to refine structure analysis.
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Affiliation(s)
- Lu Xiao
- Department of Chemistry and ChEM-H Institute, Stanford University, Stanford, CA 94305, USA
| | - Linglan Fang
- Department of Chemistry and ChEM-H Institute, Stanford University, Stanford, CA 94305, USA
| | - Eric T Kool
- Department of Chemistry and ChEM-H Institute, Stanford University, Stanford, CA 94305, USA.
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14
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Wang S, Chen D, Gao L, Liu Y. Short Oligonucleotides Facilitate Co-transcriptional Labeling of RNA at Specific Positions. J Am Chem Soc 2022; 144:5494-5502. [PMID: 35293210 DOI: 10.1021/jacs.2c00020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Labeling RNA molecules at specific positions is critical for RNA research and applications. Such methods are in high demand but still a challenge, especially those that enable native co-synthesis rather than post-synthesis labeling of long RNAs. The method we developed in this work meets these requirements, in which a leader RNA is extended on the hybrid solid-liquid phase by an engineered transcriptional complex following the pause-restart mode. A custom-designed short oligonucleotide is used to functionalize the engineered complex. This remarkable co-transcriptional labeling method incorporates labels into RNAs in high yields with great flexibility. We demonstrate the method by successfully introducing natural modifications, a fluorescent nucleotide analogue and a donor-acceptor fluorophore pair to specific sites located at an internal loop, a pseudoknot, a junction, a helix, and the middle of consecutive identical nucleotides of various RNAs. This newly developed method overcomes efficiency and position-choosing constraints that have hampered routine strategies to label RNAs beyond 200 nucleotides (nt).
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Affiliation(s)
- Siyu Wang
- State Key Laboratory of Microbial Metabolism, School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Dian Chen
- State Key Laboratory of Microbial Metabolism, School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Lingzhi Gao
- State Key Laboratory of Microbial Metabolism, School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yu Liu
- State Key Laboratory of Microbial Metabolism, School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.,Shanghai Artificial Intelligence Laboratory, Shanghai 200232, China
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15
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Jash B, Kool ET. Conjugation of RNA via 2'-OH acylation: Mechanisms determining nucleotide reactivity. Chem Commun (Camb) 2022; 58:3693-3696. [PMID: 35226025 PMCID: PMC9211027 DOI: 10.1039/d2cc00660j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The acylation reactivity of RNA 2'-OH groups has proven broadly useful for labeling and mapping RNA. Here we perform kinetics studies to test the mechanisms governing this reaction, and we find strong steric and inductive effects modulating reactivity. The results shed light on new strategies for improved conjugation and mapping.
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Affiliation(s)
- Biswarup Jash
- Department of Chemistry and ChEM-H Institute, Stanford University, Stanford, CA 94305, USA.
| | - Eric T Kool
- Department of Chemistry and ChEM-H Institute, Stanford University, Stanford, CA 94305, USA.
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16
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Wang F, Li P, Chu HC, Lo PK. Nucleic Acids and Their Analogues for Biomedical Applications. BIOSENSORS 2022; 12:bios12020093. [PMID: 35200353 PMCID: PMC8869748 DOI: 10.3390/bios12020093] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/20/2022] [Accepted: 01/25/2022] [Indexed: 05/07/2023]
Abstract
Nucleic acids are emerging as powerful and functional biomaterials due to their molecular recognition ability, programmability, and ease of synthesis and chemical modification. Various types of nucleic acids have been used as gene regulation tools or therapeutic agents for the treatment of human diseases with genetic disorders. Nucleic acids can also be used to develop sensing platforms for detecting ions, small molecules, proteins, and cells. Their performance can be improved through integration with other organic or inorganic nanomaterials. To further enhance their biological properties, various chemically modified nucleic acid analogues can be generated by modifying their phosphodiester backbone, sugar moiety, nucleobase, or combined sites. Alternatively, using nucleic acids as building blocks for self-assembly of highly ordered nanostructures would enhance their biological stability and cellular uptake efficiency. In this review, we will focus on the development and biomedical applications of structural and functional natural nucleic acids, as well as the chemically modified nucleic acid analogues over the past ten years. The recent progress in the development of functional nanomaterials based on self-assembled DNA-based platforms for gene regulation, biosensing, drug delivery, and therapy will also be presented. We will then summarize with a discussion on the advanced development of nucleic acid research, highlight some of the challenges faced and propose suggestions for further improvement.
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Affiliation(s)
- Fei Wang
- Department of Chemistry, City University of Hong Kong, Hong Kong SAR 999077, China; (F.W.); (P.L.); (H.C.C.)
| | - Pan Li
- Department of Chemistry, City University of Hong Kong, Hong Kong SAR 999077, China; (F.W.); (P.L.); (H.C.C.)
| | - Hoi Ching Chu
- Department of Chemistry, City University of Hong Kong, Hong Kong SAR 999077, China; (F.W.); (P.L.); (H.C.C.)
| | - Pik Kwan Lo
- Department of Chemistry, City University of Hong Kong, Hong Kong SAR 999077, China; (F.W.); (P.L.); (H.C.C.)
- Key Laboratory of Biochip Technology, Biotech and Health Care, Shenzhen Research Institute of City University of Hong Kong, Shenzhen 518057, China
- Correspondence:
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