51
|
Chalikian TV, Liu L, Macgregor RB. Duplex-tetraplex equilibria in guanine- and cytosine-rich DNA. Biophys Chem 2020; 267:106473. [PMID: 33031980 DOI: 10.1016/j.bpc.2020.106473] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 09/03/2020] [Indexed: 02/07/2023]
Abstract
Noncanonical four-stranded DNA structures, including G-quadruplexes and i-motifs, have been discovered in the cell and are implicated in a variety of genomic regulatory functions. The tendency of a specific guanine- and cytosine-rich region of genomic DNA to adopt a four-stranded conformation depends on its ability to overcome the constraints of duplex base-pairing by undergoing consecutive duplex-to-coil and coil-to-tetraplex transitions. The latter ability is determined by the balance between the free energies of participating ordered and disordered structures. In this review, we present an overview of the literature on the stability of G-quadruplex and i-motif structures and discuss the extent of duplex-tetraplex competition as a function of the sequence context of the DNA and environmental conditions including temperature, pH, salt, molecular crowding, and the presence of G-quadruplex-binding ligands. We outline how the results of in vitro studies can be expanded to understanding duplex-tetraplex equilibria in vivo.
Collapse
Affiliation(s)
- Tigran V Chalikian
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Toronto, Ontario M5S 3M2, Canada.
| | - Lutan Liu
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Toronto, Ontario M5S 3M2, Canada
| | - Robert B Macgregor
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Toronto, Ontario M5S 3M2, Canada
| |
Collapse
|
52
|
Kuang G, Zhang M, Kang S, Hu D, Li X, Wei Z, Gong X, An LK, Huang ZS, Shu B, Li D. Syntheses and Evaluation of New Bisacridine Derivatives for Dual Binding of G-Quadruplex and i-Motif in Regulating Oncogene c-myc Expression. J Med Chem 2020; 63:9136-9153. [PMID: 32787078 DOI: 10.1021/acs.jmedchem.9b01917] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The c-myc oncogene is an important regulator for cell growth and differentiation, and its aberrant overexpression is closely related to the occurrence and development of various cancers. Thus, the suppression of c-myc transcription and expression has been investigated for cancer treatment. In this study, various new bisacridine derivatives were synthesized and evaluated for their binding with c-myc promoter G-quadruplex and i-motif. We found that a9 could bind to and stabilize both G-quadruplex and i-motif, resulting in the downregulation of c-myc gene transcription. a9 could inhibit cancer cell proliferation and induce SiHa cell apoptosis and cycle arrest. a9 exhibited tumor growth inhibition activity in a SiHa xenograft tumor model, which might be related to its binding with c-myc promoter G-quadruplex and i-motif. Our results suggested that a9 as a dual G-quadruplex/i-motif binder could be effective in both oncogene replication and transcription and become a promising lead compound for further development with improved potency and selectivity.
Collapse
Affiliation(s)
- Guotao Kuang
- School of Pharmaceutical Sciences, Sun Yat-sen University, 132 Waihuan East Road, Guangzhou 510006, P. R. China
| | - Meiling Zhang
- School of Pharmaceutical Sciences, Sun Yat-sen University, 132 Waihuan East Road, Guangzhou 510006, P. R. China
| | - Shuangshuang Kang
- School of Pharmaceutical Sciences, Sun Yat-sen University, 132 Waihuan East Road, Guangzhou 510006, P. R. China
| | - Dexuan Hu
- School of Pharmaceutical Sciences, Sun Yat-sen University, 132 Waihuan East Road, Guangzhou 510006, P. R. China
| | - Xiaoya Li
- School of Pharmaceutical Sciences, Sun Yat-sen University, 132 Waihuan East Road, Guangzhou 510006, P. R. China
| | - Zuzhuang Wei
- School of Pharmaceutical Sciences, Sun Yat-sen University, 132 Waihuan East Road, Guangzhou 510006, P. R. China
| | - Xue Gong
- School of Pharmaceutical Sciences, Sun Yat-sen University, 132 Waihuan East Road, Guangzhou 510006, P. R. China
| | - Lin-Kun An
- School of Pharmaceutical Sciences, Sun Yat-sen University, 132 Waihuan East Road, Guangzhou 510006, P. R. China
| | - Zhi-Shu Huang
- School of Pharmaceutical Sciences, Sun Yat-sen University, 132 Waihuan East Road, Guangzhou 510006, P. R. China
| | - Bing Shu
- School of Pharmaceutical Sciences, Sun Yat-sen University, 132 Waihuan East Road, Guangzhou 510006, P. R. China.,School of Pharmacy, Guangdong Pharmaceutical University, Guangzhou 510006, P. R. China
| | - Ding Li
- School of Pharmaceutical Sciences, Sun Yat-sen University, 132 Waihuan East Road, Guangzhou 510006, P. R. China
| |
Collapse
|
53
|
Nearest-neighbor parameters for predicting DNA duplex stability in diverse molecular crowding conditions. Proc Natl Acad Sci U S A 2020; 117:14194-14201. [PMID: 32522884 DOI: 10.1073/pnas.1920886117] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The intracellular environment is crowded and heterogeneous. Although the thermodynamic stability of nucleic acid duplexes is predictable in dilute solutions, methods of predicting such stability under specific intracellular conditions are not yet available. We recently showed that the nearest-neighbor model for self-complementary DNA is valid under molecular crowding condition of 40% polyethylene glycol with an average molecular weight of 200 (PEG 200) in 100 mM NaCl. Here, we determined nearest-neighbor parameters for DNA duplex formation under the same crowding condition to predict the thermodynamics of DNA duplexes in the intracellular environment. Preferential hydration of the nucleotides was found to be the key factor for nearest-neighbor parameters in the crowding condition. The determined parameters were shown to predict the thermodynamic parameters (∆H°, ∆S°, and ∆G°37) and melting temperatures (T m) of the DNA duplexes in the crowding condition with significant accuracy. Moreover, we proposed a general method for predicting the stability of short DNA duplexes in different cosolutes based on the relationship between duplex stability and the water activity of the cosolute solution. The method described herein would be valuable for investigating biological processes that occur under specific intracellular crowded conditions and for the application of DNA-based biotechnologies in crowded environments.
Collapse
|
54
|
Berroyer A, Alvarado G, Larson ED. Response of Sulfolobus solfataricus Dpo4 polymerase in vitro to a DNA G-quadruplex. Mutagenesis 2020; 34:289-297. [PMID: 31169295 DOI: 10.1093/mutage/gez010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 05/06/2019] [Indexed: 12/12/2022] Open
Abstract
Repetitive DNA sequences support the formation of structures that can interrupt replication and repair, leading to breaks and mutagenesis. One particularly stable structure is G-quadruplex (G4) DNA, which is four-stranded and formed from tandemly repetitive guanine bases. When folded within a template, G4 interferes with DNA synthesis. Similar to non-duplex structures, DNA base lesions can also halt an advancing replication fork, but the Y-family polymerases solve this problem by bypassing the damage. In order to better understand how guanine-rich DNA is replicated, we have investigated the activity of the model Y-family polymerase, Sulfolobus solfataricus P2 DNA polymerase IV (Dpo4), on guanine-rich templates in vitro. We find that Dpo4 progression on templates containing either a single GC-rich hairpin or a G4 DNA structure is greatly reduced and synthesis stalls at the structure. Human polymerase eta (hPol eta) showed the same pattern of stalling at G4; however, and in contrast to Klenow, hPol eta and Dpo4 partially synthesise into the guanine repeat. Substitution of the nucleotide selectivity residue in Dpo4 with alanine permitted ribonucleotide incorporation on unstructured templates, but this further reduced the ability of Dpo4 to synthesise across from the guanine repeats. The advancement of Dpo4 on G4 templates was highest when the reaction was supplied with only deoxycytidine triphosphate, suggesting that high-fidelity synthesis is favoured over misincorporation. Our results are consistent with a model where the Y-family polymerases pause upon encountering G4 structures but have an ability to negotiate some synthesis through tetrad-associated guanines. This suggests that the Y-family polymerases reduce mutagenesis by catalysing the accurate replication of repetitive DNA sequences, but most likely in concert with additional replication and structure resolution activities.
Collapse
Affiliation(s)
- Alexandra Berroyer
- School of Biological Sciences, Illinois State University, Normal, IL, USA
| | - Gloria Alvarado
- School of Biological Sciences, Illinois State University, Normal, IL, USA
| | - Erik D Larson
- School of Biological Sciences, Illinois State University, Normal, IL, USA
| |
Collapse
|
55
|
Abstract
The formation of guanine-quadruplexes (G4s) in genomic DNA and RNA inhibits replication, transcription, and translation. Although several regions of the human genome exhibit G4-forming potential, the stability and topology of the G4s formed vary depending on the molecular environment. Here, we describe a protocol to quantitatively analyze the inhibitory effects of G4s with different stabilities and topologies on replication in conditions of molecular crowding.
Collapse
|
56
|
Tateishi-Karimata H, Sugimoto N. Chemical biology of non-canonical structures of nucleic acids for therapeutic applications. Chem Commun (Camb) 2020; 56:2379-2390. [PMID: 32022004 DOI: 10.1039/c9cc09771f] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
DNA forms not only the canonical duplex structure but also non-canonical structures. Most potential sequences that induce the formation of non-canonical structures are present in disease-related genes. Interestingly, biological reactions are inhibited or dysregulated by non-canonical structure formation in disease-related genes. To control biological reactions, methods for inducing the formation of non-canonical structures have been developed using small molecules and oligonucleotides. In this feature article, we review biological reactions such as replication, transcription, and reverse transcription controlled by non-canonical DNA structures formed by disease-related genes. Furthermore, we discuss recent studies aimed at developing methods for regulating these biological reactions using drugs targeting the DNA structure.
Collapse
Affiliation(s)
- Hisae Tateishi-Karimata
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 17-1-20 Minatojima-minamimachi, Kobe, 650-0047, Japan.
| | | |
Collapse
|
57
|
Deng M, Li M, Mao X, Li F, Zuo X. Nucleic Acid Nanoprobes for Biosensor Development in Complex Matrices. Chem Res Chin Univ 2020. [DOI: 10.1007/s40242-020-9073-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
58
|
Takahashi S, Bhattacharjee S, Ghosh S, Sugimoto N, Bhowmik S. Preferential targeting cancer-related i-motif DNAs by the plant flavonol fisetin for theranostics applications. Sci Rep 2020; 10:2504. [PMID: 32054927 PMCID: PMC7018961 DOI: 10.1038/s41598-020-59343-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Accepted: 01/14/2020] [Indexed: 12/01/2022] Open
Abstract
The relationship of i-motif DNAs with cancer has prompted the development of specific ligands to detect and regulate their formation. Some plant flavonols show unique fluorescence and anti-cancer properties, which suggest the utility of the theranostics approach to cancer therapy related to i-motif DNA. We investigated the effect of the plant flavonol, fisetin (Fis), on the physicochemical property of i-motif DNAs. Binding of Fis to the i-motif from the promoter region of the human vascular endothelial growth factor (VEGF) gene dramatically induced the excited state intramolecular proton transfer (ESIPT) reaction that significantly enhanced the intensity of the tautomer emission band of Fis. This unique response was due to the coincidence of the structural change from i-motif to the hairpin-like structure which is stabilized via putative Watson-Crick base pairs between some guanines within the loop region of the i-motif and cytosines in the structure. As a result, the VEGF i-motif did not act as a replication block in the presence of Fis, which indicates the applicability of Fis for the regulation of gene expression of VEGF. The fluorescence and biological properties of Fis may be utilised for theranostics applications for cancers related to a specific cancer-related gene, such as VEGF.
Collapse
Affiliation(s)
- Shuntaro Takahashi
- FIBER (Frontier Institute for Biomolecular Engineering Research), Konan University, 7-1-20 Minatojima-Minamimachi, Chuo-ku, Kobe, 650-0047, Japan
| | - Snehasish Bhattacharjee
- Department of Biophysics, Molecular Biology & Bioinformatics, University of Calcutta, University College of Science, 92, A.P.C. Road, Kolkata, 700009, India
| | - Saptarshi Ghosh
- FIBER (Frontier Institute for Biomolecular Engineering Research), Konan University, 7-1-20 Minatojima-Minamimachi, Chuo-ku, Kobe, 650-0047, Japan
| | - Naoki Sugimoto
- FIBER (Frontier Institute for Biomolecular Engineering Research), Konan University, 7-1-20 Minatojima-Minamimachi, Chuo-ku, Kobe, 650-0047, Japan. .,FIRST (Graduate School of Frontiers of Innovative Research in Science and Technology), Konan University, 7-1-20 Minatojima-Minamimachi, Chuo-ku, Kobe, 650-0047, Japan.
| | - Sudipta Bhowmik
- Department of Biophysics, Molecular Biology & Bioinformatics, University of Calcutta, University College of Science, 92, A.P.C. Road, Kolkata, 700009, India.
| |
Collapse
|
59
|
Ma Y, Iida K, Nagasawa K. Topologies of G-quadruplex: Biological functions and regulation by ligands. Biochem Biophys Res Commun 2020; 531:3-17. [PMID: 31948752 DOI: 10.1016/j.bbrc.2019.12.103] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Revised: 12/20/2019] [Accepted: 12/28/2019] [Indexed: 01/06/2023]
Abstract
G-Quadruplex (G4) is one of the higher-order structures occurring in guanine-rich sequences of nucleic acids, and plays critical roles in biological processes. The G4-forming sequences can generate three kinds of topologies, i.e., parallel, anti-parallel, and hybrid, and these polymorphic structures have an important influence on G4-related biological functions. In this review, we highlight variety of structures generated by G4s containing various sequences and under diverse conditions. We also discuss the G4 ligands which induce specific topologies and/or conversion between different topologies.
Collapse
Affiliation(s)
- Yue Ma
- Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Japan.
| | - Keisuke Iida
- Department of Chemistry, Chiba University, Japan
| | - Kazuo Nagasawa
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Japan.
| |
Collapse
|
60
|
Devaux A, Bonnat L, Lavergne T, Defrancq E. Access to a stabilized i-motif DNA structure through four successive ligation reactions on a cyclopeptide scaffold. Org Biomol Chem 2020; 18:6394-6406. [DOI: 10.1039/d0ob01311k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Four successive chemical ligations were used for the assembly of a sophisticated biomolecular system allowing the formation of a stabilized i-motif DNA at pH 7.
Collapse
Affiliation(s)
- Alexandre Devaux
- Univ. Grenoble Alpes
- Département de Chimie Moléculaire
- CNRS
- Grenoble 38000
- France
| | - Laureen Bonnat
- Univ. Grenoble Alpes
- Département de Chimie Moléculaire
- CNRS
- Grenoble 38000
- France
| | - Thomas Lavergne
- Univ. Grenoble Alpes
- Département de Chimie Moléculaire
- CNRS
- Grenoble 38000
- France
| | - Eric Defrancq
- Univ. Grenoble Alpes
- Département de Chimie Moléculaire
- CNRS
- Grenoble 38000
- France
| |
Collapse
|
61
|
Takahashi S, Sugimoto N. Stability prediction of canonical and non-canonical structures of nucleic acids in various molecular environments and cells. Chem Soc Rev 2020; 49:8439-8468. [DOI: 10.1039/d0cs00594k] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This review provides the biophysicochemical background and recent advances in stability prediction of canonical and non-canonical structures of nucleic acids in various molecular environments and cells.
Collapse
Affiliation(s)
- Shuntaro Takahashi
- Frontier Institute for Biomolecular Engineering Research (FIBER)
- Konan University
- Kobe
- Japan
| | - Naoki Sugimoto
- Frontier Institute for Biomolecular Engineering Research (FIBER)
- Konan University
- Kobe
- Japan
- Graduate School of Frontiers of Innovative Research in Science and Technology (FIRST)
| |
Collapse
|
62
|
Meeting report: Seventh International Meeting on Quadruplex Nucleic Acids (Changchun, P.R. China, September 6–9, 2019). Biochimie 2020; 168:100-109. [DOI: 10.1016/j.biochi.2019.10.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Accepted: 10/31/2019] [Indexed: 12/24/2022]
|
63
|
Megalathan A, Cox BD, Wilkerson PD, Kaur A, Sapkota K, Reiner JE, Dhakal S. Single-molecule analysis of i-motif within self-assembled DNA duplexes and nanocircles. Nucleic Acids Res 2019; 47:7199-7212. [PMID: 31287873 PMCID: PMC6698746 DOI: 10.1093/nar/gkz565] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 06/13/2019] [Accepted: 07/04/2019] [Indexed: 12/20/2022] Open
Abstract
The cytosine (C)-rich sequences that can fold into tetraplex structures known as i-motif are prevalent in genomic DNA. Recent studies of i-motif-forming sequences have shown increasing evidence of their roles in gene regulation. However, most of these studies have been performed in short single-stranded oligonucleotides, far from the intracellular environment. In cells, i-motif-forming sequences are flanked by DNA duplexes and packed in the genome. Therefore, exploring the conformational dynamics and kinetics of i-motif under such topologically constrained environments is highly relevant in predicting their biological roles. Using single-molecule fluorescence analysis of self-assembled DNA duplexes and nanocircles, we show that the topological environments play a key role on i-motif stability and dynamics. While the human telomere sequence (C3TAA)3C3 assumes i-motif structure at pH 5.5 regardless of topological constraint, it undergoes conformational dynamics among unfolded, partially folded and fully folded states at pH 6.5. The lifetimes of i-motif and the partially folded state at pH 6.5 were determined to be 6 ± 2 and 31 ± 11 s, respectively. Consistent with the partially folded state observed in fluorescence analysis, interrogation of current versus time traces obtained from nanopore analysis at pH 6.5 shows long-lived shallow blockades with a mean lifetime of 25 ± 6 s. Such lifetimes are sufficient for the i-motif and partially folded states to interact with proteins to modulate cellular processes.
Collapse
Affiliation(s)
- Anoja Megalathan
- Department of Chemistry, Virginia Commonwealth University, 1001 West Main Street, Richmond, VA 23284, USA
| | - Bobby D Cox
- Department of Physics, Virginia Commonwealth University, 701 West Grace Street, Richmond, VA 23284, USA
| | - Peter D Wilkerson
- Department of Physics, Virginia Commonwealth University, 701 West Grace Street, Richmond, VA 23284, USA
| | - Anisa Kaur
- Department of Chemistry, Virginia Commonwealth University, 1001 West Main Street, Richmond, VA 23284, USA
| | - Kumar Sapkota
- Department of Chemistry, Virginia Commonwealth University, 1001 West Main Street, Richmond, VA 23284, USA
| | - Joseph E Reiner
- Department of Physics, Virginia Commonwealth University, 701 West Grace Street, Richmond, VA 23284, USA
| | - Soma Dhakal
- Department of Chemistry, Virginia Commonwealth University, 1001 West Main Street, Richmond, VA 23284, USA
| |
Collapse
|
64
|
Pages BJ, Gurung SP, McQuaid K, Hall JP, Cardin CJ, Brazier JA. Stabilization of Long-Looped i-Motif DNA by Polypyridyl Ruthenium Complexes. Front Chem 2019; 7:744. [PMID: 31750292 PMCID: PMC6848161 DOI: 10.3389/fchem.2019.00744] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 10/17/2019] [Indexed: 12/21/2022] Open
Abstract
A spectroscopic study of the interactions of Λ- and Δ-[Ru(phen)2(dppz)]2+ with i-motif DNA containing thymine loops of various lengths. In the presence of i-motifs, the luminescence of the Λ enantiomer was enhanced much more than the Δ. Despite this, the effect of each enantiomer on i-motif thermal stability was comparable. The sequences most affected by [Ru(phen)2(dppz)]2+ were those with long thymine loops; this suggests that long-looped i-motifs are attractive targets for potential transition metal complex drugs and should be explored further in drug design.
Collapse
Affiliation(s)
- Benjamin J Pages
- School of Pharmacy, University of Reading, Reading, United Kingdom
| | - Sarah P Gurung
- Department of Chemistry, University of Reading, Reading, United Kingdom.,Diamond Light Source, Didcot, United Kingdom
| | - Kane McQuaid
- Department of Chemistry, University of Reading, Reading, United Kingdom.,Diamond Light Source, Didcot, United Kingdom
| | - James P Hall
- School of Pharmacy, University of Reading, Reading, United Kingdom.,Diamond Light Source, Didcot, United Kingdom
| | | | - John A Brazier
- School of Pharmacy, University of Reading, Reading, United Kingdom
| |
Collapse
|
65
|
A label-free colorimetric detection of microRNA via G-quadruplex-based signal quenching strategy. Anal Chim Acta 2019; 1079:207-211. [DOI: 10.1016/j.aca.2019.06.063] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 06/24/2019] [Accepted: 06/30/2019] [Indexed: 11/19/2022]
|
66
|
Mondal M, Bhattacharyya D, Gao YQ. Structural properties and influence of solvent on the stability of telomeric four-stranded i-motif DNA. Phys Chem Chem Phys 2019; 21:21549-21560. [PMID: 31536074 DOI: 10.1039/c9cp03253c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Repetitive cytosine rich i-motif forming sequences are abundant in the telomere, centromere and promoters of several oncogenes and in some instances are known to regulate transcription and gene expression. The in vivo existence of i-motif structures demands further insight into the factors affecting their formation and stability and development of better understanding of their gene regulatory functions. Most prior studies characterizing the conformational dynamics of i-motifs are based on i-motif forming synthetic constructs. Here, we present a systematic study on the stability and structural properties of biologically relevant i-motifs of telomeric and centromeric repeat fragments. Our results based on molecular dynamics simulations and quantum chemical calculations indicate that along with base pairing interactions within the i-motif core the overall folded conformation is associated with the stable C-HO sugar "zippers" in the narrow grooves and structured water molecules along the wide grooves. The stacked geometry of the hemi-protonated cytosine pairs within the i-motif core is mainly governed by the repulsive base stacking interaction. The loop sequence can affect the structural dynamics of the i-motif by altering the loop motion and backbone conformation. Overall this study provides microscopic insight into the i-motif structure that will be helpful to understand the structural aspect of mechanisms of gene regulation by i-motif DNA.
Collapse
Affiliation(s)
- Manas Mondal
- Institute of Theoretical and Computational Chemistry, College of Chemistry and Molecular Engineering, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871, China.
| | | | | |
Collapse
|
67
|
Abou Assi H, Garavís M, González C, Damha MJ. i-Motif DNA: structural features and significance to cell biology. Nucleic Acids Res 2019; 46:8038-8056. [PMID: 30124962 PMCID: PMC6144788 DOI: 10.1093/nar/gky735] [Citation(s) in RCA: 233] [Impact Index Per Article: 46.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 08/13/2018] [Indexed: 12/20/2022] Open
Abstract
The i-motif represents a paradigmatic example of the wide structural versatility of nucleic acids. In remarkable contrast to duplex DNA, i-motifs are four-stranded DNA structures held together by hemi- protonated and intercalated cytosine base pairs (C:C+). First observed 25 years ago, and considered by many as a mere structural oddity, interest in and discussion on the biological role of i-motifs have grown dramatically in recent years. In this review we focus on structural aspects of i-motif formation, the factors leading to its stabilization and recent studies describing the possible role of i-motifs in fundamental biological processes.
Collapse
Affiliation(s)
- Hala Abou Assi
- Department of Chemistry, McGill University, Montreal, QC H3A 0B8, Canada
| | - Miguel Garavís
- Instituto de Química Física 'Rocasolano', CSIC, C/Serrano 119, 28006 Madrid, Spain
| | - Carlos González
- Instituto de Química Física 'Rocasolano', CSIC, C/Serrano 119, 28006 Madrid, Spain
| | - Masad J Damha
- Department of Chemistry, McGill University, Montreal, QC H3A 0B8, Canada
| |
Collapse
|
68
|
Sheppard EC, Rogers S, Harmer NJ, Chahwan R. A universal fluorescence-based toolkit for real-time quantification of DNA and RNA nuclease activity. Sci Rep 2019; 9:8853. [PMID: 31222049 PMCID: PMC6586798 DOI: 10.1038/s41598-019-45356-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 05/31/2019] [Indexed: 12/12/2022] Open
Abstract
DNA and RNA nucleases play a critical role in a growing number of cellular processes ranging from DNA repair to immune surveillance. Nevertheless, many nucleases have unknown or poorly characterized activities. Elucidating nuclease substrate specificities and co-factors can support a more definitive understanding of cellular mechanisms in physiology and disease. Using fluorescence-based methods, we present a quick, safe, cost-effective, and real-time versatile nuclease assay, which uniquely studies nuclease enzyme kinetics. In conjunction with a substrate library we can now analyse nuclease catalytic rates, directionality, and substrate preferences. The assay is sensitive enough to detect kinetics of repair enzymes when confronted with DNA mismatches or DNA methylation sites. We have also extended our analysis to study the kinetics of human single-strand DNA nuclease TREX2, DNA polymerases, RNA, and RNA:DNA nucleases. These nucleases are involved in DNA repair, immune regulation, and have been associated with various diseases, including cancer and immune disorders.
Collapse
Affiliation(s)
- Emily C Sheppard
- Living Systems Institute, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
| | - Sally Rogers
- Living Systems Institute, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
| | - Nicholas J Harmer
- Living Systems Institute, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
| | - Richard Chahwan
- Living Systems Institute, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK. .,Institute of Experimental Immunology, University of Zurich, 8057, Zurich, Switzerland.
| |
Collapse
|
69
|
Lepper CP, Williams MAK, Edwards PJB, Filichev VV, Jameson GB. Effects of Pressure and pH on the Physical Stability of an I‐Motif DNA Structure. Chemphyschem 2019; 20:1567-1571. [DOI: 10.1002/cphc.201900145] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 05/01/2019] [Indexed: 12/21/2022]
Affiliation(s)
| | - Martin A. K. Williams
- School of Fundamental Sciences The MacDiarmid Institute and the Riddet InstituteMassey University Palmerston North New Zealand
| | | | | | - Geoffrey B. Jameson
- School of Fundamental Sciences The MacDiarmid Institute and the Riddet InstituteMassey University Palmerston North New Zealand
| |
Collapse
|
70
|
Endoh T, Sugimoto N. Conformational Dynamics of the RNA G-Quadruplex and its Effect on Translation Efficiency. Molecules 2019; 24:molecules24081613. [PMID: 31022854 PMCID: PMC6514569 DOI: 10.3390/molecules24081613] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 04/22/2019] [Accepted: 04/22/2019] [Indexed: 11/16/2022] Open
Abstract
During translation, intracellular mRNA folds co-transcriptionally and must refold following the passage of ribosome. The mRNAs can be entrapped in metastable structures during these folding events. In the present study, we evaluated the conformational dynamics of the kinetically favored, metastable, and hairpin-like structure, which disturbs the thermodynamically favored G-quadruplex structure, and its effect on co-transcriptional translation in prokaryotic cells. We found that nascent mRNA forms a metastable hairpin-like structure during co-transcriptional folding instead of the G-quadruplex structure. When the translation progressed co-transcriptionally before the metastable hairpin-like structure transition to the G-quadruplex, function of the G-quadruplex as a roadblock of the ribosome was sequestered. This suggested that kinetically formed RNA structures had a dominant effect on gene expression in prokaryotes. The results of this study indicate that it is critical to consider the conformational dynamics of RNA-folding to understand the contributions of the mRNA structures in controlling gene expression.
Collapse
Affiliation(s)
- Tamaki Endoh
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20 Minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, Japan.
| | - Naoki Sugimoto
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20 Minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, Japan.
- Graduate School of Frontiers of Innovative Research in Science and Technology (FIRST), Konan University, 7-1-20 Minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, Japan.
| |
Collapse
|
71
|
Sun Y, Ji Y, Wang D, Wang J, Liu D. Stabilization of an intermolecular i-motif by lipid modification of cytosine-oligodeoxynucleotides. Org Biomol Chem 2019; 16:4857-4863. [PMID: 29926887 DOI: 10.1039/c8ob00920a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
This paper describes the stabilization of an intermolecular i-motif by lipophilic modification on the 3'-terminus of oligonucleotides. The hydrophobic aliphatic chain connected at the 3'-terminus of a trinucleotide (dC)3 promoted the formation of an i-motif and significantly enhanced the quadruplex's stability. The impact of lipophilic modification on i-motif's thermal stability was studied by UV-thermal denaturation melting experiments and isothermal titration calorimetry. We found that alkyl chains containing more than 14 carbon atoms could elevate the i-motif structure's stability in a wide range of pH and concentrations.
Collapse
Affiliation(s)
- Yawei Sun
- State Key Laboratory of Heavy Oil Processing, College of Chemical Engineering, China University of Petroleum (Huadong), Qingdao, 258000, China.
| | | | | | | | | |
Collapse
|
72
|
Fleming AM, Stewart KM, Eyring GM, Ball TE, Burrows CJ. Unraveling the 4n - 1 rule for DNA i-motif stability: base pairs vs. loop lengths. Org Biomol Chem 2019; 16:4537-4546. [PMID: 29873385 DOI: 10.1039/c8ob01198b] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Previously our laboratory identified that poly-2'-deoxycytidine (dCn) strands of DNA with lengths greater than 12 nucleotides could adopt i-motif folds, while the pH-dependent stabilities follow a 4n - 1 repeat pattern with respect to chain length (J. Am. Chem. Soc., 2017, 139, 4682-4689). Herein, model i-motif folds in which loop configurations were forced by judiciously mutating dC to non-dC nucleotides allowed a structural model to be proposed to address this phenomenon. The model was developed by systematically studying two i-motifs with either an even or odd number of d(C·C)+ hemiprotonated base pairs in the core. First, a trend in the pH-dependent stability vs. loop nucleotide identity was observed: dC > dT ∼ dU ≫ dA ∼ dG. Next, loops comprised of dT nucleotides in the two different core base pair configurations were studied while systematically changing the loop lengths. We found that an i-motif with an even number of base pairs in the core with a single nucleotide in each of the three loops was the most stable, as well as an i-motif with an odd number of core base pairs having one nucleotide in the two exterior loops and three nucleotides in the central loop. A systematic increase in the central loop from 1-4 nucleotides for an odd number of base pairs in the i-motif core reproduced the 4n - 1 repeat pattern observed in the poly-dCn strands. Additional loop configurations were studied to further support the model. The results are discussed with respect to their biological relevance.
Collapse
Affiliation(s)
- Aaron M Fleming
- Department of Chemistry, 315 S. 1400 East. and University of Utah, Salt Lake City, UT 84112-0850, USA.
| | | | | | | | | |
Collapse
|
73
|
Takahashi S, Yamamoto J, Kitamura A, Kinjo M, Sugimoto N. Characterization of Intracellular Crowding Environments with Topology-Based DNA Quadruplex Sensors. Anal Chem 2019; 91:2586-2590. [PMID: 30624050 DOI: 10.1021/acs.analchem.8b04177] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Molecular crowding creates a unique environment in cells and imposes physical constraints such as the excluded volume effect, water activity, and dielectric constant that can affect the structure and function of biomolecules. It is therefore important to develop a method for quantifying the effects of molecular crowding in cells. In this study, we developed a Förster resonance energy transfer (FRET) probe based on a guanine-quadruplex (G4) DNA motif that shows distinct FRET signals in response to crowding conditions in the presence of salt and poly(ethylene glycol). FRET efficiencies varied in different solutions, reflecting the dependence of G4 stability and topology on salt concentration and water activity. In living cells, FRET signals in the nucleus were higher than those in the cytosol; the signals in membraneless nuclear compartments (i.e., nucleolus) were especially high, suggesting that a decrease in water activity is important for the crowding effect in the nucleus. Thus, the use of DNA sensors with variable structures can elucidate the local effects of molecular crowding in cells.
Collapse
Affiliation(s)
- Shuntaro Takahashi
- FIBER (Frontier Institute for Biomolecular Engineering Research) , Konan University , 7-1-20 Minatojima-Minamimachi , Chuo-ku, Kobe 650-0047 , Japan
| | - Johtaro Yamamoto
- Biomedical Research Institute , National Institute of Advanced Industrial Science and Technology (AIST) , 1-1-1 Higashi , Tsukuba , Ibaraki , 305-8566 , Japan
| | - Akira Kitamura
- Laboratory of Molecular Cell Dynamics, Faculty of Advanced Life Science , Hokkaido University , Sapporo , 001-0021 , Japan
| | - Masataka Kinjo
- Laboratory of Molecular Cell Dynamics, Faculty of Advanced Life Science , Hokkaido University , Sapporo , 001-0021 , Japan
| | - Naoki Sugimoto
- FIBER (Frontier Institute for Biomolecular Engineering Research) , Konan University , 7-1-20 Minatojima-Minamimachi , Chuo-ku, Kobe 650-0047 , Japan.,FIRST (Graduate School of Frontiers of Innovative Research in Science and Technology) , Konan University , 7-1-20 Minatojima-Minamimachi , Chuo-ku, Kobe 650-0047 , Japan
| |
Collapse
|
74
|
Huang ZL, Dai J, Luo WH, Wang XG, Tan JH, Chen SB, Huang ZS. Identification of G-Quadruplex-Binding Protein from the Exploration of RGG Motif/G-Quadruplex Interactions. J Am Chem Soc 2018; 140:17945-17955. [PMID: 30517002 DOI: 10.1021/jacs.8b09329] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The arginine/glycine-rich region termed the RGG domain is usually found in G-quadruplex (G4)-binding proteins and is important in G4-protein interactions. Studies on the binding mechanism of RGG domains found that small segments (RGG motif) inside the domain contribute greatly to the G4 binding affinity. However, unlike the entire RGG domains that have been broadly explored, the role of the RGG motif remains obscure, with very limited study. Herein, to clarify the role of the RGG motif in G4-protein interactions, we systematically investigated the binding affinity and mode between RGG-motif peptides and G4s. The internal arrangement of RGG repeats and gap amino acids played a more crucial role in the G4-binding mechanism than a critical number of RGG repeats. Arginines and phenylalanines at the exact position of the RGG motif might enable additional hydrogen bonding and π-stacking interaction with nucleobases and strengthen the binding of G4. Impressively, proceeding from a G4-binding RGG peptide, 12, discovered above, we identified the cold-inducible RNA-binding protein (CIRBP) as a new G4 DNA-binding protein both in vitro and in cells. In addition, we found that the key amino acids for G4 binding in peptide 12 and CIRBP were highly similar, and peptide 12 clearly played a key role in the G4 binding of CIRBP. This report is the first in which a G4-binding protein was identified from exploration of the G4-binding RGG motif. Our findings suggest a novel strategy for discovering new G4-binding proteins by exploring key peptide segments.
Collapse
Affiliation(s)
- Zhou-Li Huang
- School of Pharmaceutical Sciences , Sun Yat-sen University , Guangzhou 510006 , People's Republic of China
| | - Jing Dai
- School of Pharmaceutical Sciences , Sun Yat-sen University , Guangzhou 510006 , People's Republic of China
| | - Wen-Hua Luo
- School of Pharmaceutical Sciences , Sun Yat-sen University , Guangzhou 510006 , People's Republic of China
| | - Xiang-Gui Wang
- School of Pharmaceutical Sciences , Sun Yat-sen University , Guangzhou 510006 , People's Republic of China
| | - Jia-Heng Tan
- School of Pharmaceutical Sciences , Sun Yat-sen University , Guangzhou 510006 , People's Republic of China
| | - Shuo-Bin Chen
- School of Pharmaceutical Sciences , Sun Yat-sen University , Guangzhou 510006 , People's Republic of China
| | - Zhi-Shu Huang
- School of Pharmaceutical Sciences , Sun Yat-sen University , Guangzhou 510006 , People's Republic of China
| |
Collapse
|
75
|
Ma C, Chan RCT, Chan CTL, Wong AKW, Chung BPY, Kwok WM. Fluorescence and Ultrafast Fluorescence Unveil the Formation, Folding Molecularity, and Excitation Dynamics of Homo-Oligomeric and Human Telomeric i-Motifs at Acidic and Neutral pH. Chem Asian J 2018; 13:3706-3717. [PMID: 30230251 DOI: 10.1002/asia.201801117] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 08/28/2018] [Indexed: 01/07/2023]
Abstract
i-Motifs are tetraplex DNAs known to be stable at acidic pH. The structure of i-motifs is important in DNA nanotechnology; i-motif-forming sequences with consecutive cytosine (C) molecules are abundant throughout the human genome. There is, however, little information on the structure of C-rich DNAs under physiologically relevant neutral conditions. The electron dynamics of i-motifs, crucial to both biology and materials applications, also remains largely unexplored. In this work, we report a combined femtosecond and nanosecond broadband time-resolved fluorescence (TRF) and steady-state fluorescence investigation on homo-oligomer dC20 , a human telomeric sequence (HTS) 5'-dC3 (TA2 C3 )3 , and its analogue performed with different excitation at both acidic and neutral pH. Our study provides direct observation of intrinsic fluorescence and the first full probe of the real-time dynamics of the intrinsic fluorescence from i-motifs formed from varied sequences and pH conditions. The results obtained demonstrate concrete evidence for the existence at neutral pH of i-motifs from both dC20 and the HTS. It also identifies that, under neutral conditions, the i-motif from dC20 adopting the bimolecular folding structure is significantly more stable than the HTS i-motif featuring the unimolecular topology. Our femtosecond and nanosecond TRF study unveils excitation dynamics distinctive of the interdigitated architecture of i-motifs with the excited states involved exhibiting deactivation over a remarkably broad timescale through multiple channels involving proton-coupled electron transfer lasting tens of picoseconds, as signified by the solvent kinetic isotope effect, and structure-dependent charge recombination in the hundreds of picoseconds to tens of nanoseconds time regime.
Collapse
Affiliation(s)
- Chensheng Ma
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, Guangdong, P. R. China
| | - Ruth Chau-Ting Chan
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, P. R. China
| | - Chris Tsz-Leung Chan
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, Guangdong, P. R. China
| | - Allen Ka-Wa Wong
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, P. R. China
| | - Bowie Po-Yee Chung
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, P. R. China
| | - Wai-Ming Kwok
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, P. R. China
| |
Collapse
|
76
|
Satpathi S, Das K, Hazra P. Silica nano-channel induced i-motif formation and stabilization at neutral and alkaline pH. Chem Commun (Camb) 2018; 54:7054-7057. [PMID: 29876546 DOI: 10.1039/c8cc02811g] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Here, we have developed a new strategy to stabilize i-motif DNA in neutral and alkaline media by incorporating C-rich sequences inside silica nano-channels. Subsequently, the reversibility of this conformational transition has been achieved using a positively charged protein. Importantly, this entire conformational transition can be performed in multiple cycles, which offers an alternative way to control i-motif formation other than pH and thermal annealing.
Collapse
Affiliation(s)
- Sagar Satpathi
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune. Dr. Homi Bhabha Road, Pashan, Pune, 411008, India.
| | | | | |
Collapse
|
77
|
Abstract
Advances in understanding mechanisms of nucleic acids have revolutionized molecular biology and medicine, but understanding of nontraditional nucleic acid conformations is less developed. The guanine quadruplex (G4) alternative DNA structure was first described in the 1960s, but the existence of G4 structures (G4-S) and their participation in myriads of biological functions are still underappreciated. Despite many tools to study G4s and many examples of roles for G4s in eukaryotic molecular processes and issues with uncontrolled G4-S formation, there is relatively little knowledge about the roles of G4-S in viral or prokaryotic systems. This review summarizes the state of the art with regard to G4-S in eukaryotes and their potential roles in human disease before discussing the evidence that G4-S have equivalent importance in affecting viral and bacterial life.
Collapse
Affiliation(s)
- H Steven Seifert
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA;
| |
Collapse
|
78
|
Omaga CA, Fleming AM, Burrows CJ. The Fifth Domain in the G-Quadruplex-Forming Sequence of the Human NEIL3 Promoter Locks DNA Folding in Response to Oxidative Damage. Biochemistry 2018; 57:2958-2970. [PMID: 29718661 DOI: 10.1021/acs.biochem.8b00226] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
DNA oxidation is an inevitable and usually detrimental process, but the cell is capable of reversing this state because the cell possesses a highly developed set of DNA repair machineries, including the DNA glycosylase NEIL3 that is encoded by the NEIL3 gene. In this work, the G-rich promoter region of the human NEIL3 gene was shown to fold into a dynamic G-quadruplex (G4) structure under nearly physiological conditions using spectroscopic techniques (e.g., nuclear magnetic resonance, circular dichroism, fluorescence, and ultraviolet-visible) and DNA polymerase stop assays. The presence of 8-oxo-7,8-dihydroguanine (OG) modified the properties of the NEIL3 G4 and entailed the recruitment of the fifth domain to function as a "spare tire", in which an undamaged fifth G-track is swapped for the damaged section of the G4. The polymerase stop assay findings also revealed that owing to its dynamic polymorphism, the NEIL3 G4 is more readily bypassed by DNA polymerase I (Klenow fragment) than well-known oncogene G4s are. This study identifies the NEIL3 promoter possessing a G-rich element that can adopt a G4 fold, and when OG is incorporated, the sequence can lock into a more stable G4 fold via recruitment of the fifth track of Gs.
Collapse
Affiliation(s)
- Carla A Omaga
- Department of Chemistry , University of Utah , Salt Lake City , Utah 84112-0850 , United States
| | - Aaron M Fleming
- Department of Chemistry , University of Utah , Salt Lake City , Utah 84112-0850 , United States
| | - Cynthia J Burrows
- Department of Chemistry , University of Utah , Salt Lake City , Utah 84112-0850 , United States
| |
Collapse
|
79
|
Giassa IC, Rynes J, Fessl T, Foldynova-Trantirkova S, Trantirek L. Advances in the cellular structural biology of nucleic acids. FEBS Lett 2018; 592:1997-2011. [PMID: 29679394 DOI: 10.1002/1873-3468.13054] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 03/31/2018] [Accepted: 04/09/2018] [Indexed: 01/01/2023]
Abstract
Conventional biophysical and chemical biology approaches for delineating relationships between the structure and biological function of nucleic acids (NAs) abstract NAs from their native biological context. However, cumulative experimental observations have revealed that the structure, dynamics and interactions of NAs might be strongly influenced by a broad spectrum of specific and nonspecific physical-chemical environmental factors. This consideration has recently sparked interest in the development of novel tools for structural characterization of NAs in the native cellular context. Here, we review the individual methods currently being employed for structural characterization of NA structure in a native cellular environment with a focus on recent advances and developments in the emerging fields of in-cell NMR and electron paramagnetic resonance spectroscopy and in-cell single-molecule FRET of NAs.
Collapse
Affiliation(s)
- Ilektra-Chara Giassa
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Jan Rynes
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Tomas Fessl
- Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic
| | - Silvie Foldynova-Trantirkova
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic.,Institute of Biophysics, Academy of Science of the Czech Republic, Brno, Czech Republic
| | - Lukas Trantirek
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| |
Collapse
|
80
|
I-motif DNA structures are formed in the nuclei of human cells. Nat Chem 2018; 10:631-637. [PMID: 29686376 DOI: 10.1038/s41557-018-0046-3] [Citation(s) in RCA: 338] [Impact Index Per Article: 56.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 03/14/2018] [Indexed: 12/25/2022]
Abstract
Human genome function is underpinned by the primary storage of genetic information in canonical B-form DNA, with a second layer of DNA structure providing regulatory control. I-motif structures are thought to form in cytosine-rich regions of the genome and to have regulatory functions; however, in vivo evidence for the existence of such structures has so far remained elusive. Here we report the generation and characterization of an antibody fragment (iMab) that recognizes i-motif structures with high selectivity and affinity, enabling the detection of i-motifs in the nuclei of human cells. We demonstrate that the in vivo formation of such structures is cell-cycle and pH dependent. Furthermore, we provide evidence that i-motif structures are formed in regulatory regions of the human genome, including promoters and telomeric regions. Our results support the notion that i-motif structures provide key regulatory roles in the genome.
Collapse
|
81
|
Takahashi S, Kim KT, Podbevšek P, Plavec J, Kim BH, Sugimoto N. Recovery of the Formation and Function of Oxidized G-Quadruplexes by a Pyrene-Modified Guanine Tract. J Am Chem Soc 2018; 140:5774-5783. [PMID: 29608858 DOI: 10.1021/jacs.8b01577] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Oxidation is one of the frequent causes of DNA damage, especially to guanine bases. Guanine bases in the G-quadruplex (G4) are sensitive to damage by oxidation, resulting in transformation to 8-oxo-7,8-dihydroguanine (8-oxoG). Because the formation of G4 represses the expression of some cancer-related genes, the presence of 8-oxoG in a G4 sequence might affect G4 formation and induce cancer progression. Thus, oxidized-G4 formation must be controlled using a chemical approach. In the present study, we investigated the effect of introduction of 8-oxoG into a G4 sequence on the formation and function of the G4 structure. The 8-oxoG-containing G4 derived from the promoter region of the human vascular endothelial growth factor ( VEGF) gene differed topologically from unoxidized G4. The oxidized VEGF G4 did not act as a replication block and was not stabilized by the G4-binding protein nucleolin. To recover G4 function, we developed an oligonucleotide consisting of a pyrene-modified guanine tract that replaces the oxidized guanine tract and forms stable intermolecular G4s with the other intact guanine tracts. When this oligonucleotide was used, the oxidized G4 stalled replication and was stabilized by nucleolin as with the unmodified G4. This strategy generally enables recovery of the function of any oxidized G4s and therefore has potential for cancer therapy.
Collapse
Affiliation(s)
| | - Ki Tae Kim
- Department of Chemistry, Division of Advanced Materials Science , Pohang University of Science and Technology (POSTECH) , Pohang 37673 , Republic of Korea
| | - Peter Podbevšek
- Slovenian NMR Center , National Institute of Chemistry , SI-1000 Ljubljana , Slovenia
| | - Janez Plavec
- Slovenian NMR Center , National Institute of Chemistry , SI-1000 Ljubljana , Slovenia
| | - Byeang Hyean Kim
- Department of Chemistry, Division of Advanced Materials Science , Pohang University of Science and Technology (POSTECH) , Pohang 37673 , Republic of Korea
| | | |
Collapse
|
82
|
Tsvetkov VB, Zatsepin TS, Belyaev ES, Kostyukevich YI, Shpakovski GV, Podgorsky VV, Pozmogova GE, Varizhuk AM, Aralov AV. i-Clamp phenoxazine for the fine tuning of DNA i-motif stability. Nucleic Acids Res 2018; 46:2751-2764. [PMID: 29474573 PMCID: PMC5888743 DOI: 10.1093/nar/gky121] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 02/01/2018] [Accepted: 02/13/2018] [Indexed: 12/13/2022] Open
Abstract
Non-canonical DNA structures are widely used for regulation of gene expression, in DNA nanotechnology and for the development of new DNA-based sensors. I-motifs (iMs) are two intercalated parallel duplexes that are held together by hemiprotonated C-C base pairs. Previously, iMs were used as an accurate sensor for intracellular pH measurements. However, iM stability is moderate, which in turn limits its in vivo applications. Here, we report the rational design of a new substituted phenoxazine 2'-deoxynucleotide (i-clamp) for iM stabilization. This residue contains a C8-aminopropyl tether that interacts with the phosphate group within the neighboring chain without compromising base pairing. We studied the influence of i-clamp on pH-dependent stability for intra- and intermolecular iM structures and found the optimal positions for modification. Two i-clamps on opposite strands provide thermal stabilization up to 10-11°C at a pH of 5.8. Thus, we developed a new modification that shows significant iM-stabilizing effect both at strongly and mildly acidic pH and increases iM transition pH values. i-Clamp can be used for tuning iM-based pH probes or assembling extra stable iM structures for various applications.
Collapse
Affiliation(s)
- Vladimir B Tsvetkov
- Biophysics Department, Research and Clinical Center for Physical Chemical Medicine, Malaya Pirogovskaya str. 1a, Moscow 119435, Russia
- Department of Molecular Virology, FSBI Research Institute of Influenza, Ministry of Health of Russian Federation, prof. Popov str. 15/17, Saint-Petersburg, 197376, Russia
- Polyelectrolytes and Biomedical Polymers Laboratory, A.V. Topchiev Institute of Petrochemical Synthesis, RAS, Leninsky prospect str. 29, Moscow 119991, Russia
| | - Timofei S Zatsepin
- Center for Translational Biomedicine, Skolkovo Institute of Science and Technology, 3 Nobel street, Skolkovo, Moscow 143026, Russia
- Chemistry Department, Lomonosov Moscow State University, Leninskie gory str. 1–3, Moscow 119992, Russia
| | - Evgeny S Belyaev
- Frumkin Institute of Physical Chemistry and Electrochemistry of the Russian Academy of Science, Leninsky prospect str. 31, Moscow 119071 Russia
| | - Yury I Kostyukevich
- Center for Translational Biomedicine, Skolkovo Institute of Science and Technology, 3 Nobel street, Skolkovo, Moscow 143026, Russia
| | - George V Shpakovski
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya str. 16/10, Moscow 117997, Russia
| | - Victor V Podgorsky
- Biophysics Department, Research and Clinical Center for Physical Chemical Medicine, Malaya Pirogovskaya str. 1a, Moscow 119435, Russia
| | - Galina E Pozmogova
- Biophysics Department, Research and Clinical Center for Physical Chemical Medicine, Malaya Pirogovskaya str. 1a, Moscow 119435, Russia
| | - Anna M Varizhuk
- Biophysics Department, Research and Clinical Center for Physical Chemical Medicine, Malaya Pirogovskaya str. 1a, Moscow 119435, Russia
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov str. 32, Moscow 119991, Russia
| | - Andrey V Aralov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya str. 16/10, Moscow 117997, Russia
| |
Collapse
|
83
|
Sato N, Takahashi S, Tateishi-Karimata H, Hazemi ME, Chikuni T, Onizuka K, Sugimoto N, Nagatsugi F. Alkylating probes for the G-quadruplex structure and evaluation of the properties of the alkylated G-quadruplex DNA. Org Biomol Chem 2018; 16:1436-1441. [PMID: 29412214 DOI: 10.1039/c7ob03179c] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The G-quadruplex structure has been found in biologically significant regions of the genomic DNA, including the telomere and promoter regions, and is known to play an important role in a number of biological processes. In this paper, we report the development of alkylating probes for the G-quadruplex structure and evaluation of the properties of the modified G-quadruplex structure.
Collapse
Affiliation(s)
- Norihiro Sato
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai-shi, 980-8577, Japan.
| | | | | | | | | | | | | | | |
Collapse
|
84
|
Dzatko S, Krafcikova M, Hänsel‐Hertsch R, Fessl T, Fiala R, Loja T, Krafcik D, Mergny J, Foldynova‐Trantirkova S, Trantirek L. Evaluation of the Stability of DNA i-Motifs in the Nuclei of Living Mammalian Cells. Angew Chem Int Ed Engl 2018; 57:2165-2169. [PMID: 29266664 PMCID: PMC5820743 DOI: 10.1002/anie.201712284] [Citation(s) in RCA: 137] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Indexed: 11/21/2022]
Abstract
C-rich DNA has the capacity to form a tetra-stranded structure known as an i-motif. The i-motifs within genomic DNA have been proposed to contribute to the regulation of DNA transcription. However, direct experimental evidence for the existence of these structures in vivo has been missing. Whether i-motif structures form in complex environment of living cells is not currently known. Herein, using state-of-the-art in-cell NMR spectroscopy, we evaluate the stabilities of i-motif structures in the complex cellular environment. We show that i-motifs formed from naturally occurring C-rich sequences in the human genome are stable and persist in the nuclei of living human cells. Our data show that i-motif stabilities in vivo are generally distinct from those in vitro. Our results are the first to interlink the stability of DNA i-motifs in vitro with their stability in vivo and provide essential information for the design and development of i-motif-based DNA biosensors for intracellular applications.
Collapse
Affiliation(s)
- Simon Dzatko
- CEITEC-Central European Institute of TechnologyMasaryk UniversityBrno625 00Czech Republic
| | - Michaela Krafcikova
- CEITEC-Central European Institute of TechnologyMasaryk UniversityBrno625 00Czech Republic
| | - Robert Hänsel‐Hertsch
- Cancer Research (UK) Cambridge InstituteUniversity of CambridgeLi Ka Shing CentreCambridgeCB2 0REUK
| | - Tomas Fessl
- Faculty of ScienceUniversity of South Bohemia370 05Ceske BudejoviceCzech Republic
| | - Radovan Fiala
- CEITEC-Central European Institute of TechnologyMasaryk UniversityBrno625 00Czech Republic
| | - Tomas Loja
- CEITEC-Central European Institute of TechnologyMasaryk UniversityBrno625 00Czech Republic
| | - Daniel Krafcik
- CEITEC-Central European Institute of TechnologyMasaryk UniversityBrno625 00Czech Republic
| | - Jean‐Louis Mergny
- Université de Bordeaux, INSERM U1212, CNRS UMR 5320ARNA LaboratoryIECBPessacFrance
- Institute of BiophysicsAcademy of Sciences of the Czech Republic612 65BrnoCzech Republic
| | - Silvie Foldynova‐Trantirkova
- CEITEC-Central European Institute of TechnologyMasaryk UniversityBrno625 00Czech Republic
- Institute of BiophysicsAcademy of Sciences of the Czech Republic612 65BrnoCzech Republic
| | - Lukas Trantirek
- CEITEC-Central European Institute of TechnologyMasaryk UniversityBrno625 00Czech Republic
| |
Collapse
|
85
|
Liu L, Kim BG, Feroze U, Macgregor RB, Chalikian TV. Probing the Ionic Atmosphere and Hydration of the c-MYC i-Motif. J Am Chem Soc 2018; 140:2229-2238. [DOI: 10.1021/jacs.7b11537] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Lutan Liu
- Department of Pharmaceutical Sciences,
Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College
Street, Toronto, Ontario M5S 3M2, Canada
| | - Byul G. Kim
- Department of Pharmaceutical Sciences,
Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College
Street, Toronto, Ontario M5S 3M2, Canada
| | - Ujala Feroze
- Department of Pharmaceutical Sciences,
Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College
Street, Toronto, Ontario M5S 3M2, Canada
| | - Robert B. Macgregor
- Department of Pharmaceutical Sciences,
Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College
Street, Toronto, Ontario M5S 3M2, Canada
| | - Tigran V. Chalikian
- Department of Pharmaceutical Sciences,
Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College
Street, Toronto, Ontario M5S 3M2, Canada
| |
Collapse
|
86
|
Dzatko S, Krafcikova M, Hänsel-Hertsch R, Fessl T, Fiala R, Loja T, Krafcik D, Mergny JL, Foldynova-Trantirkova S, Trantirek L. Evaluation of the Stability of DNA i-Motifs in the Nuclei of Living Mammalian Cells. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201712284] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Simon Dzatko
- CEITEC-Central European Institute of Technology; Masaryk University; Brno 625 00 Czech Republic
| | - Michaela Krafcikova
- CEITEC-Central European Institute of Technology; Masaryk University; Brno 625 00 Czech Republic
| | - Robert Hänsel-Hertsch
- Cancer Research (UK) Cambridge Institute; University of Cambridge; Li Ka Shing Centre Cambridge CB2 0RE UK
| | - Tomas Fessl
- Faculty of Science; University of South Bohemia; 370 05 Ceske Budejovice Czech Republic
| | - Radovan Fiala
- CEITEC-Central European Institute of Technology; Masaryk University; Brno 625 00 Czech Republic
| | - Tomas Loja
- CEITEC-Central European Institute of Technology; Masaryk University; Brno 625 00 Czech Republic
| | - Daniel Krafcik
- CEITEC-Central European Institute of Technology; Masaryk University; Brno 625 00 Czech Republic
| | - Jean-Louis Mergny
- Université de Bordeaux, INSERM U1212, CNRS UMR 5320; ARNA Laboratory; IECB; Pessac France
- Institute of Biophysics; Academy of Sciences of the Czech Republic; 612 65 Brno Czech Republic
| | - Silvie Foldynova-Trantirkova
- CEITEC-Central European Institute of Technology; Masaryk University; Brno 625 00 Czech Republic
- Institute of Biophysics; Academy of Sciences of the Czech Republic; 612 65 Brno Czech Republic
| | - Lukas Trantirek
- CEITEC-Central European Institute of Technology; Masaryk University; Brno 625 00 Czech Republic
| |
Collapse
|
87
|
Abou Assi H, Lin YC, Serrano I, González C, Damha MJ. Probing Synergistic Effects of DNA Methylation and 2′-β-Fluorination on i-Motif Stability. Chemistry 2017; 24:471-477. [PMID: 29096420 DOI: 10.1002/chem.201704591] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Indexed: 12/12/2022]
Affiliation(s)
- Hala Abou Assi
- Department of Chemistry; McGill University; 801 Sherbrooke St. West Montreal QC H3A 0B8 Canada
| | - Yu Chen Lin
- Department of Chemistry; McGill University; 801 Sherbrooke St. West Montreal QC H3A 0B8 Canada
| | - Israel Serrano
- Instituto de Química Física “Rocasolano”; CSIC; Serrano 119 28006 Madrid Spain
| | - Carlos González
- Instituto de Química Física “Rocasolano”; CSIC; Serrano 119 28006 Madrid Spain
| | - Masad J. Damha
- Department of Chemistry; McGill University; 801 Sherbrooke St. West Montreal QC H3A 0B8 Canada
| |
Collapse
|
88
|
Subirana JA, Messeguer X. Evolution of Tandem Repeat Satellite Sequences in Two Closely Related Caenorhabditis Species. Diminution of Satellites in Hermaphrodites. Genes (Basel) 2017; 8:genes8120351. [PMID: 29182550 PMCID: PMC5748669 DOI: 10.3390/genes8120351] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 11/13/2017] [Accepted: 11/15/2017] [Indexed: 01/15/2023] Open
Abstract
The availability of the genome sequence of the unisexual (male-female) Caenorhabditis nigoni offers an opportunity to compare its non-coding features with the related hermaphroditic species Caenorhabditis briggsae; to understand the evolutionary dynamics of their tandem repeat sequences (satellites), as a result of evolution from the unisexual ancestor. We take advantage of the previously developed SATFIND program to build satellite families defined by a consensus sequence. The relative number of satellites (satellites/Mb) in C. nigoni is 24.6% larger than in C. briggsae. Some satellites in C. nigoni have developed from a proto-repeat present in the ancestor species and are conserved as an isolated sequence in C. briggsae. We also identify unique satellites which occur only once and joint satellite families with a related sequence in both species. Some of these families are only found in C. nigoni, which indicates a recent appearance; they contain conserved adjacent 5′ and 3′ regions, which may favor transposition. Our results show that the number, length and turnover of satellites are restricted in the hermaphrodite C. briggsae when compared with the unisexual C. nigoni. We hypothesize that this results from differences in unequal recombination during meiotic chromosome pairing, which limits satellite turnover in hermaphrodites.
Collapse
Affiliation(s)
- Juan A Subirana
- Department of Computer Science, Universitat Politècnica de Catalunya, Jordi Girona 1-3, 08034 Barcelona, Spain.
- Evolutionary Genomics Group, Research Program on Biomedical Informatics (GRIB)-Hospital del Mar Research Institute (IMIM), Universitat Pompeu Fabra (UPF), Doctor Aiguader 86, 08003 Barcelona, Spain.
| | - Xavier Messeguer
- Department of Computer Science, Universitat Politècnica de Catalunya, Jordi Girona 1-3, 08034 Barcelona, Spain.
| |
Collapse
|
89
|
Abou Assi H, El-Khoury R, González C, Damha MJ. 2'-Fluoroarabinonucleic acid modification traps G-quadruplex and i-motif structures in human telomeric DNA. Nucleic Acids Res 2017; 45:11535-11546. [PMID: 29036537 PMCID: PMC5714228 DOI: 10.1093/nar/gkx838] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 09/10/2017] [Accepted: 09/15/2017] [Indexed: 12/30/2022] Open
Abstract
Human telomeres and promoter regions of genes fulfill a significant role in cellular aging and cancer. These regions comprise of guanine and cytosine-rich repeats, which under certain conditions can fold into G-quadruplex (G4) and i-motif structures, respectively. Herein, we use UV, circular dichroism and NMR spectroscopy to study several human telomeric sequences and demonstrate that G4/i-motif-duplex interconversion kinetics are slowed down dramatically by 2'-β-fluorination and the presence of G4/i-motif-duplex junctions. NMR-monitored kinetic experiments on 1:1 mixtures of native and modified C- and G-rich human telomeric sequences reveal that strand hybridization kinetics are controlled by G4 or i-motif unfolding. Furthermore, we provide NMR evidence for the formation of a hybrid complex containing G4 and i-motif structures proximal to a duplex DNA segment at neutral pH. While the presence of i-motif and G4 folds may be mutually exclusive in promoter genome sequences, our results suggest that they may co-exist transiently as intermediates in telomeric sequences.
Collapse
Affiliation(s)
- Hala Abou Assi
- Department of Chemistry, McGill University, Montreal, QC H3A 0B8, Canada
| | - Roberto El-Khoury
- Department of Chemistry, McGill University, Montreal, QC H3A 0B8, Canada
| | - Carlos González
- Instituto de Química Física ‘Rocasolano’, CSIC, Serrano 119, 28006 Madrid, Spain
| | - Masad J. Damha
- Department of Chemistry, McGill University, Montreal, QC H3A 0B8, Canada
| |
Collapse
|