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Probing the Competition Between Duplex and G-quadruplex/i-motif Structures Using a Conformation-sensitive Fluorescent Nucleoside Probe

Overview
Journal Org Biomol Chem
Specialties Biochemistry
Chemistry
Date 2018 May 22
PMID 29781489
Citations 4
Authors
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Abstract

Double-stranded segments of a genome that can potentially form G-quadruplex (GQ) and/or i-motif (iM) structures are considered to be important regulatory elements. Hence, the development of a common probe that can detect GQ and iM structures and also distinguish them from a duplex structure will be highly useful in understanding the propensity of such segments to adopt duplex or non-canonical four-stranded structures. Here, we describe the utility of a conformation-sensitive fluorescent nucleoside analog, which was originally developed as a GQ sensor, in detecting the iM structures of C-rich DNA oligonucleotides (ONs). The analog is based on a 5-(benzofuran-2-yl)uracil scaffold, which when incorporated into C-rich ONs (e.g., telomeric repeats) fluorescently distinguishes an iM from random coil and duplex structures. Steady-state and time-resolved fluorescence techniques enabled the determination of transition pH for the transformation of a random coil to an iM structure. Furthermore, a qualitative understanding on the relative population of duplex and GQ/iM forms under physiological conditions could be gained by correlating the fluorescence, CD and thermal melting data. Taken together, this sensor could provide a general platform to profile double-stranded promoter regions in terms of their ability to adopt four-stranded structures, and also could support approaches to discover functional GQ and iM binders.

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References
1.
Brooks T, Kendrick S, Hurley L . Making sense of G-quadruplex and i-motif functions in oncogene promoters. FEBS J. 2010; 277(17):3459-69. PMC: 2971675. DOI: 10.1111/j.1742-4658.2010.07759.x. View

2.
Balasubramanian S, Hurley L, Neidle S . Targeting G-quadruplexes in gene promoters: a novel anticancer strategy?. Nat Rev Drug Discov. 2011; 10(4):261-75. PMC: 3119469. DOI: 10.1038/nrd3428. View

3.
Henderson A, Wu Y, Huang Y, Chavez E, Platt J, Johnson F . Detection of G-quadruplex DNA in mammalian cells. Nucleic Acids Res. 2013; 42(2):860-9. PMC: 3902944. DOI: 10.1093/nar/gkt957. View

4.
Lam E, Beraldi D, Tannahill D, Balasubramanian S . G-quadruplex structures are stable and detectable in human genomic DNA. Nat Commun. 2013; 4:1796. PMC: 3736099. DOI: 10.1038/ncomms2792. View

5.
Dong Y, Yang Z, Liu D . DNA nanotechnology based on i-motif structures. Acc Chem Res. 2014; 47(6):1853-60. DOI: 10.1021/ar500073a. View