Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
???displayArticle.abstract???
Although the telomeric sequence has been reported to form various G-quadruplex topologies in vitro and in Xenopus laevis oocytes, in living human cells, the topology of telomeric DNA G-quadruplex remains a challenge. To investigate the human telomeric DNA G-quadruplex in a more realistic human cell environment, in the present study, we demonstrated that the telomeric DNA sequence can form two hybrid-type and two-tetrad antiparallel G-quadruplex structures by in-cell 19F NMR in living human cells (HELA CELLS). This result provides valuable information for understanding the structures of human telomeric DNA in living human cells and for the design of new drugs that target telomeric DNA.
Figure 1.
19F NMR spectra of 19F-labeled 22-mer ODN 1 d[AGGG(TTAGGG)3] in Na+ and K+ solutions. (A) Chemical structure of 19F-labeled DNA bearing 19F group at the 5′ terminal. (B)19F NMR of 19F-labeled DNA at different temperatures in Na+ solution. (C) 19F NMR of 19F-labeled DNA at different temperatures in K+ solution. Blue and black spots indicated antiparallel G-quadruplex and single strand, respectively. Green indicated hybrid-1 and hybrid-2 G-quadruplexes conformations. Temperatures indicated on the right. Condition: 0.1 mM DNA in (B) 300 mM NaCl and 20 mM Na-PO4 buffer (pH 7.0) or (C) 100 mM KCl and 20 mM K-PO4 buffer (pH 7.0). The sample is kept for 10 min of each temperature for 19F NMR detection.
Figure 2.
19F NMR spectra of 19F-labeled ODN 1 in PEG 200. (A) 19F NMR of 19F-labeled 22-mer DNA at different concentration of PEG 200 in K+ solution. (B) 19F NMR of 19F-labeled ODN 1 at different temperatures in 40% PEG 200. Green indicated hybrid-1 and hybrid-2 G-quadruplexes conformations. Orange and black spots indicated parallel G-quadruplex and single strand, respectively. PEG 200 ratio and temperatures indicated on the right. Condition: 0.1 mM DNA in 100 mM KCl and 20 mM K-PO4 buffer (pH 7.0). The sample is kept for 10 min of each temperature for 19F NMR detection.
Figure 3. In-cell 19F NMR of 19F labeled ODN 1. (A) Schematic overview of the SLO treatment cell system for transfection DNA into HeLa cells. (B) Comparison with the position of reference in vitro spectrum provides a reliable determination of intracellular 19F-labeled DNA. (C) Comparison of 19F NMR spectra of ODN 1 in K+ solution, in HeLa cell, in supernatant, difference spectrum between HeLa cell and supernatant, in K+ solution (23 and 60°C) and in 30% PEG 200.
Ambrus,
Human telomeric sequence forms a hybrid-type intramolecular G-quadruplex structure with mixed parallel/antiparallel strands in potassium solution.
2006, Pubmed
Ambrus,
Human telomeric sequence forms a hybrid-type intramolecular G-quadruplex structure with mixed parallel/antiparallel strands in potassium solution.
2006,
Pubmed Bao,
Investigation of higher-order RNA G-quadruplex structures in vitro and in living cells by 19F NMR spectroscopy.
2018,
Pubmed
,
Xenbase Bao,
Characterization of human telomere RNA G-quadruplex structures in vitro and in living cells using 19F NMR spectroscopy.
2017,
Pubmed
,
Xenbase Biffi,
Quantitative visualization of DNA G-quadruplex structures in human cells.
2013,
Pubmed Blackburn,
Human telomere biology: A contributory and interactive factor in aging, disease risks, and protection.
2015,
Pubmed Buket,
DNA G-quadruplex and its potential as anticancer drug target.
2014,
Pubmed Chen,
19F NMR: a valuable tool for studying biological events.
2013,
Pubmed Dai,
Structure of the Hybrid-2 type intramolecular human telomeric G-quadruplex in K+ solution: insights into structure polymorphism of the human telomeric sequence.
2007,
Pubmed Dzatko,
Evaluation of the Stability of DNA i-Motifs in the Nuclei of Living Mammalian Cells.
2018,
Pubmed Fauster,
2'-SCF3 uridine-a powerful label for probing structure and function of RNA by 19F NMR spectroscopy.
2012,
Pubmed Graber,
19F NMR spectroscopy for the analysis of RNA secondary structure populations.
2008,
Pubmed Granqvist,
Characterization of G-Quadruplex/Hairpin Transitions of RNAs by 19 F NMR Spectroscopy.
2016,
Pubmed Granqvist,
4'-C-[(4-trifluoromethyl-1H-1,2,3-triazol-1-yl)methyl]thymidine as a sensitive (19)F NMR sensor for the detection of oligonucleotide secondary structures.
2014,
Pubmed Guo,
Synthesis and biological applications of fluoro-modified nucleic acids.
2017,
Pubmed Hänsel,
Evaluation of parameters critical for observing nucleic acids inside living Xenopus laevis oocytes by in-cell NMR spectroscopy.
2009,
Pubmed
,
Xenbase Hänsel,
In-cell NMR and EPR spectroscopy of biomacromolecules.
2014,
Pubmed Hänsel,
High-resolution insight into G-overhang architecture.
2013,
Pubmed Hänsel,
The parallel G-quadruplex structure of vertebrate telomeric repeat sequences is not the preferred folding topology under physiological conditions.
2011,
Pubmed
,
Xenbase Hänsel-Hertsch,
DNA G-quadruplexes in the human genome: detection, functions and therapeutic potential.
2017,
Pubmed Jiang,
Structure of Telomerase with Telomeric DNA.
2018,
Pubmed Kim,
Specific association of human telomerase activity with immortal cells and cancer.
1994,
Pubmed Li,
G4LDB: a database for discovering and studying G-quadruplex ligands.
2013,
Pubmed Lim,
Structure of the human telomere in K+ solution: a stable basket-type G-quadruplex with only two G-tetrad layers.
2009,
Pubmed Luu,
Structure of the human telomere in K+ solution: an intramolecular (3 + 1) G-quadruplex scaffold.
2006,
Pubmed Manna,
A Dual-App Nucleoside Probe Provides Structural Insights into the Human Telomeric Overhang in Live Cells.
2018,
Pubmed
,
Xenbase Marchand,
Folding and misfolding pathways of G-quadruplex DNA.
2016,
Pubmed Nakano,
Effects of molecular crowding on the structures, interactions, and functions of nucleic acids.
2014,
Pubmed Neidle,
Telomere maintenance as a target for anticancer drug discovery.
2002,
Pubmed Neidle,
The structure of telomeric DNA.
2003,
Pubmed Ogino,
Observation of NMR signals from proteins introduced into living mammalian cells by reversible membrane permeabilization using a pore-forming toxin, streptolysin O.
2009,
Pubmed O'Sullivan,
Telomeres: protecting chromosomes against genome instability.
2010,
Pubmed Parkinson,
Crystal structure of parallel quadruplexes from human telomeric DNA.
2002,
Pubmed Phan,
Different loop arrangements of intramolecular human telomeric (3+1) G-quadruplexes in K+ solution.
2006,
Pubmed Salgado,
G-quadruplex DNA and ligand interaction in living cells using NMR spectroscopy.
2015,
Pubmed
,
Xenbase Wang,
Solution structure of the human telomeric repeat d[AG3(T2AG3)3] G-tetraplex.
1993,
Pubmed Xu,
Chemistry in human telomere biology: structure, function and targeting of telomere DNA/RNA.
2011,
Pubmed Xu,
The new models of the human telomere d[AGGG(TTAGGG)3] in K+ solution.
2006,
Pubmed Xu,
A 6-mer photocontrolled oligonucleotide as an effective telomerase inhibitor.
2010,
Pubmed Yamaoki,
The first successful observation of in-cell NMR signals of DNA and RNA in living human cells.
2018,
Pubmed
,
Xenbase Zhang,
Real-time monitoring of DNA G-quadruplexes in living cells with a small-molecule fluorescent probe.
2018,
Pubmed Zhang,
Structure of a two-G-tetrad intramolecular G-quadruplex formed by a variant human telomeric sequence in K+ solution: insights into the interconversion of human telomeric G-quadruplex structures.
2010,
Pubmed
