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G-quadruplex

About: G-quadruplex is a research topic. Over the lifetime, 2383 publications have been published within this topic receiving 120523 citations. The topic is also known as: G4 DNA & G-Quadruplexes.


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Journal ArticleDOI
TL;DR: This survey focuses on the folding and structural features on quadruplexes formed from telomeric and non-telomeric DNA sequences, and examines fundamental aspects of topology and the emerging relationships with sequence.
Abstract: G-quadruplexes are higher-order DNA and RNA structures formed from G-rich sequences that are built around tetrads of hydrogen-bonded guanine bases. Potential quadruplex sequences have been identified in G-rich eukaryotic telomeres, and more recently in non-telomeric genomic DNA, e.g. in nuclease-hypersensitive promoter regions. The natural role and biological validation of these structures is starting to be explored, and there is particular interest in them as targets for therapeutic intervention. This survey focuses on the folding and structural features on quadruplexes formed from telomeric and non-telomeric DNA sequences, and examines fundamental aspects of topology and the emerging relationships with sequence. Emphasis is placed on information from the high-resolution methods of X-ray crystallography and NMR, and their scope and current limitations are discussed. Such information, together with biological insights, will be important for the discovery of drugs targeting quadruplexes from particular genes.

2,047 citations

Journal ArticleDOI
TL;DR: The principle that c-MYC transcription can be controlled by ligand-mediated G-quadruplex stabilization is established, establishing the principle that the purine-rich strand of the DNA in this region can form two different intramolecular G- quadruplex structures.
Abstract: The nuclease hypersensitivity element III1 upstream of the P1 promoter of c-MYC controls 85–90% of the transcriptional activation of this gene. We have demonstrated that the purine-rich strand of the DNA in this region can form two different intramolecular G-quadruplex structures, only one of which seems to be biologically relevant. This biologically relevant structure is the kinetically favored chair-form G-quadruplex, which is destabilized when mutated with a single G → A transition, resulting in a 3-fold increase in basal transcriptional activity of the c-MYC promoter. The cationic porphyrin TMPyP4, which has been shown to stabilize this G-quadruplex structure, is able to suppress further c-MYC transcriptional activation. These results provide compelling evidence that a specific G-quadruplex structure formed in the c-MYC promoter region functions as a transcriptional repressor element. Furthermore, we establish the principle that c-MYC transcription can be controlled by ligand-mediated G-quadruplex stabilization.

1,969 citations

Journal ArticleDOI
20 Jun 2002-Nature
TL;DR: This crystal structure of a quadruplex formed from four consecutive human telomeric DNA repeats and grown at a K+ concentration that approximates its intracellular concentration suggests a straightforward path for telomere folding and unfolding, as well as ways in which it can recognize telomerre-associated proteins.
Abstract: Telomeric ends of chromosomes, which comprise noncoding repeat sequences of guanine-rich DNA, are fundamental in protecting the cell from recombination and degradation. Disruption of telomere maintenance leads to eventual cell death, which can be exploited for therapeutic intervention in cancer. Telomeric DNA sequences can form four-stranded (quadruplex) structures, which may be involved in the structure of telomere ends. Here we describe the crystal structure of a quadruplex formed from four consecutive human telomeric DNA repeats and grown at a K(+) concentration that approximates its intracellular concentration. K(+) ions are observed in the structure. The folding and appearance of the DNA in this intramolecular quadruplex is fundamentally different from the published Na(+)-containing quadruplex structures. All four DNA strands are parallel, with the three linking trinucleotide loops positioned on the exterior of the quadruplex core, in a propeller-like arrangement. The adenine in each TTA linking trinucleotide loop is swung back so that it intercalates between the two thymines. This DNA structure suggests a straightforward path for telomere folding and unfolding, as well as ways in which it can recognize telomere-associated proteins.

1,849 citations

Journal ArticleDOI
TL;DR: It is shown explicitly that G-quadruplex formation in DNA is modulated during cell-cycle progression and that endogenous G- quadruplex DNA structures can be stabilized by a small-molecule ligand and corroborate the application of stabilizing ligands in a cellular context to target G- Quadruplexes and intervene with their function.
Abstract: Four-stranded G-quadruplex nucleic acid structures are of great interest as their high thermodynamic stability under near-physiological conditions suggests that they could form in cells. Here we report the generation and application of an engineered, structure-specific antibody employed to quantitatively visualize DNA G-quadruplex structures in human cells. We show explicitly that G-quadruplex formation in DNA is modulated during cell-cycle progression and that endogenous G-quadruplex DNA structures can be stabilized by a small-molecule ligand. Together these findings provide substantive evidence for the formation of G-quadruplex structures in the genome of mammalian cells and corroborate the application of stabilizing ligands in a cellular context to target G-quadruplexes and intervene with their function.

1,682 citations

Journal ArticleDOI
28 Jul 1988-Nature
TL;DR: It is speculated that this self-recognition of guanine-rich motifs of DNA serves to bring together, and to zipper up in register, the four homologous chromatids during meiosis.
Abstract: We have discovered that single-stranded DNA containing short guanine-rich motifs will self-associate at physiological salt concentrations to make four-stranded structures in which the strands run in parallel fashion. We believe these complexes are held together by guanines bonded to each other by Hoogsteen pairing. Such guanine-rich sequences occur in immunoglobulin switch regions, in gene promoters, and in chromosomal telomeres. We speculate that this self-recognition of guanine-rich motifs of DNA serves to bring together, and to zipper up in register, the four homologous chromatids during meiosis.

1,562 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023184
2022373
2021155
2020165
2019168
2018158