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Showing 1 to 20 of 47 for “"G-quadruplexes"”.
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Studies on Genomic G-Quadruplexes
… by guanine-rich sequences. These are known as G-quadruplexes or G-tetrads. I begin by investigating the structural properties of this structure, and how sensitive it is to mutations and deletions. I then consider the structural properties of the loops that join the four strands, and develop an …
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G-Quadruplexes As Molecular Targets For Transcriptional Control
DNA G-quadruplexes (G4s) have gained interest in modern drug discovery efforts. The majority of G4 research, including the mass of this research, heavily focuses on cancer therapeutic development, as G4s are more pronounced in oncogenic promoters compared to the rest of the genome, our efforts …
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Structural characterization of G-Quadruplexes within duplex DNA
The G-Quadruplex (GQ) is a repetitive, guanine rich DNA sequence that occurs throughout the genome. This specific DNA motif is capable of forming an alternative DNA secondary structure similar to a rectangular prism. The most common GQ motif consists of four sets of three guanine bases separated by …
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Identification et caractérisation des G-quadruplexes dans le transcriptome humain
Guanine-rich RNA sequences can fold into a very stable non-canonical tetrahelical structure called G-quadruplex (G4). In RNA, these structures can be associated with several of post-transcriptional roles such as translation, splicing and polyadenylation. However, the assessment and study of G4 …
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Investigating the interactions of G-quadruplexes with transcription and chromatin structure
Four stranded G-quadruplexes (G4s) are non-canonical nucleic acid secondary structures that are primarily found in nucleosome-depleted promoters and mark sites of elevated transcription within the human genome. Although numerous studies have indicated an association between G4 formation and active …
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Unveiling Global Roles of G-Quadruplexes and G4-22 In Human Genetics
<p>G-quadruplexes are non-B DNA structures formed by four or more runs of repeated guanines that confer unique features to living organism’s genomes. These sequences are enriched in regulatory regions, such as promoters and 5’ UTRs, and have distinct regulatory roles in both health and disease …
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A data mining study of g-quadruplexes and their effect on DNA replication
G-quadruplexes are guanine rich sequences of DNA that can form non-Watson-Crick four stranded structures. They have been found to exist in various regions of the genome and are believed to play a biological role. We hypothesize that the presence of these structures poses a barrier to DNA …
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INVESTIGATING GENOME PROTECTION AT G-QUADRUPLEXES: STRUCTURAL-FUNCTIONAL ANALYSIS OF S. CEREVISIAE DOMESTICATED TRANSPOSASE VID22
L'instabilità del genoma è una caratteristica distintiva dell'invecchiamento e di varie patologie umane, tra cui il cancro. L'instabilità genomica è provocata da agenti esogeni che danneggiano il DNA e da molteplici fattori endogeni, tra cui le G-tetradi, strutture secondarie non canoniche del …
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Vulnerability to G - Quadruplexes in BRCA2 - Null Medulloblastoma: A Protective Role for the PIF1 Helicase
… and aberrant mitoses. In Brca2-/-cells, G-quadruplexes represent a hurdle to normal replication that must be resolved by helicases like PIF1 to prevent mutagenesis. Down regulation of PIF1 could sensitize Brca2-/-cells to treatment with PDS and other G4-ligands and could represent a new …
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Nucleic acid clamp-mediated transcriptional and translational modulation of oncogenes via the stabilization of G-quadruplexes
G-quadruplexes (G4s) are non-canonical secondary nucleic acid structures that exit in various biologically important regions within a cell, such as the promoters of DNA, 5’-Untranslated regions (UTR) of mRNA and telomeres. These secondary structures tend to cluster around 1 kb from transcriptional …
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Exploring the Forces Underlying the Dynamics and Energetics of G-quadruplexes with Polarizable Molecular Dynamics Simulations
G-quadruplexes (GQs) are highly stable noncanonical nucleic acid structures that form in the DNA of human cells and play fundamental roles in maintaining genomic stability and regulating gene expression. These unique structures exert broad influence over biologically important processes and can …
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Investigation of Genomic Instability Induced By G-Quadruplexes In The Absence of Functional to poisomerase 1 In Yeast
<p>Topoisomerase 1 (Top1) is an enzyme that removes transcriptionally generated negative supercoils by binding and nicking DNA. Since transcription of guanine-rich DNA leads to the formation of G-quadruplex (G4) structures, Top1’s function likely suppresses G4-formation. In support of this, Top1 …
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RNA G-quadruplexes and polyamines effects on translation: data analysis and development of software for ribosome pause prediction
… of metabolites such as polyamines. G-quadruplexes is a type of RNA secondary structures that has been implicated in mRNA translation. These G-quadruplex structures have been suggested to play roles in capdependent, cap-independent and repeat associated non-AUG (RAN) translation. …
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Structural Dynamics and Electrostatic Properties of the VEGF and PIM-1 Oncogenic Promoter G-Quadruplexes from Polarizable Molecular Dynamics Simulations
G-Quadruplexes (GQs) are higher ordered nucleic acid structures that form within regions of DNA and RNA that are enriched with guanine nucleobases. These structures are highly stable and have been shown to function in genomic maintenance and regulating key biological processes. Due to their role in …
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Study of DNA damage on DNA G-quadruplexes and biophysical evaluation of the effects of modified bases (lesions) on their conformation and stability
<p>Exposure of DNA to reactive oxygen species (ROS) results in the modified nucleobases (lesions) as well as strand scissions under physiological conditions. Due to its lowest oxidation potential (1.29 eV), guanine is the most easily oxidisable nucleobase. Furthermore, it has been observed that the …
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Mechanisms Behind the Chaperone Activity of Nucleic Acids
… In a follow up study, we found that G-quadruplexes were an even more powerful chaperone than bulk DNA (which on a per-weight basis was more powerful than any known protein-based chaperone). G-quadruplexes appear to be particularly adept at interacting with misfolded proteins and are …
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Synthetic Ion Channels From Lipophilic Guanosine Derivatives
… ion channels. The potential of lipophilic G-quadruplexes to function as synthetic ion channels has been investigated by tracing the cation exchange process between free cations and G-quadruplex bound cations. Cation exchange between bulk cations (K+, NH4+) in solution and the bound cations in …
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Computational analyses of non-canonical architectural and structural features associated with alternative splicing
… Interestingly, I found stronger enrichment of G-quadruplexes associated with weak splice sites, suggesting that they could function as cis-regulatory elements of alternative splicing events. Finally, to explore if microexons and exons flanked by intronic G-quadruplexes were involved in dynamic …
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Characterisation of DNA i-motif structures in the human genome and the role of non-canonical nucleic acid structures
… non-canonical structures include triplexes, quadruplexes, or Z-DNA, to name a few, which have been observed to affect biological roles. Understanding these structures and harnessing their unique properties is a promising field not only in basic genomic research but also in synthetic …
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Search for new types of deoxyribozymes and development of human topoisomerases inhibitors on the basis of oligonucleotides
… oligonucleotides with potential to form G-quadruplexes were constructed and their self-cleaving activities are examined during our investigations. Our studies demonstrated that certain guanine-rich sequences could exhibit highly site-specific self-cleaving activities. Subsequent studies on …
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