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  1. Article ; Online: Preferential formation of Z-RNA over intercalated motifs in long noncoding RNA.

    Bhatt, Uditi / Cucchiarini, Anne / Luo, Yu / Evans, Cameron W / Mergny, Jean-Louis / Iyer, K Swaminathan / Smith, Nicole M

    Genome research

    2024  Volume 34, Issue 2, Page(s) 217–230

    Abstract: Secondary structure is a principal determinant of lncRNA function, predominantly regarding scaffold formation and interfaces with target molecules. Noncanonical secondary structures that form in nucleic acids have known roles in regulating gene ... ...

    Abstract Secondary structure is a principal determinant of lncRNA function, predominantly regarding scaffold formation and interfaces with target molecules. Noncanonical secondary structures that form in nucleic acids have known roles in regulating gene expression and include G-quadruplexes (G4s), intercalated motifs (iMs), and R-loops (RLs). In this paper, we used the computational tools G4-iM Grinder and QmRLFS-finder to predict the formation of each of these structures throughout the lncRNA transcriptome in comparison to protein-coding transcripts. The importance of the predicted structures in lncRNAs in biological contexts was assessed by combining our results with publicly available lncRNA tissue expression data followed by pathway analysis. The formation of predicted G4 (pG4) and iM (piM) structures in select lncRNA sequences was confirmed in vitro using biophysical experiments under near-physiological conditions. We find that the majority of the tested pG4s form highly stable G4 structures, and identify many previously unreported G4s in biologically important lncRNAs. In contrast, none of the piM sequences are able to form iM structures, consistent with the idea that RNA is unable to form stable iMs. Unexpectedly, these C-rich sequences instead form Z-RNA structures, which have not been previously observed in regions containing cytosine repeats and represent an interesting and underexplored target for protein-RNA interactions. Our results highlight the prevalence and potential structure-associated functions of noncanonical secondary structures in lncRNAs, and show G4 and Z-RNA structure formation in many lncRNA sequences for the first time, furthering the understanding of the structure-function relationship in lncRNAs.
    MeSH term(s) RNA ; RNA, Long Noncoding/genetics ; G-Quadruplexes ; Proteins/genetics
    Chemical Substances RNA (63231-63-0) ; RNA, Long Noncoding ; Proteins
    Language English
    Publishing date 2024-03-20
    Publishing country United States
    Document type Journal Article
    ZDB-ID 1284872-4
    ISSN 1549-5469 ; 1088-9051 ; 1054-9803
    ISSN (online) 1549-5469
    ISSN 1088-9051 ; 1054-9803
    DOI 10.1101/gr.278236.123
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: DNA Quadruplex Structure with a Unique Cation Dependency.

    Gajarsky, Martin / Stadlbauer, Petr / Sponer, Jiri / Cucchiarini, Anne / Dobrovolna, Michaela / Brazda, Vaclav / Mergny, Jean-Louis / Trantirek, Lukas / Lenarcic Zivkovic, Martina

    Angewandte Chemie (International ed. in English)

    2024  Volume 63, Issue 7, Page(s) e202313226

    Abstract: DNA quadruplex structures provide an additional layer of regulatory control in genome maintenance and gene expression and are widely used in nanotechnology. We report the discovery of an unprecedented tetrastranded structure formed from a native G-rich ... ...

    Abstract DNA quadruplex structures provide an additional layer of regulatory control in genome maintenance and gene expression and are widely used in nanotechnology. We report the discovery of an unprecedented tetrastranded structure formed from a native G-rich DNA sequence originating from the telomeric region of Caenorhabditis elegans. The structure is defined by multiple properties that distinguish it from all other known DNA quadruplexes. Most notably, the formation of a stable so-called KNa-quadruplex (KNaQ) requires concurrent coordination of K
    MeSH term(s) Animals ; Humans ; G-Quadruplexes ; Caenorhabditis elegans/genetics ; DNA/chemistry ; Base Sequence ; Cations ; Telomere/genetics
    Chemical Substances DNA (9007-49-2) ; Cations
    Language English
    Publishing date 2024-01-15
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 2011836-3
    ISSN 1521-3773 ; 1433-7851
    ISSN (online) 1521-3773
    ISSN 1433-7851
    DOI 10.1002/anie.202313226
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: G-quadruplex forming motifs in the promoter region of the B-MYB proto-oncogene.

    Miranda, André / Cucchiarini, Anne / Esnault, Cyril / Andrau, Jean-Christophe / Oliveira, Paula A / Mergny, Jean-Louis / Cruz, Carla

    International journal of biological macromolecules

    2024  , Page(s) 132244

    Abstract: To combat cancer, a comprehensive understanding of the molecular mechanisms and behaviors involved in carcinogenesis is crucial, as tumorigenesis is a complex process influenced by various genetic events and disease hallmarks. The B-MYB gene encodes a ... ...

    Abstract To combat cancer, a comprehensive understanding of the molecular mechanisms and behaviors involved in carcinogenesis is crucial, as tumorigenesis is a complex process influenced by various genetic events and disease hallmarks. The B-MYB gene encodes a transcription factor involved in cell cycle regulation, survival, and differentiation in normal cells. B-MYB can be transformed into an oncogene through mutations, and abnormal expression of B-MYB has been identified in various cancers, including lung cancer, and is associated with poor prognosis. Targeting this oncogene is a promising approach for anti-cancer drug design. B-MYB has been deemed undruggable in previous reports, necessitating the search for novel therapeutic options. In this study, we found that the B-MYB gene promoter contains several G/C rich motifs compatible with G-quadruplex (G4) formation. We investigated and validated the existence of G4 structures in the promoter region of B-MYB, first in vitro using a combination of bioinformatics, biophysical, and biochemical methods, then in cell with the recently developed G4access method.
    Language English
    Publishing date 2024-05-08
    Publishing country Netherlands
    Document type Journal Article
    ZDB-ID 282732-3
    ISSN 1879-0003 ; 0141-8130
    ISSN (online) 1879-0003
    ISSN 0141-8130
    DOI 10.1016/j.ijbiomac.2024.132244
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Strong and selective interactions of palmatine with G-rich sequences in TRF2 promoter; experimental and computational studies.

    Fazelifar, Pegah / Cucchiarini, Anne / Khoshbin, Zahra / Mergny, Jean-Louis / Kazemi Noureini, Sakineh

    Journal of biomolecular structure & dynamics

    2023  , Page(s) 1–15

    Abstract: G-rich sequences have the potential to fold into G-quadruplexes (GQs). G-quadruplexes, particularly those positioned in the regulatory regions of proto-oncogenes, have recently garnered attention in anti-cancer drug design. A thermal FRET assay was ... ...

    Abstract G-rich sequences have the potential to fold into G-quadruplexes (GQs). G-quadruplexes, particularly those positioned in the regulatory regions of proto-oncogenes, have recently garnered attention in anti-cancer drug design. A thermal FRET assay was employed to conduct preliminary screening of various alkaloids, aiming to identify stronger interactions with a specific set of G-rich double-labeled oligonucleotides in both K + and Na + buffers. These oligonucleotides were derived from regions associated with Kit, Myc, Ceb, Bcl2, human telomeres, and potential G-quadruplex forming sequences found in the Nrf2 and Trf2 promoters. Palmatine generally increased the stability of different G-rich sequences into their folded GQ structures, more or less in a concentration dependent manner. The thermal stability and interaction of palmatine was further studied using transition FRET (t-FRET), CD and UV-visible spectroscopy and molecular dynamics simulation methods. Palmatine showed the strongest interaction with T RF2 in both K+ and Na+ buffers even at equimolar concentration ratio. T-FRET studies revealed that palmatine has the potential to disrupt double-strand formation by the T RF2 sequence in the presence of its complementary strand. Palmatine exhibits a stronger interaction with G-rich strand DNA, promoting its folding into G-quadruplex structures. It is noteworthy that palmatine exhibits the strongest interaction with T RF2, which is the shortest sequence among the G-rich oligonucleotides studied, featuring only one nucleotide for two of its loops. Palmatine represents a suitable structure for drug design to develop more specific ligands targeting G-quadruplexes. Whether palmatine can also affect the expression of the T RF2 gene requires further studies.Communicated by Ramaswamy H. Sarma.
    Language English
    Publishing date 2023-12-15
    Publishing country England
    Document type Journal Article
    ZDB-ID 49157-3
    ISSN 1538-0254 ; 0739-1102
    ISSN (online) 1538-0254
    ISSN 0739-1102
    DOI 10.1080/07391102.2023.2292793
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Quadruplex DNA-guided ligand selection from dynamic combinatorial libraries of acylhydrazones.

    Reznichenko, Oksana / Cucchiarini, Anne / Gabelica, Valérie / Granzhan, Anton

    Organic & biomolecular chemistry

    2020  Volume 19, Issue 2, Page(s) 379–386

    Abstract: Dynamic combinatorial libraries of acylhydrazones were prepared from diacylhydrazides and several cationic or neutral aldehydes in the presence of 5-methoxyanthranilic acid catalyst. Pull-down experiments with magnetic beads functionalized with a G- ... ...

    Abstract Dynamic combinatorial libraries of acylhydrazones were prepared from diacylhydrazides and several cationic or neutral aldehydes in the presence of 5-methoxyanthranilic acid catalyst. Pull-down experiments with magnetic beads functionalized with a G-quadruplex (G4)-forming oligonucleotide led to the identification of putative ligands, which were resynthesized or emulated by close structural analogues. G4-binding properties of novel derivatives were assessed by fluorimetric titrations, mass spectrometry and thermal denaturation experiments, giving evidence of strong binding (Kd < 10 nM) for two compounds.
    Language English
    Publishing date 2020-12-15
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2097583-1
    ISSN 1477-0539 ; 1477-0520
    ISSN (online) 1477-0539
    ISSN 1477-0520
    DOI 10.1039/d0ob01908a
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: G-quadruplex forming sequences in the genes coding for cytochrome P450 enzymes and their potential roles in drug metabolism.

    Saad, Mona / Zhang, Rongxin / Cucchiarini, Anne / Mehawej, Cybel / Mergny, Jean-Louis / Mroueh, Mohamad / Faour, Wissam H

    Biochimie

    2023  Volume 214, Issue Pt A, Page(s) 45–56

    Abstract: The majority of drugs are metabolized by cytochrome P450 (CYP) enzymes, primarily belonging to the CYP1, CYP2 and CYP3 families. Genetic variations are the main cause of inter-individual differences in drug response, which constitutes a major concern in ... ...

    Abstract The majority of drugs are metabolized by cytochrome P450 (CYP) enzymes, primarily belonging to the CYP1, CYP2 and CYP3 families. Genetic variations are the main cause of inter-individual differences in drug response, which constitutes a major concern in pharmacotherapy. G-quadruplexes (G4s), are non-canonical DNA and RNA secondary structures formed by guanine-rich sequences. G4s have been implicated in cancer and gene regulation. In this study, we investigated putative G4-forming sequences (PQSs) in the CYP genes. Our findings reveal a high density of PQSs in the full genes of CYP family 2. Moreover, we observe an increased density of PQSs in the promoters of CYP family 1 genes compared to non-CYP450 genes. Importantly, stable PQSs were also identified in all studied CYP genes. Subsequently, we assessed the impact of the most frequently reported genetic mutations in the selected genes and the possible effect of these mutations on G4 formation as well as on the thermodynamic stability of predicted G4s. We found that 4 SNPs overlap G4 sequences and lead to mutated DNA and RNA G4 forming sequences in their context. Notably, the mutation in the CYP2C9 gene, which is associated with impaired (S)-warfarin metabolism in patients, alters a G4 sequence. We then demonstrated that at least 10 of the 13 chosen cytochrome P450 G4 candidates form G-quadruplex structures in vitro, using a combination of spectroscopic methods. In conclusion, our findings indicate the potential role of G-quadruplexes in the regulation of cytochrome genes, and emphasize the importance of G-quadruplexes in drug metabolism.
    MeSH term(s) Humans ; G-Quadruplexes ; Promoter Regions, Genetic ; DNA ; RNA ; Cytochrome P-450 Enzyme System/genetics
    Chemical Substances DNA (9007-49-2) ; RNA (63231-63-0) ; Cytochrome P-450 Enzyme System (9035-51-2)
    Language English
    Publishing date 2023-09-01
    Publishing country France
    Document type Journal Article
    ZDB-ID 120345-9
    ISSN 1638-6183 ; 0300-9084
    ISSN (online) 1638-6183
    ISSN 0300-9084
    DOI 10.1016/j.biochi.2023.08.014
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: Guidelines for G-quadruplexes: I. In vitro characterization

    Luo, Yu / Granzhan, Anton / Marquevielle, Julien / Cucchiarini, Anne / Lacroix, Laurent / Amrane, Samir / Verga, Daniela / Mergny, Jean-Louis

    Biochimie. 2022 Dec. 31,

    2022  

    Abstract: Besides the well-known DNA double-helix, non-canonical nucleic acid structures regulate crucial biological activities. Among these oddities, guanine-rich DNA sequences can form unusual four-stranded secondary structures called G-quadruplexes (G4s). G4- ... ...

    Abstract Besides the well-known DNA double-helix, non-canonical nucleic acid structures regulate crucial biological activities. Among these oddities, guanine-rich DNA sequences can form unusual four-stranded secondary structures called G-quadruplexes (G4s). G4-prone sequences have been found in the genomes of most species, and G4s play important roles in essential processes such as transcription, replication, genome integrity and epigenetic regulation. Here, we present a short overview of G-quadruplexes followed by a detailed description of the biophysical and biochemical methods used to characterize G4s in vitro. The principles, experimental details and possible shortcomings of each method are discussed to provide a comprehensive view of the techniques used to study these structures. We aim to provide a set of guidelines for standardizing research on G-quadruplexes; these guidelines are not meant to be a dogmatic set of rules, but should rather provide useful information on the methods currently used to study these fascinating motifs.
    Keywords DNA ; epigenetics ; genome ; G-quadruplexes ; Nucleic acids ; Structure determination ; Spectroscopy ; Quadruplex ligand
    Language English
    Dates of publication 2022-1231
    Publishing place Elsevier B.V.
    Document type Article ; Online
    Note Pre-press version
    ZDB-ID 120345-9
    ISSN 0300-9084
    ISSN 0300-9084
    DOI 10.1016/j.biochi.2022.12.019
    Database NAL-Catalogue (AGRICOLA)

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  8. Article ; Online: BrdU immuno-tagged G-quadruplex ligands: a new ligand-guided immunofluorescence approach for tracking G-quadruplexes in cells.

    Masson, Thibaut / Landras Guetta, Corinne / Laigre, Eugénie / Cucchiarini, Anne / Duchambon, Patricia / Teulade-Fichou, Marie-Paule / Verga, Daniela

    Nucleic acids research

    2022  Volume 49, Issue 22, Page(s) 12644–12660

    Abstract: G-quadruplexes (G4s) are secondary structures forming in G-rich nucleic acids. G4s are assumed to play critical roles in biology, nonetheless their detection in cells is still challenging. For tracking G4s, synthetic molecules (G4 ligands) can be used as ...

    Abstract G-quadruplexes (G4s) are secondary structures forming in G-rich nucleic acids. G4s are assumed to play critical roles in biology, nonetheless their detection in cells is still challenging. For tracking G4s, synthetic molecules (G4 ligands) can be used as reporters and have found wide application for this purpose through chemical functionalization with a fluorescent tag. However, this approach is limited by a low-labeling degree impeding precise visualization in specific subcellular regions. Herein, we present a new visualization strategy based on the immuno-recognition of 5-bromo-2'-deoxyuridine (5-BrdU) modified G4 ligands, functionalized prior- or post-G4-target binding by CuAAC. Remarkably, recognition of the tag by antibodies leads to the detection of the modified ligands exclusively when bound to a G4 target both in vitro, as shown by ELISA, and in cells, thereby providing a highly efficient G4-ligand Guided Immunofluorescence Staining (G4-GIS) approach. The obtained signal amplification revealed well-defined fluorescent foci located in the perinuclear space and RNase treatment revealed the preferential binding to G4-RNA. Furthermore, ligand treatment affected significantly BG4 foci formation in cells. Our work headed to the development of a new imaging approach combining the advantages of immunostaining and G4-recognition by G4 ligands leading to visualization of G4/ligands species in cells with unrivaled precision and sensitivity.
    MeSH term(s) A549 Cells ; Bromodeoxyuridine ; Cell Line ; Click Chemistry ; Enzyme-Linked Immunosorbent Assay ; Fluorescence Resonance Energy Transfer ; Fluorescent Antibody Technique/methods ; G-Quadruplexes ; Humans ; Ligands
    Chemical Substances Ligands ; Bromodeoxyuridine (G34N38R2N1)
    Language English
    Publishing date 2022-01-25
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 186809-3
    ISSN 1362-4962 ; 1362-4954 ; 0301-5610 ; 0305-1048
    ISSN (online) 1362-4962 ; 1362-4954
    ISSN 0301-5610 ; 0305-1048
    DOI 10.1093/nar/gkab1166
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: Guidelines for G-quadruplexes: I. In vitro characterization.

    Luo, Yu / Granzhan, Anton / Marquevielle, Julien / Cucchiarini, Anne / Lacroix, Laurent / Amrane, Samir / Verga, Daniela / Mergny, Jean-Louis

    Biochimie

    2022  Volume 214, Issue Pt A, Page(s) 5–23

    Abstract: Besides the well-known DNA double-helix, non-canonical nucleic acid structures regulate crucial biological activities. Among these oddities, guanine-rich DNA sequences can form unusual four-stranded secondary structures called G-quadruplexes (G4s). G4- ... ...

    Abstract Besides the well-known DNA double-helix, non-canonical nucleic acid structures regulate crucial biological activities. Among these oddities, guanine-rich DNA sequences can form unusual four-stranded secondary structures called G-quadruplexes (G4s). G4-prone sequences have been found in the genomes of most species, and G4s play important roles in essential processes such as transcription, replication, genome integrity and epigenetic regulation. Here, we present a short overview of G-quadruplexes followed by a detailed description of the biophysical and biochemical methods used to characterize G4s in vitro. The principles, experimental details and possible shortcomings of each method are discussed to provide a comprehensive view of the techniques used to study these structures. We aim to provide a set of guidelines for standardizing research on G-quadruplexes; these guidelines are not meant to be a dogmatic set of rules, but should rather provide useful information on the methods currently used to study these fascinating motifs.
    MeSH term(s) G-Quadruplexes ; Epigenesis, Genetic ; DNA/chemistry ; Genome
    Chemical Substances DNA (9007-49-2)
    Language English
    Publishing date 2022-12-31
    Publishing country France
    Document type Journal Article ; Review
    ZDB-ID 120345-9
    ISSN 1638-6183 ; 0300-9084
    ISSN (online) 1638-6183
    ISSN 0300-9084
    DOI 10.1016/j.biochi.2022.12.019
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article ; Online: G4access identifies G-quadruplexes and their associations with open chromatin and imprinting control regions.

    Esnault, Cyril / Magat, Talha / Zine El Aabidine, Amal / Garcia-Oliver, Encar / Cucchiarini, Anne / Bouchouika, Soumya / Lleres, David / Goerke, Lutz / Luo, Yu / Verga, Daniela / Lacroix, Laurent / Feil, Robert / Spicuglia, Salvatore / Mergny, Jean-Louis / Andrau, Jean-Christophe

    Nature genetics

    2023  Volume 55, Issue 8, Page(s) 1359–1369

    Abstract: Metazoan promoters are enriched in secondary DNA structure-forming motifs, such as G-quadruplexes (G4s). Here we describe 'G4access', an approach to isolate and sequence G4s associated with open chromatin via nuclease digestion. G4access is antibody- and ...

    Abstract Metazoan promoters are enriched in secondary DNA structure-forming motifs, such as G-quadruplexes (G4s). Here we describe 'G4access', an approach to isolate and sequence G4s associated with open chromatin via nuclease digestion. G4access is antibody- and crosslinking-independent and enriches for computationally predicted G4s (pG4s), most of which are confirmed in vitro. Using G4access in human and mouse cells, we identify cell-type-specific G4 enrichment correlated with nucleosome exclusion and promoter transcription. G4access allows measurement of variations in G4 repertoire usage following G4 ligand treatment, HDAC and G4 helicases inhibitors. Applying G4access to cells from reciprocal hybrid mouse crosses suggests a role for G4s in the control of active imprinting regions. Consistently, we also observed that G4access peaks are unmethylated, while methylation at pG4s correlates with nucleosome repositioning on DNA. Overall, our study provides a new tool for studying G4s in cellular dynamics and highlights their association with open chromatin, transcription and their antagonism to DNA methylation.
    MeSH term(s) Animals ; Humans ; Mice ; Chromatin/genetics ; G-Quadruplexes ; Nucleosomes/genetics ; DNA/genetics ; Promoter Regions, Genetic
    Chemical Substances Chromatin ; Nucleosomes ; DNA (9007-49-2)
    Language English
    Publishing date 2023-07-03
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 1108734-1
    ISSN 1546-1718 ; 1061-4036
    ISSN (online) 1546-1718
    ISSN 1061-4036
    DOI 10.1038/s41588-023-01437-4
    Database MEDical Literature Analysis and Retrieval System OnLINE

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