Small-molecule-based Human Genome G4 Profiling Reveals Potential Gene Regulation Activity
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE109369 | GEO | 2019/02/15
REPOSITORIES: GEO
Similar Datasets
Project description:G-quadruplexes (G4s) are noncanonical DNA secondary structures formed through the self-association of guanines, and they are distributed widely across the genome. G4 participates in multiple biological processes including gene transcription, and G4-targeted ligands serve as potential therapeutic agents for DNA-targeted therapies. However, genome-wide studies of the exact roles of G4s in transcriptional regulation are still lacking. We found that drug-induced promoter-proximal RNA polymerase II pausing promotes nearby G4 formation, and oppositely, G4 stabilization by G4-targeted ligands globally reduces RNA polymerase II occupancy at gene promoters as well as nascent RNA synthesis. To study the underlying mechanisms by which native G4 affects transcriptional regulation, we annealed the biotin-labeled core promoter DNA to form G4s and performed pull-down assays with nuclear extraction proteins in the presence or absence of TMPyP4. Mass spectrometry analysis was performed to identify the interacting proteins with G4-forming core promoter DNA.
2021-07-19 | PXD026830 | Pride
Project description:The pqs operon of the bacteria P. aeruginosa is responsible for the production of at least 60 secreted compounds mainly hidroxy-quinolones (HAQs). Some of them, like PQS and HHQ, were found to be important signal that control the virulence of the bacteria. We have discover that one of the most abandon molecule produced by the pqs operon, 2 aminoacetophenone (2-AA), a volatile molecule serves as a unique signal. In contrast to the previous described PQS and HHQ, 2-AA is downregulating virulence and acute phase proteins and upregulating chronic phase proteins. In addition we have found that 2-AA promotes the formation of persisters cells that antibiotic tolerant. we have compared the genes profile of wild-type PA14 strain and its derivatives topA which lacks Topoisomerase I and pqsA that do not produces HAQs or 2-AA to cultures that were treated with 3mM of 2-AA. Cell were grown with and without 2-AA (3mM) to OD 2.0.
2011-12-21 | E-GEOD-24036 | biostudies-arrayexpress
Project description:Unicellular organisms living in a marine environment sometimes have to cope with massive fluctuations in inorganic phosphate (Pi) availability. We studied phosphatases and phosphate transporters of the diatom Phaeodactylum tricornutum with respect to the extracellular Pi-concentration depending expression as well as their extra- or intracellular localization. These studies, which add a further level of knowledge to already existing transcriptomic data, highlight the capacity of the diatom to distribute Pi intracellularly and to mobilize Pi from extra- and intracellular resources
2020-04-30 | PXD016456 | Pride
Project description:The pqs operon of the bacteria P. aeruginosa is responsible for the production of at least 60 secreted compounds mainly hidroxy-quinolones (HAQs). Some of them, like PQS and HHQ, were found to be important signal that control the virulence of the bacteria. We have discover that one of the most abandon molecule produced by the pqs operon, 2 aminoacetophenone (2-AA), a volatile molecule serves as a unique signal. In contrast to the previous described PQS and HHQ, 2-AA is downregulating virulence and acute phase proteins and upregulating chronic phase proteins. In addition we have found that 2-AA promotes the formation of persisters cells that antibiotic tolerant. we have compared the genes profile of wild-type PA14 strain and its derivatives topA which lacks Topoisomerase I and pqsA that do not produces HAQs or 2-AA to cultures that were treated with 3mM of 2-AA.
2011-12-21 | GSE24036 | GEO
Project description:Virulence factor production and the development of biofilms in Pseudomonas aeruginosa have been shown to be regulated by two hierarchically organised quorum sensing (QS) systems via small acyl-homoserine lactone (AHL) signal molecules. Recently, a third bacterial signal molecule, the Pseudomonas quinolone signal (PQS), has been identified, which positively regulates a subset of genes dependent on the QS systems. To further dissect the various independent regulation levels for many QS induced genes and to evaluate the impact of PQS on the QS circuitry, we performed a transcriptome analysis of PAO1 cultures supplemented with PQS. The global transcriptional profile in response to PQS revealed a marked up-regulation of genes belonging to the tightly interdependent functional groups of iron acquisition and oxidative stress response. Remarkably, not only most of the differentially regulated genes but also the induction of a lacZ transcriptional fusion of rhlR could be traced back to a iron chelating effect of PQS. Nevertheless, although iron deficiency per se induced rhlR, there seems to be PQS specific effects that are independent of the PQS effect on P. aeruginosa iron homeostasis Keywords: PQS response
2006-12-12 | GSE3836 | GEO
Project description:DNA secondary structures are important for fundamental genome functions such as transcription and replication1. The G-quadruplex (G4) structural motif has been linked to gene regulation2,3 and genome instability4,5 and may be important to cancer development and other diseases6-8. Recently, ~700,000 discrete G4s have been observed in naked human single-stranded genomic DNA using G4-seq, a high-throughput sequencing technique that detects structural features in vitro.9 It is of vital importance to investigate G4 structures within an endogenous chromatin context, which until now remained elusive10,11. Herein, we address this via the development of G4 ChIP-seq, an antibody-based G4 chromatin immunoprecipitation and high-throughput sequencing approach. We identified ~10,000 endogenous G4 structures and show that G4s are predominantly seen in regulatory, nucleosome-depleted, chromatin regions. G4s were enriched in the promoters and 5âUTR regions of highly transcribed genes, particularly in genes related to cancer and in somatic copy number amplifications, such as MYC. Reorganization of the chromatin landscape using a histone deacetylase inhibitor, resulted in de novo G4 formation in new and more prominent regulatory, nucleosome-depleted regions associated with increased transcriptional output. Our findings suggest a striking relationship between promoter nucleosome-depleted regions, G4 formation and elevated transcriptional activity. Comparison between normal human epidermal keratinocytes and their immortalized counterparts revealed a ï¾7-fold greater G4 abundance in immortalized cells, of which 80 % were found in regulatory, nucleosome-depleted regions common to both cell types. Consequently, cells exhibiting more G4s displayed significantly increased transcriptional output and were more sensitive to growth inhibition by a small molecule G4 ligand. Overall, our results provide new mechanistic insights into where and when DNA adopts G4 structure in vivo. Our findings show for the first time that regulatory, nucleosome-depleted chromatin and transcriptional states predominantly shape the endogenous G4 DNA landscape. Two cell lines, treated with entinostat or untreated, analyzed to detect gene expression differences, presence of G-Qudruplexes and chromatin state. Each combination of conditions replicated in duplicates or triplicates.
2016-08-05 | E-GEOD-76688 | biostudies-arrayexpress
Project description:DNA G-quadruplexes (G4s) have been identified as important biological targets for transcriptional, translational, and epigenetic regulation. The stabilisation of G4s with small molecule ligands has emerged as a technique to regulate gene expression and as a potential therapeutic approach for human diseases. Here, we demonstrate that ligand stabilisation of G4s causes altered chromatin accessibility dependant on the targeting specificity of the molecule. In particular, stabilisation of a target G4 using the highly specific GTC365 ligand resulted in differential accessibility of 61 genomic regions, while the broad targeted GQC-05 ligand stabilised many G4s and induced a global shift towards increased accessibility of gene promoter regions. Interestingly, while we observed distinct effects of each ligand on RNA expression levels and the induction of DNA double-stranded breaks, both ligands modified DNA damage response pathways. Our work represents the dual possibility of G4-stabilising ligands for specific or global chromatin modulation via unique targeting characteristics.
2023-06-28 | GSE235953 | GEO
Project description:DNA G-quadruplexes (G4s) have been identified as important biological targets for transcriptional, translational, and epigenetic regulation. The stabilisation of G4s with small molecule ligands has emerged as a technique to regulate gene expression and as a potential therapeutic approach for human diseases. Here, we demonstrate that ligand stabilisation of G4s causes altered chromatin accessibility dependant on the targeting specificity of the molecule. In particular, stabilisation of a target G4 using the highly specific GTC365 ligand resulted in differential accessibility of 61 genomic regions, while the broad targeted GQC-05 ligand stabilised many G4s and induced a global shift towards increased accessibility of gene promoter regions. Interestingly, while we observed distinct effects of each ligand on RNA expression levels and the induction of DNA double-stranded breaks, both ligands modified DNA damage response pathways. Our work represents the dual possibility of G4-stabilising ligands for specific or global chromatin modulation via unique targeting characteristics.
2023-06-28 | GSE235952 | GEO
Project description:The maintenance of cellular phosphate (Pi) homeostasis is of paramount importance in living organisms. Little is known about how cells sense intracellular Pi status in multi-cellular eukaryotes. Here, we report the identification of inositol pyrophosphate InsP8, a ligand that binds to the Pi sensor protein SPX1 to inhibit PHR1, the central regulator of Pi starvation responses in Arabidopsis. The concentration of InsP8, synthesized by diphosphoinositol pentakisphosphate kinases VIH1 and VIH2, depends on cellular Pi level and the double mutants accumulated higher amounts of Pi. The paradox of Pi toxicity and induction of Pi starvation inducible genes indicated that the cells could not sense cellular Pi without InsP8. Our study reveals that InsP8 acts as a Pi signaling molecule and binds to the receptor SPX1 to regulate Pi homeostasis.
2022-02-22 | GSE126927 | GEO
Project description:Gene expression is governed by transcription factors (TFs) that commonly recognize short DNA sequence motifs. However, TF recruitment to genomic target sites in chromatin is complex and many parameters that ultimately dictate binding-site specificity are still unknown. Here, we systematically explore the interaction of TFs with synthetic and endogenous G-quadruplexes (G4s) DNA secondary structures. Our findings reveal that certain TFs are directly recruited to promoters by endogenous G4s with binding affinities comparable to canonical B-DNA binding and that endogenous G4-TF interactions can be disrupted with synthetic small molecule ligands. G4s in promoters are bound by a large number of TFs and associated with high transcriptional activity. This discovery of structure-specific recognition expands our understanding of how TFs regulate gene transcription.
2021-03-24 | GSE145090 | GEO