A fine kinetic balance of interactions directs transcription factor hubs to genes [Cut and Run]
Ontology highlight
ABSTRACT:
ORGANISM(S): Drosophila melanogaster
PROVIDER: GSE263999 | GEO | 2024/04/15
REPOSITORIES: GEO
Similar Datasets
Project description:Eukaryotic gene regulation relies on the binding of sequence-specific transcription factors (TFs). TFs bind chromatin transiently yet occupy their target sites by forming high-local concentration microenvironments (hubs and condensates) that increase the frequency of binding events. Despite their ubiquity, such microenvironments have been difficult to study in endogenous contexts due to technical limitations. Here, we overcome these limitations and investigate how hubs drive TF occupancy at their targets. Using a DNA binding perturbation to a hub-forming TF, Zelda, in Drosophila embryos, we find that hub properties, including the stability and frequencies of associations to targets, are key determinants of TF occupancy. Our data suggest that hub targeting is driven not just by specific DNA motif recognition, but also by a fine-tuned kinetic balance of interactions between TFs and their co-binding partners.
2024-04-15 | GSE263718 | GEO
Project description:Eukaryotic gene regulation relies on the binding of sequence-specific transcription factors (TFs). TFs bind chromatin transiently yet occupy their target sites by forming high-local concentration microenvironments (hubs and condensates) that increase the frequency of binding events. Despite their ubiquity, such microenvironments have been difficult to study in endogenous contexts due to technical limitations. Here, we overcome these limitations and investigate how hubs drive TF occupancy at their targets. Using a DNA binding perturbation to a hub-forming TF, Zelda, in Drosophila embryos, we find that hub properties, including the stability and frequencies of associations to targets, are key determinants of TF occupancy. Our data suggest that hub targeting is driven not just by specific DNA motif recognition, but also by a fine-tuned kinetic balance of interactions between TFs and their co-binding partners.
2024-04-15 | GSE263997 | GEO
Project description:It is widely believed that reorganization of nucleosomes result in availability of transcription factor (TF) binding sites for eukaryotic gene regulation. Recent findings also show TFs induced during physiological perturbations can alter nucleosome occupancy to facilitate DNA binding. Although, these suggest a close relationship between TF binding and nucleosomes, the nature of this interaction, or to what extent it influences transcription is not clear. Moreover, since physiological perturbations induced multiple TFs, relatively direct effect of any TF on nucleosome occupancy remains poorly addressed. With these in mind, we used a single TF to induce physiological changes and following characterization of the two states (before and after induction of the TF) we determined: (a) genome wide binding sites of the TF, (b) promoter nucleosome occupancy and (c) transcriptome profiles, independently in both conditions. We find only ~20% of TF binding results from nucleosome repositioning - interestingly, almost all corresponding genes were transcriptionally altered. Whereas, when TF-occupancy was independent of nucleosome repositioning only a small fraction of corresponding genes were expressed/repressed. These observations suggest a model where TF occupancy leads to transcriptional change only when coupled with nucleosome repositioning in close proximity. This, to our knowledge, for the first time also helps explain why genome wide TF occupancy (e.g., from ChIP-sequencing) typically overlaps with only a small fraction of genes that change expression. The nature of interaction between TF binding and nucleosomes and what extent it influences transcription
2014-08-04 | E-GEOD-40300 | biostudies-arrayexpress
Project description:Transcription factors (TFs) bind specific sequences in promoter-proximal and distal DNA elements in order to regulate gene transcription. RNA is transcribed from both promoter-proximal and distal DNA elements, and some DNA-binding TFs have also been shown to bind RNA. These obsevations led us to postulate that RNA transcribed from regulatory elements contributes to stable TF occupancy at these regulatory elements. We show here that the ubiquitously expressed TF YY1 binds to both proximal and distal regulatory elements and to the RNA species associated with these elements near active genes in embryonic stem cells. Inhibition of transcription from these elements reduces YY1 occupancy. In contrast, tethering of RNA species near YY1 DNA binding sites enhances YY1 occupancy. We propose that RNA acts as trap to maintain certain TFs at active enhancer and promoter-proximal regulatory elements. Thus, transcriptional control generally involves a positive feedback loop, where YY1 and other TFs stimulate local transcription, and newly transcribed nascent RNA reinforces local TF occupancy. This model helps explain why TFs occupy only the small fraction of their consensus motifs in the mammalian genome where transcription is detected. GRO-Seq in mouse embryonic stem cells treated with transcription-altering drugs
2015-10-29 | E-GEOD-68197 | biostudies-arrayexpress
Project description:Transcription factors (TFs) bind specific sequences in promoter-proximal and distal DNA elements in order to regulate gene transcription. RNA is transcribed from both promoter-proximal and distal DNA elements, and some DNA-binding TFs have also been shown to bind RNA. These obsevations led us to postulate that RNA transcribed from regulatory elements contributes to stable TF occupancy at these regulatory elements. We show here that the ubiquitously expressed TF YY1 binds to both proximal and distal regulatory elements and to the RNA species associated with these elements near active genes in embryonic stem cells. Inhibition of transcription from these elements reduces YY1 occupancy. In contrast, tethering of RNA species near YY1 DNA binding sites enhances YY1 occupancy. We propose that RNA acts as trap to maintain certain TFs at active enhancer and promoter-proximal regulatory elements. Thus, transcriptional control generally involves a positive feedback loop, where YY1 and other TFs stimulate local transcription, and newly transcribed nascent RNA reinforces local TF occupancy. This model helps explain why TFs occupy only the small fraction of their consensus motifs in the mammalian genome where transcription is detected. CLIP-Seq for YY1 in mouse embryonic stem cells
2015-10-29 | E-GEOD-68196 | biostudies-arrayexpress
Project description:Transcription factors (TFs) bind specific sequences in promoter-proximal and distal DNA elements in order to regulate gene transcription. RNA is transcribed from both promoter-proximal and distal DNA elements, and some DNA-binding TFs have also been shown to bind RNA. These obsevations led us to postulate that RNA transcribed from regulatory elements contributes to stable TF occupancy at these regulatory elements. We show here that the ubiquitously expressed TF YY1 binds to both proximal and distal regulatory elements and to the RNA species associated with these elements near active genes in embryonic stem cells. Inhibition of transcription from these elements reduces YY1 occupancy. In contrast, tethering of RNA species near YY1 DNA binding sites enhances YY1 occupancy. We propose that RNA acts as trap to maintain certain TFs at active enhancer and promoter-proximal regulatory elements. Thus, transcriptional control generally involves a positive feedback loop, where YY1 and other TFs stimulate local transcription, and newly transcribed nascent RNA reinforces local TF occupancy. This model helps explain why TFs occupy only the small fraction of their consensus motifs in the mammalian genome where transcription is detected. Affinity purification (ChIP-Seq) for YY1 in mouse embryonic stem cells treated with transcription-affecting compounds
2015-05-28 | E-GEOD-68195 | biostudies-arrayexpress
Project description:Transcription factors (TFs) bind specific sequences in promoter-proximal and distal DNA elements in order to regulate gene transcription. RNA is transcribed from both promoter-proximal and distal DNA elements, and some DNA-binding TFs have also been shown to bind RNA. These obsevations led us to postulate that RNA transcribed from regulatory elements contributes to stable TF occupancy at these regulatory elements. We show here that the ubiquitously expressed TF YY1 binds to both proximal and distal regulatory elements and to the RNA species associated with these elements near active genes in embryonic stem cells. Inhibition of transcription from these elements reduces YY1 occupancy. In contrast, tethering of RNA species near YY1 DNA binding sites enhances YY1 occupancy. We propose that RNA acts as trap to maintain certain TFs at active enhancer and promoter-proximal regulatory elements. Thus, transcriptional control generally involves a positive feedback loop, where YY1 and other TFs stimulate local transcription, and newly transcribed nascent RNA reinforces local TF occupancy. This model helps explain why TFs occupy only the small fraction of their consensus motifs in the mammalian genome where transcription is detected. RNA-Seq in mouse embryonic stem cells before and after knockdown of exosome protein
2015-10-29 | E-GEOD-73859 | biostudies-arrayexpress
Project description:Previous studies have analyzed patterns of transcription, transcription factor (TF) binding or mapped nucleosome occupancy across the genome. These suggest that the three aspects are genetically connected but the cause and effect relationships are still unknown. For example, physiologic TF binding studies involve many TFs, consequently, it is difficult to assign nucleosome reorganization to the binding site occupancy of any particular TF. Therefore, several aspects remain unclear: does TF binding influence nucleosome (re)organizations locally (in close vicinity of their binding sites) or impact the chromatin landscape at a more global level; are all or only a fraction of TF binding a result of reorganization in nucleosome occupancy; finally, do all TF binding and associated nucleosome occupancy changes result in altered gene expression? With these in mind, we sought to study a single TF that induces physiological changes, and following characterization of the two states (before and after induction of the TF) we determined: (a) genomic binding sites of the TF, (b) promoter nucleosome occupancy and (c) transcriptome profiles, independently in both conditions. Results demonstrate that TF binding influences expression of the target gene only when it is coupled to nucleosome repositioning at or close to its binding site, and not when transcription factor binding occurs without local associated nucleosome reorganization. The nature of interaction between TF binding and nucleosomes and what extent it influences transcription
2014-08-04 | E-GEOD-40363 | biostudies-arrayexpress
Project description:Detecting in vivo transcription factor (TF) binding is important for understanding gene regulatory circuitries. ChIP-seq is a powerful technique to empirically define TF binding in vivo. However, the multitude of distinct TFs makes genome-wide profiling for them all labor-intensive and costly. Algorithms for in silico prediction of TF binding have been developed, based mostly on histone modification or DNase I hypersensitivity data in conjunction with DNA motif and other genomic features. However, technical limitations of these methods prevent them from being applied broadly, especially in clinical settings. We conducted a comprehensive survey involving multiple cell lines, TFs, and methylation types and found that there are intimate relationships between TF binding and methylation level changes around the binding sites. Exploiting the connection between DNA methylation and TF binding, we proposed a novel supervised learning approach to predict TF-DNA interaction using data from base-resolution whole-genome methylation sequencing experiments. We devised beta-binomial models to characterize methylation data around TF binding sites and the background. Along with other static genomic features, we adopted a random forest framework to predict TF-DNA interaction. After conducting comprehensive tests, we saw that the proposed method accurately predicts TF binding and performs favorably versus competing methods. Examine Oct4 genome-wide binding in mouse embryonic stem cells (E14)
2015-03-02 | E-GEOD-65093 | biostudies-arrayexpress
Project description:It is widely believed that reorganization of nucleosomes result in availability of transcription factor (TF) binding sites for eukaryotic gene regulation. Recent findings also show TFs induced during physiological perturbations can alter nucleosome occupancy to facilitate DNA binding. Although, these suggest a close relationship between TF binding and nucleosomes, the nature of this interaction, or to what extent it influences transcription is not clear. Moreover, since physiological perturbations induced multiple TFs, relatively direct effect of any TF on nucleosome occupancy remains poorly addressed. With these in mind, we used a single TF to induce physiological changes and following characterization of the two states (before and after induction of the TF) we determined: (a) genome wide binding sites of the TF, (b) promoter nucleosome occupancy and (c) transcriptome profiles, independently in both conditions. We find only ~20% of TF binding results from nucleosome repositioning - interestingly, almost all corresponding genes were transcriptionally altered. Whereas, when TF-occupancy was independent of nucleosome repositioning only a small fraction of corresponding genes were expressed/repressed. These observations suggest a model where TF occupancy leads to transcriptional change only when coupled with nucleosome repositioning in close proximity. This, to our knowledge, for the first time also helps explain why genome wide TF occupancy (e.g., from ChIP-sequencing) typically overlaps with only a small fraction of genes that change expression.
2014-08-04 | GSE40300 | GEO