B-globin enhancers regulate bistable gene expression states
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA793436 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR17395700_1.fastq.gz | Fastqsanger.gz | |||
| SRR17395700_2.fastq.gz | Fastqsanger.gz | |||
| SRR17395800_1.fastq.gz | Fastqsanger.gz | |||
| SRR17395800_2.fastq.gz | Fastqsanger.gz | |||
| SRR17395900_1.fastq.gz | Fastqsanger.gz |
Items per page: 5 1 - 5 of 4488 |
Similar Datasets
Project description:Multiple enhancers can coordinately regulate a target gene to ensure robust expression. Under the failure rate model, each redundant enhancer contributes a probability of target gene expression in the cell, and genetic deletion will cause single-cell expression phenotypes. However, this model has been challenging to test in human cells. To examine the role of the human β-globin enhancers in controlling single-cell expression phenotypes, we engineered a haploid locus in K562 cells that fluorescently reports the expression of HBG1. We isolated combinatorial enhancer deletion clones having single-cell expression phenotypes. Genetic and epigenetic analysis shows that deletion of HS3 or HS4 yields clonal cells having bimodal expression of HBG1. Time course analysis indicates that clonal cells can transition between bimodal expression states, and that GFP+ cells have more open chromatin at the HBG1 promoter than GFP- cells. Finally, we derive failure rate contributions for several enhancers. Thus, β-globin enhancers regulate bistable gene expression states, supporting the failure rate model of enhancer redundancy in human cells.
2022-01-21 | GSE192841 | GEO
Project description:A highly selective and non-genotoxic G9a inhibitor, RK-701 was discovered, which upregulated the mRNA level of γ-globin but not β-globin both in human erythroid cells and in mice. Using RK-701, we examined the induction of the fetal (γ-) globin protein in human erythroid cells; HUDEP-2 and human CD34+ bone marrow and peripheral blood cells.
2023-03-11 | PXD033536 | Pride
Project description:Human fetal γ-globin gene is developmentally silenced around the birth, and reactivation of γ-globin gene in adulthood sheds new light on ameliorating symptoms of hemoglobin disorders, such as sickle cell disease (SCD) and β-thalassemias. However, the precise regulation process of γ-globin remains incompletely understood. Here, we found that a new protein directly interacted with SOX6 and exerted a significant repression effect on the expression of γ-globin gene in erythroid cells. Further studies have demonstrated that it bound directly to γ-globin gene promoter via octamer binding motif, which in turn suppressed the transcriptional activity of γ-globin gene promoter. Thus, these data indicate that this new protein acts as a novel transcriptional repressor in the regulation of γ-globin gene expression through direct promoter binding, implying a potential alternative therapeutic target for the treatment of SCD and β-thalassemias.
2022-02-16 | PXD024259 | Pride
Project description:Super-enhancers are compound regulatory elements which control expression of key cell-identity genes. They recruit high levels of tissue-specific transcription factors, co-activators such as the mediator complex, and they contact their target gene promoters with high frequency. Most super-enhancers contain multiple constituent regulatory elements, but it is unclear whether these elements have distinct roles in activating expression of their cognate genes. Here, through comprehensively rebuilding the endogenous α-globin super-enhancer, we show that super-enhancers comprise bioinformatically equivalent but functionally distinct element types: classical enhancers and facilitator elements. Facilitators have no intrinsic enhancer activity, yet in their absence, classical enhancers are unable to fully up-regulate their target genes. Without facilitators, classical enhancers exhibit reduced mediator recruitment, enhancer RNA transcription and enhancer-promoter interactions. Facilitators are interchangeable, but display functional hierarchy based on their position within a super-enhancer. Facilitators thus play an important role in potentiating super-enhancer activity and ensuring robust activation of target genes.
2023-12-31 | GSE219077 | GEO
Project description:Super-enhancers are compound regulatory elements which control expression of key cell-identity genes. They recruit high levels of tissue-specific transcription factors, co-activators such as the mediator complex, and they contact their target gene promoters with high frequency. Most super-enhancers contain multiple constituent regulatory elements, but it is unclear whether these elements have distinct roles in activating expression of their cognate genes. Here, through comprehensively rebuilding the endogenous α-globin super-enhancer, we show that super-enhancers comprise bioinformatically equivalent but functionally distinct element types: classical enhancers and facilitator elements. Facilitators have no intrinsic enhancer activity, yet in their absence, classical enhancers are unable to fully up-regulate their target genes. Without facilitators, classical enhancers exhibit reduced mediator recruitment, enhancer RNA transcription and enhancer-promoter interactions. Facilitators are interchangeable, but display functional hierarchy based on their position within a super-enhancer. Facilitators thus play an important role in potentiating super-enhancer activity and ensuring robust activation of target genes.
2023-12-31 | GSE219062 | GEO
Project description:Super-enhancers are compound regulatory elements which control expression of key cell-identity genes. They recruit high levels of tissue-specific transcription factors, co-activators such as the mediator complex, and they contact their target gene promoters with high frequency. Most super-enhancers contain multiple constituent regulatory elements, but it is unclear whether these elements have distinct roles in activating expression of their cognate genes. Here, through comprehensively rebuilding the endogenous α-globin super-enhancer, we show that super-enhancers comprise bioinformatically equivalent but functionally distinct element types: classical enhancers and facilitator elements. Facilitators have no intrinsic enhancer activity, yet in their absence, classical enhancers are unable to fully up-regulate their target genes. Without facilitators, classical enhancers exhibit reduced mediator recruitment, enhancer RNA transcription and enhancer-promoter interactions. Facilitators are interchangeable, but display functional hierarchy based on their position within a super-enhancer. Facilitators thus play an important role in potentiating super-enhancer activity and ensuring robust activation of target genes.
2023-12-31 | GSE219056 | GEO
Project description:Super-enhancers are compound regulatory elements which control expression of key cell-identity genes. They recruit high levels of tissue-specific transcription factors, co-activators such as the mediator complex, and they contact their target gene promoters with high frequency. Most super-enhancers contain multiple constituent regulatory elements, but it is unclear whether these elements have distinct roles in activating expression of their cognate genes. Here, through comprehensively rebuilding the endogenous α-globin super-enhancer, we show that super-enhancers comprise bioinformatically equivalent but functionally distinct element types: classical enhancers and facilitator elements. Facilitators have no intrinsic enhancer activity, yet in their absence, classical enhancers are unable to fully up-regulate their target genes. Without facilitators, classical enhancers exhibit reduced mediator recruitment, enhancer RNA transcription and enhancer-promoter interactions. Facilitators are interchangeable, but display functional hierarchy based on their position within a super-enhancer. Facilitators thus play an important role in potentiating super-enhancer activity and ensuring robust activation of target genes.
2023-12-31 | GSE220456 | GEO
Project description:The benign condition Hereditary Persistence of Foetal Haemoglobin (HPFH) is known to ameliorate symptoms when co-inherited with beta-haemoglobinopathies, such as sickle cell disease and beta-thalassaemia. The condition is sometimes associated with point mutations in the foetal globin promoters that disrupt the binding of the repressors BCL11A or ZBTB7A/LRF, which have been extensively studied. HPFH is also associated with a range of deletions within the beta-globin locus that all reside downstream of the foetal HBG2 gene. These deletional forms of HPFH are poorly understood and are the focus of this study. Numerous different mechanisms have been proposed to explain how downstream deletions can boost the expression of the foetal globin genes, including the deletion of silencer elements, of genes encoding non-coding RNA, and bringing downstream enhancer elements into proximity with the foetal globin gene promoters. Here we systematically analyse the deletions associated with both HPFH and a related condition known as beta-thalassaemia and propose a unifying mechanism. In all cases where foetal globin is up-regulated, the proximal adult beta-globin (HBB) promoter is deleted. We use CRISPR gene editing to delete or disrupt elements within the promoter and find that virtually all mutations that reduce promoter activity, result in elevated foetal globin expression. These results fit with previous models where the foetal and adult globin genes compete for the distal Locus Control Region and suggest that targeting the promoter might be explored to elevate foetal globin and reduce sickle globin expression as a treatment for beta-haemoglobinopathies.
2022-01-20 | GSE194064 | GEO
Project description:A key problem in development is to understand how genes turn on or off at the right place and right time during embryogenesis. Such decisions are made by non-coding sequences called 'enhancers.' Much of our models of how enhancers work rely on the assumption that genes are activated de novo as stable domains across embryonic tissues. Such a view has been strengthened by the intensive landmark studies of the early patterning of the anterior-posterior (AP) axis of the Drosophila embryo, where indeed gene expression domains seem to arise more or less stably. However, careful analysis of gene expression patterns in other model systems (including the AP patterning in vertebrates and short-germ insects like the beetle Tribolium castaneum) painted a different, very dynamic view of gene regulation, where genes are oftentimes expressed in a wavelike fashion. How such gene expression waves are mediated at the enhancer level is so far unclear. Here, we establish the AP patterning of the short-germ beetle Tribolium as a model system to study dynamic and temporal pattern formation at the enhancer level. To that end, we established an enhancer prediction system in Tribolium based on time- and tissue-specific ATAC-seq and an enhancer live reporter system based on MS2 tagging. Using this experimental framework, we discovered several Tribolium enhancers, and assessed the spatiotemporal activities of some of them in live embryos. We found our data consistent with a model in which the timing of gene expression during embryonic pattern formation is mediated by a balancing act between enhancers that induce rapid changes in gene expression patterns (that we call 'dynamic enhancers') and enhancers that stabilize gene expression patterns (that we call 'static enhancers'). However, more data is needed for a strong support for this or any other alternative models.
| S-EPMC10368423 | biostudies-literature
Project description:Background: Developmental stage-specific globin expression is a complex phenomenon that involves both trans- and cis-acting elements. While functional analyses ensuing recent genome-wide association studies have highlighted the important roles of trans-factors in regulating hemoglobin expression, these factors can not exert their functions without permissive chromatin domains. By transferring thoroughly profiled beta globin locus of undifferentiated human embryonic stem cells (hESCs) or hESC-derived erythroid cells into an adult erythroid transcriptional environment, we studied the influences of histone modifications on the globin expression decision within a fixed transcriptional environment. Shortly after the locus transfer, embryonic epsilon globin was not expressed regardless of original chromatin states, whereas fetal gamma globin was either expressed or not activated depending on original chromatin configurations, and the originally silent adult beta globin either remained silent or became activated depending on the expression status of gamma globin. These data suggest the interplay between transcriptional environment and the chromatin modifications determine the outcome of globin expression. As the ultimate silencing of gamma globin from hESC-derived erythroid cells in the adult transcriptional environment occurred after months-long cell proliferation, our work also has implications on attempts to generate beta globin expressing erythroid cells from hESCs or induced pluripotent stem cells.
2012-08-19 | GSE31523 | GEO