Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Massively parallel characterization of insulator activity across the genome [insulator_libraries]

ABSTRACT: Insulators are cis-regulatory sequences (CRSs) that can block enhancers from activating target promoters or act as barriers to block the spread of heterochromatin. Their name derives from their ability to ‘insulate’ transgenes from genomic position effects, an important function in gene therapy and biotechnology applications that require high levels of sustained transgene expression. In theory, flanking transgenes with insulators protects them from position effects, but in practice, efforts to insulate transgenes meet with mixed success because the contextual requirements for insulator function in the genome are not well understood. A key question is whether insulators are modular elements that can function anywhere in the genome or whether they are adapted to function only in certain genomic locations. To distinguish between these two possibilities we developed MPIRE (Massively Parallel Integrated Regulatory Elements) and used it to measure the effects of three insulators (A2, cHS4, ALOXE3) and their mutants at thousands of locations across the genome. Our results show that each insulator functions in only a small number of genomic locations, and that insulator function depends on the sequence motifs that comprise each insulator. All three insulators can block enhancers in the genome, but specificity arises because each insulator blocks enhancers that are bound by different sets of transcription factors. In contrast, only ALOXE3 can act as a heterochromatin barrier. We conclude that insulator function is highly context dependent and that MPIRE is a robust and systematic method for revealing the context dependencies of insulators and other cis-regulatory elements across the genome.

ORGANISM(S): Homo sapiens

PROVIDER: GSE223402 | GEO | 2023/01/27

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Similar Datasets

Massively parallel characterization of insulator activity across the genome [pilot_rBC]

Project description:Insulators are cis-regulatory sequences (CRSs) that can block enhancers from activating target promoters or act as barriers to block the spread of heterochromatin. Their name derives from their ability to ‘insulate’ transgenes from genomic position effects, an important function in gene therapy and biotechnology applications that require high levels of sustained transgene expression. In theory, flanking transgenes with insulators protects them from position effects, but in practice, efforts to insulate transgenes meet with mixed success because the contextual requirements for insulator function in the genome are not well understood. A key question is whether insulators are modular elements that can function anywhere in the genome or whether they are adapted to function only in certain genomic locations. To distinguish between these two possibilities we developed MPIRE (Massively Parallel Integrated Regulatory Elements) and used it to measure the effects of three insulators (A2, cHS4, ALOXE3) and their mutants at thousands of locations across the genome. Our results show that each insulator functions in only a small number of genomic locations, and that insulator function depends on the sequence motifs that comprise each insulator. All three insulators can block enhancers in the genome, but specificity arises because each insulator blocks enhancers that are bound by different sets of transcription factors. In contrast, only ALOXE3 can act as a heterochromatin barrier. We conclude that insulator function is highly context dependent and that MPIRE is a robust and systematic method for revealing the context dependencies of insulators and other cis-regulatory elements across the genome.

2023-01-27 | GSE223384 | GEO

Massively parallel characterization of insulator activity across the genome [GWLP_pools]

2023-01-27 | GSE223389 | GEO

NURF301 contributes to gypsy chromatin insulator-mediated nuclear organization

Project description:Chromatin insulators are DNA-protein complexes that can prevent the spread of repressive chromatin and block communication between enhancers and promoters to regulate gene expression. In Drosophila, the gypsy chromatin insulator complex consists of three core proteins: CP190, Su(Hw), and Mod(mdg4)67.2. These factors concentrate at nuclear foci termed insulator bodies, and their normal localization is correlated with proper insulator function. Here, we identified NURF301/E(bx), a nucleosome remodeling factor, as a novel regulator of gypsy insulator body localization through a high-throughput RNAi imaging screen. NURF301 promotes gypsy-dependent insulator barrier activity and physically interacts with gypsy insulator proteins. Using ChIP-seq, we found that NURF301 co-localizes with insulator proteins genome-wide, and NURF301 promotes chromatin association of Su(Hw) and CP190 at gypsy insulator binding sites. These effects correlate with NURF301-dependent nucleosome repositioning. At the same time, CP190 and Su(Hw) are also required for recruitment of NURF301 to chromatin. Finally, Oligopaint FISH combined with immunofluorescence revealed that NURF301 promotes 3D contact between insulator bodies and gypsy binding site DNA, and NURF301 is required for proper nuclear positioning of gypsy binding sites. Our data provide new insights into how a nucleosome remodeling factor and insulator proteins cooperatively contribute to nuclear organization.

2022-10-14 | PXD032165 | Pride

Tandem CTCF sites function as insulators to balance spatial chromatin contacts and topological enhancer-promoter selection [III]

Project description:CTCF is a key insulator-binding protein and mammalian genomes contain numerous CTCF-binding sites (CBSs), many of which are organized in tandem arrays. Here we provide direct evidence that CBSs, if located between enhancers and promoters in the clustered Pcdh and b-globin clusters, function as an enhancer-blocking insulator by forming distinct directional chromatin loops, regardless whether enhancers contain CBS or not. Moreover, computational simulation and experimental capture revealed balanced promoter usage in vivo in cell populations and stochastic monoallelic expression in single cells by large arrays of tandem variable CBSs. Finally, gene expression levels are negatively correlated with CBS insulators located between enhancers and promoters on a genome-wide scale. Thus, single CBS insulators ensure proper enhancer insulation and promoter activation while tandem-arrayed CBS insulators determine balanced promoter choice. This finding has interesting implications on the role of topological insulators in 3D genome folding and developmental gene regulation.

2020-03-01 | GSE138645 | GEO

Tandem CTCF sites function as insulators to balance spatial chromatin contacts and topological enhancer-promoter selection [II]

2020-03-01 | GSE136328 | GEO

Tandem CTCF sites function as insulators to balance spatial chromatin contacts and topological enhancer-promoter selection [V]

2020-03-01 | GSE139679 | GEO

Tandem CTCF sites function as insulators to balance spatial chromatin contacts and topological enhancer-promoter selection [I]

2020-03-01 | GSE135394 | GEO

CP190 and CTCF mediated enhancer blocking is augmented by SUMOylation

Project description:Chromatin insulators shield promoters and chromatin domains from neighbouring enhancers or chromatin regions with opposing activities. Insulator binding proteins and their cofactors mediate the boundary function. In general, covalent modification of proteins by the Small Ubiqutin-like Modifier (SUMO) is an important mechanism to control the interaction of proteins within complexes. Here we addressed the impact of SUMO in respect to insulator function, chromatin binding of insulator factors and formation of insulator speckles. SUMOylation augments the enhancer blocking function of four different insulator sequences and increases the genome-wide binding of the insulator cofactor CP190. A model is discussed with enhanced chromatin binding of SUMOylated CP190 causing fusion of insulator speckles, which may allow for more efficient insulation.

2017-08-07 | GSE96581 | GEO

The zinc-finger protein CLAMP promotes gypsy chromatin insulator function in Drosophila: differential ChIP-seq of CP190 and CLAMP under CP190 knockdown

Project description:Chromatin insulators are DNA-protein complexes that establish higher order independent DNA domains to influence transcriptional regulation. Insulators are defined by two different functions: they can block communication between an enhancer and a promoter and also act as a barrier between heterochromatin and euchromatin. In Drosophila, the gypsy-insulator complex contains three core components: Su(Hw), CP190 and Mod(mdg4)67.2. Here we identify a novel role for Chromatin-linked adaptor for MSL proteins (CLAMP) in promoting gypsy chromatin insulator function. When Clamp is depleted by RNAi, gypsy-dependent enhancer blocking activity decreases and barrier activity is reduced in all tissues. Furthermore, Clamp RNAi knockdowns and mutation result in disorganized insulator complex localization in the nucleus. Co-immunoprecipitation experiments showed that CLAMP physically associates with core gypsy-insulator proteins. Co-localization of CLAMP with gypsy components on polytene chromosomes and ChIP-seq analysis demonstrates co-localization of CLAMP with a subset of insulator sites across the genome. Thus, our findings suggest a ubiquitous, genome-wide role for CLAMP in promoting gypsy-dependent chromatin insulator activity.

2019-01-28 | GSE118699 | GEO

The zinc-finger protein CLAMP promotes gypsy chromatin insulator function in Drosophila: ChIP-seq of CP190, Su(Hw), Mod(mdg4) for genome-wide overlap with CLAMP

2019-01-28 | GSE103601 | GEO

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data