GLI transcriptional repression regulates enhancer activity and chromatin accessibility for Hedgehog target genes
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA428995 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Purpose: This study seeks to determine whether Smarcc1 mediates GLI repression through chromatin compaction in the limb. Methods: To determine if Smarcc1 mediated GLI repression through chormatin compaction, we used genomic approached to determine changes in chromatin accessibility in control and Smarcc1-conditional mutants. We performed ATAC-seq on individually genotyped anterior forelimbs at E11.5 (40-48s) on control (2 replicates) and PrxCre/+;Smarcc1c/c (3 replicates) embryos. From this experiment we identified ~10,000 differentially accessible regions (FDR<0.05). Results: We find that SMARCC1 is required to maintain chromatin accessibility at thousands of regions within the mouse limb, including most HH-responsive GLI enhancers
2024-02-03 | GSE224506 | GEO
Project description:Purpose: Most Hedgehog responsive gene expression is mediated through GLI de-repression. Additionally GLI -repression is proposed to play roles in limb pre-patterning before HH pathway activation. This study evaluates if GLI repression is established prior to HH pathway activation. Methods: To determine if GLI-repression is established prior to pathway activation, we used genomic approaches to study GLI-mediated repression using the mouse developing limb as a model. We identified pre-HH (E9.25, 21-23S) and post-HH (E10.5, 32-25S) GLI3 binding regions using CUT&RUN for endogenous FLAG-tagged GLI3 proteins. Using a combination of ChIP-seq, CUT&RUN, CUT&Tag, ATAC-seq and RNA-seq, we tested whether loss of Gli3 prior to HH signaling was able to de-repress genes and enhancers, as it does after HH signaling. Results: Prior to HH signaling, GLI3 binds to poised, accessible regions with histone deacetylase (HDAC) proteins, similar to post-HH signaling. Despite GLI3 binding to most regions as it does in the post-HH limb, loss of Gli3 is unable to prematurely active target genes or enhancers. Furthermore, we find that GLI3-dependent chromatin compaction does not occur until roughly 10 hours after HH signaling would have normally been induced. Collectively, these results support that GLI repressor proteins are inert prior to HH pathway activation.
2022-01-21 | GSE178838 | GEO
Project description:This SuperSeries is composed of the SubSeries listed below.
2020-01-21 | GSE108880 | GEO
Project description:Purpose: The response to Hedgehog signaling in the limb is driven by GLI bound enhancers and the majority of Hh targets in the developing limb bud are regulated solely by the activity of GLI-repressor. Currently, we do not have a comprehensive understanding of how GLI bound enhancers respond to Hedgehog signaling. The goal of this study is to identify how GLI bound enhancers are regulated by Hedgehog signaling and specifically by GLI-repressor. Methods: ATAC-seq was done in embryonic day 10.5 posterior limb buds from control and Shh-null embryos to identify GLI enhancers that change chromatin accessibility in response to Hedgehog signaling. Results: We found that Hedgehog signaling regulates the chromatin accessibility of a subset of GLI binding regions. This subset of GLI bound enhancers has reduced accessibility in the absence of Hedgehog signaling and largely overlaps with GLI enhancers that also have reduced H3K27ac in the absence of Hedgehog signaling.
2020-01-21 | GSE107877 | GEO
Project description:Aberrant activation of Hedgehog (HH) signaling has been identified as a key etiologic factor of many human malignancies. Signal strength, target gene specificity, and oncogenic activity of HH signaling profoundly depend on interactions with other pathways such as epidermal growth factor receptor-mediated signaling which has been shown to cooperate with HH/GLI in basal cell carcinoma and pancreatic cancer. We demonstrate that the human medulloblastoma cell line Daoy possesses a fully inducible endogenous HH pathway. Treatment of Daoy cells with Sonic Hedgehog or Smoothened agonist induced expression of GLI1 protein and prevented processing of GLI3 to its repressor form. To study interactions between HH- and EGF-induced signaling in greater detail, time-resolved measurements were carried out and analyzed on the transcriptomic as well as proteomic level. Daoy cells responded to the co-treatment by downregulating GLI1, PTCH, and HHIP on the transcript level which was also seen when Amphiregulin (AREG) was used instead of EGF. The finding that EGFR signaling silences proteins acting as negative regulators of HH signaling is firstly described here as a novel crosstalk mechanism. Furthermore, combined EGFR/HH signaling maintains high GLI1 protein levels contrasting its downregulation on the transcript level. On the other hand, high level synergism was observed with respect to a strong and significant upregulation of numerous canonical EGF-targets with putative tumor-promoting properties such as MMP7, VEGFA, and IL-8. In conclusion, synergistic effects between EGFR and HH signaling can selectively induce a switch from a canonical HH/GLI profile to a modulated specific target gene profile pointing to more wide-spread, yet context-dependent, interactions between HH/GLI and growth factor receptor signaling in human malignancies. To study interactions between HH- and EGF-induced signaling, time-resolved measurements were carried out over a period of 24 h at 14 different time points after stimulation by EGF with and without additional stimulation by SHH. Furthermore, as a control, cells without any stimulation by EGF and SHH (control) and cells in the presents of SHH were analyzed. Overall, three biological replicates of 60 different treatment/timepoints were analyzed yielding 180 different samples.
2014-07-31 | E-GEOD-46045 | biostudies-arrayexpress
Project description:The Hedgehog signaling pathway is essential for the maintenance and response of several types of stem cells. To study the transcriptional response of stem cells to HH signaling, we searched for proteins binding to GLI proteins, the transcriptional effectors of the HH pathway in mouse embryonic stem (ES) cells. We purified GLI protein complex from an ES cell line that contained a tamoxifen-inducible 3XFLAG-tagged GLI3 repressor allele by anti-FLAG immunoprecipitation and several novel GLI co-factors were identified in the complex by subsequent mass spectrometry analysis.
2016-02-04 | PXD002494 | Pride
Project description:Aberrant activation of Hedgehog (HH) signaling has been identified as a key etiologic factor of many human malignancies. Signal strength, target gene specificity, and oncogenic activity of HH signaling profoundly depend on interactions with other pathways such as epidermal growth factor receptor-mediated signaling which has been shown to cooperate with HH/GLI in basal cell carcinoma and pancreatic cancer. We demonstrate that the human medulloblastoma cell line Daoy possesses a fully inducible endogenous HH pathway. Treatment of Daoy cells with Sonic Hedgehog or Smoothened agonist induced expression of GLI1 protein and prevented processing of GLI3 to its repressor form. To study interactions between HH- and EGF-induced signaling in greater detail, time-resolved measurements were carried out and analyzed on the transcriptomic as well as proteomic level. Daoy cells responded to the co-treatment by downregulating GLI1, PTCH, and HHIP on the transcript level which was also seen when Amphiregulin (AREG) was used instead of EGF. The finding that EGFR signaling silences proteins acting as negative regulators of HH signaling is firstly described here as a novel crosstalk mechanism. Furthermore, combined EGFR/HH signaling maintains high GLI1 protein levels contrasting its downregulation on the transcript level. On the other hand, high level synergism was observed with respect to a strong and significant upregulation of numerous canonical EGF-targets with putative tumor-promoting properties such as MMP7, VEGFA, and IL-8. In conclusion, synergistic effects between EGFR and HH signaling can selectively induce a switch from a canonical HH/GLI profile to a modulated specific target gene profile pointing to more wide-spread, yet context-dependent, interactions between HH/GLI and growth factor receptor signaling in human malignancies.
2014-07-31 | GSE46045 | GEO
Project description:Transcriptional repression needs to be rapidly reversible during embryonic development. This extends to the Hedgehog pathway, which primarily serves to counter GLI repression by processing GLI proteins into transcriptional activators. In investigating the mechanisms underlying GLI repression, we find that a subset of GLI binding regions, termed HH-responsive enhancers, specifically loses acetylation in the absence of HH signaling. These regions are highly enriched around HH target genes and primarily drive HH-specific transcriptional activity in the mouse limb bud. They also retain H3K27ac enrichment in limb buds devoid of GLI activator and repressor, indicating that their activity is primarily regulated by GLI repression. Furthermore, the Polycomb repression complex is not active at most of these regions, suggesting it is not a major mechanism of GLI repression. We propose a model for tissue-specific enhancer activity in which an HDAC-associated GLI repression complex regulates target genes by altering the acetylation status at enhancers.
| S-EPMC6986877 | biostudies-literature
Project description:GLI transcriptional repression is inert prior to HH pathway activation
| PRJNA741224 | ENA
Project description:Sonic hedgehog (Shh) signals via Gli transcription factors to direct digit number and identity in the vertebrate limb. We have characterized the Gli-dependent cis-regulatory network through a combination of whole genome ChIP-on-chip and transcriptional profiling of the developing mouse limb. These analyses identified approximately 5,000 high quality Gli3 binding sites, including all known Gli-dependent enhancers. Discrete binding regions exhibit a higher-order clustering, highlighting the complexity of cis-regulatory interactions. Further, Gli3 binds inertly to previously identified neural-specific Gli enhancers, demonstrating the accessibility of their cis-regulatory elements. Intersection of DNA binding data with gene expression profiles predicted 205 putative limb target genes. A subset of putative cis-regulatory regions were analyzed in transgenic embryos, establishing Blimp1 as a direct Gli target and identifying Gli-activator signaling in a direct, long-range regulation of the BMP antagonist Gremlin. In contrast, a long range silencer cassette downstream of Hand2 likely mediates Gli3 repression in the anterior limb. These studies provide the first comprehensive characterization of the transcriptional output of a Shh-patterning process in the mammalian embryo and a framework for elaborating regulatory networks in the developing limb. This SuperSeries is composed of the SubSeries listed below.
2008-09-15 | GSE11077 | GEO