CG dinucleotides enhance promoter activity independent of DNA methylation
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE116704 | GEO | 2019/01/20
REPOSITORIES: GEO
Similar Datasets
Project description:CpG island elements are associated with most mammalian gene promoters, yet how they contribute to gene regulation remains poorly understood. Recently it has become clear that a subset of CpG islands in embryonic stem cells can act as polycomb response elements and are recognized by the polycomb silencing systems to regulate the expression of genes involved in pluripotency and early developmental transcription programs. How CpG islands function mechanistically as nucleation sites for polycomb repressive complexes remains unknown. Here we discover that the KDM2B protein, by virtue of its ZF-CxxC DNA binding domain, specifically recognizes non-methylated DNA in CpG islands elements genome-wide. Through a physical interaction with the polycomb repressive complex 1 (PRC1), KDM2B targets PRC1 to CpG islands where it contributes to H2AK119ub1 and gene repression at a subset of polycomb targets. Unexpectedly, we also find that CpG islands are occupied by low levels of PRC1 throughout the genome, suggesting that the KDM2B-PRC1 complex may sample CpG island associated genes for susceptibility to polycomb mediated silencing. These observations demonstrate an unexpected and direct link between recognition of CpG islands by KDM2B and targeting of the polycomb repressive system. This provides the basis for a new model describing the functionality of CpG islands as mammalian PREs.
2012-12-26 | GSE40860 | GEO
Project description:CpG island elements are associated with most mammalian gene promoters, yet how they contribute to gene regulation remains poorly understood. Recently it has become clear that a subset of CpG islands in embryonic stem cells can act as polycomb response elements and are recognized by the polycomb silencing systems to regulate the expression of genes involved in pluripotency and early developmental transcription programs. How CpG islands function mechanistically as nucleation sites for polycomb repressive complexes remains unknown. Here we discover that the KDM2B protein, by virtue of its ZF-CxxC DNA binding domain, specifically recognizes non-methylated DNA in CpG islands elements genome-wide. Through a physical interaction with the polycomb repressive complex 1 (PRC1), KDM2B targets PRC1 to CpG islands where it contributes to H2AK119ub1 and gene repression at a subset of polycomb targets. Unexpectedly, we also find that CpG islands are occupied by low levels of PRC1 throughout the genome, suggesting that the KDM2B-PRC1 complex may sample CpG island associated genes for susceptibility to polycomb mediated silencing. These observations demonstrate an unexpected and direct link between recognition of CpG islands by KDM2B and targeting of the polycomb repressive system. This provides the basis for a new model describing the functionality of CpG islands as mammalian PREs. ChIP-Seq to compare KDM2A vs. KDM2B genome-wide binding profiles and to understand the contribution of KDM2B to RING1B nucleation. Binding of Kdm2a and Kdm2b to the genome was examined in wildtype mESC, and Kdm2b and Ring1b in mESC where Kdm2b has been stably knocked down by shRNA.
2012-12-26 | E-GEOD-40860 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the following subset Series: GSE38560: CpG islands and GC content dictate nucleosome depletion in a transcription independent manner at mammalian promoters (RNA-seq) GSE38561: CpG islands and GC content dictate nucleosome depletion in a transcription independent manner at mammalian promoters (ChIP-seq) GSE38562: CpG islands and GC content dictate nucleosome depletion in a transcription independent manner at mammalian promoters (genomic SEQ) GSE38563: CpG islands and GC content dictate nucleosome depletion in a transcription independent manner at mammalian promoters (MNase-seq) GSE38564: CpG islands and GC content dictate nucleosome depletion in a transcription independent manner at mammalian promoters (5) Refer to individual Series
2012-06-11 | E-GEOD-38577 | biostudies-arrayexpress
Project description:Methylation is a repressive modification of DNA prevalent throughout mammalian genomes yet mostly absent at CG rich stretches referred to as CGI. Here we identify their building principles by parallel genomic targeting of sequence libraries. Iterative insertions generated over 3,000 variants of genome-derived and artificial sequences at the same genomic site. Single molecule profiling of the methylation status of this collection allowed modeling the contribution of CG content and DNA binding factors towards the unmethylated state. It made the surprising prediction that the majority of CGs within endogenous islands are susceptible to methylation changes modulated by the presence of transcription factors, which is indeed confirmed by genome-wide methylation dynamics during multiple cellular differentiations. Our model further predicts blocks of constitutively unmethylated CGs independent from TF binding, which have a median size of ~300bp but are only present in half of all islands. Their constitutively unmethylated state is a hallmark of untransformed cells but their increased methylation is a specific and predictive feature of cancer. This study quantifies the two principal mechanisms governing methylation patterns in mammalian genomes. It provides a framework to interpret methylation data across normal and cancer samples and refines the concept of CpG islands. Methylation is a repressive modification of DNA prevalent throughout mammalian genomes yet mostly absent at CG rich stretches referred to as CGI. Here we identify their building principles by parallel genomic targeting of sequence libraries. Iterative insertions generated over 3,000 variants of genome-derived and artificial sequences at the same genomic site. Single molecule profiling of the methylation status of this collection allowed modeling the contribution of CG content and DNA binding factors towards the unmethylated state. It made the surprising prediction that the majority of CGs within endogenous islands are susceptible to methylation changes modulated by the presence of transcription factors, which is indeed confirmed by genome-wide methylation dynamics during multiple cellular differentiations. Our model further predicts blocks of constitutively unmethylated CGs independent from TF binding, which have a median size of ~300bp but are only present in half of all islands. Their constitutively unmethylated state is a hallmark of untransformed cells but their increased methylation is a specific and predictive feature of cancer. This study quantifies the two principal mechanisms governing methylation patterns in mammalian genomes. It provides a framework to interpret methylation data across normal and cancer samples and refines the concept of CpG islands. Libraries of DNA sequences were constructed either by mouse genome (129S6) or E.coli genome (NC_010473.1) subrepresentation or custom synthesis. DNA fragments were inserted into the genome of mouse embryonic stem cells by recombination mediated casette exchange (RMCE) at the B-globin locus. Methylation status of the inserted DNA sequences was profiled by bisulfite sequencing using a pair of universal primers flanking the fragments.
2014-09-30 | E-GEOD-51170 | biostudies-arrayexpress
Project description:In mammalian genomes, the vast majority of RNA polymerase II initiation events take place at CpG island promoters. Despite their relevance our understanding of their regulation remains limited. Here we identify Banp as the long sought-after TF that binds the orphan CGCG element in CpG islands by combining single-molecule footprinting with interaction proteomics. We show that Banp drives activity of CpG islands that control essential metabolic genes in the mouse and human genome. Banp binding is strongly repelled by DNA methylation of its motif in vitro and in vivo, which restricts most binding to CpG islands and accounts for its absence at aberrantly methylated CpG islands in cancer cells. Upon binding to an unmethylated motif, Banp opens chromatin and positions nucleosomes. These findings expand our understanding of CpG island gene regulation and put forth a model whereby CpG islands rely for their activity on methylation sensitive TFs capable of opening and organizing chromatin.
2021-05-17 | GSE155664 | GEO
Project description:In mammalian genomes, the vast majority of RNA polymerase II initiation events take place at CpG island promoters. Despite their relevance our understanding of their regulation remains limited. Here we identify Banp as the long sought-after TF that binds the orphan CGCG element in CpG islands by combining single-molecule footprinting with interaction proteomics. We show that Banp drives activity of CpG islands that control essential metabolic genes in the mouse and human genome. Banp binding is strongly repelled by DNA methylation of its motif in vitro and in vivo, which restricts most binding to CpG islands and accounts for its absence at aberrantly methylated CpG islands in cancer cells. Upon binding to an unmethylated motif, Banp opens chromatin and positions nucleosomes. These findings expand our understanding of CpG island gene regulation and put forth a model whereby CpG islands rely for their activity on methylation sensitive TFs capable of opening and organizing chromatin.
2021-05-17 | GSE155603 | GEO
Project description:In mammalian genomes, the vast majority of RNA polymerase II initiation events take place at CpG island promoters. Despite their relevance our understanding of their regulation remains limited. Here we identify Banp as the long sought-after TF that binds the orphan CGCG element in CpG islands by combining single-molecule footprinting with interaction proteomics. We show that Banp drives activity of CpG islands that control essential metabolic genes in the mouse and human genome. Banp binding is strongly repelled by DNA methylation of its motif in vitro and in vivo, which restricts most binding to CpG islands and accounts for its absence at aberrantly methylated CpG islands in cancer cells. Upon binding to an unmethylated motif, Banp opens chromatin and positions nucleosomes. These findings expand our understanding of CpG island gene regulation and put forth a model whereby CpG islands rely for their activity on methylation sensitive TFs capable of opening and organizing chromatin.
2021-05-17 | GSE155601 | GEO
Project description:In mammalian genomes, the vast majority of RNA polymerase II initiation events take place at CpG island promoters. Despite their relevance our understanding of their regulation remains limited. Here we identify Banp as the long sought-after TF that binds the orphan CGCG element in CpG islands by combining single-molecule footprinting with interaction proteomics. We show that Banp drives activity of CpG islands that control essential metabolic genes in the mouse and human genome. Banp binding is strongly repelled by DNA methylation of its motif in vitro and in vivo, which restricts most binding to CpG islands and accounts for its absence at aberrantly methylated CpG islands in cancer cells. Upon binding to an unmethylated motif, Banp opens chromatin and positions nucleosomes. These findings expand our understanding of CpG island gene regulation and put forth a model whereby CpG islands rely for their activity on methylation sensitive TFs capable of opening and organizing chromatin.
2021-05-17 | GSE155600 | GEO
Project description:In mammalian genomes, the vast majority of RNA polymerase II initiation events take place at CpG island promoters. Despite their relevance our understanding of their regulation remains limited. Here we identify Banp as the long sought-after TF that binds the orphan CGCG element in CpG islands by combining single-molecule footprinting with interaction proteomics. We show that Banp drives activity of CpG islands that control essential metabolic genes in the mouse and human genome. Banp binding is strongly repelled by DNA methylation of its motif in vitro and in vivo, which restricts most binding to CpG islands and accounts for its absence at aberrantly methylated CpG islands in cancer cells. Upon binding to an unmethylated motif, Banp opens chromatin and positions nucleosomes. These findings expand our understanding of CpG island gene regulation and put forth a model whereby CpG islands rely for their activity on methylation sensitive TFs capable of opening and organizing chromatin.
2021-05-17 | GSE155598 | GEO
Project description:Using 4C-Seq experimental procedure we have characterized, in cultured chicken lymphoid and erythroid cells, genome-wide patterns of spatial contacts of several CpG islands scattered along the chromosome 14. A clear tendency for interaction of CpG islands present within the same and different chromosomes has been observed. Accordingly, preferential spatial contacts between Sp1 binding motifs, and other GC-rich genomic elements including DNA sequence motifs capable to form G-quadruplexes were demonstrated. On the other hand, an anchor placed in gene/CpG islands-poor area was found to form spatial contacts with other gene/CpG islands-poor areas within chromosome 14 and other chromosomes. These results corroborate the two compartments model of interphase chromosome spatial organization and suggest that clustering of CpG islands harboring promoters and origins of DNA replication constitutes an important determinant of the 3D organization of eukaryotic genome in the cell nucleus. Using ChIP-Seq experimental procedure we have mapped genome-wide the CTCF deposition sites in chicken lymphoid and erythroid cells subjected to the 4C analysis. A good correlation between the density of these sites and the level of 4C signals was observed for the anchors located in CpG islands. It is thus possible that CTCF contributes to the clustering of CpG islands revealed in our experiments.
2014-03-01 | GSE51937 | GEO