SUVH1, a histone methyltransferase, is required for the expression of genes targeted by DNA methylation
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ABSTRACT:
ORGANISM(S): Arabidopsis thaliana
PROVIDER: GSE64600 | GEO | 2017/02/09
SECONDARY ACCESSION(S): PRJNA271395
REPOSITORIES: GEO
Similar Datasets
Project description:Epigenetic regulation is important for organismal development and response to the environment. Alteration in epigenetic status has been known mostly from the perspective of enzymatic actions of DNA methylation and/or histone modifications. In a genetic screen for cellular factors involved in preventing epigenetic silencing, we isolated an Arabidopsis mutant defective in SAC3B, a component of the conserved TREX-2 complex that couples mRNA transcription with nuleo-cytoplasmic export. Arabidopsis SAC3B dysfunction causes gene silencing at transgenic and endogenous loci, accompanied by elevation in the repressive histone mark H3K9me2 and by reduction in RNA polymerase Pol II occupancy. SAC3B dysfunction does not alter promoter DNA methylation level of the transgene d35S::LUC, although the DNA demethylase ROS1 is also required for d35S::LUC anti-silencing. THP1 and NUA were identified as SAC3B-associated proteins whose mutations also caused d35S::LUC silencing. RNA-DNA hybrid exists at the repressed loci but is unrelated to gene suppression by the sac3b mutation. Genomewide analyses demonstrated minor but clear involvement of SAC3B in regulating siRNAs and DNA methylation, particularly at a group of TAS and TAS-like loci. Together our results revealed not only a critical role of mRNA-export factors in transcriptional anti-silencing but also the contribution of SAC3B in shaping plant epigenetic landscapes.
2016-11-02 | GSE89433 | GEO
Project description:DNA methylation and histone H3 lysine 9 dimethylation (H3K9me2) are important epigenetic repression marks for silencing transposons in heterochromatin and regulating gene expression in plant development. However, the mechanistic relationship to other repressive marks, such as histone H3 lysine 27 trimethylation (H3K27me3), is unclear. OsFIE1 (Fertilization Independent Endosperm 1) encodes an Esc-like core component of the Polycomb repressive complex 2 (PRC2), which is involved in H3K27me3-mediated gene repression. Here, we identify a gain-of-function epi-allele (Epi-df) of rice OsFIE1; this allele exhibits a dwarf stature and various floral defects that are inherited in a dominant fashion. We found that Epi-df has no changes in its nucleotide sequence, but is hypo-methylated in the promoter and the 5' region of OsFIE1 and has reduced H3K9me2 and increased H3K4me3. In Epi-df, OsFIE1 was ectopically expressed and its imprinting status was disrupted. OsFIE1 interacted with rice E(z) homologs, consistent with its role in H3K27me3 repression. Ectopic expression of OsFIE1 in Epi-df resulted in alteration of H3K27me3 levels in hundreds of genes. Therefore, this work identifies a novel epi-allele involved in H3K27me3-mediated gene repression, that itself is highly regulated by histone H3K9me2, thereby shedding light on the link between two important epigenetic marks regulating rice development. We report the application of ChIP-Seq technology for high-throughput profiling of histone modifications in WT (wild type) and Epi-df (mutant). We demonstrate that the H3K27me3 status is perturbed at target genes and leads to mis-regulated expression in Epi-df.
2013-12-04 | E-GEOD-40674 | biostudies-arrayexpress
Project description:DNA methylation and histone H3 lysine 9 dimethylation (H3K9me2) are important epigenetic repression marks for silencing transposons in heterochromatin and regulating gene expression in plant development. However, the mechanistic relationship to other repressive marks, such as histone H3 lysine 27 trimethylation (H3K27me3), is unclear. OsFIE1 (Fertilization Independent Endosperm 1) encodes an Esc-like core component of the Polycomb repressive complex 2 (PRC2), which is involved in H3K27me3-mediated gene repression. Here, we identify a gain-of-function epi-allele (Epi-df) of rice OsFIE1; this allele exhibits a dwarf stature and various floral defects that are inherited in a dominant fashion. We found that Epi-df has no changes in its nucleotide sequence, but is hypo-methylated in the promoter and the 5' region of OsFIE1 and has reduced H3K9me2 and increased H3K4me3. In Epi-df, OsFIE1 was ectopically expressed and its imprinting status was disrupted. OsFIE1 interacted with rice E(z) homologs, consistent with its role in H3K27me3 repression. Ectopic expression of OsFIE1 in Epi-df resulted in alteration of H3K27me3 levels in hundreds of genes. Therefore, this work identifies a novel epi-allele involved in H3K27me3-mediated gene repression, that itself is highly regulated by histone H3K9me2, thereby shedding light on the link between two important epigenetic marks regulating rice development.
2013-12-04 | GSE40674 | GEO
Project description:Heterochromatin is a tightly packed form of DNA, which is associated with histone 3 lysine 9 methylation (H3K9me). Here, we identify an H3K9me2 binding protein, Agenet domain (AGD)-containing protein 1 (AGDP1), in Arabidopsis thaliana. Our biochemical studies revealed that the AGDP1 can specifically recognize the H3K9me2 marks by the three pairs of tandem-AGDs. We determined the crystal structure of the AGD12 of Raphanus sativus AGDP1 in complex with an H3K9me2 peptide. In the complex, the histone peptide adopts a unique helical conformation. AGD12 employs a newly defined interacting interface to specifically recognize the H3K4me0 and H3K9me2 marks. In addition, we found that AGDP1 is required for transcriptional gene silencing, non-CG DNA methylation, and H3K9 dimethylation. Our ChIP-seq data showed that AGDP1 is enriched in TE regions and associated with the heterochromatin marks. Our findings suggest that, as a heterochromatin binding protein, AGDP1 links H3K9me2 to DNA methylation in heterochromatin regions.
2018-10-23 | GSE111609 | GEO
Project description:Histone modifications associated with gene silencing typically mark large contiguous regions of the genome forming repressive chromatin domain structures. Since the repressive domains exist in close proximity to active regions, maintenance of domain structure is critically important. This study shows that nickel, a nonmutagenic carcinogen, can disrupt histone H3 lysine 9 dimethylation (H3K9me2) domain structures genome-wide, resulting in spreading of H3K9me2 marks into the active regions, which is associated with gene silencing. Our results suggest inhibition of DNA binding of the insulator protein CCCTC-binding factor (CTCF) at the H3K9me2 domain boundaries as a potential reason for H3K9me2 domain disruption. These findings have major implications in understanding chromatin dynamics and the consequences of chromatin domain disruption during pathogenesis. Investigations into the genomic landscape of histone modifications in heterochromatic regions have revealed histone H3 lysine 9 dimethylation (H3K9me2) to be important for differentiation and maintaining cell identity. H3K9me2 is associated with gene silencing and is organized into large repressive domains that exist in close proximity to active genes, indicating the importance of maintenance of proper domain structure. Here we show that nickel, a nonmutagenic environmental carcinogen, disrupted H3K9me2 domains, resulting in the spreading of H3K9me2 into active regions, which was associated with gene silencing. We found weak CCCTC-binding factor (CTCF)-binding sites and reduced CTCF binding at the Ni-disrupted H3K9me2 domain boundaries, suggesting a loss of CTCF-mediated insulation function as a potential reason for domain disruption and spreading. We furthermore show that euchromatin islands, local regions of active chromatin within large H3K9me2 domains, can protect genes from H3K9me2-spreadingM-bM-^@M-^Sassociated gene silencing. These results have major implications in understanding H3K9me2 dynamics and the consequences of chromatin domain disruption during pathogenesis.
2014-09-24 | E-GEOD-56053 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the SubSeries listed below. Histone modifications associated with gene silencing typically mark large contiguous regions of the genome forming repressive chromatin domain structures. Since the repressive domains exist in close proximity to active regions, maintenance of domain structure is critically important. This study shows that nickel, a nonmutagenic carcinogen, can disrupt histone H3 lysine 9 dimethylation (H3K9me2) domain structures genome-wide, resulting in spreading of H3K9me2 marks into the active regions, which is associated with gene silencing. Our results suggest inhibition of DNA binding of the insulator protein CCCTC-binding factor (CTCF) at the H3K9me2 domain boundaries as a potential reason for H3K9me2 domain disruption. These findings have major implications in understanding chromatin dynamics and the consequences of chromatin domain disruption during pathogenesis.
2014-09-24 | GSE56053 | GEO
Project description:DNA methylation is a chromatin modification that is associated with gene silencing in eukaryotic organisms. Although pathways controlling the establishment, maintenance and removal of DNA methylation have been identified, relatively little is understood about how DNA methylation influences gene expression. Using complementary genetic and biochemical approaches we identified a protein complex that antagonizes the transcriptional gene silencing of two LUCIFERASE (LUC) reporters in a manner that requires DNA methylation. At its core, this complex contains LOW IN LUCIFERASE EXPRESSION (LIL), an α-crystallin domain protein, and METHYL-CpG-BINDING DOMAIN 7 (MBD7), a protein previously associated with DNA methylation. At the LUC reporters, loss of MBD7 or LIL resulted in decreased LUC expression concomitant with modest, but reproducible increases in DNA methylation that can be phenocopied by DNA demethylase mutants. These findings are consistent with other reports and reveal a genetic connection between MBD7, LIL and DNA demethylation. However, we found that the hyper-methylation and gene expression phenotypes at a LUC reporter can be genetically uncoupled, demonstrating that changes in DNA methylation alone are not sufficient to silence LUC expression, and suggesting a role for the MBD7-LIL complex downstream of DNA methylation. Consistent with this hypothesis, our more extensive analysis of DNA methylation in mbd7 and lil mutants revealed only a small number of hyper-methylated loci genome wide. Furthermore, these loci displayed minimal overlap with demethylase targets, suggesting that, in general, the DNA demethylation machinery does not function in a manner dependent on the MBD7-LIL complex. Taken together, our findings place the MBD7-LIL complex amongst a small number of factors that regulate gene expression without causing significant changes in DNA methylation. This complex, however, is unique in that it functions to suppress, rather than enforce the silencing effects of DNA methylation, enabling gene expression of several transgene reporters despite high levels of promoter methylation.
2017-04-26 | GSE83355 | GEO
Project description:DNA methylation is a chromatin modification that is associated with gene silencing in eukaryotic organisms. Although pathways controlling the establishment, maintenance and removal of DNA methylation have been identified, relatively little is understood about how DNA methylation influences gene expression. Using complementary genetic and biochemical approaches we identified a protein complex that antagonizes the transcriptional gene silencing of two LUCIFERASE (LUC) reporters in a manner that requires DNA methylation. At its core, this complex contains LOW IN LUCIFERASE EXPRESSION (LIL), an α-crystallin domain protein, and METHYL-CpG-BINDING DOMAIN 7 (MBD7), a protein previously associated with DNA methylation. At the LUC reporters, loss of MBD7 or LIL resulted in decreased LUC expression concomitant with modest, but reproducible increases in DNA methylation that can be phenocopied by DNA demethylase mutants. These findings are consistent with other reports and reveal a genetic connection between MBD7, LIL and DNA demethylation. However, we found that the hyper-methylation and gene expression phenotypes at a LUC reporter can be genetically uncoupled, demonstrating that changes in DNA methylation alone are not sufficient to silence LUC expression, and suggesting a role for the MBD7-LIL complex downstream of DNA methylation. Consistent with this hypothesis, our more extensive analysis of DNA methylation in mbd7 and lil mutants revealed only a small number of hyper-methylated loci genome wide. Furthermore, these loci displayed minimal overlap with demethylase targets, suggesting that, in general, the DNA demethylation machinery does not function in a manner dependent on the MBD7-LIL complex. Taken together, our findings place the MBD7-LIL complex amongst a small number of factors that regulate gene expression without causing significant changes in DNA methylation. This complex, however, is unique in that it functions to suppress, rather than enforce the silencing effects of DNA methylation, enabling gene expression of several transgene reporters despite high levels of promoter methylation.
2017-05-05 | GSE59639 | GEO
Project description:DNA methylation is a chromatin modification that is associated with gene silencing in eukaryotic organisms. Although pathways controlling the establishment, maintenance and removal of DNA methylation have been identified, relatively little is understood about how DNA methylation influences gene expression. Using complementary genetic and biochemical approaches we identified a protein complex that antagonizes the transcriptional gene silencing of two LUCIFERASE (LUC) reporters in a manner that requires DNA methylation. At its core, this complex contains LOW IN LUCIFERASE EXPRESSION (LIL), an α-crystallin domain protein, and METHYL-CpG-BINDING DOMAIN 7 (MBD7), a protein previously associated with DNA methylation. At the LUC reporters, loss of MBD7 or LIL resulted in decreased LUC expression concomitant with modest, but reproducible increases in DNA methylation that can be phenocopied by DNA demethylase mutants. These findings are consistent with other reports and reveal a genetic connection between MBD7, LIL and DNA demethylation. However, we found that the hyper-methylation and gene expression phenotypes at a LUC reporter can be genetically uncoupled, demonstrating that changes in DNA methylation alone are not sufficient to silence LUC expression, and suggesting a role for the MBD7-LIL complex downstream of DNA methylation. Consistent with this hypothesis, our more extensive analysis of DNA methylation in mbd7 and lil mutants revealed only a small number of hyper-methylated loci genome wide. Furthermore, these loci displayed minimal overlap with demethylase targets, suggesting that, in general, the DNA demethylation machinery does not function in a manner dependent on the MBD7-LIL complex. Taken together, our findings place the MBD7-LIL complex amongst a small number of factors that regulate gene expression without causing significant changes in DNA methylation. This complex, however, is unique in that it functions to suppress, rather than enforce the silencing effects of DNA methylation, enabling gene expression of several transgene reporters despite high levels of promoter methylation.
2017-05-05 | GSE83557 | GEO
Project description:DNA methylation generally functions as a repressive transcriptional signal, but it is also known to activate gene expression. In either case, the downstream factors remain largely unknown. By using comparative interactomics, we isolated proteins in Arabidopsis thaliana that associate with methylated DNA. Two SU(VAR)3-9 homologs, the transcriptional antisilencing factor SUVH1, and SUVH3, were among the methyl reader candidates. SUVH1 and SUVH3 bound methylated DNA in vitro, were associated with euchromatic methylation in vivo, and formed a complex with two DNAJ domain-containing homologs, DNAJ1 and DNAJ2. Ectopic recruitment of DNAJ1 enhanced gene transcription in plants, yeast, and mammals. Thus, the SUVH proteins bind to methylated DNA and recruit the DNAJ proteins to enhance proximal gene expression, thereby counteracting the repressive effects of transposon insertion near genes.
2018-12-06 | GSE108414 | GEO