Dynamic evolution of the heterochromatin sensing histone demethylase IBM1
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ABSTRACT:
PROVIDER: PRJNA1063220 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR27482800_1.fastq.gz | Fastqsanger.gz | |||
| SRR27482800_2.fastq.gz | Fastqsanger.gz | |||
| SRR27482801_1.fastq.gz | Fastqsanger.gz | |||
| SRR27482801_2.fastq.gz | Fastqsanger.gz | |||
| SRR27482802_1.fastq.gz | Fastqsanger.gz |
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Project description:Heterochromatin constitutes a fundamental aspect of genomes that is crucial for maintaining genome stability. In flowering plants, maintenance of heterochromatin relies on a positive feedback loop involving the histone 3 lysine nine methyltransferase (H3K9), KRYPTONITE (KYP), and the DNA methyltransferase, CHROMOMETHYLASE3 (CMT3). An H3K9 demethylase, INCREASED IN BONSAI METHYLATION 1 (IBM1), has evolved to modulate the activity of KYP-CMT3 within transcribed genes. The absence of IBM1 activity results in aberrant methylation of gene bodies, which is deleterious. This study demonstrates extensive genetic and gene expression variations in KYP, CMT3, and IBM1 within and between flowering plant species. IBM1 activity in Arabidopsis thaliana is uniquely regulated by the abundance of H3K9me2 in a repetitive sequence within an intron preceding the histone demethylase domain. This mechanism enables IBM1 to monitor global levels of H3K9me2. We discovered that the methylated intron is prevalent across flowering plants, however, its underlying sequence exhibits dynamic evolution. Its absence in species lacking gene body DNA methylation suggests its primary role in sensing H3K9me2 and preventing its integration into these constitutively expressed genes. Furthermore, our investigation uncovered Arabidopsis thaliana accessions resembling weak ibm1 mutants, several Brassicaceae species with reduced IBM1 expression, and a potential IBM1 deletion. Evolution towards reduced IBM1 activity in some flowering plants could explain the frequent natural occurrence of diminished or lost CMT3 activity, as cmt3 mutants in A. thaliana mitigate the deleterious effects of IBM1.
2024-05-10 | GSE252913 | GEO
Project description:Heterochromatin is a specialized form of chromatin that restricts access to DNA and inhibits genetic processes, including transcription and recombination. In Neurospora crassa, constitutive heterochromatin is characterized by trimethylation of lysine 9 on histone H3, hypoacetylation of histones, and DNA methylation. Here we explore whether the conserved histone demethylase, lysine-specific demethylase 1 (LSD1), regulates heterochromatin in Neurospora, and if so, how. Though LSD1 is implicated in heterochromatin regulation, its function is inconsistent across different systems; orthologs of LSD1 have been shown to either promote or antagonize heterochromatin expansion by removing H3K4me or H3K9me respectively. We identify three members of the Neurospora LSD complex (LSDC): LSD1, PHF1, and BDP-1, and strains deficient for any exhibit variable spreading of heterochromatin and establishment of new heterochromatin domains dispersed across the genome. Heterochromatin establishment outside of canonical domains in Neurospora share the unusual characteristic of DNA methylation-dependent H3K9me3; typically, H3K9me3 establishment is independent of DNA methylation. Consistent with this, the hyper-H3K9me3 phenotype of LSD1 knock-out strains is dependent on the presence of DNA methylation, as well as HCHC-mediated histone deacetylation, suggesting spreading is dependent on some feedback mechanism. Altogether, our results suggest LSD1 works in opposition to HCHC to maintain proper heterochromatin boundaries.
2021-07-21 | PXD017300 | Pride
Project description:Root microbiota is important for plant growth and fitness. Little is known about whether and how the assembly of root microbiota may be controlled by epigenetic regulation, which is crucial for gene transcription and genome stability. Here we show that dysfunction of the histone demethylase IBM1 (INCREASE IN BONSAI METHYLATION 1) in Arabidopsis thaliana substantially reshaped the root microbiota, with the majority of the significant amplicon sequence variants (ASVs) being decreased. Transcriptome analyses of plants grown in soil and in sterile growth-medium jointly disclosed salicylic acid (SA)-mediated autoimmunity and production of the defense metabolite camalexin in the ibm1 mutants. Analyses of genome-wide histone modifications and DNA methylation highlighted epigenetic modifications permissive for transcription at several important defense regulators. Consistently, ibm1 mutants showed increased resistance to the pathogen Pseudomonas syringae DC3000 with stronger immune responses. In addition, ibm1 showed substantially impaired plant growth-promotion in response to beneficial bacteria; the impairment was partially mimicked by exogenous application of SA to wild type plants, and by a null mutation of AGP19 that is important for cell expansion and that is repressed with DNA hyper methylation in ibm1. IBM1-dependent epigenetic regulation imposes strong and broad impacts on plant-microbe interactions and thereby shapes the assembly of root microbiota.
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Project description:The small RNA mediated DNA methylation (RdDM) is highly elaborated in Arabidopsis as an important epigenetic pathway controls expression of genes and multiple developmental processes. RDR2 and DCL3 are necessary factors to the 24-nt siRNA biogenesis and the RdDM pathway. Here, we find that IBM1 (increase in BONSAI methylation 1), a conserved JmjC family histone demethylase, could directly associated with the chromatin of RDR2 and DCL3. The IBM1 mutation induces hypermethylation on both H3K9 and DNA non-CG sites in these loci, and further represses their expression. The reduction of RDR2 and DCL3 may affect siRNA biogenesis in a locus-specific manner and disrupt the RdDM directed repression. It suggests an indirect way to regulate targets by IBM1 through control of siRNA biogenesis, and demonstrate the relationship between histone methylation and small RNAs. Genome-wide integrated mapping of mRNA transcripts and small RNAs, using whole plant of 10-days seedlings of the Columbia-0 wildtype and ibm1-3 mutant Arabidopsis thaliana.
2012-08-03 | E-GEOD-32284 | biostudies-arrayexpress
Project description:Epe1 histone demethylase restricts H3K9-methylation-dependent heterochromatin, preventing it from spreading over, and silencing, gene-containing regions in fission yeast. External stress induces an adaptive response allowing heterochromatin island formation that confers resistance on surviving wild-type lineages. Here we investigate the mechanism by which Epe1 is regulated in response to stress. Exposure to caffeine or antifungals results in Epe1 ubiquitylation and proteasome-dependent removal of the N-terminal 150 residues from Epe1, generating truncated tEpe1 which accumulates in the cytoplasm. Constitutive tEpe1 expression increases H3K9 methylation over several chromosomal regions, reducing expression of underlying genes and enhancing resistance. Reciprocally, constitutive non-cleavable Epe1 expression decreases resistance. tEpe1-mediated resistance requires a functional JmjC demethylase domain. Moreover, caffeine-induced Epe1-to-tEpe1 cleavage is dependent on an intact cell-integrity MAP kinase stress signalling pathway, mutations in which alter resistance. Thus, environmental changes provoke a mechanism that curtails the function of this key epigenetic modifier, allowing heterochromatin to reprogram gene expression, thereby bestowing resistance to some cells within a population. H3K9me-heterochromatin components are conserved in human and crop plant fungal pathogens for which a limited number of antifungals exist. Our findings reveal how transient heterochromatin-dependent antifungal resistant epimutations develop and thus inform on how they might be countered.
2022-10-13 | PXD030205 | Pride
Project description:Skeletal muscle possesses remarkable regenerative ability owing to the resident muscle stem cells (MuSCs). A prominent feature of quiescent MuSCs is a high content of heterochromatin. However, little is known about the mechanisms by which heterochromatin is maintained in MuSCs. We found that the mammalian Hairless (Hr) gene is expressed in quiescent MuSCs. Using a mouse model in which Hr can be specifically ablated in MuSCs, we demonstrate that Hr expression is critical for MuSC function and muscle regeneration. We show that Hr is a histone demethylase antagonist that preserves Histone 3 Lysine 9 trimethylation (H3K9me3) and maintains heterochromatin structure. Loss of Hr results in reduced H3K9me3 levels, reduced heterochromatin, increased susceptibility of MuSCs to genotoxic stress, and the accumulation of DNA damage. Our study not only elucidates the molecular mechanism by which Hr regulates histone demethylases, but also demonstrates the importance of heterochromatin maintenance in stem cell function.
2021-09-09 | GSE132220 | GEO
Project description:Skeletal muscle possesses remarkable regenerative ability owing to the resident muscle stem cells (MuSCs). A prominent feature of quiescent MuSCs is a high content of heterochromatin. However, little is known about the mechanisms by which heterochromatin is maintained in MuSCs. We found that the mammalian Hairless (Hr) gene is expressed in quiescent MuSCs. Using a mouse model in which Hr can be specifically ablated in MuSCs, we demonstrate that Hr expression is critical for MuSC function and muscle regeneration. We show that Hr is a histone demethylase antagonist that preserves Histone 3 Lysine 9 trimethylation (H3K9me3) and maintains heterochromatin structure. Loss of Hr results in reduced H3K9me3 levels, reduced heterochromatin, increased susceptibility of MuSCs to genotoxic stress, and the accumulation of DNA damage. Our study not only elucidates the molecular mechanism by which Hr regulates histone demethylases, but also demonstrates the importance of heterochromatin maintenance in stem cell function.
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Project description:A forward genetics screen led to the identification of the putative chromatin regulator EDM2 as a cellular anti-silencing factor and regulator of genome DNA methylation patterns. EDM2 contains a composite PHD finger domain that recognizes both active H3K4 and repressive H3K9 methylation marks at the intronic repeat elements in genes such as the histone H3K9 demethylase gene IBM1, and is necessary for maintaining the expression of these genes by promoting mRNA distal polyadenylation. Because of its role in maintaining IBM1 expression, EDM2 is required for preventing CHG methylation in the bodies of thousands of genes.Our results thus increase the understanding of anti-silencing, genome methylation patterns, and regulation of alternative RNA processing by intronic heterochromatin. Col-0 and edm2-4 total genomic DNAs are extracted from leaves and then subjected to bisulfite convertion and sequencing in accordance with standard protocol.
2013-10-29 | E-GEOD-51762 | biostudies-arrayexpress
Project description:A forward genetics screen led to the identification of the putative chromatin regulator EDM2 as a cellular anti-silencing factor and regulator of genome DNA methylation patterns. EDM2 contains a composite PHD finger domain that recognizes both active H3K4 and repressive H3K9 methylation marks at the intronic repeat elements in genes such as the histone H3K9 demethylase gene IBM1, and is necessary for maintaining the expression of these genes by promoting mRNA distal polyadenylation. Because of its role in maintaining IBM1 expression, EDM2 is required for preventing CHG methylation in the bodies of thousands of genes.Our results thus increase the understanding of anti-silencing, genome methylation patterns, and regulation of alternative RNA processing by intronic heterochromatin. Col-0 and edm2-4 total RNA are extracted from leaves and then polyA mRNAs are isolated for mRNA-seq.
2013-10-29 | E-GEOD-51763 | biostudies-arrayexpress
Project description:The small RNA mediated DNA methylation (RdDM) is highly elaborated in Arabidopsis as an important epigenetic pathway controls expression of genes and multiple developmental processes. RDR2 and DCL3 are necessary factors to the 24-nt siRNA biogenesis and the RdDM pathway. Here, we find that IBM1 (increase in BONSAI methylation 1), a conserved JmjC family histone demethylase, could directly associated with the chromatin of RDR2 and DCL3. The IBM1 mutation induces hypermethylation on both H3K9 and DNA non-CG sites in these loci, and further represses their expression. The reduction of RDR2 and DCL3 may affect siRNA biogenesis in a locus-specific manner and disrupt the RdDM directed repression. It suggests an indirect way to regulate targets by IBM1 through control of siRNA biogenesis, and demonstrate the relationship between histone methylation and small RNAs.
2012-08-03 | GSE32284 | GEO