Similar Datasets
Project description:Mechanistic basis for maintenance of CHG methylation in plants
| PRJNA749004 | ENA
Project description:DNA methylation is an evolutionarily conserved epigenetic mechanism essential for transposon silencing and heterochromatin assembly. In plants, DNA methylation widely occurs in the CG, CHG, and CHH (H = A, C, or T) contexts, with the maintenance of CHG methylation mediated by CMT3 chromomethylase. However, how CMT3 interacts with the chromatin environment for faithful maintenance of CHG methylation is unclear. Here we report structure-function characterization of the H3K9me2-directed maintenance of CHG methylation by CMT3 and its Zea mays ortholog ZMET2. Base-specific interactions and DNA deformation coordinately underpin the substrate specificity of CMT3 and ZMET2, while a bivalent readout of H3K9me2 and H3K18 allosterically stimulates substrate binding. Disruption of the interaction with DNA or H3K9me2/H3K18 led to loss of CMT3/ZMET2 activity in vitro and impairment of genome-wide CHG methylation in vivo. Together, our study uncovers how the intricate interplay of CMT3, repressive histone marks, and DNA sequence mediates heterochromatic CHG methylation.
| S-EPMC9256654 | biostudies-literature
Project description:DNA methylation and histone modification exert epigenetic control over gene expression. CHG methylation by CHROMOMETHYLASE3 (CMT3) depends on histone H3K9 dimethylation (H3K9me2), but the mechanism underlying this relationship is poorly understood. Here, we report multiple lines of evidence that CMT3 interacts with H3K9me2-containing nucleosomes. CMT3 genome locations nearly perfectly correlated with H3K9me2 and CMT3 stably associated with H3K9me2-containing nucleosomes. Crystal structures of maize CMT3 homologue, ZMET2, in complex with H3K9me2 peptides, showed that ZMET2 binds H3K9me2 via both BAH and chromo domains. The structures reveal an aromatic cage within both BAH and chromo domains as interaction interfaces that capture H3K9me2. Mutations that abolish either interaction disrupt CMT3 binding to nucleosomes, and show a complete loss of CMT3 activity in vivo. Our study establishes dual recognition of H3K9me2 marks by BAH and chromo domains, and reveals a novel mechanism of interplay between DNA methylation and histone modification.
2012-11-11 | GSE39097 | GEO
Project description:In many plant species, a subset of transcribed genes are characterized by strictly CG-context DNA methylation, referred to as gene body methylation (gbM). The mechanisms that establish gbM are unclear, yet flowering plant species naturally without gbM lack the DNA methyltransferase, CMT3, which maintains CHG (H=A, C, or T) and not CG methylation at constitutive heterochromatin. Here, we identify the mechanistic basis for gbM establishment by expressing CMT3 in a species naturally lacking CMT3. CMT3 expression reconstituted gbM through a progression of de novo CHG methylation on expressed genes, followed by the accumulation of CG methylation that could be inherited even following loss of the CMT3 transgene. Thus, gbM originates from the simultaneous targeting of loci by pathways that promote euchromatin and heterochromatin, which primes genes for the formation of stably inherited epimutations in the form of CG DNA methylation.
2019-08-06 | GSE128687 | GEO
Project description:DNA methylation is an evolutionarily conserved epigenetic mechanism essential for transposon silencing and heterochromatin assembly. In plants, Chromomethylase3 (CMT3) and CMT2 are the major DNA methyltransferases mediating DNA methylation on CHG and CHH (H = A, C or T), respectively, but the underlying mechanisms of how CMT3 and CMT2 methylate different contexts during evolution is poorly known. Here we reveal the mechanisms of CMT3 and CMT2 divergence in flowering plants. CMT2 originates from a duplication of the evolutionarily more ancient CMT3 and change of a key arginine residue recognizing CHG in CMT2 makes it lose CHG methylation activity in most flowering plants. Mutation of the residue to arginine in Arabidopsis (V1200R) greatly increases its methylation activity on CHG DNA. Besides different substrate specificity, CMT2 contains a long and disordered N-terminus compared with a short one in CMT3. The long N-terminus reduces protein stability, especially under high temperature. Moreover, CMT2 N-terminus is plastic to various natural mutations. Together, our study reveals the mechanisms of chromomethylase divergence for methylating different DNA contexts in plants and sheds light on understanding of plant evolution.
2024-11-08 | GSE247352 | GEO
Project description:In this work, we analyzed DNA methylation in rice male meiocyte, microspore and sperm and studied the function of a set of chromatin regulators during the process. The results indicate that that DNA methylation remodeling started after meiosis of the male meiocytes and that non-CG, particularly CHG, methylation is dynamically remodeling during rice male gametogenesis. The work reveals distinct function of DNA methyltransfesaes and histone demethylase in the remodeling of CHG methylation and suggests that the CHG methylation remodeling has functional significance for male gametogenesis and fertilization.
2023-06-24 | GSE235680 | GEO
Project description:DNA methylation and histone modification exert epigenetic control over gene expression. CHG methylation by CHROMOMETHYLASE3 (CMT3) depends on histone H3K9 dimethylation (H3K9me2), but the mechanism underlying this relationship is poorly understood. Here, we report multiple lines of evidence that CMT3 interacts with H3K9me2-containing nucleosomes. CMT3 genome locations nearly perfectly correlated with H3K9me2 and CMT3 stably associated with H3K9me2-containing nucleosomes. Crystal structures of maize CMT3 homologue, ZMET2, in complex with H3K9me2 peptides, showed that ZMET2 binds H3K9me2 via both BAH and chromo domains. The structures reveal an aromatic cage within both BAH and chromo domains as interaction interfaces that capture H3K9me2. Mutations that abolish either interaction disrupt CMT3 binding to nucleosomes, and show a complete loss of CMT3 activity in vivo. Our study establishes dual recognition of H3K9me2 marks by BAH and chromo domains, and reveals a novel mechanism of interplay between DNA methylation and histone modification. Investigation of genome-wide occupancy of CMT3 by ChIP-seq
2012-11-11 | E-GEOD-39097 | biostudies-arrayexpress
Project description:DNA methylation is an evolutionarily conserved epigenetic mechanism essential for transposon silencing and heterochromatin assembly. In plants, Chromomethylase3 (CMT3) and CMT2 are the major DNA methyltransferases mediating DNA methylation on CHG and CHH (H = A, C or T), respectively, but the underlying mechanisms of how CMT3 and CMT2 methylate different contexts during evolution is poorly known. Here we reveal the mechanisms of CMT3 and CMT2 divergence in flowering plants. CMT2 originates from a duplication of the evolutionarily more ancient CMT3 and change of a key arginine residue recognizing CHG in CMT2 makes it lose CHG methylation activity in most flowering plants. Mutation of the residue to arginine in Arabidopsis (V1200R) greatly increases its methylation activity on CHG DNA. Besides different substrate specificity, CMT2 contains a long and disordered N-terminus compared with a short one in CMT3. The long N-terminus reduces protein stability, especially under high temperature. Moreover, CMT2 N-terminus is plastic to various natural mutations. Together, our study reveals the mechanisms of chromomethylase divergence for methylating different DNA contexts in plants and sheds light on understanding of plant evolution.
2024-11-08 | GSE247353 | GEO
Project description:Function of CHG methylation dynamics in rice male gametogenesis
| PRJNA986895 | ENA
Project description:In Arabidopsis, CHG DNA methylation is controlled by the H3K9 methylation mark through a self-reinforcing loop between DNA methyltransferase CHROMOMETHYLASE3 (CMT3) and H3K9 histone methyltransferase KRYPTONITE/SUVH4 (KYP). We report on the structure of KYP in complex with methylated DNA, substrate H3 peptide and cofactor SAH, thereby defining the spatial positioning of the SRA domain relative to the SET domain. The methylated DNA is bound by the SRA domain with the 5mC flipped out of the DNA, while the H3(1-15) peptide substrate binds between the SET and post-SET domains, with the epsilon-ammonium of K9 positioned adjacent to bound SAH. These structural insights complemented by in vivo functional data on key mutants of residues lining the 5mC and H3K9-binding pockets within KYP, establish how methylated DNA recruits KYP to the histone substrate. Together, the structures of KYP and previously reported CMT3 complexes provide insights into molecular mechanisms linking DNA and histone methylation.
2014-08-01 | GSE57963 | GEO