Locus-specific control of the de novo DNA methylation pathway
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PROVIDER: PRJNA389306 | ENA |
REPOSITORIES: ENA
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Project description:Abstract: Cytosine DNA methylation plays crucial roles in gene regulation, transposon silencing, and diverse developmental processes. While methylation patterns are known to differ between cell-types, tissues, and disease states, how these differences arise remains poorly understood. In plants, DNA methylation is established via the RNA-directed DNA methylation pathway (RdDM), wherein 24-nucleotide small interfering RNAs (siRNAs) guide methylation at cognate genomic loci1. RNA POLYMERASE-IV (Pol-IV), a plant-specific polymerase, initiates the biogenesis of these methylation-targeting RNAs, thus understanding how Pol-IV is regulated is critical in determining how specific patterns of DNA methylation are generated. Here we show roles for four Pol-IV-associated factors, CLASSY (CLSY) 1-42,3, in both locus-specific and global regulation of Pol-IV function. Individually, each CLSY protein controls siRNA production and Pol-IV chromatin association at unique set of loci. This translates into locus-specific DNA methylation losses and the release of silencing. In addition to locus-specific effects, several layers of redundancy were identified: The clsy1,2 and clsy3,4 mutants act synergistically, regulating thousands more siRNA loci than the single mutants. Furthermore, the clsy1,2- and clsy3,4-dependent loci are mutually exclusive and geographically distinct, revealing a striking division of labor amongst the CLSY family. Finally, the clsy quadruple mutant causes global siRNA losses, demonstrating that Pol-IV is completely dependent on the CLSY family. Investigation into the mechanisms underlying the CLSY specificity revealed connections between clsy1,2- and clsy3,4-dependent loci and either SAWADEE HOMEODOMAIN HOMOLOG 1 or DNA METHYLTRANSFERASE 1, demonstrating a reliance on different chromatin modifications, H3K9 or CG DNA methylation, respectively4,5. Together, these findings not only shed light on Pol-IV function, but also reveal an additional layer of complexity to the RdDM pathway that enables the locus-specific control of DNA methylation patterns. Given the parallels between methylation systems in plants and mammals1, these findings will be informative for analogous processes in a broad range of organisms.
2018-04-14 | GSE99692 | GEO
Project description:Abstract: Cytosine DNA methylation plays crucial roles in gene regulation, transposon silencing, and diverse developmental processes. While methylation patterns are known to differ between cell-types, tissues, and disease states, how these differences arise remains poorly understood. In plants, DNA methylation is established via the RNA-directed DNA methylation pathway (RdDM), wherein 24-nucleotide small interfering RNAs (siRNAs) guide methylation at cognate genomic loci1. RNA POLYMERASE-IV (Pol-IV), a plant-specific polymerase, initiates the biogenesis of these methylation-targeting RNAs, thus understanding how Pol-IV is regulated is critical in determining how specific patterns of DNA methylation are generated. Here we show roles for four Pol-IV-associated factors, CLASSY (CLSY) 1-42,3, in both locus-specific and global regulation of Pol-IV function. Individually, each CLSY protein controls siRNA production and Pol-IV chromatin association at unique set of loci. This translates into locus-specific DNA methylation losses and the release of silencing. In addition to locus-specific effects, several layers of redundancy were identified: The clsy1,2 and clsy3,4 mutants act synergistically, regulating thousands more siRNA loci than the single mutants. Furthermore, the clsy1,2- and clsy3,4-dependent loci are mutually exclusive and geographically distinct, revealing a striking division of labor amongst the CLSY family. Finally, the clsy quadruple mutant causes global siRNA losses, demonstrating that Pol-IV is completely dependent on the CLSY family. Investigation into the mechanisms underlying the CLSY specificity revealed connections between clsy1,2- and clsy3,4-dependent loci and either SAWADEE HOMEODOMAIN HOMOLOG 1 or DNA METHYLTRANSFERASE 1, demonstrating a reliance on different chromatin modifications, H3K9 or CG DNA methylation, respectively4,5. Together, these findings not only shed light on Pol-IV function, but also reveal an additional layer of complexity to the RdDM pathway that enables the locus-specific control of DNA methylation patterns. Given the parallels between methylation systems in plants and mammals1, these findings will be informative for analogous processes in a broad range of organisms.
2018-04-14 | GSE99691 | GEO
Project description:Abstract: Cytosine DNA methylation plays crucial roles in gene regulation, transposon silencing, and diverse developmental processes. While methylation patterns are known to differ between cell-types, tissues, and disease states, how these differences arise remains poorly understood. In plants, DNA methylation is established via the RNA-directed DNA methylation pathway (RdDM), wherein 24-nucleotide small interfering RNAs (siRNAs) guide methylation at cognate genomic loci1. RNA POLYMERASE-IV (Pol-IV), a plant-specific polymerase, initiates the biogenesis of these methylation-targeting RNAs, thus understanding how Pol-IV is regulated is critical in determining how specific patterns of DNA methylation are generated. Here we show roles for four Pol-IV-associated factors, CLASSY (CLSY) 1-42,3, in both locus-specific and global regulation of Pol-IV function. Individually, each CLSY protein controls siRNA production and Pol-IV chromatin association at unique set of loci. This translates into locus-specific DNA methylation losses and the release of silencing. In addition to locus-specific effects, several layers of redundancy were identified: The clsy1,2 and clsy3,4 mutants act synergistically, regulating thousands more siRNA loci than the single mutants. Furthermore, the clsy1,2- and clsy3,4-dependent loci are mutually exclusive and geographically distinct, revealing a striking division of labor amongst the CLSY family. Finally, the clsy quadruple mutant causes global siRNA losses, demonstrating that Pol-IV is completely dependent on the CLSY family. Investigation into the mechanisms underlying the CLSY specificity revealed connections between clsy1,2- and clsy3,4-dependent loci and either SAWADEE HOMEODOMAIN HOMOLOG 1 or DNA METHYLTRANSFERASE 1, demonstrating a reliance on different chromatin modifications, H3K9 or CG DNA methylation, respectively4,5. Together, these findings not only shed light on Pol-IV function, but also reveal an additional layer of complexity to the RdDM pathway that enables the locus-specific control of DNA methylation patterns. Given the parallels between methylation systems in plants and mammals1, these findings will be informative for analogous processes in a broad range of organisms.
2018-04-14 | GSE99689 | GEO
Project description:Abstract: Cytosine DNA methylation plays crucial roles in gene regulation, transposon silencing, and diverse developmental processes. While methylation patterns are known to differ between cell-types, tissues, and disease states, how these differences arise remains poorly understood. In plants, DNA methylation is established via the RNA-directed DNA methylation pathway (RdDM), wherein 24-nucleotide small interfering RNAs (siRNAs) guide methylation at cognate genomic loci1. RNA POLYMERASE-IV (Pol-IV), a plant-specific polymerase, initiates the biogenesis of these methylation-targeting RNAs, thus understanding how Pol-IV is regulated is critical in determining how specific patterns of DNA methylation are generated. Here we show roles for four Pol-IV-associated factors, CLASSY (CLSY) 1-42,3, in both locus-specific and global regulation of Pol-IV function. Individually, each CLSY protein controls siRNA production and Pol-IV chromatin association at unique set of loci. This translates into locus-specific DNA methylation losses and the release of silencing. In addition to locus-specific effects, several layers of redundancy were identified: The clsy1,2 and clsy3,4 mutants act synergistically, regulating thousands more siRNA loci than the single mutants. Furthermore, the clsy1,2- and clsy3,4-dependent loci are mutually exclusive and geographically distinct, revealing a striking division of labor amongst the CLSY family. Finally, the clsy quadruple mutant causes global siRNA losses, demonstrating that Pol-IV is completely dependent on the CLSY family. Investigation into the mechanisms underlying the CLSY specificity revealed connections between clsy1,2- and clsy3,4-dependent loci and either SAWADEE HOMEODOMAIN HOMOLOG 1 or DNA METHYLTRANSFERASE 1, demonstrating a reliance on different chromatin modifications, H3K9 or CG DNA methylation, respectively4,5. Together, these findings not only shed light on Pol-IV function, but also reveal an additional layer of complexity to the RdDM pathway that enables the locus-specific control of DNA methylation patterns. Given the parallels between methylation systems in plants and mammals1, these findings will be informative for analogous processes in a broad range of organisms.
2018-04-14 | GSE99693 | GEO
Project description:This SuperSeries is composed of the SubSeries listed below.
2018-04-14 | GSE99694 | GEO
Project description:DNA methylation is essential for gene regulation, transposon silencing and imprinting. Although the generation of specific DNA methylation patterns is critical for these processes, how methylation is regulated at individual loci remains unclear. Here we show that a family of four putative chromatin remodeling factors, CLASSY (CLSY) 1-4, are required for both locus-specific and global regulation of DNA methylation in Arabidopsis thaliana. Mechanistically, these factors act in connection with RNA polymerase-IV (Pol-IV) to control the production of 24-nucleotide small interfering RNAs (24nt-siRNAs), which guide DNA methylation. Individually, the CLSYs regulate Pol-IV-chromatin association and 24nt-siRNA production at thousands of distinct loci, and together, they regulate essentially all 24nt-siRNAs. Depending on the CLSYs involved, this regulation relies on different repressive chromatin modifications to facilitate locus-specific control of DNA methylation. Given the conservation between methylation systems in plants and mammals, analogous pathways may operate in a broad range of organisms.
| S-EPMC6317521 | biostudies-literature
Project description:To investigate the role of de novo methylation by Clr4, we performed the reintroduction of Clr4 and ecopic insertion of lnc230
2024-01-01 | GSE223203 | GEO
Project description:Mycobacteria can synthesize NAD+ using either the de novo biosynthesis pathway or the salvage pathway. The deletion of the three genes involved specifically in the NAD+ de novo biosynthesis pathway in the human pathogen Mycobacterium tuberculosis had no effect on the growth of the strain in vivo. In contrast, the same deletion in the bovine pathogen Mycobacterium bovis resulted in a strain that could not grow in vivo and could only grow in vitro with substantial nicotinamide supplmentation. This striking difference was attributed to the known defect in the nicotinamidase PncA of M. bovis, since introducing the M. tuberculosis pncA gene into the M. bovis strain defective for de novo NAD+ biosynthesis restored growth in vitro and in vivo. This study demonstrates that NAD+ starvation is a cidal event in mycobacteria and confirms that enzymes common to the de novo and salvage pathways may be good drug targets. We also propose that simultaneously targeting both the salvage and the de novo NAD+ biosynthesis pathways represents a potentially effective way to treat infection with tubercle bacilli. To characterize the lethality induced by nicotinamide starvation transcriptional profiling of the auxotrophs was performed. Triplicate 50 mL cultures of M. tuberculosis and M. bovis Delta nadABC mutants were grown in 7H9 OADC glycerol 0.05% tween broth in 500 mL roller bottles to an OD600nm= 0.1 in a roller incubator at 37°C. The cells were washed 1x in PBS and resuspended in 50 mL 7H9 OADC glycerol 0.05% tween broth with or without 20mg/L nicotinamide and returned to the incubator. After 7 days, cultures were harvested. Three biological replicates of each of two species with one dye-flip each
2010-05-14 | E-GEOD-18909 | biostudies-arrayexpress
Project description:Cell cycle and metabolism are two major outputs controlled by circadian rhythm in many organisms. Here we show that the three processes were linked through inosine 5'-phosphate dehydrogenase (impdh), a rate-limiting enzyme in de novo purine synthesis. We using adult zebrafish as a model system,we applied a genome-wide transcriptome approach that allowed us to investigate circadian gene expression. The whole-genome transcriptome profiles of adult brain in time-series were assayed on Agilent zebrafish microarrays. We used a similar statistical method to identify zebrafish circadian genes (ZCOG) as our previous study in larval zebrafish. Three isoforms of impdh show strong circadian oscillations in different tissues of zebrafish. impdh1a contributes to the ocular development and pigment synthesis, impdh2 promotes and impdh1b delays the development. By limiting the GTP required by DNA synthesis, impdh2 contributes to the daily rhythm of S phase in cell cycle. Multiple enzymes in the de novo purine synthesis pathway show the same circadian oscillations with peaks similar to impdh2. The circadian expression of this pathway is conserved in mouse liver. In summary, we show that the circadian regulation of de novo purine synthesis that supplies crucial building blocks for DNA replication is critical for gating cell cycle in circadian rhythm. Adult zebrafish were sacrificed and dissected at 4h intervals starting at CT0 in both LD and DD conditions for 12 time points. Total RNA of individual zebrafish brain was extracted using Trizol (Invitrogen, Carlsbad, CA) according to the manufacturerM-bM-^@M-^Ys instruction. Microarrays were manufactured by Agilent Technologies (Agilent Technologies, Palo Alto, CA), containing 43,603 probes for zebrafish whole-genome transcriptional profiling.
2013-10-01 | E-GEOD-51277 | biostudies-arrayexpress
Project description:De novo methylation of CpG islands is seen in many tumors, but the general rules governing this process are not known. By analyzing DNA from tumors, as well as normal tissues, and by utilizing a wide range of published data, we have been able to identify a well-defined set of tumor targets, each of which has its own M-bM-^@M-^\coefficientM-bM-^@M-^] of methylation that is largely determined by its inherent relative ability to recruit the polycomb complex. This pattern is initially formed by a slow process of de novo methylation that occurs during aging and then undergoes expansion early in tumorigenesis, where it may play a role as an inhibitor of development-associated gene activation. We also demonstrate that DNA methylation patterns can be used to diagnose the primary tissue source of tumor metastases. CpG-methylated genomic DNA was enriched using a methyl-DNA immunoprecipitation (mDIP) assay. DNA from the input and bound (enriched) DNA for each sample were labeled and hybridized on the array to define the methylation state of each region.
2014-03-26 | E-GEOD-38142 | biostudies-arrayexpress