Genome-wide mapping of demethylase, REF6 binding targets and H3K27me3 marked regions as well as expression analysis in various Arabidopsis genetic backgrounds
Ontology highlight
ABSTRACT:
ORGANISM(S): Arabidopsis thaliana
PROVIDER: GSE106944 | GEO | 2018/07/09
REPOSITORIES: GEO
Similar Datasets
Project description:We report genome-wide binding targets of REF6, a H3K27me3 demethylase and also high-throughput profiling of histone modifications of H3K27me3 in Arabidopsis flowers. Using chromatin-immunoprecipitation followed by high-throughput sequencing, we mapped thousands of binding targets of REF6 in flowers and in addition, we used a second fixative, DSG to capture more indirect targets of REF6. In order to investigate the function of indirect binding of REF6 represented H3K27me3 demethylase, the binding targets of DNA binding domain deleted REF6 were identified in the triple mutant background in which REF6 and its two homologs were mutated. Meanwhile, the H3K27me3 marked regions in both wild type and triple mutant flowers were defined. By analyzing the differentially enriched H3K27me3 region and REF6 binding profile, we found that REF6 functions to determine the boundary of H3K27me3 regions. Comparison of binding profiles of REF6 in flowers and in seedlings (ref) revealed a tissue-specific binding manner. More importantly, we found that the indirect binding of REF6 is mediated by trans factors and this indirect binding is crucial for REF6 function, especially in reproductive organs in Arabidopsis. Our results provide novel molecular insights into REF6 functions.
2018-07-09 | GSE106942 | GEO
Project description:We report genome-wide binding targets of REF6, a H3K27me3 demethylase and also high-throughput profiling of histone modifications of H3K27me3 in Arabidopsis flowers. To further investigate the downstream targets of REF6 represented H3K27me3 demethylase, we performed RNA-seq using single, double mutant and triple mutant. Using chromatin-immunoprecipitation followed by high-throughput sequencing, we mapped thousands of binding targets of REF6 in flowers and in addition, we used a second fixative, DSG to capture more indirect targets of REF6. In order to investigate the function of indirect binding of REF6 represented H3K27me3 demethylase, the binding targets of DNA binding domain deleted REF6 were identified in the triple mutant background in which REF6 and its two homologs were mutated. Meanwhile, the H3K27me3 marked regions in both wild type and triple mutant flowers were defined. By analyzing the differentially enriched H3K27me3 region and REF6 binding profile, we found that REF6 functions to determine the boundary of H3K27me3 regions. Comparison of binding profiles of REF6 in flowers and in seedlings (ref) revealed a tissue-specific binding manner. More importantly, we found that the indirect binding of REF6 is mediated by trans factors and this indirect binding is crucial for REF6 function, especially in reproductive organs in Arabidopsis. Our results provide novel molecular insights into REF6 functions.
2018-07-09 | GSE106943 | GEO
Project description:Genome-wide mapping of demethylase, REF6 binding targets and H3K27me3 marked regions as well as expression analysis in various Arabidopsis genetic backgrounds
| PRJNA418497 | ENA
Project description:Genome-wide mapping of demethylase, REF6 binding targets and H3K27me3 marked regions in various Arabidopsis genetic backgrounds [ChIP-seq]
| PRJNA418657 | ENA
Project description:Genome-wide mapping of demethylase, REF6 binding targets and H3K27me3 marked regions as well as expression analysis in various Arabidopsis genetic backgrounds [RNA-seq]
| PRJNA418578 | ENA
Project description:Metformin, the first drug chosen to be tested in a clinical trial aimed to target the biology of aging per se, has been clinically exploited for decades in the absence of a complete understanding of its therapeutic targets or chemical determinants. We here outline a systematic chemoinformatics approach to computationally predict biomolecular targets of metformin. Using several structure- and ligand-based software tools and reference databases containing 1,300,000 chemical compounds and more than 9,000 binding sites protein cavities, we identified 41 putative metformin targets including several epigenetic modifiers such as the member of the H3K27me3-specific demethylase subfamily, KDM6A/UTX. AlphaScreen and AlphaLISA assays confirmed the ability of metformin to inhibit the demethylation activity of purified KDM6A/UTX enzyme. Structural studies revealed that metformin might occupy the same set of residues involved in H3K27me3 binding and demethylation within the catalytic pocket of KDM6A/UTX. Millimolar metformin augmented global levels of H3K27me3 in cultured cells, including reversion of global loss of H3K27me3 occurring in premature aging syndromes, irrespective of mitochondrial complex I or AMPK. Pharmacological doses of metformin in drinking water or intraperitoneal injection significantly elevated the global levels of H3K27me3 in the hepatic tissue of low-density lipoprotein receptor-deficient mice and in the tumor tissues of highly aggressive breast cancer xenograft-bearing mice. Moreover, nondiabetic breast cancer patients receiving oral metformin in addition to standard therapy presented an elevated level of circulating H3K27me3. Our biocomputational approach coupled to experimental validation reveals that metformin might directly regulate the biological machinery of aging by targeting core chromatin modifiers of the epigenome.
| S-EPMC6052472 | biostudies-literature
Project description:The roles of histone demethylation in the regulation of plant flowering, disease resistance, rhythmical response, and seed germination have been elucidated recently; however, how histone demethylation affects leaf senescence remains largely unclear. In this study, we exploited yeast one-hybrid (Y1H) to screen for the upstream regulators of NONYELLOWING1 (NYE1), and identified RELATIVE OF EARLY FLOWERING6 (REF6), a histone H3 lysine 27 tri-methylation (H3K27me3) demethylase, as a putative binding protein of NYE1 promoter. By in vivo and in vitro analyses, we demonstrated that REF6 directly binds to the motif CTCGYTY in NYE1/2 promoters through its zinc finger domain and positively regulates their expression. Loss-of-function of REF6 delayed chlorophyll (Chl) degradation, whereas overexpression of REF6 accelerated Chl degradation. Subsequently, we revealed that REF6 positively regulates the general senescence process by directly up-regulating ETHYLENE INSENSITIVE 2 (EIN2), ORESARA1 (ORE1), NAC-LIKE, ACTIVATED BY AP3/PI (NAP), PYRUVATE ORTHOPHOSPHATE DIKINASE (PPDK), PHYTOALEXIN DEFICIENT 4 (PAD4), LIPOXYGENASE 1 (LOX1), NAC DOMAIN CONTAINING PROTEIN 3 (AtNAC3), and NAC TRANSCRIPTION FACTOR-LIKE 9 (NTL9), the key regulatory and functional genes predominantly involved in the regulation of developmental leaf senescence. Importantly, loss-of-function of REF6 increased H3K27me3 levels at all the target Senescence associated genes (SAGs). We therefore conclusively demonstrate that H3K27me3 methylation represents an epigenetic mechanism prohibiting the premature transcriptional activation of key developmentally up-regulated senescence regulatory as well as functional genes in Arabidopsis.
| S-EPMC6457497 | biostudies-literature
Project description:Dynamic trimethylation of histone H3 at Lys27 (H3K27me3) affects gene expression and controls plant development and environmental responses. In Arabidopsis thaliana, RELATIVE OF EARLY FLOWERING 6 (REF6)/JUMONJI DOMAIN-CONTAINING PROTEIN 12 demethylates H3K27me3 by recognizing a specific DNA motif. However, little is known about how REF6 activates target gene expression after recognition, especially in environmental responses. In response to warm ambient temperature, plants undergo thermomorphogenesis, which involves accelerated growth, early flowering and changes in morphology. Here we show that REF6 regulates thermomorphogenesis and cooperates with the transcription factor PHYTOCHROME INTERACTING FACTOR 4 to synergistically activate thermoresponsive genes under warm ambient temperature. The ref6 loss-of-function mutants exhibited attenuated hypocotyl elongation at warm temperature, partially due to downregulation of GIBBERELLIN 20-OXIDASE 2 and BASIC HELIX-LOOP-HELIX 87. REF6 enzymatic activity is necessary for warm ambient temperature responses. Together, our results provide direct evidence of an epigenetic modifier and a transcription factor working together to respond to the environment.
| S-EPMC9113104 | biostudies-literature
Project description:The Arabidopsis ROS1/DEMETER family of 5-methylcytosine (5mC) DNA glycosylases are the first genetically characterized DNA demethylases in eukaryotes. However, the features of ROS1-targeted genomic loci are not well understood. In this study, we characterized ROS1 target loci in Arabidopsis Col-0 and C24 ecotypes. We found that ROS1 preferentially targets transposable elements (TEs) and intergenic regions. Compared with most TEs, ROS1-targeted TEs are closer to protein coding genes, suggesting that ROS1 may prevent DNA methylation spreading from TEs to nearby genes. ROS1-targeted TEs are specifically enriched for H3K18Ac and H3K27me3, and depleted of H3K27me and H3K9me2. Importantly, we identified thousands of previously unknown RNA-directed DNA methylation (RdDM) targets following depletion of ROS1, suggesting that ROS1 strongly antagonizes RdDM at these loci. In addition, we show that ROS1 also antagonizes RdDM-independent DNA methylation at some loci. Our results provide important insights into the genome-wide targets of ROS1 and the crosstalk between DNA methylation and ROS1-mediated active DNA demethylation.
| S-EPMC5123759 | biostudies-literature
Project description:SWI/SNF-type chromatin remodelers, such as BRAHMA (BRM), and H3K27 demethylases both have active roles in regulating gene expression at the chromatin level, but how they are recruited to specific genomic sites remains largely unknown. Here we show that RELATIVE OF EARLY FLOWERING 6 (REF6), a plant-unique H3K27 demethylase, targets genomic loci containing a CTCTGYTY motif via its zinc-finger (ZnF) domains and facilitates the recruitment of BRM. Genome-wide analyses showed that REF6 colocalizes with BRM at many genomic sites with the CTCTGYTY motif. Loss of REF6 results in decreased BRM occupancy at BRM-REF6 co-targets. Furthermore, REF6 directly binds to the CTCTGYTY motif in vitro, and deletion of the motif from a target gene renders it inaccessible to REF6 in vivo. Finally, we show that, when its ZnF domains are deleted, REF6 loses its genomic targeting ability. Thus, our work identifies a new genomic targeting mechanism for an H3K27 demethylase and demonstrates its key role in recruiting the BRM chromatin remodeler.
| S-EPMC5134324 | biostudies-literature