Arabidopsis thaliana
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA119849 | ENA |
REPOSITORIES: ENA
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Project description:In plants, multiple levels of epigenetic control suppress transposon movement and permit somatic as well as transgenerational transmission of gene expression patterns. A variety of factors are involved that establish and/or maintain epigenetic marks, such as covalent modification of DNA and histones. Alteration of epigenetic marks leads to the enhancement or release of transcriptional gene silencing (TGS). TGS regulator MOM1 is special in this respect since it silences transcription by an unknown mechanism operating without obvious changes in epigenetic marks. We have isolated an enhancer of the mom1 mutation that points towards regulatory interplay between MOM1 and the plant-specific RNA Polymerase V (Pol V). Pol V transcribes heterochromatic loci and silences them. Although its biochemical properties have been studied; it is still not clear how Pol V is targeted to heterochromatin. We now provide evidence that Pol V is required for MOM1-mediated suppression of transcription at a subset of its chromosomal targets. Thus, Pol V interacts with MOM1 in the control of gene silencing. Interestingly, functional relationships between mutations in MOM1 and Pol V genes range from enhancement to independence or even suppression at different target loci. 4 samples: wt, mom1, nrpe1, mom/nrpe1 with 3 replicates each
2010-06-19 | E-GEOD-17940 | biostudies-arrayexpress
Project description:In plants, multiple levels of epigenetic control suppress transposon movement and permit somatic as well as transgenerational transmission of gene expression patterns. A variety of factors are involved that establish and/or maintain epigenetic marks, such as covalent modification of DNA and histones. Alteration of epigenetic marks leads to the enhancement or release of transcriptional gene silencing (TGS). TGS regulator MOM1 is special in this respect since it silences transcription by an unknown mechanism operating without obvious changes in epigenetic marks. We have isolated an enhancer of the mom1 mutation that points towards regulatory interplay between MOM1 and the plant-specific RNA Polymerase V (Pol V). Pol V transcribes heterochromatic loci and silences them. Although its biochemical properties have been studied; it is still not clear how Pol V is targeted to heterochromatin. We now provide evidence that Pol V is required for MOM1-mediated suppression of transcription at a subset of its chromosomal targets. Thus, Pol V interacts with MOM1 in the control of gene silencing. Interestingly, functional relationships between mutations in MOM1 and Pol V genes range from enhancement to independence or even suppression at different target loci.
2009-11-24 | GSE17940 | GEO
Project description:Epigenetic gene silencing is of central importance to maintain genome integrity and is mediated by an elaborate interplay between DNA methylation, histone posttranslational modifications and chromatin remodeling complexes. DNA methylation and repressive histone marks usually correlate with transcriptionally silent heterochromatin, however there are exceptions to this interdependence. In Arabidopsis, mutation of MORPHEUS MOLECULE 1 (MOM1) causes transcriptional derepression of heterochromatin independently of changes in DNA methylation. More recently, two Arabidopsis homologs of mouse Microrchidia (MORC) have also been implicated in gene silencing and heterochromatin condensation without altering genome-wide DNA methylation patterns. In this study, we show that AtMORC6 physically interacts with AtMORC1 and with its close homologue AtMORC2 in two mutually exclusive protein complexes. RNA-seq analysis of high-order mutants indicates that AtMORC1 and AtMORC2 act redundantly to repress a common set of loci. We also examined the genetic interactions between AtMORC6 and MOM1 pathways. Although AtMORC6 and MOM1 control the silencing of a very similar set of genomic loci, we observed synergistic transcriptional regulation in the mom1/atmorc6 double mutant, suggesting that these epigenetic regulators act mainly by independent silencing mechanisms.
2014-06-01 | GSE54677 | GEO
Project description:MOM1 is an Arabidopsis factor previously shown to mediate transcriptional silencing independent of major DNA methylation changes. Here we found that MOM1 localizes with sites of RNA-directed DNA methylation (RdDM). Tethering MOM1 with artificial zinc finger to unmethylated FWA promoter led to establishment of DNA methylation and FWA silencing. This process was blocked by mutations in components of the Pol V arm of the RdDM machinery, as well as by mutation of MORC6. We found that at some endogenous RdDM sites, MOM1 is required to maintain DNA methylation and a closed chromatin state. In addition, efficient silencing of newly introduced FWA transgenes was impaired by mutation of MOM1 or mutation of genes encoding the MOM1 interacting PIAL1/2 proteins. In addition to RdDM sites, we identified a group of MOM1 peaks at active chromatin near genes that colocalized with MORC6. These findings demonstrate a multifaceted role of MOM1 in genome regulation.
2023-06-10 | PXD039991 | Pride
Project description:Epigenetic gene silencing is of central importance to maintain genome integrity and is mediated by an elaborate interplay between DNA methylation, histone posttranslational modifications and chromatin remodeling complexes. DNA methylation and repressive histone marks usually correlate with transcriptionally silent heterochromatin, however there are exceptions to this interdependence. In Arabidopsis, mutation of MORPHEUS MOLECULE 1 (MOM1) causes transcriptional derepression of heterochromatin independently of changes in DNA methylation. More recently, two Arabidopsis homologs of mouse Microrchidia (MORC) have also been implicated in gene silencing and heterochromatin condensation without altering genome-wide DNA methylation patterns. In this study, we show that AtMORC6 physically interacts with AtMORC1 and with its close homologue AtMORC2 in two mutually exclusive protein complexes. RNA-seq analysis of high-order mutants indicates that AtMORC1 and AtMORC2 act redundantly to repress a common set of loci. We also examined the genetic interactions between AtMORC6 and MOM1 pathways. Although AtMORC6 and MOM1 control the silencing of a very similar set of genomic loci, we observed synergistic transcriptional regulation in the mom1/atmorc6 double mutant, suggesting that these epigenetic regulators act mainly by independent silencing mechanisms. RNA-seq libraries were prepared for two suites of mutants to allow direct comparisons between mutants within each set. The two sets consisted of the following samples: Set_1) A wildtype (Col) control, the morc1 mutant, the morc2 mutant, the morc1 morc2 double mutant, the morc6 mutant, and the morc1 morc2 morc6 triple mutant ; Set_2) A wildtpe (Col) control, the morc6 mutant, the mom1 mutant, and the mom1 morc6 double mutant. For each sample, two biological replicates were performed (denoted "bio_replicate_1" or "bio_replicate_2"). Whole genome bisulifte libraries were sequenced from material grown in parallel.
2014-06-01 | E-GEOD-54677 | biostudies-arrayexpress
Project description:MOM1 is an Arabidopsis factor previously shown to mediate transcriptional silencing independent of major DNA methylation changes. Here we found that MOM1 localizes with sites of RNA-directed DNA methylation (RdDM). Tethering MOM1 with artificial zinc finger to unmethylated FWA promoter led to establishment of DNA methylation and FWA silencing. This process was blocked by mutations in components of the Pol V arm of the RdDM machinery, as well as by mutation of MORC6. We found that at some endogenous RdDM sites, MOM1 is required to maintain DNA methylation and a closed chromatin state. In addition, efficient silencing of newly introduced FWA transgenes was impaired by mutation of MOM1 or mutation of genes encoding the MOM1 interacting PIAL1/2 proteins. In addition to RdDM sites, we identified a group of MOM1 peaks at active chromatin near genes, again colocalized with MORC6. These findings demonstrate a multifaceted role of MOM1 in genome regulation.
2023-06-09 | GSE221679 | GEO
Project description:The mechanism by which MORPHEUS'MOLECULE1 (MOM1) contributes to transcriptional gene silencing remained elusive since the gene was first identified and characterized (Amedeo et al., 2000). Here, we report that two PIAS (PROTEIN INHIBITOR OF ACTIVATED STAT)-type SUMO E3 ligase-like proteins PIAL1 and PIAL2 function redundantly to mediate transcriptional silencing at MOM1 target loci. PIAL1 and PIAL2 physically interact with each other and with MOM1 to form a high-molecular-weight complex. In the absence of either PIAL2 or MOM1, the formation of the high-molecular-weight complex was disrupted. We identified a previously uncharacterized IND (interacting domain) in PIAL1 and PIAL2, and demonstrated that IND directly interacts with MOM1. The CMM2 (conserved MOM1 motif 2) domain of MOM1 was previously shown to be required for the dimerization of MOM1. We demonstrated that the CMM2 domain is also required for the interaction of MOM1 with PIAL1 and PIAL2. We found that although PIAL2 has a SUMO E3 ligase activity, the activity is dispensable for PIAL2 in transcriptional silencing. This study suggests that PIAL1 and PIAl2 act as components of the MOM1-containing complex to mediate transcriptional silencing at heterochromatin regions.
2016-04-15 | GSE80302 | GEO
Project description:The mechanism by which MORPHEUS'MOLECULE1 (MOM1) contributes to transcriptional gene silencing remained elusive since the gene was first identified and characterized (Amedeo et al., 2000). Here, we report that two PIAS (PROTEIN INHIBITOR OF ACTIVATED STAT)-type SUMO E3 ligase-like proteins PIAL1 and PIAL2 function redundantly to mediate transcriptional silencing at MOM1 target loci. PIAL1 and PIAL2 physically interact with each other and with MOM1 to form a high-molecular-weight complex. In the absence of either PIAL2 or MOM1, the formation of the high-molecular-weight complex was disrupted. We identified a previously uncharacterized IND (interacting domain) in PIAL1 and PIAL2, and demonstrated that IND directly interacts with MOM1. The CMM2 (conserved MOM1 motif 2) domain of MOM1 was previously shown to be required for the dimerization of MOM1. We demonstrated that the CMM2 domain is also required for the interaction of MOM1 with PIAL1 and PIAL2. We found that although PIAL2 has a SUMO E3 ligase activity, the activity is dispensable for PIAL2 in transcriptional silencing. This study suggests that PIAL1 and PIAl2 act as components of the MOM1-containing complex to mediate transcriptional silencing at heterochromatin regions.
2016-04-15 | GSE80301 | GEO
Project description:In plants, transposons and non-protein-coding repeats are epigenetically silenced by CG and non-CG methylation. This pattern of methylation is mediated in part by small RNAs and two specialized RNA polymerases, Pol IV and Pol V, in a process called RNA-directed DNA methylation. By contrast, many protein-coding genes transcribed by Pol II contain in their gene bodies exclusively CG methylation that is independent of small RNAs and Pol IV/Pol V activities. It is unclear how the different methylation machineries distinguish between transposons and genes. Here we report on a group of atypical genes that display in their coding region a transposon-like methylation pattern, which is associated with gene silencing in sporophytic tissues.
2012-11-22 | GSE34207 | GEO
Project description:Transcriptional gene silencing (TGS) in Arabidopsis is regulated by two distinct pathways, DNA methylation-dependent and –independent. ddm1 and mom1 mutants are defective in the DNA-dependent and –independent pathway, respectively. We used microarrays to detail the global changes in gene expression in the TGS mutants Keywords: TGS mutants
2007-08-29 | GSE5771 | GEO