Project description:DNA methylation can be established by RNA-directed DNA methylation (RdDM) in plants. The association of RNA polymerase V (Pol V) with chromatin is a critical step for RdDM. While the SRA-domain-containing proteins SUVH2 and SUVH9 and the DDR complex are known to be required for the association of Pol V with chromatin, it is unknown whether the association of Pol V with chromatin requires other unidentified regulators. Here we found that SUVH9 is able to interact with a conserved histone-interaction protein, FVE, and a previously uncharacterized RRM domain-containing protein, which we named RRM1. We demonstrated that FVE facilitates the association of Pol V with chromatin and thus contributes to DNA methylation at a substantial subset of RdDM target loci, while RRM1 is only slightly involved in RdDM. FVE-dependent RdDM target loci are more abundant in gene-rich chromosome arms than FVE-independent RdDM target loci. FVE was previously shown to be a shared subunit of the RPD3-type histone deacetylase complex and the polycomb-type histone H3K27 trimethyltransferase complex, both of which are involved in transcriptional repression. This study reveals a previously uncharacterized role of FVE in RdDM and suggests that FVE may coordinate RdDM, histone deacetylation, and H3K27 trimethylation, thus ensuring transcriptional silencing of TEs in gene-rich chromosome arms to protect genes from harmful effects of potentially transcribed TEs.
Project description:DNA methylation can be established by RNA-directed DNA methylation (RdDM) in plants. The association of RNA polymerase V (Pol V) with chromatin is a critical step for RdDM. While the SRA-domain-containing proteins SUVH2 and SUVH9 and the DDR complex are known to be required for the association of Pol V with chromatin, it is unknown whether the association of Pol V with chromatin requires other unidentified regulators. Here we found that SUVH9 is able to interact with a conserved histone-interaction protein, FVE, and a previously uncharacterized RRM domain-containing protein, which we named RRM1. We demonstrated that FVE facilitates the association of Pol V with chromatin and thus contributes to DNA methylation at a substantial subset of RdDM target loci, while RRM1 is only slightly involved in RdDM. FVE-dependent RdDM target loci are more abundant in gene-rich chromosome arms than FVE-independent RdDM target loci. FVE was previously shown to be a shared subunit of the RPD3-type histone deacetylase complex and the polycomb-type histone H3K27 trimethyltransferase complex, both of which are involved in transcriptional repression. This study reveals a previously uncharacterized role of FVE in RdDM and suggests that FVE may coordinate RdDM, histone deacetylation, and H3K27 trimethylation, thus ensuring transcriptional silencing of TEs in gene-rich chromosome arms to protect genes from harmful effects of potentially transcribed TEs.
Project description:DNA methylation can be established by RNA-directed DNA methylation (RdDM) in plants. The association of RNA polymerase V (Pol V) with chromatin is a critical step for RdDM. While the SRA-domain-containing proteins SUVH2 and SUVH9 and the DDR complex are known to be required for the association of Pol V with chromatin, it is unknown whether the association of Pol V with chromatin requires other unidentified regulators. Here we found that SUVH9 is able to interact with a conserved histone-interaction protein, FVE, and a previously uncharacterized RRM domain-containing protein, which we named RRM1. We demonstrated that FVE facilitates the association of Pol V with chromatin and thus contributes to DNA methylation at a substantial subset of RdDM target loci, while RRM1 is only slightly involved in RdDM. FVE-dependent RdDM target loci are more abundant in gene-rich chromosome arms than FVE-independent RdDM target loci. FVE was previously shown to be a shared subunit of the RPD3-type histone deacetylase complex and the polycomb-type histone H3K27 trimethyltransferase complex, both of which are involved in transcriptional repression. This study reveals a previously uncharacterized role of FVE in RdDM and suggests that FVE may coordinate RdDM, histone deacetylation, and H3K27 trimethylation, thus ensuring transcriptional silencing of TEs in gene-rich chromosome arms to protect genes from harmful effects of potentially transcribed TEs.
Project description:DNA methylation can be established by RNA-directed DNA methylation (RdDM) in plants. The association of RNA polymerase V (Pol V) with chromatin is a critical step for RdDM. While the SRA-domain-containing proteins SUVH2 and SUVH9 and the DDR complex are known to be required for the association of Pol V with chromatin, it is unknown whether the association of Pol V with chromatin requires other unidentified regulators. Here we found that SUVH9 is able to interact with a conserved histone-interaction protein, FVE, and a previously uncharacterized RRM domain-containing protein, which we named RRM1. We demonstrated that FVE facilitates the association of Pol V with chromatin and thus contributes to DNA methylation at a substantial subset of RdDM target loci, while RRM1 is only slightly involved in RdDM. FVE-dependent RdDM target loci are more abundant in gene-rich chromosome arms than FVE-independent RdDM target loci. FVE was previously shown to be a shared subunit of the RPD3-type histone deacetylase complex and the polycomb-type histone H3K27 trimethyltransferase complex, both of which are involved in transcriptional repression. This study reveals a previously uncharacterized role of FVE in RdDM and suggests that FVE may coordinate RdDM, histone deacetylation, and H3K27 trimethylation, thus ensuring transcriptional silencing of TEs in gene-rich chromosome arms to protect genes from harmful effects of potentially transcribed TEs
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.