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:RNA-directed DNA methylation (RdDM) functions in de novo methylation in CG, CHG, and CHH contexts. Here, we performed map-based cloning of OsNRPE1, which encodes the largest subunit of Pol V, a key regulator of gene silencing and reproductive development in rice. We found that rice Pol V is required for CHH methylation on RdDM loci by transcribing long non-coding RNAs. Pol V influences the accumulation of 24-nt siRNAs in a locus-specific manner. Biosynthesis of 24-nt siRNAs on loci with high CHH methylation levels and low CG and CHG methylation levels tends to depend on Pol V. In contrast, low methylation levels in the CHH context and high methylation levels in CG and CHG contexts predisposes 24-nt siRNA accumulation to be independent of Pol V. H3K9me1 and H3K9me2 tend to be enriched on Pol V-independent 24-nt siRNA loci, whereas various active histone modifications are enriched on Pol V-dependent 24-nt siRNA loci. DNA methylation is required for 24-nt siRNAs biosynthesis on Pol V-dependent loci but not on Pol V-independent loci. Our results reveal the function of rice Pol V for long non-coding RNA production, DNA methylation, 24-nt siRNA accumulation, and reproductive development. This SuperSeries is composed of the SubSeries listed below.