METTL14 is a chromatin regulator independent of RNA N6-methyladenosine (m6A MeRIP-Seq)
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ABSTRACT: METTL3 and METTL14 are two components that form the core heterodimer of the main RNA m6A methyltransferase complex (MTC, also known as m6A writer) that installs m6A. Surprisingly, depletion of METTL3 or METTL14 displayed distinct effects on mouse embryonic stem cell (mESC) self-renewal. While comparable global hypo-methylation in RNA m6A was observed in Mettl3 or Mettl14 knockout mESCs, respectively. Mettl14 knockout led to a globally decreased nascent RNA synthesis, whereas Mettl3 depletion resulted in transcription upregulation, suggesting that METTL14 might possess an m6A-indenepent role in gene regulation. We found that METTL14 colocalizes with the repressive H3K27me3 modification and PRC2 complex. Mechanically, METTL14, but not METTL3, recognizes H3K27me3 and recruits KDM6B to induce H3K27me3 demethylation independent of METTL3. Depletion of METTL14 thus led to a global increase in H3K27me3 level along with a global gene suppression . The regulation of H3K27me3 by METTL14 is essential to the transition of mESCs from self-renewal to differentiation. This work reveals a regulation mechanism on heterochromatin by METTL14 in a manner distinct from METTL3 and independently of m6A, and critically impacts transcriptional regulation, stemness maintenance and differentiation of mESCs.
Project description:METTL3 and METTL14 are two components that form the core heterodimer of the main RNA m6A methyltransferase complex (MTC, also known as m6A writer) that installs m6A. Surprisingly, depletion of METTL3 or METTL14 displayed distinct effects on mouse embryonic stem cell (mESC) self-renewal. While comparable global hypo-methylation in RNA m6A was observed in Mettl3 or Mettl14 knockout mESCs, respectively. Mettl14 knockout led to a globally decreased nascent RNA synthesis, whereas Mettl3 depletion resulted in transcription upregulation, suggesting that METTL14 might possess an m6A-indenepent role in gene regulation. We found that METTL14 colocalizes with the repressive H3K27me3 modification and PRC2 complex. Mechanically, METTL14, but not METTL3, recognizes H3K27me3 and recruits KDM6B to induce H3K27me3 demethylation independent of METTL3. Depletion of METTL14 thus led to a global increase in H3K27me3 level along with a global gene suppression . The regulation of H3K27me3 by METTL14 is essential to the transition of mESCs from self-renewal to differentiation. This work reveals a regulation mechanism on heterochromatin by METTL14 in a manner distinct from METTL3 and independently of m6A, and critically impacts transcriptional regulation, stemness maintenance and differentiation of mESCs.
Project description:METTL3 and METTL14 are two components that form the core heterodimer of the main RNA m6A methyltransferase complex (MTC, also known as m6A writer) that installs m6A. Surprisingly, depletion of METTL3 or METTL14 displayed distinct effects on mouse embryonic stem cell (mESC) self-renewal. While comparable global hypo-methylation in RNA m6A was observed in Mettl3 or Mettl14 knockout mESCs, respectively. Mettl14 knockout led to a globally decreased nascent RNA synthesis, whereas Mettl3 depletion resulted in transcription upregulation, suggesting that METTL14 might possess an m6A-indenepent role in gene regulation. We found that METTL14 colocalizes with the repressive H3K27me3 modification and PRC2 complex. Mechanically, METTL14, but not METTL3, recognizes H3K27me3 and recruits KDM6B to induce H3K27me3 demethylation independent of METTL3. Depletion of METTL14 thus led to a global increase in H3K27me3 level along with a global gene suppression . The regulation of H3K27me3 by METTL14 is essential to the transition of mESCs from self-renewal to differentiation. This work reveals a regulation mechanism on heterochromatin by METTL14 in a manner distinct from METTL3 and independently of m6A, and critically impacts transcriptional regulation, stemness maintenance and differentiation of mESCs.
Project description:METTL3 and METTL14 are two components that form the core heterodimer of the main RNA m6A methyltransferase complex (MTC, also known as m6A writer) that installs m6A. Surprisingly, depletion of METTL3 or METTL14 displayed distinct effects on mouse embryonic stem cell (mESC) self-renewal. While comparable global hypo-methylation in RNA m6A was observed in Mettl3 or Mettl14 knockout mESCs, respectively. Mettl14 knockout led to a globally decreased nascent RNA synthesis, whereas Mettl3 depletion resulted in transcription upregulation, suggesting that METTL14 might possess an m6A-indenepent role in gene regulation. We found that METTL14 colocalizes with the repressive H3K27me3 modification and PRC2 complex. Mechanically, METTL14, but not METTL3, recognizes H3K27me3 and recruits KDM6B to induce H3K27me3 demethylation independent of METTL3. Depletion of METTL14 thus led to a global increase in H3K27me3 level along with a global gene suppression . The regulation of H3K27me3 by METTL14 is essential to the transition of mESCs from self-renewal to differentiation. This work reveals a regulation mechanism on heterochromatin by METTL14 in a manner distinct from METTL3 and independently of m6A, and critically impacts transcriptional regulation, stemness maintenance and differentiation of mESCs.
Project description:METTL3 and METTL14 are two components that form the core heterodimer of the main RNA m6A methyltransferase complex (MTC, also known as m6A writer) that installs m6A. Surprisingly, depletion of METTL3 or METTL14 displayed distinct effects on mouse embryonic stem cell (mESC) self-renewal. While comparable global hypo-methylation in RNA m6A was observed in Mettl3 or Mettl14 knockout mESCs, respectively. Mettl14 knockout led to a globally decreased nascent RNA synthesis, whereas Mettl3 depletion resulted in transcription upregulation, suggesting that METTL14 might possess an m6A-indenepent role in gene regulation. We found that METTL14 colocalizes with the repressive H3K27me3 modification and PRC2 complex. Mechanically, METTL14, but not METTL3, recognizes H3K27me3 and recruits KDM6B to induce H3K27me3 demethylation independent of METTL3. Depletion of METTL14 thus led to a global increase in H3K27me3 level along with a global gene suppression . The regulation of H3K27me3 by METTL14 is essential to the transition of mESCs from self-renewal to differentiation. This work reveals a regulation mechanism on heterochromatin by METTL14 in a manner distinct from METTL3 and independently of m6A, and critically impacts transcriptional regulation, stemness maintenance and differentiation of mESCs.
Project description:METTL3 and METTL14 are two components that form the core heterodimer of the main RNA m6A methyltransferase complex (MTC, also known as m6A writer) that installs m6A. Surprisingly, depletion of METTL3 or METTL14 displayed distinct effects on mouse embryonic stem cell (mESC) self-renewal. While comparable global hypo-methylation in RNA m6A was observed in Mettl3 or Mettl14 knockout mESCs, respectively. Mettl14 knockout led to a globally decreased nascent RNA synthesis, whereas Mettl3 depletion resulted in transcription upregulation, suggesting that METTL14 might possess an m6A-indenepent role in gene regulation. We found that METTL14 colocalizes with the repressive H3K27me3 modification and PRC2 complex. Mechanically, METTL14, but not METTL3, recognizes H3K27me3 and recruits KDM6B to induce H3K27me3 demethylation independent of METTL3. Depletion of METTL14 thus led to a global increase in H3K27me3 level along with a global gene suppression . The regulation of H3K27me3 by METTL14 is essential to the transition of mESCs from self-renewal to differentiation. This work reveals a regulation mechanism on heterochromatin by METTL14 in a manner distinct from METTL3 and independently of m6A, and critically impacts transcriptional regulation, stemness maintenance and differentiation of mESCs.
Project description:We show that N6-methyladenosine (m6A), the most abundant internal modification in mRNA/lncRNA with still poorly characterized function, alters RNA structure to facilitate the access of RBM for heterogeneous nuclear ribonucleoprotein C (hnRNP C). We term this mechanism m6A-switch. Through combining PAR-CLIP with Me-RIP, we identify 39,060 m6A-switches among hnRNP C binding sites transcriptome-wide. We show that m6A-methyltransferases METTL3 or METTL14 knockdown decreases hnRNP C binding at 16,582 m6A-switches. Taken together, 2,798 m6A-switches of high confidence are identified to mediate RNA-hnRNP C interactions and affect diverse biological processes including cell cycle regulation. These findings reveal the biological importance of m6A and provide insights into the sophisticated regulation of RNA-RBP interactions through m6A-induced RNA structural remodeling. Measure the m6A methylated hnRNP C binding sites transcriptome-wide by PARCLIP-MeRIP; measure the differential hnRNP C occupancies upon METTL3/METTL14 knockdown by PAR-CLIP; measure RNA abundance and splicing level changes upon HNRNPC, METTL3 and METTL14 knockdown
Project description:METTL14 (methyltransferase-like 14) is an RNA binding protein that partners with METTL3 to mediate N6-methyladenosine (m6A) methylation of mRNA. Recent studies identified a function for METTL3 in heterochromatin and transcription, but the role of METTL14 in these contexts remains unclear. Here we show that METTL14 binds and regulates mouse embryonic stem cell bivalent domains, which are marked with tri-methylation at lysine 27 of histone H3 (H3K27me3) and tri-methylation at lysine 4 of histone H3 (H3K4me3). Knockout of Mettl14 results in decreased H3K27me3 but increased H3K4me3 levels at bivalent regions, resulting in the resolution of the bivalency and in increased transcription. We demonstrate that bivalent domain regulation by METTL14 is independent of METTL3 or m6A modification. Instead, METTL14 enhances H3K27me3 and reduces H3K4me3 by interacting with and probably recruiting the histone 3 lysine 27 (H3K27) methyltransferase complex PRC2 and the histone 3 lysine 4 (H3K4) demethylases KDM5B to chromatin. Our findings identify a METTL3-independent function of METTL14, important for maintaining the bivalent domains in mESCs, thus revealing a new mechanism of bivalent domain regulation in mammals.
Project description:METTL14 (methyltransferase-like 14) is an RNA binding protein that partners with METTL3 to mediate N6-methyladenosine (m6A) methylation of mRNA. Recent studies identified a function for METTL3 in heterochromatin and transcription, but the role of METTL14 in these contexts remains unclear. Here we show that METTL14 binds and regulates mouse embryonic stem cell bivalent domains, which are marked with tri-methylation at lysine 27 of histone H3 (H3K27me3) and tri-methylation at lysine 4 of histone H3 (H3K4me3). Knockout of Mettl14 results in decreased H3K27me3 but increased H3K4me3 levels at bivalent regions, resulting in the resolution of the bivalency and in increased transcription. We demonstrate that bivalent domain regulation by METTL14 is independent of METTL3 or m6A modification. Instead, METTL14 enhances H3K27me3 and reduces H3K4me3 by interacting with and probably recruiting the histone 3 lysine 27 (H3K27) methyltransferase complex PRC2 and the histone 3 lysine 4 (H3K4) demethylases KDM5B to chromatin. Our findings identify a METTL3-independent function of METTL14, important for maintaining the bivalent domains in mESCs, thus revealing a new mechanism of bivalent domain regulation in mammals.
Project description:Chemical modification of RNAs is important for post-transcriptional gene regulation. The METTL3-METTL14 complex generates most N6-methyladenosine (m6A) modifications in mRNAs, and dysregulated methyltransferase expression has been linked to numerous cancers. Here we show that m6A modification location, rather than the overall modification level, can impact oncogenesis. A gain-of-function missense mutation found in cancer patients, METTL14R298P, promotes malignant cell growth in culture and in transgenic mice. The mutant methyltransferase preferentially modifies noncanonical sites and transforms gene expression without increasing global m6A levels in mRNAs. The altered substrate specificity is intrinsic to METTL3-METTL14, helping us to propose a structural model for how the METTL3-METTL14 complex detects RNA sequences. Together, our work highlights that m6A location is important for function and that noncanonical methylation sites may impact aberrant gene expression and oncogenesis.
Project description:Both mRNA and proteins can be modified through addition of methyl groups. For example, addition of N6-methyladenosine (m6A) to mRNAs is critical for human development and health. Post-translational methylation of proteins can impact the dynamic regulation of enzymatic activity. Here we sought to explore the nexus of transcriptional and post-translational methylation by studying the role of methylation of the core methyltransferase METTL3/METTL14 in m6A regulation. We found by mass spectrometry that METTL14 arginine 255 (R255) is methylated (R255me). Global mRNA m6A levels were greatly decreased in METTL14 R255K mutant mouse embryonic stem cells (mESCs). We further found that R255me greatly enhances the interaction of METTL3/METTL14 with WTAP and promotes the binding of the complex to substrate RNA.