Project description:Here we determine the map of RNA methylation (m6A) in mouse embrionic stem cells, and Mettl3 knock out cells Examination of m6A modification sites on the transcriptome of mouse Embryonic stem cells and Embryonic Mettl3 knock out cells, using a m6A specific antibody.
Project description:Here, we use a novel technique for locating regions of N6-adenosine methylation (m6A) throughout the transcriptome and present a profile of m6A sites in the mouse brain. Our use of methylated RNA immunoprecipitation combined with RNA-seq (MeRIP-Seq) identifies thousands of RNAs which contain m6A sites. In addition, we find that regions of m6A formation are particularly enriched near stop codons, which might provide clues into the potential funciton of this highly prevalent RNA modificaiton. Examination of m6A sites in murine brain RNA and human embryonic kidney cells.
Project description:In this study we identify Mettl3, an m6A RNA modification writer, as a critical regulator for terminating naïve pluripotency and a positive maintainer of primed pluripotency in vitro and in vivo. Remarkably, Mettl3 knockout pre-implantation epiblasts and naïve ES cells, entirely lack m6A on coding mRNAs and are viable. Yet, they fail to adequately terminate the naïve pluripotent state, and subsequently undergo aberrant priming and early lineage commitment at the post-implantation stage. A comprehensive functional and genomic analysis involving profiling of m6A, RNA transcription and translation in Mettl3 wild-type and knockout pluripotent and differentiated cells, identified m6A as a critical determinant that destabilizes secondary naïve specific pluripotency genes Esrrb, Klf4 and Nanog, and restrains their transcript stability and translation efficiency. In summary, our findings provide for the first time evidence for a critical role for an mRNA epigenetic modification in early mammalian development in vivo, and identify a mechanism that functionally regulates mouse naïve and primed pluripotency in an opposing manner. Ribosome footprint (Ribo-Seq) was measured from mouse embryonic stem cells and mouse embriod bodies, in WT and Mettl3-KO cell lines.
Project description:In this study we identify Mettl3, an m6A RNA modification writer, as a critical regulator for terminating naM-CM-/ve pluripotency and a positive maintainer of primed pluripotency in vitro and in vivo. Remarkably, Mettl3 knockout pre-implantation epiblasts and naM-CM-/ve ES cells, entirely lack m6A on coding mRNAs and are viable. Yet, they fail to adequately terminate the naM-CM-/ve pluripotent state, and subsequently undergo aberrant priming and early lineage commitment at the post-implantation stage. A comprehensive functional and genomic analysis involving profiling of m6A, RNA transcription and translation in Mettl3 wild-type and knockout pluripotent and differentiated cells, identified m6A as a critical determinant that destabilizes secondary naM-CM-/ve specific pluripotency genes Esrrb, Klf4 and Nanog, and restrains their transcript stability and translation efficiency. In summary, our findings provide for the first time evidence for a critical role for an mRNA epigenetic modification in early mammalian development in vivo, and identify a mechanism that functionally regulates mouse naM-CM-/ve and primed pluripotency in an opposing manner. m6A-seq was measured from total RNA in mouse embryonic stem cells (ESCs), embroid bodies (EBs) and embronic fibroblasts (MEF). 3 biological replicates are available from BVSC ESC line and EBs, and two biological replicates are available for MEFs. Each sample consist of IP to m6A and control input
Project description:m6A is the most abundant modification of mRNA in mammals and plays an important role in human development and disease. METTL14 is a key component of m6A methyltransferase complex. The project showed that its post-translational arginine methylation can regulate the generation of m6A and the endoderm differentiation of mouse embryonic stem cells, indicating its essential function in the normal development of embryos.
Project description:N6-methyladenosine RNA (m6A) is the most abundant internal modification on mRNA which influences most steps of mRNA metabolism and is involved in several biological functions, including circadian clock, metabolism and embryonic stem cell differentiation. The E3 ubiquitin ligase Hakai was previously found in complex with components of the m6A methylation machinery in plants and mammalian cells but its precise function remained to be investigated. Here we show that Hakai is a conserved component of the methyltransferase complex in Drosophila. Its depletion results in reduced m6A levels and altered m6A-dependent functions including sex determination. We show that its ubiquitination domain is required for dimerisation and interaction with other members of the m6A machinery, while its catalytic activity seems dispensable. Finally, we demonstrate that the loss of Hakai destabilizes the level of several subunits of the methyltransferase complex, resulting in impaired m6A deposition. Thus, our work adds new functional and molecular insights into the mechanism of the m6A mRNA writer complex.
Project description:In this study we identify Mettl3, an m6A RNA modification writer, as a critical regulator for terminating naM-CM-/ve pluripotency and a positive maintainer of primed pluripotency in vitro and in vivo. Remarkably, Mettl3 knockout pre-implantation epiblasts and naM-CM-/ve ES cells, entirely lack m6A on coding mRNAs and are viable. Yet, they fail to adequately terminate the naM-CM-/ve pluripotent state, and subsequently undergo aberrant priming and early lineage commitment at the post-implantation stage. A comprehensive functional and genomic analysis involving profiling of m6A, RNA transcription and translation in Mettl3 wild-type and knockout pluripotent and differentiated cells, identified m6A as a critical determinant that destabilizes secondary naM-CM-/ve specific pluripotency genes Esrrb, Klf4 and Nanog, and restrains their transcript stability and translation efficiency. In summary, our findings provide for the first time evidence for a critical role for an mRNA epigenetic modification in early mammalian development in vivo, and identify a mechanism that functionally regulates mouse naM-CM-/ve and primed pluripotency in an opposing manner. 3' polyA RNA-sequencing (equivalent to Digital Gene Expression) measured in mouse Embryonic Stem Cells (ESCs) and mouse Embriod bodies (EBs) 0,4 & 8 hours after treatment with Actinomycin which halts transcription. Measured in both WT and Mettl3-KO cells.