Determine the methyltransferase activities of METTL16 via MeRIP-seq (m6A-seq)
Ontology highlight
ABSTRACT: METTL16 belongs to methyltransferase like (METTL) family and could install m6A marks on its substrates. Here, we uncover a tumor-promoting role of METTL16 in AML and LSC self-renewal. To explore the mechanism underlying the oncogenic function of METTL16 in AML, we performed m6A-seq and RNA-seq. Via integrated analysis of m6A-seq data and RNA-seq data, we identified two bona fide targets of METTL16, BCAT1 and BCAT2. METTL16 functions as an m6A methyltransferase to regulate expression of BCAT1 and BCAT2, which contribute to reprogramming of BCAA metabolism.
Project description:METTL16 belongs to methyltransferase like (METTL) family and could install m6A marks on its substrates. Here, we uncover a tumor-promoting role of METTL16 in AML and LSC self-renewal. To explore the mechanism underlying the oncogenic function of METTL16 in AML, we performed m6A-seq and RNA-seq. Via integrated analysis of m6A-seq data and RNA-seq data, we identified two bona fide targets of METTL16, BCAT1 and BCAT2. METTL16 functions as an m6A methyltransferase to regulate expression of BCAT1 and BCAT2, which contribute to reprogramming BCAA metabolism.
Project description:All the three enzymes, METTL3, METTL14, and METTL16, belong to methyltransferase like (METTL) family and possess the ability to deposit N6-methyladenosine (m6A) in mRNA. Via immunofluorescence staining and wertern blotting, we discovered either METTL3 or METTL14 mainly localize in nuclear, but METTL16 localizes in both cytosol and nuclei. To compare the m6A methyltransferase activities of the three m6A 'writers' and better understand their differences, MeRIP-seq (m6A-seq) was conducted with poly(A) RNAs isolaed from HEK293T cells with METTL3, 14 and 16 knockout.
Project description:METTL16 belong to methyltransferase like (METTL) family and possesses the ability to deposit N6-methyladenosine (m6A) in mRNA. We have conducted m6A-seq with poly(A) RNAs isolated from the whole HEK293T cells upon METTL16 knockdown to identify the transcripts with hypo m6A peaks after METTL16 knockdown, and also conducted RIP-seq with HEK293T cells to determine the METTL16-bound transcripts. However, we found that the transcripts with hypo m6A peaks upon METTL16 knockdown only account for a small proportion of METTL16-bound transcripts. We suppose one of the possibility reasons might be due to spatiotemporal installation of m6A. To support our hypothesis, we performed additional m6A seq with nascent RNA and nuclear poly(A) RNA isolated from HEK293T cells with METTL16 knockdown.
Project description:METTL16 has recently been identified as an RNA methyltransferase that installs m6A marks on a few transcripts. But its function in cytosol remains unclear. Puromycin-labelling and renilla luciferase assay revealed that METTL16 can promote translation efficiency in an m6A-independent manner. To explore the mechanism, we performed co-immunoprecipitation using METTL16 antibody and mass spectroscopy to identify its interaction proteins. Moreover, we find that METTL16 is essential for tumorigenesis of non-small cell lung cancer.
Project description:The RNA N6-methyladenosine (m6A) modification has emerged as an essential regulator of vertebrate embryogenesis and malignancies. However, its functions and underlying molecular mechanisms in the expansion of hematopoietic stem and progenitor cells (HSPCs) during early embryonic development remain elusive. Here we show that Mettl16, an RNA methyltransferase identified recently, is specifically required for HSPC expansion during zebrafish early embryonic development in an m6A-dependent manner. In mettl16 deficient embryos, HSPCs exhibit defective proliferation capacity due to G0/G1 arrest. Mechanistically, HSPC proliferation is blocked by impaired methyltransferase function of Mettl16 in vivo. We identify cell cycle gene mybl2b as a novel direct m6A target of Mettl16, and Mettl16 deficiency destabilizes mybl2b mRNA, which is mediated by m6A reader Igf2bp1. Moreover, we revealed that the METTL16-m6A-MYBL2-IGF2BP1 signaling axis in G1/S progression is conserved in humans. Collectively, our findings demonstrate the critical function of m6A modification deposited by Mettl16 in HSPC expansion during early embryonic development.
Project description:The RNA N6-methyladenosine (m6A) modification has emerged as an essential regulator of vertebrate embryogenesis and malignancies. However, its functions and underlying molecular mechanisms in the expansion of hematopoietic stem and progenitor cells (HSPCs) during early embryonic development remain elusive. Here we show that Mettl16, an RNA methyltransferase identified recently, is specifically required for HSPC expansion during zebrafish early embryonic development in an m6A-dependent manner. In mettl16 deficient embryos, HSPCs exhibit defective proliferation capacity due to G0/G1 arrest. Mechanistically, HSPC proliferation is blocked by impaired methyltransferase function of Mettl16 in vivo. We identify cell cycle gene mybl2b as a novel direct m6A target of Mettl16, and Mettl16 deficiency destabilizes mybl2b mRNA, which is mediated by m6A reader Igf2bp1. Moreover, we revealed that the METTL16-m6A-MYBL2-IGF2BP1 signaling axis in G1/S progression is conserved in humans. Collectively, our findings demonstrate the critical function of m6A modification deposited by Mettl16 in HSPC expansion during early embryonic development.
Project description:METTL16 is a member of methyltransferase like (METTL) family. Unlike well-studied METTL3 and METTL14, we found a much higher percentage of METTL16 is localized in the cytosol. The subcellular distribution holds the ability to potentiate translation efficiency. Via Far-western blotting and Co-Immunoprecipitation (Co-IP) assays, we have identified the direct interactions between METTL16 and eukaryotic initiation factor 3 (eIF3) a and b. Via cross-linking immunoprecipitation and qPCR (CLIP-qPCR), we have discovered the direct associations between METTL16 and rRNAs. The METTL16-eIF3a/b and METTL16-rRNAs interactions induce the binding between eIF3 and 18S rRNA, promote the formation of 43S preinitiation complex, and eventually expedite translation initiation, the rate-limiting step of translation. To determine the exact effects of METTL16 on translation efficiency, we performed ribosome profiling (Ribo-seq) with HEK293T upon CRISPR-Cas9-induced METTL16 knockout. To guarantee the repeatability and avoid any potential off-target effects, we included 3 distint sgRNAs against METTL16.
Project description:METTL16 was previously identified as an m6A methyltransferase. In this study, we validated the cytoplasmic location of METTL16 and explored its function in the cytoplasm. We found that METTL16 promoted translation by sequestering eIF4E2, a translation initiation repressor, from the 5' cap structure.
Project description:METTL16, a human m6A RNA methyltransferase, contains multiple RNA binding domains and is known to modify U6 and MAT2A RNAs. Usingmutagensis, we generated HEK293 cell lines stabling expressing nutated or WT forms of METTL16 to dtermine the imapct these mutations have on cell processes after removal of endogenous METTL16. We performed bottom-up, untargeted data dependent proteomics analysison all five cell lines to determine the global changes in peptide/protein abdundances; we identified 200-300 statistically significant altered proteinscompared to the wild-type exogenous METTL16 clone.
Project description:Internal modification of RNAs with N6-methyladenosine (m6A) is a highly conserved and widely used means of gene expression control. METTL16 is an m6A writer but how it recognizes its RNA targets and its physiological roles remain unknown. Here we describe the crystal structure of human METTL16 to reveal a classical methyltransferase domain but with an extra N-terminal module that is essential for catalysis. Together, they form a deep-cut groove lined by highly conserved positively charged residues that are essential for RNA binding and methylation activity. When given a random pool of RNAs, METTL16 selects structured RNAs for m6A methylation. We demonstrate that mouse Mettl16 is essential for early embryonic development, and acts via regulation of the SAM synthetase Mat2a mRNA. Our results highlight the pivotal role of an m6A RNA methyltransferase in facilitating early developmental decisions via regulation of SAM availability.