Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

M7G-quant-seq: Quantitative Detection of RNA Internal N7-Methylguanosine

ABSTRACT: Methods for the precise detection and quantification of RNA modifications are critical to uncover functional roles of diverse RNA modifications. The internal m7G modification in mammalian cytoplasmic tRNAs is known to affect tRNA function and impact embryonic stem cell self-renewal, tumorigenesis, cancer progression, and other cellular processes. Here, we introduce m7G-quant-seq, a quantitative method that accurately detects internal m7G sites in human cytoplasmic tRNAs at single-base resolution. The efficient chemical reduction and mild depurination can almost completely convert internal m7G sites into RNA abasic sites (AP sites). We demonstrate that RNA abasic sites induce a mixed variation pattern during reverse transcription, including G → A or C or T mutations as well as deletions. We calculated the total variation ratio to quantify the m7G modification fraction at each methylated site. The calibration curves of all relevant motif contexts allow us to more quantitatively determine the m7G methylation level. We detected internal m7G sites in 22 human cytoplasmic tRNAs from HeLa and HEK293T cells and successfully estimated the corresponding m7G methylation stoichiometry. m7G-quant-seq could be applied to monitor the tRNA m7G methylation level change in diverse biological processes.

ORGANISM(S): synthetic construct Homo sapiens

PROVIDER: GSE209646 | GEO | 2022/11/18

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Similar Datasets

Transcriptome Mapping of Internal N7-methylguanosine Methylome in Mammalian mRNA

Project description:N7-methylguanosine (m7G) is a positively charged, essential modification at the 5′ cap of eukaryotic mRNA, regulating mRNA export, translation, and splicing. m7G also occurs internally within tRNA and rRNA, but its existence and distribution within eukaryotic mRNA remain to be investigated. Here, we show the presence of internal m7G sites within mammalian mRNA. We then performed transcriptome-wide profiling of internal m7G methylome using m7G-MeRIP sequencing (MeRIP-seq). To map this modification at base resolution, we developed a chemical-assisted sequencing approach that selectively converts internal m7G sites into abasic sites, inducing misincorporation at these sites during reverse transcription. This base-resolution m7G-seq enabled transcriptome-wide mapping of m7G in human tRNA and mRNA, revealing distribution features of the internal m7G methylome in human cells. We also identified METTL1 as a methyltransferase that installs a subset of m7G within mRNA and showed that internal m7G methylation could affect mRNA translation.

2019-04-26 | GSE112276 | GEO

Detection of internal N7-methylguanosine (m7G) RNA modifications by mutational profiling sequencing

Project description:Methylation of guanosine on position N7 (m7G) on internal RNA positions have been found in all domains of life and have been implicated in human disease, but m7G modifications has so far only been mapped in a limited number of RNA molecules. Here, we present m7G Mutational Profiling sequencing (m7G-MaP-seq), which allows high throughput detection of m7G modifications. In our method, m7G modified positions are converted to abasic sites by mild reduction, recorded as cDNA mutations through reverse transcription, sequenced and subsequently detected by identification of positions with increased mutation rates in the reduced sample compared to the control. We show that m7G-MaP-seq efficiently detects m7G modifications in rRNA, including a previously uncharacterised rRNA modification in Arabidopsis thaliana. Furthermore, we identify m7G tRNA modifications in budding yeast, human and arabidopsis tRNA and show that m7G modification occurs before tRNA splicing. We do not find any evidence for internal m7G modifications being present in other small RNA, such as miRNA, snoRNA and sRNA. Likewise, high coverage m7G-MaP-seq analysis of mRNA from E. coli or yeast cells failed to identify any internal m7G modifications.

2018-10-30 | GSE121927 | GEO

N7-methylguanosine methylation of tRNAs regulates survival to stress in cancer

Project description:Combining transcriptome-wide approaches to detect m7G RNA methylation, in vitro functional assays and Mettl1 knockout mouse models, we provide evidence that guanosine-7 tRNA methylation is required to protect tRNAs from cleavage in response to stress, leading to impaired regulation of protein synthesis. Loss of METTL1 and tRNA methylation sensitises cancer cells to stress, reducing tumour growth and increasing cytotoxic responses to convectional cancer treatments in vitro and in vivo. Our study uncovers the role of m7G methylation of tRNAs in stress responses and highlights the potential of targeting METTL1 to sensitise cancer cells to therapy.

2024-01-26 | PXD036009 | Pride

Guanosine-7 tRNA methylation steers tRNA-derived fragment biogenesis and translational control in prostate cancer

Project description:Transfer RNAs (tRNAs) are exceptionally subject to modifications, including methylation. While mRNA methylation is emerging as an important regulator of biological and pathological processes in cancer, how post-transcriptional methylation of tRNAs contributes to cancer is largely unknown. Here we show that the RNA N7-methylguanosine (m7G) methyltransferase METTL1 is highly differentially expressed in prostate cancer compared to non-tumour prostate tissues. METTL1 expression regulation is mediated under the oncogenic PI3K-PTEN pathway. Knockdown of METTL1 dramatically inhibits prostate cancer cell growth and tumour progression in vivo. In contrast, overexpression of the wild type but not the catalytically inactive METTL1 potentiates cell growth. Thus, METTL1-mediated methylation is important for prostate tumorigenesis. Mechanistically we find that METTL1 depletion causes loss of m7G tRNA methylation and increases endonucleolytic cleavage of tRNA leading to an accumulation of 5′ tRNA-derived small RNA fragments. 5′ tRNA-derived fragments steer translation control to favour synthesis of key regulators of tumour growth suppression and immune rejection. In summary, our findings uncover a critical function of m7G tRNA methylation in directing translation control in cancer cells with important implications for tumour growth and unveil METTL1 inhibition as a promising anti-cancer therapeutic strategy.

2023-10-24 | PXD030141 | Pride

The m7G tRNA methylome regulates embryonic stem cell self-renewal and differentiation

Project description:tRNAs are subject to numerous modifications including methylation. Mutations in the human N7-methylguanosine (m7G) methyltransferase complex METTL1-WDR4 cause primordial dwarfism and brain malformation yet the molecular and cellular function in mammals is not well understood. We developed m7G methylated tRNA immunoprecipitation sequencing (MeRIP-Seq) and tRNA reduction and cleavage sequencing (TRAC-Seq) to reveal the m7G tRNA methylome in mouse embryonic stem cells (mESCs). A subset of 22 tRNAs are modified at a ‘RAGGU’ motif within the variable loop. We observe increased ribosome occupancy at the corresponding codons in Mettl1 knockout mESCs implying widespread effects on tRNA function, ribosome pausing, and mRNA translation. Translation of cell cycle genes and those associated with brain abnormalities is particularly affected. Mettl1 or Wdr4 knockout mESCs display defective self-renewal and neural differentiation. Our study uncovers the complexity of the mammalian m7G tRNA methylome and highlights its essential role in ESCs with links to human disease.

2018-07-01 | GSE112670 | GEO

Guanosine-7 tRNA methylation steers tRNA-derived fragment biogenesis and translational control in prostate cancer

Project description:Abstract Transfer RNAs (tRNAs) are exceptionally subject to modifications, including methylation. While mRNA methylation is emerging as an important regulator of biological and pathological processes in cancer, how post-transcriptional methylation of tRNAs contributes to cancer is largely unknown. Here we show that the RNA N7-methylguanosine (m7G) methyltransferase METTL1 is highly differentially expressed in prostate cancer compared to non-tumour prostate tissues. METTL1 expression regulation is mediated by the oncogenic regulator PI3K, which is altered in most advanced prostate tumours. Knockdown of METTL1 dramatically inhibits prostate cancer cell growth and tumour progression in vivo. In contrast, overexpression of the wild type but not the catalytically inactive METTL1 potentiates cell growth. Thus, METTL1-mediated methylation is important for prostate tumorigenesis. Mechanistically we find that METTL1 depletion causes loss of m7G tRNA methylation and increases endonucleolytic cleavage of Cysteine tRNA leading to an accumulation of 5′ tRNA-derived small RNA fragments. 5′ tRNA-derived fragments steer translation control to favour synthesis of key regulators of tumour growth suppression and immune rejection. In summary, our findings uncover a critical function of m7G tRNA methylation in directing translation control in cancer cells with important implications for tumour growth and unveil METTL1 inhibition as a promising anti-cancer therapeutic strategy. induction and maintenance of naïve human pluripotency are governed by distinct signaling requirements. tRNAs from WT and METTL1 KO cells were subjected to NaBH4-Aniline treatment followed by RNA-seq to unveil methylation of guanosine-7 in tRNA with nucleotie resolution. RNA-seq libraries were also analysed to unveil tRNA stability or processing into tRNA-derived fragments in METTL1 KO cells.

2023-08-08 | GSE190911 | GEO

m7G methylation by METTL1 regulates let-7 microRNAs [BoRed-Seq & m7G-RIP-Seq A549]

Project description:Methylation of N7-methylguanosine (m7G) is found at mRNA caps and at defined internal positions within abundant tRNAs and rRNAs. However, its detection within low abundance mRNAs and microRNAs (miRNAs) has been hampered by lack of sensitive detection strategies. Here, we adapt a chemical reactivity assay to detect internal m7G in RNA from eukaryotic cells. Using this approach, alongside a confirmational RNA immunoprecipitation assay, we identify m7G within miRNAs inhibiting cell migration, and show that METTL1 mediates this m7G methylation. Using Let-7 as an example we demonstrate that METTL1 activity is necessary for correct processing, is required for Let-7 dependent gene regulation and consequently has a negative effect on cell migration. These results identify m7G modification as a new pathway for the regulation of miRNAs.

2019-04-26 | GSE112181 | GEO

m7G methylation by METTL1 regulates let-7 microRNAs [Expression Microarray KD A549]

2019-04-26 | GSE112180 | GEO

m7G methylation by METTL1 regulates let-7 microRNAs [m7G-RIP-Seq KD A549]

2019-04-26 | GSE120455 | GEO

m7G methylation by METTL1 regulates let-7 microRNAs [m7G-RIP-Seq Caco2]

2019-04-26 | GSE120454 | GEO