Glioblastoma stem cells after METTL8 knockdown.
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE190804 | GEO | 2024/02/12
REPOSITORIES: GEO
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Project description:This project investigates the role METTL8 in human glioblastoma stem cells. In order to understand the transcriptomic changes upon deletion of METTL8, we performed this ChIP-seq and further downstream analyses. From this, we hope to identify novel methods to target glioblastoma stem cells via manipulation of METTL8.
2024-04-12 | GSE229482 | GEO
Project description:Glioblastoma stem cells after METTL8 knockdown.
| PRJNA788505 | ENA
Project description:Increasing evidence implicates critical roles of various epitranscriptomic RNA modifications in different biological processes. Methyltransferase METTL8 installs 3-methylcytosine modification of mitochondrial tRNAs in vitro, however, its role in intact biological systems is completely unknown. Here we show that Mettl8 is localized in the mitochondria and installs m3C in mitochondrial tRNASer(UCN)/Thr in mouse embryonic cortical neural stem cells. At molecular and cellular levels, Mettl8 deletion in cortical neural stem cells leads to reduced mitochondrial protein translation and attenuated respiration activity. At the functional level, conditional Mettl8 deletion in mice results in impaired embryonic cortical neural stem cell maintenance in vivo, which can be rescued by pharmacologically enhancing mitochondrial functions. Similarly, METTL8 regulates mitochondrial protein expression and neural stem cell maintenance in human forebrain cortical organoids. Together, our study reveals a conserved epitranscriptomic mechanism of Mettl8 and mitochondrial tRNA m3C modification in maintaining embryonic cortical neural stem cells in mice and humans.
2023-01-12 | GSE214445 | GEO
Project description:The capacity of embryonic stem cells to differentiate into all lineages of mature organism is precisely regulated by cellular signaling factors. STAT3 is a crucial transcription factor that plays a central role in maintaining embryonic stem cells identity. However the underlying mechanism how Stat3 directs differentiation is still not completely understood. Here we show that Stat3 positively regulates gene expression of methyltransferase like protein 8 (Mettl8) in mouse ES cells. We found that Mettl8 is dispensable for pluripotency but affects ESCs differentiation. Subsequently we discovered that Mettl8 interacts with Mapkbp1’s mRNA, which is an intermediate factor in JNK signaling, and inhibits the translation of the mRNA. Thereby, Mettl8 prohibits the activation of JNK signaling and enhances the differentiation of mouse ESCs. Collectively, our study uncovers a Stat3 target Mettl8 which regulates mouse ESCs differentiation via JNK signaling.
2018-06-14 | GSE112360 | GEO
Project description:Dendritic cell (DC)-based immunotherapy against glioblastoma multiforme is a novel treatment hope. Glioblastoma stem-like cells are, however, potentially causing immunoresistance. Glioblastoma cells cultured as gliomaspheres show a stem-like phenotype as opposed to classical adherent culture. They are thus a promising antigen source to specifically target glioblastoma stem-like cells via DC therapy and so overcome immunoresistance. Here we study the importance of gliomasphere-specific. Methodologically, we used 7 gliomaspheres, 3 of them patient-derived, as model system. Gliomasphere-specific protein expression was explored via quantitative proteomics.
2019-04-15 | PXD008244 | Pride
Project description:A subset of eukaryotic tRNAs is methylated in the anticodon loop to form the 3-methylcytosine (m3C) modification. In mammals, the number of tRNAs containing m3C has expanded to include mitochondrial (mt) tRNA-Ser-UGA and mt-tRNA-Thr-UGU. Whereas the enzymes catalyzing m3C formation in nuclear-encoded cytoplasmic tRNAs have been identified, the proteins responsible for m3C modification in mt-tRNAs are unknown. Here, we show that m3C formation in human mt-tRNAs is dependent upon the Methyltransferase-Like 8 (METTL8) enzyme. We find that METTL8 is a mitochondria-associated protein that interacts with mitochondrial seryl-tRNA synthetase along with mt-tRNAs containing m3C. Human cells deficient in METTL8 exhibit loss of m3C modification in mt-tRNAs but not nuclear-encoded tRNAs. Consistent with the mitochondrial import of METTL8, the formation of m3C in METTL8-deficient cells can be rescued by re-expression of wildtype METTL8 but not by a METTL8 variant lacking the N-terminal mitochondrial localization signal. Notably, METTL8-deficiency in human cells causes alterations in the native migration pattern of mt-tRNA-Ser-UGA suggesting a role for m3C in tRNA folding. Altogether, these findings demonstrate that METTL8 is required for m3C formation in mitochondrial tRNAs and uncover a potential role for m3C modification in mitochondrial tRNA structure.
2022-05-19 | PXD030418 | Pride
Project description:Modified nucleotides in tRNAs are important determinants of folding, structure and function. Here, we identify METTL8 as a mitochondrial matrix protein and active RNA methyltransferase responsible for installing m3C32 in the human mitochondrial (mt-)tRNAThr and mt-tRNASer(UCN). METTL8 crosslinks to the anticodon stem loop (ASL) of many mt-tRNAs in cells, raising the question of how methylation target specificity is achieved. Dissection of mt-tRNA recognition elements revealed U34G35 and t6A37/(ms2)i6A37, present concomitantly only in the ASLs of the two substrate mt-tRNAs, as key determinations for METTL8-mediated methylation of C32. Several lines of evidence demonstrate the influence of U34, G35, and the m3C32 and t6A37/(ms2)i6A37 modifications in mt-tRNAThr/Ser(UCN) on the structure of these mt-tRNAs. Although mt-tRNAThr/Ser(UCN) lacking METTL8-mediated m3C32 are efficiently aminoacylated and associate with mitochondrial ribosomes, mitochondrial translation is mildly impaired by lack of METTL8. Together these results define the cellular targets of METTL8 and shed new light on the role of m3C32 within mt-tRNAs.
2021-12-04 | GSE174448 | GEO
Project description:Modified nucleotides in tRNAs are important determinants of folding, structure and function. Here, we identify METTL8 as a mitochondrial matrix protein and active RNA methyltransferase responsible for installing m3C32 in the human mitochondrial (mt-)tRNAThr and mt-tRNASer(UCN). METTL8 crosslinks to the anticodon stem loop (ASL) of many mt-tRNAs in cells, raising the question of how methylation target specificity is achieved. Dissection of mt-tRNA recognition elements revealed U34G35 and t6A37/(ms2)i6A37, present concomitantly only in the ASLs of the two substrate mt-tRNAs, as key determinations for METTL8-mediated methylation of C32. Several lines of evidence demonstrate the influence of U34, G35, and the m3C32 and t6A37/(ms2)i6A37 modifications in mt-tRNAThr/Ser(UCN) on the structure of these mt-tRNAs. Although mt-tRNAThr/Ser(UCN) lacking METTL8-mediated m3C32 are efficiently aminoacylated and associate with mitochondrial ribosomes, mitochondrial translation is mildly impaired by lack of METTL8. Together these results define the cellular targets of METTL8 and shed new light on the role of m3C32 within mt-tRNAs.
2021-12-04 | GSE185015 | GEO
Project description:Mitochondria contain a specific translation machinery for the synthesis of respiratory chain components encoded on the mitochondrial genome. Mitochondrial tRNAs (mt-tRNAs) are also generated from the mitochondrial genome and, similar to their cytoplasmic counterparts, are modified at various positions. Here, we find that the RNA methyltransferase METTL8, is a mitochondrial protein that facilitates m3C methylation at position C32 of mt-tRNASer(UCN) and mt-tRNAThr. METTL8 knock out cells show reduced and over expressing cells enhanced respiratory chain activity. In pancreatic cancer, METTL8 levels are high, which correlates with patient survival. Indeed, METTL8 up regulation stimulates respiratory chain activity in these cells. Ribosome occupancy analysis using ribosome profiling revealed ribosome stalling on mt-tRNASer(UCN) and mt-tRNAThr codons and mass spectrometry analysis of native ribosomal subcomplexes unraveled reduced respiratory chain incorporation of the mitochondria encoded proteins ND6 and ND1. A well-balanced translation of mt-tRNASer(UCN) and mt-tRNAThr codons through METTL8-mediated C32 methylation might therefore provide optimal respiratory chain compositions and function.
2023-01-02 | GSE180400 | GEO
Project description:Methyltransferase-like 8 (METTL8) is a RNA methyltransferase that plays a crucial role in mitochondrial translation. Previous study reported that METTL8 is overexpressed in cancer, but whether it contributes to GBM pathogenesis has not been explored. Here, we find that METTL8 is overexpressed in GBM stem cells (GSC) relative to non-cancerous human neural progenitor cells and astrocytes. METTL8 depletion significantly reduces GSC tumorsphere formation, differentiation potential, invasiveness and tumorigenicity. As expected, METTL8 is localized to the mitochondrial matrix of GSC. Although it is established that METTL8 binds to tRNAs, the protein interactors of METTL8 remains uncharacterized. To this end, we aim to define the METTL8 interactome using mitochondrial fractions of 293T cells, and then validate the identified interactors in GSC.
2024-03-22 | PXD041018 | JPOST Repository