NSUN2 introduces 5-methylcytosines in mammalian mitochondrial tRNAs
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ABSTRACT:
PROVIDER: PRJNA545637 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR9165393.fastq.gz | Fastqsanger.gz | |||
| SRR9165394.fastq.gz | Fastqsanger.gz | |||
| SRR9165395.fastq.gz | Fastqsanger.gz | |||
| SRR9165397.fastq.gz | Fastqsanger.gz |
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Project description:We show that NSUN2 in necessary for the generation of m5C at positions 48, 49 and 50 of several mammalian mitochondrial tRNAs
2019-06-19 | GSE132020 | GEO
Project description:Expression of human mitochondrial DNA is indispensable for proper function of the oxidative phosphorylation machinery. The mitochondrial genome encodes 22 tRNAs, 2 rRNAs and 11 mRNAs and their post-transcriptional modification constitutes one of the key regulatory steps during mitochondrial gene expression. Cytosine-5 methylation (m5C) has been detected in mitochondrial transcriptome, however its biogenesis has not been investigated in details. Mammalian NOP2/Sun RNA Methyltransferase Family Member 2 (NSUN2) has been characterized as an RNA methyltransferase introducing m5C in nuclear-encoded tRNAs, mRNAs and microRNAs and associated with cell proliferation and differentiation, with pathogenic variants in NSUN2 being linked to neurodevelopmental disorders. Here we employ spatially restricted proximity labelling and immunodetection to demonstrate that NSUN2 is imported into the matrix of mammalian mitochondria. Using three genetic models for NSUN2 inactivation-knockout mice, patient-derived fibroblasts and CRISPR/Cas9 knockout in human cells-we show that NSUN2 is necessary for the generation of m5C at positions 48, 49 and 50 of several mammalian mitochondrial tRNAs. Finally, we show that inactivation of NSUN2 does not have a profound effect on mitochondrial tRNA stability and oxidative phosphorylation in differentiated cells. We discuss the importance of the newly discovered function of NSUN2 in the context of human disease.
| S-EPMC6822013 | biostudies-literature
Project description:Post-transcriptional modifications in mitochondrial tRNAs (mt-tRNAs) play critical roles in mitochondrial protein synthesis, which produces respiratory chain complexes. In this study, we took advantage of mass spectrometric analysis to map 5-methylcytidine (m5C) at positions 48-50 in eight mouse and six human mt-tRNAs. We also confirmed the absence of m5C in mt-tRNAs isolated from Nsun2 knockout (KO) mice, as well as from NSUN2 KO human culture cells. In addition, we successfully reconstituted m5C at positions 48-50 of mt-tRNA in vitro with NSUN2 protein in the presence of S-adenosylmethionine. Although NSUN2 is predominantly localized to the nucleus and introduces m5C into cytoplasmic tRNAs and mRNAs, structured illumination microscopy clearly revealed NSUN2 foci inside mitochondria. These observations provide novel insights into the role of NSUN2 in the physiology and pathology of mitochondrial functions.
| S-EPMC6895283 | biostudies-literature
Project description:The role of transfer (t)RNA cytosine methyl-transferases as epitranscriptomic regulators of brain proteomes remains unexplored. We report that fear memory and antidepressant-like behaviors are highly sensitive to bi-directional changes in Nsun2 tRNA methyltransferase activity in prefrontal cortex (PFC) neurons. Nsun2-deficient mutant cortex showed a selective deficit in multiple glycine tRNAs, resulting in codon-specific shifts in translational efficiencies and a distorted proteomic landscape with deficits in glycine-rich neuronal proteins impacting synaptic signaling and behavior.
2021-07-02 | PXD023437 | Pride
Project description:Epitranscriptomic mechanisms linking the brain proteome to cognition and complex behaviors essentially remain unexplored. Here, we describe bi-directional changes in depression-related behaviors after genetic disruption of neuronal tRNA cytosine methylation, including conditional ablation and transgene-derived overexpression of NOL1/NOP2/SUN domain 2 (Nsun2) in the prefrontal cortex (PFC). Neuronal Nsun2-deficiency was associated with a sharp drop in tRNA m5C levels, resulting in significant deficits in expression of 70% (7/10) of tRNAGlyGCC, GlyCCC GlyTCC isodecoders, while expression changes in non-glycinergic tRNAs were minimal (4/152). Altogether, 1488/5820 proteins were sensitive to neuronal Nsun2-deficiency, in conjunction with GCC and CCC codon-specific defects in translational efficiencies and loss of Gly-rich proteins critical for glutamatergic neurotransmission, resulting in impaired synaptic signaling at PFC pyramidal neurons and impairments in contextual fear memory. These distortions in the neuronal translatome were associated with an adaptive, 2.46-fold up-regulation in PFC glycine levels with increased expression of multiple enzymes in the glycine biosynthetic pathway. These findings highlight the methylation sensitivity of glycinergic tRNAs in the adult PFC and link synaptic plasticity and complex behaviors to epitranscriptomic regulation of cognate tRNAs and the proteomic homeostasis associated with specific amino acids.
2021-07-01 | GSE165202 | GEO
Project description:While performing mitochondrial isolations and recently developed tRNA-seq methods (AlkB treatment and YAMAT-Seq) in plant tissue, we inadvertently sequenced the mitochondrial tRNAs from a common plant pest, the acariform mite Tetranychus urticae, to a high enough coverage to detect all previously annotated T. urticae tRNA regions. The results not only confirm expression, CCA-tailing and post-transcriptional base modification of these highly divergent tRNAs, but also revealed paired sense and antisense expression of multiple T. urticae mitochondrial tRNAs.
2020-12-10 | GSE162913 | 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:Balancing of mitochondrial translation through METTL8-mediated m3C modification of mitochondrial tRNAs
| PRJNA748058 | ENA
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:Aims: Mammalian mRNA internal modification m6A has been suggested to be essential in the maintenance of cardiac homeostasis. The role of mRNA cytosine methylation (m5C) in the heart remains unexplored.Methods and results: In contrast with human normal heart, the expression of RNA cytosine methyltransferase NSun2 was found to be significantly elevated in the hypertrophied one. Consistently, NSun2 expression was increased in hypertrophic rat ventricular myocytes induced in vitro, as well as in TAC (transverse aortic constriction) developed hypertrophied murine heart. Cardiomyocyte-specific knockout of NSun2 (Myh6-CreERT2, NSun2 flox+/+) dramatically accelerated heart failure progression in TAC mice. RNA m5C immunoprecipitation followed by sequencing and MeRIP (methylation-specific RNA immunoprecipitation) revealed that NSun2 particularly methylates the mRNA of protein kinase A (PKA) catalytic subunit alpha (PRKACA). Polyribosome and dual luciferase reporter gene analysis further suggested that NSun2 promotes PRKACA translation via RNA methylation. In TAC hypertrophic cardiomyocytes, NSun2 ablation markedly dampened PKA signaling, as evidenced by reduced PKA activity and protein phosphorylation levels of PKA diverse substrates, impaired myocyte contraction and relaxation, and disturbed calcium transients. Cardiac-restricted overexpression of NSun2 via adeno-associated virus 9 (AAV9, NSun2 expression cassette driven by cTnT promoter) sensitized heart hypertrophic response, whereas administration of PKA inhibitor H89 successfully blocked this process, reiterating the importance of NSun2-PRKACA regulation in cardiac hypertrophic program.Conclusions: Our study showed that RNA methyltransferase NSun2 promotes PRKACA translation via RNA methylation, whereby achieving its modulation of PKA signaling within the cardiomyocyte. NSun2-PRKACA regulation is required for cardiac homeostasis maintenance and adaptation to hypertrophic stresses. These findings furnish us with novel understanding of heart function mediated by mRNA cytosine methylation in cardiac homeostasis.
2025-02-26 | GSE234445 | GEO