tRNA methylation

N 6 -methyladenosine (m6 A) is a prevalent internal modification in eukaryotic mRNA, tRNA, miRNA, and long non-coding RNA. It is also known for its role in plant responses to biotic and abiotic stresses. However, a comprehensive m6 A transcriptome-wide map for Puccinia striiformis f. sp. tritici ( Pst ) infections in wheat ( Triticum aestivum ) is currently unavailable. Our study is the first to profile m6 A modifications in wheat infected with a virulent Pst race. Analysis of RNA-seq and MeRIP-seq data revealed that the majority of differentially expressed genes are up-regulated and hyper-methylated...

The wobble bases of tRNAs that decode split codons are often heavily modified. In bacteria, tRNAGlu, Gln, Asp contains a variety of xnm5 s2 U derivatives. The synthesis pathway for these modifications is complex and fully elucidated only in a handful of organisms, including the Gram-negative Escherichia coli K12 model. Despite the ubiquitous presence of mnm5 s2 U modification, genomic analysis shows the absence of mnmC orthologous genes, suggesting the occurrence of alternate biosynthetic schemes for the conversion of cmnm5 s2 U to mnm5 s2 U...

Human APOBEC3 enzymes are a family of single-stranded (ss)DNA and RNA cytidine deaminases that act as part of the intrinsic immunity against viruses and retroelements. These enzymes deaminate cytosine to form uracil which can functionally inactivate or cause degradation of viral or retroelement genomes. In addition, APOBEC3s have deamination independent antiviral activity through protein and nucleic acid interactions. If expression levels are misregulated, some APOBEC3 enzymes can access the human genome leading to deamination and mutagenesis, contributing to cancer initiation and evolution...

RNA 2'-O-methylation (Nm) is highly abundant in noncoding RNAs including ribosomal RNA (rRNA), transfer RNA (tRNA), and small nuclear RNA (snRNA), and occurs in the 5' cap of virtually all messenger RNAs (mRNAs) in higher eukaryotes. More recently, Nm has also been reported to occur at internal sites in mRNA. High-throughput methods have been developed for the transcriptome-wide detection of Nm. However, these methods have mostly been applied to abundant RNAs such as rRNA, and the validity of the internal mRNA Nm sites detected with these approaches remains controversial...

N 1 -methyl adenosine (m1 A) is a wide-spread RNA modification present in tRNA, rRNA and mRNA. m1 A modification sites in tRNAs are evolutionary conserved and its formation on tRNA is catalyzed by methyltransferase TRMT61A and TRMT6 complex. m1 A promotes translation initiation and elongation. Due to its positive charge under physiological conditions, m1 A can notably modulate RNA structure. It also blocks Watson-Crick-Franklin base pairing and causes mutation and truncation during reverse transcription. Several misincorporation-based high throughput sequencing methods have been developed to sequence m1 A...

YARS is responsible for catalysing the binding of tyrosine to its cognate tRNA and plays a crucial role in basic biosynthesis. However, its biological functions in bladder cancer remains to be proven. We analysed variations in YARS1 expression and survival in bladder cancer using multiple data sets, including TCGA-BLCA, GSE13507 and bladder cancer-specific tissue microarrays. Furthermore, we explored the biological functions of YARS1 using transcriptome data. Our findings revealed a noteworthy correlation between YARS1 and immune infiltration in bladder cancer, as determined using the XCELL algorithm and single-cell analysis...

To analyze the metabolites (blood, urine and feces) in normal rats after intragastric administration of the decoction of Phellodendri Amurensis Cortex (PAC) and to map the metabolic profile of PAC in vivo of rat; meanwhile, to evaluate the anti-rheumatoid arthritis (RA) effect of PAC by blood metabolomics technique and to explore its mechanism. Performing on UPLC-Q-TOF-MS technology with a Waters ACQUITY UPLC BEH-C18 column (100 mm × 2.1 mm, 1.7 μm), the mobile phase was acetonitrile-0...

Introduction: Post-transcriptional RNA modifications are crucial regulators of tumor development and progression. In many biological processes, N1 -methyladenosine (m1 A) plays a key role. However, little is known about the links between chemical modifications of messenger RNAs (mRNAs) and long noncoding RNAs (lncRNAs) and their function in bladder cancer (BLCA). Methods: Methylated RNA immunoprecipitation sequencing and RNA sequencing were performed to profile mRNA and lncRNA m1 A methylation and expression in BLCA cells, with or without stable knockdown of the m1 A methyltransferase tRNA methyltransferase 61A (TRMT61A)...

Translation of messenger RNA (mRNA) in bacteria occurs in the steps of initiation, elongation, termination, and ribosome recycling. The initiation step comprises multiple stages and uses a special transfer RNA (tRNA) called initiator tRNA (i-tRNA), which is first aminoacylated and then formylated using methionine and N10 -formyl-tetrahydrofolate (N10 -fTHF), respectively. Both methionine and N10 -fTHF are produced via one-carbon metabolism, linking translation initiation with active cellular metabolism. The fidelity of i-tRNA binding to the ribosomal peptidyl-site (P-site) is attributed to the structural features in its acceptor stem, and the highly conserved three consecutive G-C base pairs (3GC pairs) in the anticodon stem...

Human APOBEC3 enzymes are a family of single-stranded (ss)DNA and RNA cytidine deaminases that act as part of the intrinsic immunity against viruses and retroelements. These enzymes deaminate cytosine to form uracil which can functionally inactivate or cause degradation of viral or retroelement genomes. In addition, APOBEC3s have deamination independent antiviral activity through protein and nucleic acid interactions. If expression levels are misregulated, some APOBEC3 enzymes can access the human genome leading to deamination and mutagenesis, contributing to cancer initiation and evolution...

Introduction - tRNA-derived fragments (tRFs) play an important role in immune responses. To clarify the role of tRFs in autoimmunity we studied circulating tRF-levels in patients with rheumatoid arthritis (RA) and psoriatic arthritis (PsA), and in a murine model for arthritis. Material and Methods - Circulating tRF-levels were quantified by miR-Q RT-qPCR. tRNA processing and modification enzyme expression was analyzed by RT-qPCR and public transcriptomics data. Results - Significant reduction (up to 3-fold on average) of tRF-levels derived from tRNA-Gly-GCC,CCC, tRNA-Glu-CTC, and tRNA-Val-CAC,AAC was observed in RA patients, whereas tRNA-Glu-CTC and tRNA-Val-CAC,AAC tRFs were found at significantly higher levels (up to 3-fold on average) in PsA patients, compared to healthy controls...

S-adenosylmethionine (SAM), generated from methionine and ATP by S-adenosyl methionine synthetase (SAMS), is the universal methyl group donor required for numerous cellular methylation reactions. In Caenorhabditis elegans, silencing sams-1, the major isoform of SAMS, genetically or via dietary restriction induces a robust mitochondrial unfolded protein response (UPRmt ) and lifespan extension. In this study, we found that depleting SAMS-1 markedly decreases mitochondrial SAM levels. Moreover, RNAi knockdown of SLC-25A26, a carrier protein responsible for transporting SAM from the cytoplasm into the mitochondria, significantly lowers the mitochondrial SAM levels and activates UPRmt , suggesting that the UPRmt induced by sams-1 mutations might result from disrupted mitochondrial SAM homeostasis...

Alanyl-tRNA synthetase (AlaRS) incorrectly recognizes both a slightly smaller glycine and a slightly larger serine in addition to alanine, and the probability of incorrect identification is extremely low at 1/300 and 1/170, respectively. Alanine is the second smallest amino acid after glycine; however, the mechanism by which AlaRS specifically identifies small differences in side chains with high accuracy remains unknown. In this study, using a malachite green assay, we aimed to elucidate the alanine recognition mechanism of a fragment (AlaRS368N) containing only the amino acid activation domain of Escherichia coli AlaRS...

DNA cytosine methylation has been documented as a potential epigenetic mechanism of transcriptional regulation underlying opioid use disorder. However, methylation of RNA cytosine residues, which would drive another level of biological influence as an epitranscriptomic mechanism of gene and protein regulation has not been studied in the context of addiction. Here, we probed whether chronic morphine exposure could alter tRNA cytosine methylation (m5 C) and resulting expression levels in the medial prefrontal cortex (mPFC), a brain region crucial for reward processing and executive function that exhibits opioid-induced molecular restructuring...

ConspectusRNA modification is a co- or post-transcriptional process by which specific nucleotides are chemically altered by enzymes after their initial incorporation into the RNA chain, expanding the chemical and functional diversity of RNAs. Our understanding of RNA modifications has changed dramatically in recent years. In the past decade, RNA methyltransferases (MTases) have been highlighted in numerous clinical studies and disease models, modifications have been found to be dynamically regulated by demodification enzymes, and significant technological advances have been made in the fields of RNA sequencing, mass spectrometry, and structural biology...

Metabolic reprogramming is a hallmark of cancer that facilitates changes in many adaptive biological processes. Mutations in the tricarboxylic acid cycle enzyme fumarate hydratase (FH) lead to fumarate accumulation and cause hereditary leiomyomatosis and renal cell cancer (HLRCC). HLRCC is a rare, inherited disease characterized by the development of non-cancerous smooth muscle tumors of the uterus and skin, and an increased risk of an aggressive form of kidney cancer. Fumarate has been shown to inhibit 2-oxoglutarate-dependent dioxygenases (2OGDDs) involved in the hydroxylation of HIF1α, as well as in DNA and histone demethylation...

RNA modification C2 -methyladenosine (m2 A) exists in both rRNA and tRNA of Escherichia coli (E. coli), installed by the methyltransferase RlmN using a radical-S-adenosylmethionine (SAM) mechanism. However, the precise function of m2 A in tRNA and its ubiquity in plants have remained unclear. Here we discover the presence of m2 A in chloroplast rRNA and tRNA, as well as cytosolic tRNA, in multiple plant species. We identify six m2 A-modified chloroplast tRNAs and two m2 A-modified cytosolic tRNAs across different plants...

Human tRNA (uracil-5-)-methyltransferase 2 homolog A (TRMT2A) is the dedicated enzyme for the methylation of uridine 54 in transfer RNA (tRNA). Human TRMT2A has also been described as a modifier of polyglutamine (polyQ)-derived neuronal toxicity. The corresponding human polyQ pathologies include Huntington's disease and constitute a family of devastating neurodegenerative diseases. A polyQ tract in the corresponding disease-linked protein causes neuronal death and symptoms such as impaired motor function, as well as cognitive impairment...

Callus suspension techniques have been considered attractive for improving bioactive metabolite productivity; methyl jasmonate (MeJA) is a widely used elicitor for stimulating synthetic pathways. In this study, a multivariate analysis-based metabolomics approach was employed to investigate the primary and specialized metabolites in the leaves, unelicited calli, and 100 or 200 μM MeJA elicited calli of Damnacanthus major . Rubiadin, a powerful anthraquinone with various therapeutic properties, was only identified in D...

Serine is a metabolite with ever-expanding metabolic and non-metabolic signaling attributes. By providing one‑carbon units for macromolecule biosynthesis and functional modifications, serine and serine metabolism largely impinge on cellular survival and function. Cancer cells frequently have a preference for serine metabolic reprogramming to create a conducive metabolic state for survival and aggressiveness, making intervention of cancer-associated rewiring of serine metabolism a promising therapeutic strategy for cancer treatment...