Search results for "Transfer RNA"
showing 10 items of 87 documents
The ribose methylation enzyme FTSJ1 has a conserved role in neuron morphology and learning performance
2021
ABSTRACTFTSJ1 is a conserved human 2’-O-methyltransferase (Nm-MTase) that modifies several transfer RNAs (tRNAs) at position 32 and the wobble position 34 in the AntiCodon Loop (ACL). Its loss of function has been linked to Non-Syndromic X-Linked Intellectual Disability (NSXLID), and more recently to cancers. However, the molecular mechanisms underlying these pathologies are currently unclear. Here we report a novelFTSJ1pathogenic variant from a NSXLID patient. Using blood cells derived from this patient and other affected individuals carryingFTSJ1mutations, we performed an unbiased and comprehensive RiboMethSeq analysis to map the ribose methylation (Nm) on all human tRNAs and identify nov…
5’ tRNA halves are highly expressed in the primate hippocampus and sequence-specifically regulate gene expression
2019
AbstractFragments of mature tRNAs have long been considered as mere degradation products without physiological function. However, recent reports show that tRNA fragments (tRFs) play prominent roles in diverse cellular processes across a wide spectrum of species. Contrasting the situation in other small RNA pathways the mechanisms behind these effects appear more diverse, more complex and are generally less well understood. In addition, surprisingly little is known about the expression profiles of tRFs across different tissues and species. Here, we provide an initial overview of tRF expression in different species and tissues, revealing very high tRF-levels particularly in the primate hippoc…
The σ B -dependent regulatory sRNA Rli47 represses isoleucine biosynthesis in Listeria monocytogenes through a direct interaction with the ilvA trans…
2019
International audience; The facultative intracellular pathogen Listeria monocytogenes can persist and grow in a diverse range of environmental conditions, both outside and within its mammalian host. The alternative sigma factor Sigma B (sigma(B)) plays an important role in this adaptability and is critical for the transition into the host. While some of the functions of the sigma(B) regulon in facilitating this transition are understood the role of sigma(B)-dependent small regulatory RNAs (sRNAs) remain poorly characterized. In this study, we focused on elucidating the function of Rli47, a sigma(B)-dependent sRNA that is highly induced in the intestine and in macrophages. Using a combinatio…
Cytosine methylation of tRNA-Asp by DNMT2 has a role in translation of proteins containing poly-Asp sequences
2015
AbstractThe Dnmt2 RNA methyltransferase catalyses the methylation of C38 in the anticodon loop of tRNA-Asp, but the molecular role of this methylation is unknown. Here, we report that mouse aspartyl-tRNA synthetase shows a four to fivefold preference for C38-methylated tRNA-Asp. Consistently, a 30% reduced charging level of tRNA-Asp was observed in Dnmt2 knockout (KO) murine embryonic fibroblast cells. Gene expression analysis with fluorescent reporter proteins fused to an N-terminal poly-Asp sequence showed that protein synthesis of poly-Asp-tagged reporter proteins was reduced in Dnmt2 KO cells as well. The same effect was observed with endogenous proteins containing poly-Asp sequences, i…
Mapping of 7-methylguanosine (m7G), 3-methylcytidine (m3C), dihydrouridine (D) and 5-hydroxycytidine (ho5C) RNA modifications by AlkAniline-Seq
2021
Precise and reliable mapping of modified nucleotides in RNA is a challenging task in epitranscriptomics analysis. Only deep sequencing-based methods are able to provide both, a single-nucleotide resolution and sufficient selectivity and sensitivity. A number of protocols employing specific chemical reagents to distinguish modified RNA nucleotides from canonical parental residues have already proven their performance. We developed a deep-sequencing analytical pipeline for simultaneous detection of several modified nucleotides of different nature (methylation, hydroxylation, reduction) in RNA. The AlkAniline-Seq protocol uses intrinsic fragility of the N-glycosidic bond present in certain mod…
Mapping and Quantification of tRNA 2′-O-Methylation by RiboMethSeq
2018
Current development of epitranscriptomics field requires efficient experimental protocols for precise mapping and quantification of various modified nucleotides in RNA. Despite important advances in the field during the last 10 years, this task is still extremely laborious and time-consuming, even when high-throughput analytical approaches are employed. Moreover, only a very limited subset of RNA modifications can be detected and only rarely be quantified by these powerful techniques. In the past, we developed and successfully applied alkaline fragmentation-based RiboMethSeq approach for mapping and precise quantification of multiple 2'-O-methylation residues in ribosomal RNA. Here we descr…
Identification and structural characterization of O-beta-ribosyl-(1"----2')-adenosine-5"-phosphate in yeast methionine initiator tRNA.
1990
We report in this paper on the complete structure determination of the modified nucleotide A*, now called Ar(p), that was previously identified in yeast methionine initiator tRNA as an isomeric form of O-ribosyl-adenosine bearing an additional phosphoryl-monoester group on its ribose2 moiety. By using the chemical procedure of periodate oxidation and subsequent beta-elimination with cyclohexylamine on mono- and dinucleotides containing Ar(p), we characterized the location of the phosphate group on the C-5" of the ribose2 moiety, and the linkage between the two riboses as a (1"----2')-glycosidic bond. Since the structural difference between phosphatase treated Ar(p) and authentic O-alpha-rib…
Retrovirus infection and aging: Increase in UAG suppressor tRNA expression in aged mice.
1994
Summary The effect of aging on expression of a natural glutamine suppressor tRNA (tRNA Gln(UmUG) ) was studied in different tissues of mice; this tRNA recognizes UAG and inserts glutamine at the site of the termination codon. The level of tRNA Gln(UmUG) was found to be strongly increased in aged mice, compared to newborn and mature animals. An elevated expression of tRNA Gln(UmUG) has also been found in retrovirus-infected cells; in Moloney virus-infected cells the suppressor tRNA allows to read-through the UAG codon within the retroviral protease gene. We suggest that the increase in the level of tRNA Gln(UmUG) may influence retroviral gene expression with age.
Sequence of a new tRNALeu(U∗AA) from brewer's yeast
1991
The nucleotide sequence of a new tRNA(Leu)(anticodon U*AA) from Saccharomyces cerevisiae which could recognize exclusively the UUA codon has been determined. Its primary structure is: pGGAGGGUUGm2GCac4CGAGDGmGDCDAAGGCm2(2)GGCAGACmUU*AAm1GA++ + psi CUGUUGGACGGUUGUCCGm5CGCGAGT psi CGm1A(orA)ACCUCGCAUCCUUCACCA. This tRNA has a large extraloop and contains 15 modified nucleotides. So far it is the third isoacceptor tRNA for leucine in yeast. It has 61% homology with tRNA(Leu)(anticodon m5CAA) and 63% homology with tRNA(Leu)(anticodon UAG), the two other known yeast tRNAs(Leu).
tRNA stabilization by modified nucleotides.
2010
Post-transcriptional ribonucleotide modification is a phenomenon best studied in tRNA, where it occurs most frequently and in great chemical diversity. This paper reviews the intrinsic network of modifications in the structural core of the tRNA, which governs structural flexibility and rigidity to fine-tune the molecule to peak performance and to regulate its steady-state level. Structural effects of RNA modifications range from nanometer-scale rearrangements to subtle restrictions of conformational space on the angstrom scale. Structural stabilization resulting from nucleotide modification results in increased thermal stability and translates into protection against unspecific degradation …