A scaffold lncRNA shapes the mitosis to meiosis switch.

Long non-coding RNAs (lncRNAs) contribute to the regulation of gene expression in response to intra- or extracellular signals but the underlying molecular mechanisms remain largely unexplored. Here, we identify an uncharacterized lncRNA as a central player in shaping the meiotic gene expression program in fission yeast. We report that this regulatory RNA, termed mamRNA, scaffolds the antagonistic RNA-binding proteins Mmi1 and Mei2 to ensure their reciprocal inhibition and fine tune meiotic mRNA degradation during mitotic growth.

The hyperthermophilic partners Nanoarchaeum and Ignicoccus stabilize their tRNA T-loops via different but structurally equivalent modifications.

The universal L-shaped tertiary structure of tRNAs is maintained with the help of nucleotide modifications within the D- and T-loops, and these modifications are most extensive within hyperthermophilic species. The obligate-commensal Nanoarchaeum equitans and its phylogenetically-distinct host Ignicoccus hospitalis grow physically coupled under identical hyperthermic conditions. We report here two fundamentally different routes by which these archaea modify the key conserved nucleotide U54 within their tRNA T-loops.

Profiling of modified nucleosides from ribonucleic acid digestion by supercritical fluid chromatography coupled to high resolution mass spectrometry.

A method based on supercritical fluid chromatography coupled to high resolution mass spectrometry for the profiling of canonical and modified nucleosides was optimized, and compared to classical reverse-phase liquid chromatography in terms of separation, number of detected modified nucleosides and sensitivity. Limits of detection and quantification were measured using statistical method and quantifications of twelve nucleosides of a tRNA digest from E. coli are in good agreement with previously reported data.

Characterization of redundant tRNAIles with CAU and UAU anticodons in Lactobacillus plantarum.

In most eubacteria, the minor AUA isoleucine codon is decoded by tRNAIle2, which has a lysidine (L) in the anticodon loop. The lysidine is introduced by tRNAIle-lysidine synthetase (TilS) through post-transcriptional modification of cytidine to yield an LAU anticodon. Some bacteria, Lactobacillus plantarum for example, possess two tRNAIle2(UAU) genes in addition to, two tRNAIle2(CAU) genes and the tilS gene.

The human tRNA m (5) C methyltransferase Misu is multisite-specific.

The human tRNA m ( 5) C methyltransferase Misu is a novel downstream target of the proto-oncogene Myc that participates in controlling cell division and proliferation. Misu catalyzes the transfer of a methyl group from S-adenosyl-L-methionine to carbon 5 of cytosines in tRNAs. It was previously shown to catalyze in vitro the intron-dependent formation of m ( 5) C at the first position of the anticodon (position 34) within the human pre-tRNA (Leu) (CAA).