Transfer RNA-derived small RNAs (tsRNAs, or tDRs) perform a range of cellular functions. Here, we showed that a hypoxia-induced tDR, derived from the 3′ end of tRNA-Asp-GTC (tRNA-Asp-GTC-3′tDR), activ...

tRNA‑derived RNAs transmit paternal epigenetic information, yet their regulation is poorly defined. Here, the authors demonstrate RNST‑2–mediated tDR processing in C. elegans sperm, showing how tDRs s...

tRNA-derived small RNAs (tsRNAs) are a class of non-coding RNA molecules generated through the cleavage of tRNA, primarily categorized into tRNA-derived fragments (tRFs) and tRNA-derived stress-induce...

Nature Reviews Nephrology, Published online: 26 August 2025; doi:10.1038/s41581-025-01001-9Regulation of autophagy by a tRNA-derived fragment

We identify bi-allelic variants in TRMT1, encoding a tRNA-modification enzyme, that cause intellectual disability and developmental delay. Functional studies in human cells and zebrafish provide insig...

Noncanonical small RNAs, such as tRNA-derived (tsRNAs) and rRNA-derived (rsRNAs) fragments, are more abundant than microRNAs and arise from selective cleavage events rather than random degradation. Wh...

Transfer RNA–derived small RNAs (tsRNAs or tDRs) perform a range of cellular functions. Here, we showed that tRNA-Asp-GTC-3′tDR, a hypoxia-induced tDR derived from the 3′ end of tRNA-Asp-GTC, activate...

bioRxiv · 26 Aug 2026 — CRISPR-Cas systems are RNA-guided nucleases that enable prokaryotic immunity; however, some loci encode additional associated genes that cooperate with CRISPR effectors to perf...

CRISPR-Cas systems are RNA-guided nucleases that enable prokaryotic immunity; however, some loci encode additional associated genes that cooperate with CRISPR effectors to perform diverse biological functions. Here, we uncover a CRISPR-associated kinase (CASK) system that links the recognition of target RNA to protein phosphorylation. We show that the kinase Csx33 phosphorylates Csx34 following activation of Cas13, enabling Csx34 to bind DNA in a sequence-specific manner. Together, Csx33 and Csx34 function as a transcriptional activation module that upregulates cas13 and associated genes, revealing a positive autoregulatory circuit that potentiates the immune response upon detection of foreign RNA. At the molecular level, Csx33 is activated by CCA trinucleotide RNA generated by Cas13-mediated cleavage of tRNA 3′ tails, uncovering a novel linear second messenger in bacterial immunity and a previously unrecognized signaling role of collateral RNA fragments. Together, these findings establish CASK systems as a new platform for RNA sensing and for engineering programmable phosphorylation-based signaling systems. ### Competing Interest Statement The authors have declared no competing interest. National Heart, Lung, and Blood Institute Division of Intramural Research, https://ror.org/023ny1p48, DP2-HL185100

Bacterial small-molecule messengers that function in diverse immune signaling pathways have been thought to derive strictly from biosynthesis using nucleotide and cofactor substrates. Here we report a...

The human endometrium undergoes dynamic cyclical remodeling across the menstrual cycle to establish receptivity for embryo implantation. While microRNAs ar