Science

A hypoxia-responsive tRNA-derived small RNA confers renal protection through RNA autophagy

2025-07-17

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, activated autophagic flux in kidney cells and its silencing blocked autophagic flux. Functional gain-/loss-of-function studies in murine kidney disease models demonstrated a substantial renoprotective function of tRNA-Asp-GTC-3′tDR. Mechanistically, tRNA-Asp-GTC-3′tDR assembled stable G-quadruplex structures and sequestered pseudouridine synthase 7 (PUS7), preventing catalytic pseudouridylation of histone mRNAs. The resulting pseudouridylation deficiency directed histone mRNAs to the autophagosome-lysosome pathway, triggering RNA autophagy. This tDR-induced RNA autophagy pathway was activated during murine and human kidney diseases, suggesting clinical relevance. Thus, tRNA-Asp-GTC-3′tDR plays a role in regulating RNA autophagy, which helps to maintain homeostasis in kidney cells and protects against kidney injury.

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DOI https://doi.org/10.1126/science.adp5384