Eukaryotic transfer RNAs can become selectively fragmented upon various stresses, generating tRNA-derived small RNA fragments. Such fragmentation has been reported to impact a small fraction of the tRNA pool and thus presumed to not directly impact translation. We report that oxidative stress can rapidly generate tyrosine-tRNA fragments in human cells-causing significant depletion of the precursor tRNA. Tyrosine-tRNA depletion impaired translation of growth and metabolic genes enriched in cognate tyrosine codons. Depletion of tyrosine tRNA or its translationally regulated targets USP3 and SCD repressed proliferation-revealing a dedicated tRNA-regulated growth-suppressive pathway for oxidative stress response. Tyrosine fragments are generated in a DIS3L2 exoribonuclease-dependent manner and inhibit hnRNPA1-mediated transcript destabilization. Moreover, tyrosine fragmentation is conserved in C. elegans. Thus, tRNA fragmentation can coordinately generate trans-acting small RNAs and functionally deplete a tRNA. Our findings reveal the existence of an underlying adaptive codon-based regulatory response inherent to the genetic code.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7809793 | PMC |
http://dx.doi.org/10.15252/embj.2020106696 | DOI Listing |
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