Fig. 2
From: Transfer RNA-derived small RNAs in tumor microenvironment
The working pattern of tDRs. Transfer RNA-derived small RNAs (tDRs) can regulate gene expression at multiple levels. In the nucleus, for example, AS‑tDR‑007333 interacts with HSPB1 protein that epigenetically augments MED29 transcription. td-piR (Glu), another tDR can recruit H3K9 methyltransferases (SETDB1 and SUV39H1) to the CD1A promoter region promoter region through binding PIWIL4 protein to form a complex, resulting in CD1A transcription inhibition. In the cytoplasm, tRF-3 s can interact with AGO proteins to induce the formation of silencing complexes (RISC) or act as protein decoy to isolate the binding of RBPs (YBX1 and IGF2BP1), thereby regulating mRNA stability at the post-transcriptional level. tiRNAs with the TOG motifs, assisted by YBX1, can inhibit the translation of target mRNA by substituting eIF4F complex and inducing SG assembly. tRFs can also bind two ribosomal protein (RPS28/RPS15) mRNAs to enhance their translation and regulate ribosome biogenesis. tRF-3 s can also promote reverse transcription by targeting the primer binding site (PBS) of the HTLV-1 in viral particles