Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA; Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
Trends Cell Biol. 2018 Oct;28(10):793-806. doi: 10.1016/j.tcb.2018.05.006. Epub 2018 Jun 19.
tRNA fragments (tRFs) are a class of small, regulatory RNAs with diverse functions. 3'-Derived tRFs perfectly match long terminal repeat (LTR)-retroelements which use the 3'-end of tRNAs to prime reverse transcription. Recent work has shown that tRFs target LTR-retroviruses and -transposons for the RNA interference (RNAi) pathway and also inhibit mobility by blocking reverse transcription. The highly conserved tRNA primer binding site (PBS) in LTR-retroelements is a unique target for 3'-tRFs to recognize and block abundant but diverse LTR-retrotransposons that become transcriptionally active during epigenetic reprogramming in development and disease. 3'-tRFs are processed from full-length tRNAs under so far unknown conditions and potentially protect many cell types. tRFs appear to be an ancient link between RNAi, transposons, and genome stability.
tRNA 片段（tRFs）是一类具有多种功能的小调控 RNA。3'-衍生的 tRFs 与长末端重复（LTR）逆转录元件完全匹配，LTR 逆转录元件使用 tRNA 的 3'-末端启动逆转录。最近的研究表明，tRFs 通过 RNA 干扰（RNAi）途径靶向 LTR 逆转录病毒和转座子，并且通过阻断逆转录来抑制其移动性。LTR 逆转录元件中高度保守的 tRNA 引物结合位点（PBS）是 3'-tRFs 识别和阻断的独特靶标，大量但多样化的 LTR 逆转座子在发育和疾病中的表观遗传重编程期间变得转录活跃。3'-tRFs 是在目前尚不清楚的条件下从全长 tRNA 中加工而来的，可能保护多种细胞类型。tRFs 似乎是 RNAi、转座子和基因组稳定性之间的古老联系。
