《生命科学》 2014, 26(7): 745-750

tRNA来源的小片段RNA——新的基因表达调控因子

方志鹏^1，2，周小龙^1*，王恩多^1，3*

(1 中国科学院上海生命科学研究院，生物化学与细胞生物学研究所，分子生物学国家重点
    实验室，上海 200031；2 中国科学院大学，北京 100049；3 上海科技大学，上海 200031)

摘　要：摘　要：转移核糖核酸(tRNA) 是蛋白质合成的关键接头分子，特异性识别信使RNA (mRNA) 的密码子信息，将其接载的氨基酸基团掺入到新生多肽链中。最新研究表明，在很多物种中，在某些特定情况下，tRNA或其前体被特异性剪切产生tRNA 来源的小片段RNA (tRNA-derived fragment， tRF)。这类tRF 是一类新的基因表达调控因子，其发挥作用的机制多样，如某些tRF 以microRNA 方式抑制mRNA 翻译；某些tRF 作为逆转录病毒RNA 基因组的逆转录引物；而某些tRF 参与了前体rRNA 剪切复合物的组装。此外，细胞受胁迫产生的带有多聚鸟苷酸模块的tRF 则会竞争性抑制延伸因子elF4G 与mRNA 的结合，从而抑制蛋白质翻译。随着研究的继续深入，对tRF 的发生发展、作用机制以及在疾病中的潜在作用将会进一步丰富。拟从tRF 作为新的基因表达调控分子的角度，简要介绍tRF 发挥作用的分子机制。

tRNA-derived fragments: the new regulators of gene expression

FANG Zhi-Peng^1，2， ZHOU Xiao-Long^1*， WANG En-Duo^1，3*

(1 State Key Laboratory of Molecular Biology， Institute of Biochemistry and Cell Biology， Shanghai Institutes for Biological Sciences， Chinese Academy of Sciences，Shanghai 200031，China； 2 University of Chinese Academy of Science， Beijing 100049， China; 3 ShanghaiTech University， Shanghai 200031， China)

Abstract: Abstract: Transfer RNAs (tRNAs) are the key adaptors that specifically recognize the codon on the mRNA and transfer their charged amino acids into newly synthesized peptide during protein translation. Recent studies have shown that the tRNA fragments (tRFs)， which are derived from specific cleavage of tRNA， are present in many species under some specific conditions. tRFs are a class of new regulators of gene expression， which function in many ways. Some tRFs function in the microRNA-like way to inhibit the protein translation; while some tRFs serve as the primers of reverse transcription of the viral RNA genome. Other tRFs are members of a nucleoprotein complex which specifically cleaves pre-rRNA. Moreover， the stress-induced tRFs from the 5' terminus of tRNA with specific terminal oligo-guanine motif are able to obviously inhibit the protein translation by interfering with interaction between elF4G and mRNA. The continuous investigations will provide us a more detailed understanding of mechanism of generation， regulation and possible roles of tRFs in specific diseases.