A novel class of small RNAs: tRNA-derived RNA fragments (tRFs)
A novel class of small RNAs: tRNA-derived RNA fragments (tRFs)
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DOI：
10.1101/gad.1837609
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发表时间：
2009-11-15
影响因子：
10.5
通讯作者：
Dutta, Anindya
中科院分区：
文献类型：
--
作者：
Lee, Yong Sun;Shibata, Yoshiyuki;Dutta, Anindya
与microRNA（miRNAs）不同的新型小RNA正在各种生物体中逐渐被发现。为了发现这种新的小RNA，从前列腺癌细胞系中创建了17至26个碱基长的RNA文库，并通过超高通量测序进行测序。大量的序列来源于成熟或前体tRNA的59或39末端的精确加工，以形成三个系列的tRF（tRNA衍生的RNA片段）：tRF-5、tRF-3和tRF-1系列。这些序列构成了一类短RNA，其丰度仅次于miRNA。北方杂交、定量RT-PCR和夹板连接测定独立地测量至少17种tRF的水平。为了证明tRF的生物学重要性，我们进一步研究了tRF-1001，其来源于Ser-TGA tRNA前体转录物的39末端，其不保留在成熟的tRNA中。tRF-1001在多种癌细胞系中高度表达，但在组织中表达较少，并且其在细胞系中的表达与细胞增殖密切相关。siRNA介导的tRF-1001敲低损害细胞增殖，细胞在G2期特异性积聚，通过共引入对siRNA具有抗性的合成2 '-O-甲基tRF-1001寡核糖核苷酸特异性逆转表型。tRF-1001由tRNA 3 '-内切核酸酶ELAC 2（一种前列腺癌易感基因）在细胞质中产生。我们的数据表明，tRFs不是随机的tRNA降解或生物合成的副产品，而是一种丰富的和新的一类短RNA，具有精确的序列结构，具有特定的表达模式和特定的生物学作用。
New types of small RNAs distinct from microRNAs ( miRNAs) are progressively being discovered in various organisms. In order to discover such novel small RNAs, a library of 17- to 26-base-long RNAs was created from prostate cancer cell lines and sequenced by ultra-high-throughput sequencing. A significant number of the sequences are derived from precise processing at the 59 or 39 end of mature or precursor tRNAs to form three series of tRFs (tRNA-derived RNA fragments): the tRF-5, tRF-3, and tRF-1 series. These sequences constitute a class of short RNAs that are second most abundant to miRNAs. Northern hybridization, quantitative RT-PCR, and splinted ligation assays independently measured the levels of at least 17 tRFs. To demonstrate the biological importance of tRFs, we further investigated tRF-1001, derived from the 39 end of a Ser-TGA tRNA precursor transcript that is not retained in the mature tRNA. tRF-1001 is expressed highly in a wide range of cancer cell lines but much less in tissues, and its expression in cell lines was tightly correlated with cell proliferation. siRNA-mediated knockdown of tRF-1001 impaired cell proliferation with the specific accumulation of cells in G2, phenotypes that were reversed specifically by cointroducing a synthetic 2'-O-methyl tRF-1001 oligoribonucleotide resistant to the siRNA. tRF-1001 is generated in the cytoplasm by tRNA 3'-endonuclease ELAC2, a prostate cancer susceptibility gene. Our data suggest that tRFs are not random by-products of tRNA degradation or biogenesis, but an abundant and novel class of short RNAs with precise sequence structure that have specific expression patterns and specific biological roles.