Rice germline-specific Argonaute MEL1 protein binds to phasiRNAs generated from more than 700 lincRNAs
Rice germline-specific Argonaute MEL1 protein binds to phasiRNAs generated from more than 700 lincRNAs
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DOI：
10.1111/tpj.12483
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发表时间：
2014-05-01
期刊：
影响因子：
7.2
通讯作者：
Nonomura, Ken-Ichi
中科院分区：
文献类型：
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作者：
Komiya, Reina;Ohyanagi, Hajime;Nonomura, Ken-Ichi
与Argonaute（AGO）蛋白相互作用的小RNA在RNA介导的沉默中起着核心作用。减数分裂阻滞在细精蛋白1（MEL 1）是一种水稻AGO，在减数分裂前生殖细胞的发育和减数分裂的进程中具有特殊的功能。在这里，我们表明，MEL 1，这是主要位于生殖细胞的细胞质中，优先与21个核苷酸的相位小干扰RNA（phasiRNA），携带5 '-末端胞嘧啶。大多数phasiRNA来源于分布在所有水稻染色体上的1171个基因间簇。从这些簇中，超过700个含有与miR 2118互补的共有序列的大基因间非编码RNA（lincRNA）在花序中特异性转录，并在miR 2118位点内切割。切割的lincRNA通过DICER-LIKE 4（DCL 4）蛋白加工，导致产生phasiRNA。这项研究提供的证据表明，miR 2118依赖性和DCL 4依赖性途径都是与水稻生殖特异性MEL 1 AGO相关的21-nt phasiRNA生物合成所必需的，并且超过700个lincRNA是生殖特异性阶段诱导这种生物合成的关键因素。
Small RNAs that interact with Argonaute (AGO) proteins play central roles in RNA-mediated silencing. MEIOSIS ARRESTED AT LEPTOTENE1 (MEL1), a rice AGO, has specific functions in the development of pre-meiotic germ cells and the progression of meiosis. Here, we show that MEL1, which is located mostly in the cytoplasm of germ cells, associates preferentially with 21-nucleotide phased small interfering RNAs (phasiRNAs) that bear a 5 '-terminal cytosine. Most phasiRNAs are derived from 1171 intergenic clusters distributed on all rice chromosomes. From these clusters, over 700 large intergenic, non-coding RNAs (lincRNAs) that contain the consensus sequence complementary to miR2118 are transcribed specifically in inflorescences, and cleaved within the miR2118 site. Cleaved lincRNAs are processed via DICER-LIKE4 (DCL4) protein, resulting in production of phasiRNAs. This study provides the evidence that the miR2118-dependent and the DCL4-dependent pathways are both required for biogenesis of 21-nt phasiRNAs associated with germline-specific MEL1 AGO in rice, and over 700 lincRNAs are key factors for induction of this biogenesis during reproductive-specific stages.