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反式作用干扰小RNA

维基百科,自由的百科全书
tasiRNA(TAS1、TAS2与TAS4)生成的途径

反式作用干扰小RNA(Trans-acting siRNA,简称tasiRNA)是陆生植物的一类小干扰RNA(siRNA),可进行RNA干扰,抑制其他基因的表现[1][2][3]。tasiRNA最早于2004年在模式生物阿拉伯芥中发现[1][2],植物有TAS1、TAS2、TAS3与TAS4四个基因家族的基因编码tasiRNA,这些基因转录产生的RNA后会被多腺苷酸化,在miRNA介导之下TAS1、TAS2与TAS4转录的RNA5'端会被Ago1英语Ago1切割,TAS3转录的RNA则是3'端被Ago7切割[注 1][5],接着此RNA由RNA复制酶RDR6转为双股RNA后,再被DCL4切割成长21nt且3'端有突出端的小双股RNA[6][7],可与RNA诱导沉默复合体(RISC)结合以进行RNA干扰,将目标mRNA的切割移除[1]

陆生植物有数种tasiRNA可抑制生长素应答因子(auxin response factor,ARF)的mRNA表现,其突变会造成植株发育异常[4]

注脚

  1. ^ 过去认为需TAS3转录的RNA在此步骤有两个位点会与Ago7结合,但仅有3'端的位点被切割,后续研究认为仅有5'端的位点和Ago7结合并非必要,但可增进tasiRNA生成与调控的准确度[4]

参考文献

  1. ^ 1.0 1.1 1.2 Vazquez F, Vaucheret H, Rajagopalan R, Lepers C, Gasciolli V, Mallory AC, Hilbert JL, Bartel DP, Crété P. Endogenous trans-acting siRNAs regulate the accumulation of Arabidopsis mRNAs. Mol. Cell. 2004, 16 (1): 69–79. PMID 15469823. doi:10.1016/j.molcel.2004.09.028. 
  2. ^ 2.0 2.1 Peragine A, Yoshikawa M, Wu G, Albrecht HL, Poethig RS. SGS3 and SGS2/SDE1/RDR6 are required for juvenile development and the production of trans-acting siRNAs in Arabidopsis. Genes Dev. 2004, 18 (19): 2368–79. PMC 522987可免费查阅. PMID 15466488. doi:10.1101/gad.1231804. 
  3. ^ Axtell MJ, Jan C, Rajagopalan R, Bartel DP. A two-hit trigger for siRNA biogenesis in plants. Cell. 2006, 127 (3): 565–77. PMID 17081978. doi:10.1016/j.cell.2006.09.032. 
  4. ^ 4.0 4.1 de Felippes FF, Marchais A, Sarazin A, Oberlin S, Voinnet O. A single miR390 targeting event is sufficient for triggering TAS3-tasiRNA biogenesis in Arabidopsis.. Nucleic Acids Res. 2017, 45 (9): 5539–5554. PMC 5435969可免费查阅. PMID 28334969. doi:10.1093/nar/gkx119. 
  5. ^ Allen E, Howell MD. miRNAs in the biogenesis of trans-acting siRNAs in higher plants.. Semin Cell Dev Biol. 2010, 21 (8): 798–804. PMID 20359543. doi:10.1016/j.semcdb.2010.03.008. 
  6. ^ Talmor-Neiman M, Stav R, Klipcan L, Buxdorf K, Baulcombe DC, Arazi T. Identification of trans-acting siRNAs in moss and an RNA-dependent RNA polymerase required for their biogenesis. Plant J. 2006, 48 (4): 511–21. PMID 17076803. doi:10.1111/j.1365-313X.2006.02895.x. 
  7. ^ Rajeswaran R, Aregger M, Zvereva AS, Borah BK, Gubaeva EG, Pooggin MM. Sequencing of RDR6-dependent double-stranded RNAs reveals novel features of plant siRNA biogenesis.. Nucleic Acids Res. 2012, 40 (13): 6241–54. PMC 3401431可免费查阅. PMID 22434877. doi:10.1093/nar/gks242.