Warkocki Zbigniew, Figlerowicz Marek
Faculty of Biology, Adam Mickiewicz University, Poznań, Poland.
Postepy Biochem. 2006;52(3):253-9.
RNA is now considered a key factor in the regulation of gene expression. There are several classes of small regulatory RNAs in plants, functioning in posttranscriptional gene silencing (PTGS) or epigenetic DNA modification. Trans-acting short interfering RNAs (tasiRNAs) form a class of small regulatory RNAs which has been distinguished only recently. To date, five genes encoding tasiRNAs have been identified in Arabidopsis thaliana. TasiRNAs derive from non-coding RNA precursors which are initially targeted for cleavage by a miRNA. Cleavage products are then converted into dsRNAs by a RNA dependent RNA polymerase and sequentially cleaved into 21-nt tasiRNAs. Like the majority of plant miRNAs, tasiRNAs regulate gene expression at the posttranscriptional level, guiding cleavage of ARF and PPR transcripts. Here, we briefly present tasiRNAs and speculate whether they form a homogeneous class of siRNAs.
RNA现在被认为是基因表达调控中的关键因素。植物中有几类小调控RNA，在转录后基因沉默（PTGS）或表观遗传DNA修饰中发挥作用。反式作用短干扰RNA（tasiRNA）形成了一类小调控RNA，直到最近才被区分出来。迄今为止，已在拟南芥中鉴定出五个编码tasiRNA的基因。tasiRNA来源于非编码RNA前体，这些前体最初被miRNA靶向切割。切割产物随后被RNA依赖性RNA聚合酶转化为dsRNA，并依次切割成21个核苷酸的tasiRNA。与大多数植物miRNA一样，tasiRNA在转录后水平调控基因表达，指导ARF和PPR转录本的切割。在这里，我们简要介绍tasiRNA，并推测它们是否构成一类同质的siRNA。
