SMA1, a homolog of the splicing factor Prp28, has a multifaceted role in miRNA biogenesis in Arabidopsis

First author: Shengjun Li; Affiliations: University of Nebraska-Lincoln (内布拉斯加大学林肯分校): Lincoln, USA

Corresponding author: Bin Yu

MicroRNAs (miRNAs) are a class of small non-coding RNAs that repress gene expression. In plants, the RNase III enzyme Dicer-like (DCL1) processes primary miRNAs (pri-miRNAs) into miRNAs. Here, we show that SMALL1 (SMA1), a homolog of the DEAD-box pre-mRNA splicing factor Prp28, plays essential roles in miRNA biogenesis in Arabidopsis. A hypomorphic sma1-1 mutation causes growth defects and reduces miRNA accumulation correlated with increased target transcript levels. SMA1 interacts with the DCL1 complex and positively influences pri-miRNA processing. Moreover, SMA1 binds the promoter region of genes encoding pri-miRNAs (MIRs) and is required for MIR transcription. Furthermore, SMA1 also enhances the abundance of the DCL1 protein levels through promoting the splicing of the DCL1 pre-mRNAs. Collectively, our data provide new insights into the function of SMA1/Prp28 in regulating miRNA abundance in plants.

MicroRNA，即miRNA是一类小的非编码RNA，能够抑制基因的表达。在植物中，Dicer-like1核酸酶DCL1加工初级miRNA，形成成熟miRNA。本文的研究揭示了拟南芥中DEAD-box的前mRNA剪切因子Prp28的同源蛋白SMA1在miRNA的生物合成中扮演重要作用。一个sma1-1次形态突变导致的生长缺陷，减少了miRNA的积累，并与增加的靶基因转录水平相关。SMA1与DCL1复合物互作，正向调控初级miRNA的加工。此外，SMA1能够结合到编码初级miRNA的基因的启动子区，对于这类基因的转录是必需的。还有，SMA1还能够通过促进DCL1基因前体mRNA来增强DCL1蛋白水平的富集。综上，本文的数据揭示了SMA1/Prp28在植物中参与miRNA富集的调控。

通讯：Bin Yu (https://biosci.unl.edu/bin-yu)

个人简介：山东农业大学，学士；中国农业科学院，硕士；密歇根州立大学，博士。

研究方向：拟南芥miRNA代谢。

doi: https://doi.org/10.1093/nar/gky591

Journal: Nucleic Acids Research

Published date: 30 June, 2018

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