《生命科学》 2017, 29(4): 406-413

植物pri-miRNA转录及加工过程中的重要因子

宋家会1#，蔡　强1，2#，莫蓓莘1*

(1 深圳大学生命与海洋科学学院广东省表观遗传重点实验室，深圳 518060；
    2 深圳大学光电工程学院，光电子器件与系统(教育部/广东省)重点实验室，深圳 518060)

摘　要：摘　要：MicroRNA(miRNA) 是真核生物内源的一类长度为20~24 nt 的非编码小RNA，它们通过切割靶标基因mRNA 或阻止其翻译在转录后水平调控基因的表达。miRNA 广泛参与植物的生长发育、代谢及各类胁迫反应过程，在植物基因表达调控网络中发挥重要作用。编码miRNA 的MIR 基因首先经过DNA 依赖的RNA 聚合酶Pol II 复合体转录形成pri-miRNA，之后pri-miRNA 再经过DCL1 加工复合体的一系列加工形成成熟的miRNA。现介绍参与植物pri-miRNA 转录和加工过程的重要蛋白及其作用方式，并阐述植物miRNA 在转录及转录后水平复杂且精密的调控机制。

The important factors involved in plant pri-miRNA transcription and processing

SONG Jia-Hui1#， CAI Qiang1，2#， MO Bei-Xin1*

(1 Guangdong Key Laboratory of Epigenetic Inheritance， College of Life Sciences and Oceanography， Shenzhen 518060， China; 2 Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province， College of Optoelectronic Engineering， Shenzhen University， Shenzhen 518060， China)

Abstract: Abstract: MicroRNAs (miRNAs)， which are about 20~24 nucleotides in length， are a group of endogenous noncoding small RNA in eukaryotic. They regulate gene expression through cleaving their target mRNAs or repressing the translation after gene transcription. MiRNAs play an important role in the regulatory networks of plant genes as they are involved in many biological processes such as development， metabolism， and stress responses. Mature miRNAs are processed from their primary transcripts called primary miRNA transcripts (pri-miRNAs) by DCL1 processing complex， while pri-miRNAs are transcribed by DNA-dependent RNA polymerase II (Pol II) transcriptional complex. Here， we described the critical proteins involved in plant pri-miRNAs transcription and processing， and the sophisticated regulatory mechanisms of plant miRNA at the transcriptional and post-transcriptional level.