The Role of HEN1 in MicroRNA Biogenesis in Arabidopsis

HEN1 在拟南芥 MicroRNA 生物发生中的作用

• 批准号: 0343480
• 负责人: Xuemei Chen
• 金额: $ 42万
• 依托单位: Rutgers University New Brunswick
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-05-01 至 2006-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0343480&HistoricalAwards=false
• 关键词: Role; HEN1; MicroRNA; Biogenesis; Arabidopsis

MicroRNAs (miRNAs), single-stranded RNAs of usually 21-25 nucleotides in length found in diverse eukaryotes, act as sequence-specific regulators of gene expression during normal growth and development. miRNAs are processed, by an RNAse III enzyme named Dicer, from longer transcripts that fold into stem-loop structures with the miRNAs being in the double-stranded regions. In addition to Dicer, two classes of proteins of unknown molecular functions, Argonaute and HEN1, have been implicated in miRNA biogenesis. The temporally or spatially restricted expression of many miRNAs suggests that miRNA biogenesis is tightly regulated during development. However, little is known about the pathway or the regulation of miRNA biogenesis. The goal of this research is to dissect the role of HEN1 in miRNA biogenesis using molecular genetic and biochemical approaches. In particular, this research will follow clues from previous observations, such as the accumulation of a potential miRNA precursor in a dicer mutant and the presence of heterogeneous miRNA species in the hen1-1 mutant to probe the potential roles of HEN1 in miRNA biogenesis, such as production, stabilization, or nuclear export of miRNA precursors or miRNAs. This investigation will shed light on the molecular function of HEN1, a pioneer protein with homologs from metazoans, in miRNA biogenesis and also provide insights into the poorly understood miRNA biogenesis process in plants, such as the steps involved to process the primary transcript to the mature miRNA and the subcellular locations of the processing steps.

MicroRNAs(MiRNAs)是一种单链RNA，通常长度为21-25个核苷酸，存在于各种真核生物中，在正常生长和发育过程中作为基因表达的序列特异性调节因子。MiRNAs由一种名为DICER的RNaseIII酶处理，从较长的转录本折叠成茎环结构，miRNAs位于双链区。除了DICER，两类分子功能未知的蛋白质ArgAerte和HEN1也参与了miRNA的生物发生。许多miRNAs的时间或空间受限表达表明，miRNA的生物发生在发育过程中受到严格调控。然而，对miRNA生物发生的途径或调控知之甚少。本研究的目的是利用分子遗传学和生物化学方法剖析HEN1在miRNA生物发生中的作用。特别是，本研究将遵循先前观察到的线索，例如在DICER突变体中积累潜在的miRNA前体，以及在hen1-1突变体中存在异质miRNA物种，以探索HEN1在miRNA生物发生中的潜在作用，如miRNA前体或miRNAs的生产、稳定或核输出。这一研究将揭示HEN1在miRNA生物发生中的分子功能，并为植物中鲜为人知的miRNA生物发生过程提供见解，例如将初级转录物加工成成熟的miRNA所涉及的步骤以及加工步骤的亚细胞位置。