Role, function and regulation of human Dicer

人类 Dicer 的作用、功能和调节

• 批准号: 262938-2013
• 负责人: Provost, Patrick
• 金额: $ 3.13万
• 依托单位: Université Laval
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=629836
• 关键词: Role; function; regulation; human; Dicer

The molecular mechanisms regulating the expression of mammalian genomes is more complex than previously thought, with the recent discovery of gene regulatory processes based on small non-coding RNA species, such as microRNAs. Expressed in almost all living eukaryotes, microRNAs act in concert to regulate ~60% of the genes in humans, suggesting that every biochemical and cellular processes may be under microRNA control in our body! In humans, microRNAs are generated by the ribonuclease III Dicer, a large enzyme that we discovered and characterized initially in its recombinant form. Strategically positioned at the nuclear/cytoplasmic interface, Dicer would accept its microRNA precursor (pre-microRNA) substrate of nuclear origin from the transporter Exportin-5, recognize it via its central PIWI/Argonaute/Zwille (PAZ) domain and release microRNAs through the concerted action of its RNase IIIa and IIIb motifs. Despite its central importance in microRNA biogenesis, the cellular context in which Dicer functions in RNA silencing still remains poorly understood. In this proposal, we wish to address that issue by elucidating the protein interaction network of human Dicer and characterizing the interaction between human Dicer and cellular protein candidates that are very likely to modulate various aspects of Dicer, such as its intracellular localization, stability, processivity, trafficking and ability to interact with other proteins. Expected to clarify the mechanisms regulating the human genome, our findings may provide a better understanding of the cellular role, function and regulation of the microRNA-generating enzyme Dicer. This is a prerequisite for eventually identifying genetic diseases possibly linked to alterations in Dicer function or caused by malfunctioning of the microRNA pathway.

调节哺乳动物基因组表达的分子机制比以前想象的更加复杂，最近发现了基于小型非编码 RNA 种类（例如 microRNA）的基因调节过程。 microRNA 在几乎所有活的真核生物中表达，它们协同作用，调节人类约 60% 的基因，这表明我们体内的每一个生化和细胞过程都可能受到 microRNA 的控制！在人类中，microRNA 由核糖核酸酶 III Dicer 产生，这是我们最初发现并表征的重组形式的大型酶。 Dicer 战略性地位于核/细胞质界面，它将接受来自转运蛋白 Exportin-5 的核来源 microRNA 前体 (pre-microRNA) 底物，通过其中央 PIWI/Argonaute/Zwille (PAZ) 结构域识别它，并通过其 RNase IIIa 和 IIIb 基序的协同作用释放 microRNA。尽管 Dicer 在 microRNA 生物发生中具有核心重要性，但 Dicer 在 RNA 沉默中发挥作用的细胞背景仍然知之甚少。在本提案中，我们希望通过阐明人类 Dicer 的蛋白质相互作用网络并表征人类 Dicer 和细胞候选蛋白质之间的相互作用来解决这个问题，这些候选蛋白质很可能调节 Dicer 的各个方面，例如其细胞内定位、稳定性、持续性、运输以及与其他蛋白质相互作用的能力。我们的研究结果有望阐明调节人类基因组的机制，从而可以更好地理解 microRNA 生成酶 Dicer 的细胞作用、功能和调节。这是最终识别可能与 Dicer 功能改变有关或由 microRNA 通路故障引起的遗传性疾病的先决条件。