Understanding DAWDLE Function in miRNA and siRNA Biogenesis

智力优势：小rna，包括微小rna （miRNAs）和小干扰rna (sirna)，是许多生物过程的关键调节因子。参与一般RNA代谢的几种RNA结合蛋白在调节miRNA生物发生中发挥重要作用。一个挑战是了解RNA结合蛋白如何影响miRNA的生物发生，以及miRNA加工机制如何与一般RNA代谢相互联系。本研究针对这些知识空白。初步研究表明，来自拟南芥的RNA结合蛋白DAWDLE （DDL）是miRNAs和sirna子集积累所必需的。DDL与pri-miRNA （mirna的前体）和DCL1 （pri-miRNA的处理者）相互作用，并积极调节pri-miRNA的加工。我们假设DDL促进DCL1访问和/或加工一部分pri- mirna。具体目的是：1)分析DDL在miRNA生物发生中的作用；2)分析DDL蛋白结构域在pri-miRNA加工中的作用；3)分析DDL在siRNA生物发生中的作用。这项研究将促进对导致小RNA积累的过程的了解，这反过来将改善未来阐明涉及小RNA的生物过程的努力，并改进用于改善农业生产和人类健康的基于小RNA的技术。更广泛的影响：本研究将为博士后研究员、研究生、本科生和高中生提供培训。PI是参加内布拉斯加州epscor支持的内布拉斯加州青年科学家计划的学生的教师赞助商/导师，该计划旨在促进代表性不足的少数民族高中生的研究曝光和参与，以及内布拉斯加州林肯大学本科生创造性活动和研究经历（UCARE）计划。此外，PI还积极寻求与当地文理学院的教师合作，以帮助那些可能没有现成机会获得研究经验的学生。PI还将他的最新研究整合到一门新课程中，名为“RNA沉默”，面向高年级本科生和研究生。

Intellectual Merit: Small RNAs, including microRNAs (miRNAs) and small interfering RNAs (siRNAs), are key regulators of many biological processes. Several RNA-binding proteins involved in general RNA metabolism are known to play important roles in regulating miRNA biogenesis. A challenge is to understand how RNA binding proteins affect miRNA biogenesis, as well as how the miRNA processing machinery interconnects with general RNA metabolism. This research targets these knowledge gaps. Preliminary studies demonstrated that DAWDLE (DDL), an RNA binding protein from Arabidopsis, is required for the accumulation of a subset of miRNAs and siRNAs. DDL interacts with pri-miRNA (precursor of miRNAs) and DCL1 (the processor of pri-miRNA) and positively regulates pri-miRNA processing. We hypothesize that DDL facilitates DCL1 to access and/or process a subset of pri-miRNAs. Specific objectives are to: 1) Analyze the role of DDL in miRNA biogenesis; 2) Analyze the function of protein domains of DDL in pri-miRNA processing; and 3) Analyze the role of DDL in siRNA biogenesis. This research will advance knowledge of processes leading to small RNA accumulation, which in turn will improve future efforts at elucidating the biological processes involving small RNAs and to refine small RNA-based technology that has been used to improve agricultural production and human health. Broader Impacts: This research will provide training for a postdoctoral researcher, a graduate student, undergraduate students, and high school students. The PI is a faculty sponsor/mentor for students participating in the Nebraska EPSCoR-supported Young Nebraska Scientists program, which fosters research exposure and participation by underrepresented minority high school students, and in the University of Nebraska-Lincoln Undergraduate Creative Activities and Research Experiences (UCARE) program. In addition, the PI pursues active collaborations with faculty at local liberal arts colleges to help reach students that may not have ready opportunity for research experiences. The PI is also integrating his latest research into a new course, "RNA Silencing", offered to upper level undergraduate and graduate students.