Collaborative Research: Role of Arabidopsis CTD-Phosphatase-Like 1 in Gene Silencing Pathways

基因表达是通过将DNA转录成RNA转录物，即信使RNA （mrna）来实现的。建立适当的细胞转录本水平是通过平衡mrna的产生和降解活性来实现的。基因沉默是通过抑制目标转录物的产生（转录基因沉默）和促进降解（转录后基因沉默）来调节这种平衡的过程。基因沉默机制的一些核心组成部分是小双链RNA （dsRNA）和与细胞dsRNA结合的蛋白质。植物的基因沉默机制既有普遍存在的成分，也有仅存在于植物界的成分。一些独特的成分不仅与正常的植物生长发育有关，而且与抗逆性有关。该项目将确定羧基末端结构域（CTD）磷酸酶样1 （CPL1）在基因沉默途径中的作用，CPL1是一种独特的植物蛋白磷酸酶。CPL1是多种靶基因的抑制因子。初步数据表明，CPL1可以在转录沉默和转录后沉默中发挥作用，然而，这一观察结果的机制尚未阐明。本研究将采用多种方法，如遗传、分子和生化分析来剖析植物基因沉默的新成分。该项目预期的科学发现将提供更深入的了解基因表达机制，不仅与植物生物学有关，而且与更广泛的生物科学有关。本项目将培养博士后助理和一名研究生。这个项目的合作性质为参与者提供了分子遗传学和生物化学的多学科专业知识，以及通过下面描述的实验课程的教学机会。为了培养来自不同背景的未来科学家，将为植物逆境反应的生理和分子基础课程建立研究生水平的实验室模块，学生将在该课程中获得实践经验。教学材料将在合作院校之间共享，项目中产生的研究材料也将在课堂/实验室中使用。

Gene expression is achieved through transcription of DNA into RNA transcripts, known as messenger RNAs (mRNAs). Establishing the proper level of cellular transcripts is achieved by balancing the activity of production and degradation of mRNAs. Gene silencing is a process that regulates this balance both by repressing production (transcriptional gene silencing) and by promoting degradation (post-transcriptional gene silencing) of target transcripts. Some of the central components of the gene silencing machinery are small double-stranded RNA (dsRNA) and proteins that bind to cellular dsRNAs. The gene silencing machinery of plants has both universal components and components only found in the plant kingdom. Some of the unique components have been implicated not only in normal plant growth and development but also in resistance to stress. This project will determine the role of carboxyl-terminal domain (CTD) phosphatase-like 1, CPL1, a unique plant protein phosphatase in the gene silencing pathway. CPL1 is a repressor of multiple target genes. Preliminary data suggest that CPL1 can function both in transcriptional silencing and post-transcriptional silencing, however, the mechanism for this observation has not been elucidated. This study will use multiple approaches such as genetic, molecular, and biochemical analyses to dissect novel components of gene silencing in plants. The scientific discovery anticipated from this project will provide deeper insight of gene expression mechanisms relevant not only in the plant biology but also in broader biological science.This project will train post-doctoral associates and one graduate student. The collaborative nature of this project provides the participants multidisciplinary expertise in molecular genetics and biochemistry as well as teaching opportunities through the lab course described below. To train future scientists from diverse backgrounds, a graduate-level laboratory module for the course Physiological and Molecular Basis of Plant Stress Responses in which students will have hands-on experience, will be established. Teaching materials will be shared between collaborating institutions, and research materials generated in the project will be used in the classroom/lab as well.