CAREER: Molecular Evolution of Telomerase Ribonucleoprotein: A Phylogenetic Study of Telomerase RNA Structure and Function

职业：端粒酶核糖核蛋白的分子进化：端粒酶 RNA 结构和功能的系统发育研究

• 批准号: 0642857
• 负责人: Julian Chen
• 金额: $ 67.42万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-06-15 至 2013-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0642857&HistoricalAwards=false
• 关键词: CAREER; Molecular; Evolution; Telomerase; Ribonucleoprotein

Telomerase is a unique ribonucleoprotein (RNP) that varies dramatically among ciliates, yeasts and vertebrates in its biochemical composition and biogenesis pathway. In different species, telomerase RNA associates with different proteins and shares distinct biogenesis pathways with other RNP enzymes. The molecular mechanism underlying the unusual course of telomerase RNP evolution remains unclear. To better understand the diverse mechanisms of telomerase biogenesis and regulation, it is essential to identify and characterize telomerase RNA and its associated proteins from all major representatives of eukaryotes. One of the most difficult challenges in studying the telomerase RNP is identifying telomerase RNA homologues, mainly due to the lack of sequence similarity between groups of species. The goal of this research project is to identify telomerase RNA genes from invertebrates, plants, algae and some early-branching protozoa for comparative studies. To achieve this challenging goal, a novel strategy is designed to clone unknown telomerase RNA genes. In spite of its unusual sequence and size variation, telomerase RNA forms a stable complex with telomerase reverse transcriptase (TERT) protein in vitro. Taking advantage of this specific RNA-protein interaction, recombinant TERT proteins will be used as bait to affinity-purify their telomerase RNA counterparts using a modified in vitro selection scheme. The identification of telomerase RNAs from different branches of eukaryotes will be followed by structural and functional characterization of the reconstituted RNP. Collectively, the results from this project will provide new insights into the molecular evolution of telomerase structure and function.Telomerase ribonucleoprotein is a unique RNA-protein enzyme that maintains genomic stability in eukaryotic cells. The telomerase RNA unusually adopts various species-specific structural domains and interacts with various protein components in different groups of species. This project aims to determine the structure of telomerase RNAs from all major groups of eukaryotic species and to understand the structure-function relationship of these RNAs. Insights gained from this work will not only offer a comprehensive picture of the molecular evolution of telomerase enzyme, but also provide fundamental knowledge applicable to the studies of other ribonucleoprotein enzymes. This research project also involves training and mentoring students at the high school, undergraduate and graduate levels. The hands-on experience in conducting real research projects will help motivate and encourage students to pursue research careers in science.

端粒酶是一种独特的核糖核蛋白（RNP），在纤毛虫、酵母和脊椎动物中，其生化组成和生物合成途径存在显著差异。在不同的物种中，端粒酶RNA与不同的蛋白质结合，并与其他RNP酶共享不同的生物发生途径。端粒酶RNP进化过程异常的分子机制尚不清楚。为了更好地了解端粒酶生物发生和调控的不同机制，有必要从所有主要代表性的真核生物中鉴定和表征端粒酶RNA及其相关蛋白。研究端粒酶RNP最困难的挑战之一是鉴定端粒酶RNA同源物，主要是由于物种之间缺乏序列相似性。本研究的目的是从无脊椎动物、植物、藻类和一些早期分支原生动物中鉴定端粒酶RNA基因，并进行比较研究。为了实现这一具有挑战性的目标，设计了一种新的策略来克隆未知的端粒酶RNA基因。尽管端粒酶RNA具有不寻常的序列和大小变异，但其在体外可与端粒酶逆转录酶（TERT）蛋白形成稳定的复合物。利用这种特异性的RNA-蛋白质相互作用，重组的TERT蛋白将被用作诱饵，使用改良的体外选择方案亲和纯化其端粒酶RNA对应物。从真核生物的不同分支的端粒酶RNA的鉴定之后，将重组RNP的结构和功能表征。端粒酶核糖核蛋白是一种独特的RNA-蛋白酶，在真核细胞中起着维持基因组稳定性的作用。端粒酶RNA具有不同的物种特异性结构域，并与不同物种中的各种蛋白质组分相互作用。本项目旨在确定所有主要真核生物中端粒酶RNA的结构，并了解这些RNA的结构与功能的关系。从这项工作中获得的见解不仅将提供端粒酶分子进化的全面图景，而且还提供适用于其他核糖核蛋白酶研究的基础知识。该研究项目还涉及培训和指导高中、本科和研究生阶段的学生。在进行真实的研究项目的实践经验将有助于激励和鼓励学生追求科学研究事业。

项目成果

Identification and characterization of sea squirt telomerase reverse transcriptase

• DOI: 10.1016/j.gene.2007.05.013
• 发表时间: 2007-10-01
• 期刊: GENE
• 影响因子: 3.5
• 作者: Li, Yang;Yates, Joel A.;Chen, Julian J. -L.
• 通讯作者: Chen, Julian J. -L.