Molecular Mechanism of Telomerase Action: Administrative Supplement

端粒酶作用的分子机制：行政补充

• 批准号: 9026451
• 负责人: Julian J-L Chen
• 金额: $ 6.81万
• 依托单位: ARIZONA STATE UNIVERSITY-TEMPE CAMPUS
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-01 至 2016-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9026451
• 关键词: Active Sites; Administrative Supplement; Affect; Affinity; Aging; Binding; Biochemical; Biological Assay; Biology; Chromosomes; Comparative Study; DNA; DNA Primers; DNA-Directed DNA Polymerase; Data; Dissociation; Elements; Enzymes; Foundations; Goals; Inosine; Kinetics; Left; Malignant Neoplasms; Measures; Mediating; Modeling; Modification; Molecular; Natural regeneration; Nucleotides; Oligonucleotides; Outcome; Polymerase; Property; RNA; RNA Sequences; RNA-Directed DNA Polymerase; Research; Ribonucleoproteins; Role; Site-Directed Mutagenesis; Specificity; Telomerase; Telomerase RNA Component; Testing; Work; base; innovation; insight; mutant; novel; programs; research study; screening; telomerase reverse transcriptase; telomere; transcriptome sequencing

DESCRIPTION (provided by applicant): Project Summary Telomerase is a specialized reverse transcriptase (RT) that synthesizes telomere DNA repeats at chromosome ends, using only a very short region of its intrinsic telomerase RNA (TR) subunit as template. This highly specialized function of telomerase relies on a special mechanism whereby the template RNA and the telomeric DNA dissociate and realign during the processive synthesis of repeats. However, the detailed mechanism of telomerase template translocation remains to be determined. This research program aims to articulate the unique mechanism of telomerase action and identify elements that regulate specific steps of template translocation. Although telomerase uses the single-stranded telomeric DNA as its native substrate, we have recently discovered that telomerase can act as a conventional RT utilizing RNA/DNA duplex as substrate. More surprisingly, telomerase recognizes the duplex substrate with a sequence-specificity. These crucial findings have provided great insights into the molecular mechanism of telomerase action. We hypothesize that duplex- binding and duplex-dissociation are important steps of the telomere-repeat synthesis cycle, and regulate telomere-repeat addition rate and processivity. Specific Aims of the research program include (1) Determining the role duplex-binding affinity in template translocation efficiency, (2) Determining the rate-limiting step of template translocation, and (3) characterize the sequence- dependent termination of nucleotide addition by telomerase. We expect the outcomes of these experiments will greatly add to our understanding of telomerase mechanism.

描述（由申请人提供）： 项目摘要 端粒酶是一种特殊的逆转录酶 (RT)，仅使用其内在端粒酶 RNA (TR) 亚基的非常短的区域作为模板，在染色体末端合成端粒 DNA 重复序列。端粒酶的这种高度专业化的功能依赖于一种特殊的机制，模板RNA和端粒DNA在重复序列的持续合成过程中分离和重新排列。然而，端粒酶模板易位的详细机制仍有待确定。该研究计划旨在阐明端粒酶作用的独特机制，并确定调节模板易位特定步骤的元件。尽管端粒酶使用单链端粒DNA作为其天然底物，但我们最近发现端粒酶可以利用RNA/DNA双链体作为底物充当常规RT。更令人惊讶的是，端粒酶以序列特异性识别双链体底物。这些重要的发现为端粒酶作用的分子机制提供了深入的见解。我们假设双链体结合和双链体解离是端粒重复合成循环的重要步骤，并调节端粒重复添加速率和持续合成能力。该研究计划的具体目标包括（1）确定双链体结合亲和力在模板易位效率中的作用，（2）确定模板易位的限速步骤，以及（3）表征端粒酶对核苷酸添加的序列依赖性终止。我们期望这些实验的结果将极大地增进我们对端粒酶机制的理解。